Command Line Options

You can specify command-line options to the aCC command. They allow you to override the default actions of the compiler. Each option begins with either a - or a + sign. Any number of options can be interspersed anywhere in the aCC command and they are typically separated by blanks.
For a complete list of options, select Alphabetical List of Command Line Options. Otherwise, select a category:

See Also:


Alphabetical List of Command Line Options

Select the option for which you want more information:


Options to Control Code Generation

These options allow you to control what kind of code HP aC++ generates.
-Ae
Compile C source code.
-c
Compile to relocatable object file without linking.
+DAarchitecture
Generate object code for a particular version of the PA-RISC architecture. Also specify which version of the HP-UX math library to use.
+DDdata_model
Generate object code for either the ILP32 or LP64 data model.
+DOosname
Set the target operating system for the compiler.
+DSmodel
Perform instruction scheduling tuned for a particular implementation of the PA-RISC architecture.
+k
Generate code for programs that use a large number of global data items in shared libraries.
-S
Compile to assembly language without linking.
+tmtarget
Compile code for optimization with a specific machine architecture.
+z
Generate position-independent code (PIC) to go into a shared library.
+Z
Generate position-independent code (PIC) to go into a shared library.

-Ae Command Line Option Syntax

-Ae

Description:

HP is pleased to provide Partial Support for the new -Ae option, which is not yet fully implemented. This is done to allow our customers the opportunity to begin working with this feature in advance of its full implementation.

Setting the -Ae option turns on ANSI C c89 mode. This means the aC++ compiler will accept c89 compatible C source programs and compile them just like the C compiler. Additional HP ANSI C compiler options may be enabled by this option in the future.

Not all features are enabled in this release. The following is a list of current limitations. Some code that is a warning in C is a fatal error in aC++. JAGad30700 A fatal error occurs when the result of an expression does not match the expected type. int main() { int *i, j; double num = 0; i = # /* perfectly legal */ i = num ; i = 0x40000010 ; return(0); }

Error 203: "bug.c", line 5 # Cannot assign 'int *' with 'double *'.

JAGad30708,
JAGad30710:
K&R style function definitions have structs defined in
function argument declarations, etc.

     /*Bug.c */
     vararg(arg1, arg2)
     int arg1, arg2 ;
     {
     return(arg1 + arg2);
     }
     main(){
     int i,j;
     i = vararg(2, 2);
     vararg(1);
     vararg(1, 2, 3, 4);
     exit(0);
     }
     /* bug2.c */
     void foo(st_var)
     struct {int i;} st_var;
     { }
JAGad37764:
Nested struct definition is not visible at file scope.

     struct A{
     struct B { int i; } *b;
     };

     void foo(){
     struct A *a;
     struct B *b;
     a->b = b;
        }
Error 405: "bug.c", line 8 # Illegal assignment; type 'B *' is not
assignable to type 'A::B *'; 'tentative struct B' is not an
unambiguously derived class of 'struct B'.
     a->b = b;
JAGad37765:
C++ reserved words(for example, operator) are not allowed as user
defined variables.

      struct A { int operator; };
      void foo() {
      A a;
      a.operator;
            }

Error 187: # Referenced object 'operator ' is not
a member of struct A ["test.8.1.C", line 1].
      a.operator;

JAGad39135:
ENUM constants result in duplicate symbols at link time.

      /* bug.h */
      enum { RED=1, GREEN, BLUE } ;

      /* bug.c */
      #include "bug.h"
      extern int foo(void);
      main(){
      return(foo());
      }

      /* bug2.c */
      #include "bug.h"
      int foo(void){
      return( RED ) ;
      }

/usr/ccs/bin/ld: Duplicate symbol "RED" in files bug.o and bug2.o
/usr/ccs/bin/ld: Duplicate symbol "GREEN" in files bug.o and bug2.o
/usr/ccs/bin/ld: Duplicate symbol "BLUE" in files bug.o and bug2.o
/usr/ccs/bin/ld: Found 3 duplicate symbol(s)

JAGad36435: -Ae Error 24 on K&R function decl if parm matches a struct name. struct B { int a, b; }; typedef struct B A; void foo(A) int A: {}

Unwanted warning while initializing enums with ENUM constants.

      enum X { Y };
      enum X x = Y;
      main(){return;)
warning (anachronism) 440: "bug.c", line 2 #
Cannot initialize 'enum X' with 'int'.
      enum X x = Y;

-c Command Line Option Syntax

-c

Description:

Compiles one or more source files but does not enter the linking phase.

The compiler produces an object file (a file ending with .o) for each source file (a file ending with .c, .C, .s, or .i). Note that you must eventually link object files before they can be executed.

Example:

aCC -c sub.C prog.C

Compiles sub.C and prog.C and puts the relocatable object code in the files sub.o and prog.o, respectively.

+DAarchitecture Command Line Option Syntax

+DAarchitecture
architecture can be one of the following: NOTE: See the /opt/langtools/lib/sched.models file for a list of model numbers and their PA-RISC architecture designations.

Description:

Generates object code for a particular version of the PA-RISC architecture. Also specifies which version of the HP-UX math library to link in when you have specified -lm. (See the HP-UX Floating-Point Guide for more information about using math libraries.)

NOTE: Object code generated for PA-RISC 2.0 will not execute on PA-RISC 1.1 systems.

To generate code compatible across PA-RISC 1.1 and 2.0 workstations and servers, use the +DAportable option.

For best performance use +DA with the model number or architecture where you plan to execute the program.

If you do not specify a +DA option, the default code generation is based on that of the system on which you compile.

If you specify neither a +DA nor a +DS option, default instruction scheduling is based on that of the system on which you compile. If you do specify a +DA option and do not specify a +DS option, default instruction scheduling is based on what you specify in +DA, and not based on that of the system on which you compile.

For example, specify +DA1.1 and do not specify +DS, and instruction scheduling will be for 1.1. Specify +DAportable and do not specify +DS, and instruction scheduling will be for 1.1. (+DAportable is currently equivalent to +DA1.1.)

Examples:

The following examples generate code for various architectures, as noted:

For More Information:

Compiling for Different Versions of the PA-RISC Architecture

The instruction set on PA-RISC 2.0 is a superset of the instruction set on PA-RISC 1.1. Code generated for HP 9000 PA-RISC 1.1 systems will run on HP 9000 PA-RISC 2.0 systems, though possibly less efficiently than if it were specifically generated for PA-RISC 2.0.

Code generated for PA-RISC 2.0 will not run on PA-RISC 1.1 systems.

Using +DA to Generate Code for a Specific Version of PA-RISC

When you use the +DA option depends on your particular circumstances.

Compiling in Networked Environments

When compiles are performed using diskless workstations or NFS-mounted file systems, it is important to note that the default code generation and scheduling are based on the local host processor. The system model numbers of the hosts where the source or object files reside do not affect the default code generation and scheduling.

+DDdata_model Command Line Option Syntax

+DDdata_model
data_model can be one of the following:

Description:

This option specifies the data model for the compiler.

 
ILP32 Data Model LP64 Data Model
The size of an int, long, or pointer data type is 32-bits. The size of an int data type is 32-bits. The size of a long or pointer data type is 64-bits.
This is the default, currently equivalent to +DA1.1 architecture. This is currently equivalent to +DA2.OW architecture.
The preprocessor predefined macro, __LP64__ is defined.

Note that 64-bit object code (LP64) is generated for PA-RISC 2.0, and will not execute on PA-RISC 1.1 systems.

Examples:

The following example generates code for the 64-bit data model.
aCC +DD64 app.C
The following example generates code for the 32-bit data model.
aCC app.C

+DOosname Command Line Option Syntax

+DOosname
osname can be one of the following:

Description:

This option sets the target operating system for the compiler and is intended for use with the +Olibcalls option. Note that specifying +Oaggressive turns on +Olibcalls.

If +DO11.0EP9806 and +Olibcalls are both specified on an HP-UX 11.0EP9806 system, the compiler enables the fusing of libcalls where applicable. This promotes instruction level parallelism in library routines which can improve performance by computing the same function (such as sin) of two values concurrently. This becomes particularly significant in the presense of loop unrolling.

+DO can be used at any level of optimization.

Usage:

By default, when you compile your application, it is binary compatible across the 11.x release. You only need to specify +DO when you want the latest performance features supported in the OS.

CAUTION: Use of +DO makes the resulting code binary incompatible with earlier versions of HP-UX.

Examples:

The following example generates code for the HP-UX 11.0EP9806 operating system and enables the fusing of libcalls where applicable:
aCC +DO11.0EP9806 +Olibcalls app.C
The following examples generate code for any HP-UX operating system and do not enable the fusing of libcalls:
aCC +DO11.0 +Olibcalls app.C

aCC app.C

+DSmodel Command Line Option Syntax

+DSmodel
model can be either a model number of an HP 9000 system (such as 725, 890, or G40), PA-RISC architecture designation 1.1 or 2.0, or one of the PA-RISC processor names such as PA7000, PA7100, PA7100LC, or PA8000. See the file /opt/langtools/lib/sched.models for model numbers and processor names.

Description:

Performs instruction scheduling tuned for a particular implementation of the PA-RISC architecture.

Object code with scheduling tuned for a particular model will execute on other HP 9000 systems, although possibly less efficiently.

If you specify neither a +DA nor a +DS option, default instruction scheduling is based on that of the system on which you compile. If you do specify a +DA option and do not specify a +DS option, default instruction scheduling is based on what you specify in +DA, and not based on that of the system on which you compile.

For example, specify +DA1.1 and do not specify +DS, and instruction scheduling will be for 1.1. Specify +DAportable and do not specify +DS, and instruction scheduling will be for 1.1. (+DAportable is currently equivalent to +DA1.1.)

If you plan to run your program on both PA-RISC 1.1 and 2.0 systems, use the +DS2.0 designation.

Examples:

+DS720
Performs instruction scheduling tuned for one implementation of PA-RISC 1.1.
+DS745
Performs instruction scheduling for another implementation of PA-RISC 1.1.
+DSPA8000
Performs instruction scheduling for systems based on the PA-RISC 8000 processor.

For More Information:

Using +DS to Specify Instruction Scheduling

Instruction scheduling is different on different implementations of PA-RISC architectures. You can improve performance on a particular model or processor of the HP 9000 by requesting that the compiler use instruction scheduling tuned to that particular model or processor. Using scheduling for one model or processor does not prevent your program from executing on another model or processor.

By default, the compiler performs scheduling tuned for the system on which you are compiling, or, if specified, tuned for the setting of the +DA option. Use the +DS option to change this default behavior and to specify instruction scheduling tuned to a particular implementation of PA-RISC. For example, to specify instruction scheduling for the model 867, use +DS867. To specify instruction scheduling for the PA-RISC 8000 processor, use +DSPA8000. See the file /opt/langtools/lib/sched.models for model numbers and processor names.

When you use the +DS option depends on your particular circumstances.

Compiling in Networked Environments

When compiles are performed using diskless workstations or NFS-mounted file systems, it is important to note that the default code generation and scheduling are based on the local host processor. The system model numbers of the hosts where the source or object files reside do not affect the default code generation and scheduling.

+Olit Command Line Option Syntax

+Olit=kind

Description:

This option places the data items that do not require load-time or run-time initialization in a read-only data section. +Olit=all is the default in aCC and +Olit=const is the default in C.

Usage:

+Olit=kind The defined values for kind are:

    all
          All string literals and all const-qualified
          variables that do not require load-time or 
          run-time initialization will be placed in a 
          read-only data section. +Olit=all replaces the
          deprecated +ESlit option. 

   none
          No constants are placed in a read-only data
          section. +Olit=none replaces the deprecated 
          +ESnolit option.

+k Command Line Option Syntax

+k

Description:

By default, the HP aC++ compiler generates short-displacement code sequences for programs that reference global data in shared libraries. For nearly all programs this is sufficient.

If your program references a large amount of global data in shared libraries, the default code generation for referencing that global data may not be sufficient. If this is the case, when you link your program the linker gives an error message indicating that you need to recompile with the +k option. The +k option generates long-displacement code sequences so a program can reference large amounts of global data in shared libraries. Use +k only when the linker generates a message indicating you need to do so.

Example:

aCC +k prog.C mylib.sl

Compiles prog.C, generates code for accessing a large number of global data items in the shared library mylib.sl, and links with mylib.sl.

+Oprefetch_latency Command Line Option Syntax

+Oprefetch_latency=cycles

Description

+Oprefetch_latency applies to loops for which the compiler generates data prefetch instructions. cycles represents the number of cycles for a data cache miss. For a given loop, the compiler divides cycles by the estimated
loop length to arrive at the number of loop iterations for which to generate advance prefetches.

cycles must be in the range of 0 to 10000. A value of zero instructs the compiler to use the default value, which is 480 cycles for loops containing floating-point accesses and 150 cycles for loops that do not contain any floating-point accesses.

For tuning purposes, it is recommended that users measure their application's performance using a few different prefetch latency settings to determine the optimal value. Some floating-point codes may benefit by increasing the distance to 960. Parallel applications frequently benefit from a shorter prefetch distance of 150.

+Oprofile Command Line Option Syntax

+Oprofile=[use|collect]

Description:

Instructs the compiler to instrument the object code for collecting run-time profile data. The profiling information can then be used by the linker to perform profile-based optimization.

+Oprofile=collect is equivalent to +I.

+Oprofile=use[:filename] causes the compiler to look for a profile database file. Overrides the FLOW_DATA environment variable. This option is a synonym for +df and +P.

After compiling and linking with +Oprofile=collect, run the resultant program using representative input data to collect execution profile data. Finally, recompile with the +Oprofile=use option to perform profile-based optimization.

Profile data is stored in flow.data by default. See the +Oprofile=use:filename option for information on controlling the name and location of this data file.

Example:

aCC +Oprofile=collect -O -c prog.C
aCC +Oprofile=collect -O -o prog.pbo prog.o
Compiles prog.C with optimization, prepares the object code for data collection, and creates the executable file prog.pbo. Running prog.pbo collects run-time information in the file flow.data in preparation for optimization with +Oprofile=use.

Description

+Oprofile=collect [:<qualifiers>] 

In the absence of <qualifiers>, +Oprofile=collect is same as +I.
<qualifiers> are a comma-separated list of profile collection qualifiers.

Supported profile collection qualifiers:

    arc    -  Collect arc counts (synonym to +Oprofile=collect).
              This is the default value. 

    stride -  Collect stride data

    all    -  Collect all types of profile data. 
              It's a synonym for +Oprofile=collect:arc,stride
Interactions and dependencies are not changes with respect to +Oprofile=collect.

+tmtarget Command Line Option Syntax

+tmtarget

Description:

+tm target specifies the target machine architecture for which compilation is to be performed. Using this option causes the compiler to perform architecture-specific optimizations. target takes one of the following values: Using the +tm target option implies +DAarchitecture and +DSmodel settings as described in the following table.

specified target value +DAarchitecture implied +DSmodel implied
K7200 1.1 1.1
K8000 2.0 2.0
V2200 2.0 2.0

NOTE: If you specify +DA or +DS on the aCC command line, your setting takes precedence over the setting implied by +tm target.

Usage:

Use +tm target at optimization levels 0, 1, 2, 3, and 4. The default target value corresponds to the machine on which you invoke the compiler.

-S Command Line Option Syntax

-S

Description:

Compiles the named HP aC++ program and leaves the assembly language output in a corresponding file with a .s suffix.

CAUTION: The -S option is informational only. Generated output is not meant to be used as input to the assembler (as).

Example:

aCC -S prog.C

Compiles prog.C to assembly code rather than to object code, and puts the assembly code in the file prog.s.


Data Alignment and Storage

+hugesize=n
Set the threshold for huge data.
+unum
Allows pointers to access non-natively aligned data.

For More Information:

+hugesize=n Command Line Option Syntax

+hugesize=n[M][K]
M or K are optional specifiers. If neither is specified, the default is K.

Description:

This option is intended to allow you to lower the threshold for huge data.

In order for the compiler to qualify a data object as huge, its size must equal or exceed the current setting of the hugesize threshold. The threshold is initially set to .5 gigabytes (2^29 bytes). A data object whose size equals or exceeds the threshold is allocated in huge data subspace.

The number of elements that can be declared in an array depends on the data type of the array. The following table lists current object size limits in 32-bit (narrow) mode:

Data Structure Maximum Number of Elements in an Array of this Type
char arrays 2^28
float and 32-bit integer arrays (2^28)/4
double and 64-bit integer arrays (2^28)/8
long double arrays (2^28)/16
structs/unions based on element size

Note that limits in 64-bit mode are based on hardware, OS or resource limitations. The compiler itself allows higher limits.

Refer also to Default Data Storage and Alignment

Usage:

The compiler puts all small arrays into a separate subspace. An application with too many small arrays may run out of subspace creating an overflow condition. In this case linking fails. One way to solve this problem is to lower the hugesize threshold so that any array greater than or equal to the threshold (in bytes) is put into the huge data subspace instead.

Example:

The following example lowers the threshold to 2^23 bytes (8 megabytes) resulting in more data objects being put in huge data subspace.
aCC +DA2.0W +hugesize=8M app1.C app2.C

For More Informaiton:

+unum Command Line Option Syntax

+unum

Description

The +u option allows pointers to access non-natively aligned data. This option alters the way that the compiler accesses dereferenced data. Use of this option may reduce the efficiency of generated code. num can be specified as:

1
Assume single byte alignment. Dereferences are performed with a series of single-byte loads and stores.
2
Dereferences are performed with a series of two-byte loads and stores.
4
Dereferences are performed with a series of four-byte loads and stores.

Example:

aCC +u1 app.C

Default Data Storage and Alignment

This section describes default data storage allocation and alignment for HP aC++ data types.

Data storage refers to the size of data types, such as bool, short, int, float, and char*. Data alignment refers to the way the HP aC++ compiler aligns data structures in memory. Data type alignment and storage differences can cause problems when moving data between systems that have different alignment and storage schemes. These differences become apparent when a structure is exchanged between systems using files or inter-process communication. In addition, misaligned data addresses can cause bus errors when an attempt is made to dereference the address.

The following table lists the sizes and alignments of HP aC++ data types:

Data Type Size in Bytes Alignment
bool 1 1-byte
char, unsigned char, signed char 1 1
wchar_t 4 4
short, unsigned short, signed short 2 2
int, unsigned int 4 4
long, unsigned long 4 * 4 *
float 4 4
double 8 8
long double 16 8 **
long long, unsigned long long 8 8
enum 4 4
arrays size of array element type alignment of array element type
struct *** 1-, 2-, 4-, or 8-byte
union *** 1-, 2-, 4-, or 8-byte
bit-fields size of declared type alignment of declared type
pointer 4 * 4 *

* In 64-bit mode, long, unsigned long, and pointer data types are 8 bytes long and 8-byte aligned.

** In 64-bit mode, long double is 16-byte aligned.

*** struct and union alignment is the same as the strictest alignment of any member. Padding is done to a multiple of the alignment size.


Debugging Options

Debugging options enable you to use the HP WDB Debugger or the HP/DDE Debugger.

+d
Disable all inlining of functions.
-g
Generate minimal information for debugging.
-g0
Generate full information for debugging.
-g1
Generate minimal information for debugging.
+[no]objdebug
Generate debug information in object files and not in the executable.

+d Command Line Option Syntax

+d

Description:

Prevents the expansion of inline functions.

This option is useful when you are debugging your code because you cannot set breakpoints at inline functions. This option defeats inlining thereby allowing you to set breakpoints at functions specified as inline.

See Also:

-g Command Line Option Syntax

-g

Description:

Like the -g1 option, -g causes the compiler to generate minimal information for the debugger. It uses an algorithm that attempts to reduce duplication of debug information.

To suppress expansion of inline functions use the +d option.

For More Information:

-g0 Command Line Option Syntax

-g0

Description:

-g0 causes the compiler to generate full debug information for the debugger.

To suppress expansion of inline functions use the +d option.

For More Information:

-g1 Command Line Option Syntax

-g1

Description:

Like the -g option, -g1 causes the compiler to generate minimal information for the debugger. It uses an algorithm that attempts to reduce duplication of debug information.

To suppress expansion of inline functions use the +d option.

For More Information:

Difference between -g, -g0, and -g1

The -g, -g0, and -g1 options all generate debug information. The difference is that the -g0 option emits full debug information about every class referenced in a file, which can result in some redundant information.

The -g and -g1 options, on the other hand, emit a subset of this debug information, thereby decreasing the size of your object file. If you compile your entire application with -g or -g1 no debugger functionality is lost.

NOTE: If you compile part of an application with -g or -g1 and part with debug off, (that is, with neither the -g, the -g0, nor the -g1 option) the resulting executable may not contain complete debug information. You will still be able to run the executable, but in the debugger, some classes may appear to have no members.

When to Use -g, -g0, or -g1

Use -g or -g1 when

Use -g0 when either of the following is true:

NOTE: If you compile part of an application with -g or -g1 and part with debug off, (that is, with neither the -g, the -g0, nor the -g1 option) the resulting executable may not contain complete debug information. You will still be able to run the executable, but in the debugger, some classes may appear to have no members.

For More Information:

-g, -g1 Algorithm

In general, the compiler looks for the first non-inline, non-pure (non-zero) virtual function in order to emit debug information for a class.

If there are no virtual member functions, the compiler looks for the first non-inline member function.

If there are no non-inline member functions, debug information is always generated.

A problem occurs if all functions are inline; in this case, no debug information is generated.

+[no]objdebug Command Line Option Syntax

+[no]objdebug

Description:

Generate [do not generate] debug information in object files and not in the executable. The HP WDB debugger then reads the object files to construct debugging information. +objdebug is not compatible with the HP DDE debugger.

CAUTION: With +objdebug, the object files or archive libraries must not be removed.

+noobjdebug is the default at compile time and is the same as versions of the compiler prior to A.01.15. +objdebug is the default at link time.

If +noobjdebug is used at link time (not the default), all debug information goes into the executable, even if some objects were compiled with +objdebug. This can be used to enforce the debugging paradigm prior to HP aC++ version A.01.15.

If +objdebug is used at compile time, extra debug information is placed into each object file to help the debugger locate the object file and to quickly find global types and constants.

Usage

Use +objdebug option, (rather than +noobjdebug where debug information is written to the executable) to enable faster links and smaller executable file sizes for large applications.

Use +[no]objdebug with the -g, -g0, or -g1 option.

For More Information:


Error Handling Options

Use these options to control how potential errors in your C++ code are detected and handled.

+p
Disallows all anachronistic constructs.
-w
Suppresses all compiler warning messages.
+w
Warns about all questionable constructs.
+W args
Selectively suppress compiler warnings.
+We args
Selectively interpret warnings or future errors as errors.

+p Command Line Option Syntax

+p

Description:

Disallows all anachronistic constructs.

Ordinarily, the compiler gives warnings about anachronistic constructs. Using the +p option, the compiler gives errors for anachronistic constructs.

Example:

aCC +p file.C
Compiles file.C and gives errors for all anachronistic constructs rather than just giving warnings.

-w Command Line Option Syntax

-w

Description:

Suppresses all warning messages.

By default, HP aC++ reports all errors and warnings.

Example:

aCC -w file.C
Compiles file.C and reports errors but does not report any warnings.

+w Command Line Option Syntax

+w

Description:

Warns about all questionable constructs, as well as constructs that are almost certainly problems.

The default is to warn only about constructs that are almost certainly problems.

For example, this option warns you when calls to inline functions cannot be expanded inline.

Example:

aCC +w file.C
Compiles file.C and warns about both questionable constructs and constructs almost certainly problematic.

+W args Command Line Option Syntax

+W arg1[,arg2,..argn]

Description

Selectively suppresses any specified warning messages, where arg1 through argn are valid compiler warning message numbers.

Example:

aCC +W600 app.C

+We args Command Line Option Syntax

+We arg1[,arg2,..argn]

Description

Selectively interpret any specified warning or future error messages as errors. arg1 through argn are valid compiler warning message numbers.

Example:

aCC +We 600,829 app.C


Exception Handling Option

By default, exception handling is in effect. To turn off exception handling, you must use the following option.

+noeh Command Line Option Syntax

+noeh

Description:

Disables exception handling.

By default, exception handling is on. To turn off exception handling, you must use this option. With exception handling disabled, the keywords throw and try elicit an error.

Note that if your application throws no exceptions, code compiled with and without +noeh can be mixed freely. However, the mixing of code compiled with and without +noeh in an application which throws exceptions is unsupported.

Example:

aCC +noeh progex.C
Compiles and links progex.C, which does not use exception handling.

For More Information:


Extensions to the Language

This option supports extensions to the C++ language.

-ext Command Line Option Syntax

-ext

Description:

When you specify -ext, you are enabling the following HP aC++ extensions to the C++ standard:

HP aC++ Extentions
Enable 64-bit integer data type support for:
  • long long (signed 64-bit integer)
  • unsigned long long (unsigned 64-bit integer)

Use this option to declare 64-bit integer literals and for input and output of 64-bit integers.

Enable #assert and #unassert preprocessor directives allowing you to set a predicate name or predicate name and token to be tested with a #if directive.

Note, when using -ext, specify it at both compile and link time.

Example:

aCC -ext foo.C

Compiles foo.C which contains a long long declaration.

#include <iostream.h>

void main(){ long long ll = 1; cout << ll << endl; }


Floating Point Processing

+FP[flags]
Specify the run-time initialization environment for floating-point operations.
+O[no]aggressive
Optimizations that may change the behavior of code.
+O[no]fltacc
Disable [enable] all optimizations that cause imprecise floating-point results.
+O[no]moveflops
Move [do not move] conditional floating-point instructions out of loops.

+FPflags Command Line Option Syntax

+FP[flags]

Description:

Specify what floating-point traps to enable and also enable or disable fast underflow mode.

flags is a series of upper case or lower case letters from the set [VvZzOoUuIiDd] with no spaces, tabs, nor other characters between them. If the upper-case letter is selected, that behavior is enabled. If the lower-case letter is selected or if the letter is not present in the flags, the behavior is disabled. By default, all traps are disabled. The values for flags are:

flag Meaning
V Enable traps on invalid floating-point operations.
v Disable traps on invalid floating-point operations.
Z Enable traps on divide by zero. (If your program must conform to the POSIX standard, do not enable this trap.)
z Disable traps on divide by zero.
O Enables traps on floating-point overflow.
o Disable traps on floating-point overflow.
U Enable traps on floating-point underflow.
u Disable traps on floating-point underflow.
I Enable traps on floating-point operations that produce inexact results.
i Disable traps on floating-point operations that produce inexact results.
D Enable fast underflow (flush to zero) of denormalized values. (Enabling fast underflow is an undefined operation on PA-RISC 1.0 based systems, but it is defined on all subsequent versions of PA-RISC. Selecting this value enables fast underflow only if it is available on the processor that is used at run time.)
d Disable fast underflow (flush to zero) of denormalized values.

To dynamically change these settings at run time, refer to fpgetround(3M). Also see fesettrapenable(3) or fenv(5).

For More Information:


Header File Options

-Idirectory
Add directory to the directories to be searched for #include files.
-I-
Override the default -Idirectory search-path.
+m[d]
Output quote enclosed (" ") make(1) dependency files to stdout or to a .d file.
+M[d]
Output both quote enclosed and angle bracket enclosed (< >) make(1) dependency files to stdout or to a .d file.

For More Information:

-Idirectory Command Line Option Syntax

-I directory

directory is the HP-UX directory where HP aC++ looks for header files.

Description:

During the compile phase, adds directory to the directories to be searched for #include files during preprocessing. During the link phase, adds directory to the directories to be searched for #include files by the link-time template processor.

For #include files that are enclosed in double quotes ("  ") within a source file and do not begin with a /, the preprocessor searches in the following order:

  1. The directory of the source file containing the #include.
  2. The directory named in the -I option.
  3. The standard include directories /opt/aCC/include and /usr/include.

For #include files that are enclosed in angle brackets (< >), the preprocessor searches in the following order:

  1. The directory named in the -I option.
  2. The standard include directories /opt/aCC/include and /usr/include.

    (The current directory is not searched when angle brackets (< >) are used with #include.)

Example:

aCC -I /opt/aCC/include/SC file.C

This example directs HP aC++ to search in the directory /opt/aCC/include/SC for #include files.

-I- Command Line Option Syntax

[-Idirs] -I- [-Idirs]
[-Idirs] indicates an optional list of -Idirectory specifications in which a directory name cannot begin with a hyphen (-) character.

Description:

The -I- option allows you to override the default -Idirectory search-path. This feature is called view-pathing.

Specifying -I- serves a dual purpose, as follows:

The standard aCC include directories (/usr/include and /opt/aCC/include) are always searched last for both types of include files.

Usage:

View-pathing can be particularly valuable for medium to large sized projects. For example, imagine that a project comprises two sets of directories. One set contains development versions of some of the headers that the programmer currently modifies. A mirror set contains the official sources.

Without view-pathing, there is no way to completely replace the default -Idirectory search-path with one customized specifically for project development.

With view-pathing, you can designate and separate official directories from development directories and enforce an unconventional search-path order. For quote enclosed headers, the preprocessor can include any header files located in development directories and, in the absence of these, include headers located in the official directories.

If -I- is not specified view-pathing is turned off. This is the default.

Examples

With view-pathing off, the following example obtains all quoted include files from dir1 only if they are not found in the directory of a.C and from dir2 only if they are not found in dir1. Finally, if necessary, the standard include directories are searched. Angle-bracketed includes are searched for in dir1, then dir2, followed by the standard include directories.
aCC -Idir1 -Idir2 -c a.C
With view-pathing on, the following example searches for quoted include files in dir1 first and dir2 next, followed by the standard include directories, ignoring the directory of a.C. Angle-bracketed includes are searched for in dir2 first, followed by the standard include directories.
aCC -Idir1 -I- -Idir2 -c a.C
CAUTION: Some of the compiler's header files are included using double quotes. Since the -I- option redefines the search order of such includes, if any standard headers are used, it is your responsibility to supply the standard include directories (/opt/aCC/include and /usr/include) in the correct order in your -I- command line.

For example, when using -I- on the aCC command line, any specified -I directory containing a quoted include file having the same name as an HP-UX system header file, may cause the following possible conflict. (In general, if your application includes no header having the same name as an HP-UX system header, there is no chance of a conflict.)

Suppose you are compiling program a.C with view-pathing on. a.C includes the file a.out.h which is a system header in /usr/include:

aCC -IDevelopmentDir -I- -IOfficialDir a.C
If a.C contains:
// This is the file a.C
#include <a.out.h>
// ...
When a.out.h is preprocessed from the /usr/include directory, it includes other files that are quote included (like #include "filehdr.h").

Since with view-pathing, quote enclosed headers are not searched for in the including file's directory, filehdr.h which is included by a.out.h will not be searched for in a.out.h's directory (/usr/include). Instead, for the above command line, it is first searched for in DevelopmentDir, then in OfficialDir and if it is found in neither, it is finally searched for in the standard include directories (/opt/aCC/include and /usr/include) in the latter of which it will be found.

However, if you have a file named filehdr.h in DevelopmentDir or OfficialDir, that file (the wrong file) will be found.


Online Help Option Syntax

+help Command Line Option Syntax

+help

Description:

Invokes the initial menu window of this HP aC++ Online Programmer's Guide.

If +help is used on any command line, the compiler displays the online programmer's guide with the default web browser and then processes any other arguments.

If $DISPLAY is set, the default web browser is displayed. If the display variable is not set, a message so indicates. Set your $DISPLAY variable as follows:

export DISPLAY=YourDisplayAddress      (ksh shell notation)

setenv DISPLAY YourDisplayAddress      (csh shell notation)

Examples:

To use a browser other than the default, first set the BROWSER environment variable to the alternate browser's location:
export BROWSER=AlternateBrowserLocation

To invoke the online guide:

aCC +help

Inlining Options

These options allow you to specify the amount of source code inlining done by the HP aC++ compiler.

+d
Disables all inlining of functions.
+inline_level [i]num
Controls how C++ inlining hints influence HP aC++. Also allows inlining of small functions that are not explicitly tagged with the inline keyword.

See Also:

+inline_level [i]num Command Line Option Syntax

+inline_level [i]num

Description

This option controls how C++ inlining hints influence HP aC++. Such inlining happens in addition to explicitly inlined functions. By default, this option is off.

Specifying i causes implicit inlining of small functions.

Specify num as 0, 1, 2, or 3. Refer to the tables below.

Note that +d and +inline_level 0 turn off all inlining, including implicit inlining.

num Meaning
0 No inlining is done (same effect as the +d option).
1 Only small functions are inlined.
2 Only large functions are not inlined.
3 Inlining hints are respected in all cases, except when the called function is recursive or when it has a variable number of arguments.

The default level depends on +Oopt as shown in the following table:

opt num
0 1
1 1
2 2
3 2
4 2

NOTE: This option controls functions declared with the inline keyword or within the class declaration and is effective at all optimization levels.

The options +O[no]inline and +Oinlinebudget control the high level optimizer that recognizes other opportunities in the same source file (+O3) or amongst all source files (+O4).

Example:

aCC +inline_level3 app.C

See Also:


Library Options

Library options allow you to create, use, and manipulate libraries.
-AA
Enable use of Rogue Wave Standard C++ Library 2.2.1 and set all standards related options on.
+A
Link with archive libraries.
-b
Create a shared library.
+k
Generate code for programs that use a large number of global data items in shared libraries.
-lname
Specify a library for the linker to search.
-Ldirectory
Specify a directory for the linker to search for libraries.
+nostl
Indicate header files and libraries (other than those provided with HP aC++) for compilation and linking.
-Wx,args
One use of -W is to specify linking of shared or archive libraries.
+z
Generate position-independent code (PIC) to go into a shared library.
+Z
Generate position-independent code (PIC) to go into a shared library.

See Also:

+A Command Line Option Syntax

+A

Description:

Causes the linker to link with archive libraries rather than shared libraries and creates a completely archived executable.

The -a,archive linker option also links archive libraries but it links the shared library /usr/lib/libdld.sl. +A links in /opt/aCC/lib/cxxshl.o instead of /usr/lib/libdld.sl.

In 64-bit mode, /opt/aCC/lib/cxxshl.o is not used.

Example:

aCC +A file.o -lm
Links file.o and links in the archived version of the math library, /lib/libm.a, rather than the shared version, /lib/libm.sl, and does not link in /usr/lib/libdld.sl.

See Also:

-b Command Line Option Syntax

-b

Description:

Creates a shared library rather than an executable file.

The object files must have been created with the +z or +Z option to generate position-independent code (PIC).

Example:

aCC -b utils.o -o utils.sl

Links utils.o (which must have been created using the +z option) and creates the shared library utils.sl.

For More Information:

For more information on shared libraries, see Creating and Using Shared Libraries, and the HP-UX Online Linker and Libraries User's Guide.

-lname Command Line Option Syntax

-lname
The name parameter forms part of the name of the library the linker searchs when looking for routines called by your program.

Description:

Causes the linker to search one of the following default libraries, if they exist, in an attempt to resolve unresolved external references: Whether it searches the shared library (.sl) or the archive library (.a) depends on the value of the -a linker option or the +A compiler option.

NOTE: Because a library is searched when its name is encountered, placement of a -l is significant. If a file contains an unresolved external reference, the library containing the definition must be placed after the file on the command line. For details refer to the description of ld in the HP-UX Reference Manual or the ld(1) man page if it is installed on your system. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

Example:

aCC file.o -lnumeric

This example directs the linker to link file.o and (by default) search the library /usr/lib/libnumeric.sl.

See Also:

-Ldirectory Command Line Option Syntax

-Ldirectory
The directory parameter is the HP-UX directory where you want the linker to search for libraries your program uses before searching the default directories.

Description:

Causes the linker to search for libraries in directory in addition to using the default search path.

The default search path is the directory /opt/aCC/lib.

The -L option must precede any -lname option entry on the command line; otherwise -L is ignored. This option is passed directly to the linker.

Example:

aCC -L/project/libs prog.C -lmylib1 -lmylib2

Compiles and links prog.C and directs the linker to search the directories /opt/aCC/lib and /project/libs for any libraries that prog.C uses (in this case, mylib1 and mylib2).

See Also:

+z Command Line Option Syntax

+z

Description:

Causes the compiler to generate position-independent code (PIC), necessary for building a shared library.

Use -b to create a shared library.

+z is similar to the +Z option. Use +z unless the linker generates an error message indicating that you should use +Z.

The -G option is ignored if either +z or +Z is used.

Example:

aCC -c +z utils.C

Compiles utils.C and generates position-independent code in utils.o. utils.o can be placed into a shared library with the -b option.

For More Information:

For more information on shared libraries, see the tutorial Creating and Using Shared Libraries and the HP-UX Online Linker and Libraries User's Guide.

+nostl Command Line Option Syntax

+nostl

Description:

By eliminating references to the standard header files and libraries bundled with HP aC++, this option allows experienced users full control over the header files and libraries used in compilation and linking of their applications, without potential complicatons that arise in mixing different libraries.

+nostl suppresses linking of all default -Idirectory and -Ldirectory paths and some of the -lname libraries (-lstd and -lstream). Use the -v option to see the effect of +nostl.

CAUTION: Complete understanding of the linking process and the behavior of the actual (third party) libraries linked with the application is essential for avoiding link or run-time failures.

For More Information:

For more information on shared libraries, see the tutorial Creating and Using Shared Libraries and the HP-UX Online Linker and Libraries User's Guide.

+Z Command Line Option Syntax

+Z

Description:

Causes the compiler to generate position-independent code (PIC), necessary for building shared libraries.

Use -b to create a shared library.

+Z is the same as the +z option except that it allows for more imported symbols than does +z. Use the +Z option only if errors are generated when you use +z.

The -G option is ignored if either +z or +Z is used.

64-bit Mode Only: +Z is the default when +DA2.0W is specified.


Linker Options

You can specify the following linker options on the compiler command line:

-n
The linker marks the output as sharable.
-N
The linker marks the output as unsharable.
-q
The linker marks the output as demand-loadable.
-Q
The linker marks the output as not demand-loadable.
-s
The linker strips the symbol table from the executable file it produces.
-z
The linker disallows dereferencing of null pointers at run time.

In addition, you can use the -Wl,args compiler option to specify any linker option on the compiler command line. For more information on linker options, see the ld(1) man page or the HP-UX Reference Manual.

CAUTION: You must use the aCC command to link your HP aC++ programs and libraries. This ensures that all libraries and other files needed by the linker are available.

-n Command Line Option Syntax

-n

Description:

Causes the program file produced by the linker to be marked as sharable.

For More Information:

For details and system defaults, refer to the description of ld in the HP-UX Reference Manual or the ld(1) man page if it is installed on your system. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

See Also:

See also the -N option.

-N Command Line Option Syntax

-N

Description:

Causes the program file produced by the linker to be marked as unsharable.

Unsharable executable files generated with the -N option cannot be executed with exec.

For More Information:

For details and system defaults, refer to the ld description in the HP-UX Reference Manual or the ld(1) man page if it is installed on your system. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

See Also:

-q Command Line Option Syntax

-q

Description:

Causes the output file from the linker to be marked as demand-loadable.

For More Information:

For details and system defaults, see the description of ld in the HP-UX Reference Manual or the ld(1) man page if it is installed on your system. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

-Q Command Line Option Syntax

-Q

Description:

Causes the program file from the linker to be marked as not demand-loadable.

For More Information:

For details and system defaults, see the description of ld in the HP-UX Reference Manual or the ld(1) man page if it is installed on your system. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

-s Command Line Option Syntax

-s

Description:

Causes the executable program file created by the linker to be stripped of symbol table information.

Specifying this option prevents using a symbolic debugger on the resulting program.

For More Information:

For more details, refer to the description of ld in the HP-UX Reference Manual or the ld(1) man page if it is installed on your system. (If you see the message "Man page could not be formatted," ensure the man page is installed.)


Options for Naming the Output File

These options allow you to name the compilation output file something other than the default name.

-o outfile
Specifies the name of the output file from the compilation.
-.suffix
Specifies a file name suffix to be used for the output file from the compilation.

-o Command Line Option Syntax

-o outfile
The outfile parameter is the name of the file containing the output of the compilation.

Description:

Causes the output of the compilation to be placed in outfile.

Without this option the default name is a.out. When compiling a single source file with the -c option, you can use the -o option to specify the name and location of the object file.

-.suffix Command Line Option Syntax

-.suffix
The suffix parameter represents the character or characters to be used as the output file name suffix.

suffix cannot be the same as the original source file name suffix.

Description:

Causes HP aC++ to direct output from the -E option into a file with the corresponding .suffix instead of into a corresponding .c file.

Example:

aCC -E -.i prog.C

Preprocesses the C++ code in prog.C and puts the resulting code in the file prog.i.


Option to Enable Native Language Support

-Y Command Line Option Syntax

-Y

Description:

Enables Native Language Support (NLS) of 8-bit, 16-bit and 4-byte EUC characters in comments, string literals, and character constants.

The language value (refer to environ(5) for the LANG environment variable) is used to initialize the correct tables for interpreting comments, string literals, and character constants. The language value is also used to build the path name to the proper message catalog.

For More Information:

Refer to hpnls, lang, and environ in the HP-UX Reference Manual for a description of the NLS model.


Option for Handling Null Pointers

-z Command Line Option Syntax

-z

Description:

This ld(1) option disallows dereferencing of null pointers at run time.

Fatal errors result if null pointers are dereferenced. If you attempt to dereference a null pointer, a SIGSEGV error occurs at run time.

Example:

aCC -z file.C
Compiles file.C and generates code to disallow dereferencing of null pointers.

For More Information:

See signal(2) and signal(5) for more information. (If you see the message "Man page could not be formatted," ensure the man page is installed.)


Options for Optimizing Your Code

Optimization options can be used to improve the execution speed of programs compiled with HP aC++.

To use optimization, first specify the appropriate basic optimization level (+O1, +O2, +O3, or +O4) on the aCC command line followed by one or more finer or more precise options when necessary. For an introduction with examples, refer to Optimizing HP aC++ Programs.

Categories of options are listed below.

For More Information:

Basic Optimization Level Options

These options allow you specify the basic level of optimization.
-O
Specify level 2 optimization.
+O1
Specify level 1 optimization.
+O2
Specify level 2 optimization.
+O3
Specify level 3 optimization.
+O4
Specify level 4 optimization.

-O Command Line Option Syntax

-O

Description:

Invokes the optimizer to perform level 2 optimization.

Example:

aCC -O prog.C
Compiles prog.C and optimizes at level 2.

For More Information:

You can set other optimization levels by using the following options:

See Also:

+O1 Command Line Option Syntax

+O1

Description:

Performs level 1 optimization only. This includes branch optimization, dead code elimination, faster register allocation, instruction scheduling, and peephole optimization.

Example:

aCC +O1 prog.C
Compiles prog.C and optimizes at level 1.

For More Information:

You can set other optimization levels by using the following options:

See Also:

+O2 Command Line Option Syntax

+O2

Description:

Performs level 2 optimization. This includes level 1 optimizations plus optimizations performed over entire functions in a single file.

Example:

aCC +O2 prog.C
Compiles prog.C and optimizes at level 2.

For More Information:

You can set other optimization levels by using the following options:

See Also:

+O3 Command Line Option Syntax

+O3

Description:

Performs level 3 optimization. This includes level 2 optimizations plus full optimization across all subprograms within a single file.

Example:

aCC +O3 prog.C
Compiles prog.C and optimizes at level 3.

For More Information:

You can set other optimization levels by using the following options:

See Also:

+O4 Command Line Option Syntax

+O4

Description:

Performs level 4 optimization. This includes level 3 optimizations plus full optimizations across the entire application program.

When you link a program, the compiler brings all modules that were compiled at optimization level 4 into virtual memory at the same time. Depending on the size and number of the modules, compiling at +O4 can consume a large amount of virtual memory. If you are linking a large program that was compiled with the +O4 option, you may notice a system slow down. In the worst case, you may see an error indicating that you have run out of memory.

If you run out of memory when compiling at +04 optimization, there are several things you can do:

  1. Compile at +O4 only those modules that need to be compiled at optimization level 4, and compile the remaining modules at a lower level.

  2. If you still run out of memory, increase the per-process data size limit. Run the System Administrator Manager (SAM) to increase the maxdsiz process parameter from 64 MB to 128 MB. This procedure provides the process with additional data space.

    Refer to the System Administration Tasks manual, Chapter 11, "Reconfiguring the HP-UX Kernel." See Appendix A for full descriptions of the different process parameters, including maxdsiz.

  3. If increasing the per-process data size limit does not solve the problem, increase the system swap space. Refer to the System Administration Tasks manual, Chapter 6, "Managing Swap Space." Pay particular attention to the section "Adding File System Swap", because adding file system swap is easier than increasing the amount of device swap, which requires re-configuring your disk. However, if you find that you are consistently compiling beyond the available amount of device swap, you may not have a choice.

For a complete discussion of swap space, refer to How HP-UX Works: Concepts for the System Administrator.

Example:

aCC +O4 prog.C
Compiles prog.C and optimizes at level 4.

For More Information:

You can set other optimization levels by using the following options:

See Also:

Additional Optimizations for Finer Control

+ESfic
Replace millicode calls with inline fast indirect calls, for applications that do not use shared libraries.
+ES[no]lit
Place string literals into read-only memory.
+ESplabel
Replace millicode calls with inline fast indirect calls, for applications that use shared libraries.
+ESsfc
Replace millicode calls with inline code when performing simple function pointer comparisons.
-fast
Select a set of options for optimum execution speed for reasonable build times.
+O[no]all
Perform maximum optimization.
+O[no]aggressive
Optimizations that may change the behavior of code.
+O[no]conservative
Optimize with the minimum risk of side effects.
+O[no]limit
Optimize using [un]restricted compile time.
+O[no]size
Enable [disable] code expanding optimizations.

+ESfic Command Line Option Syntax

Syntax

+ESfic

Description:

Replaces millicode calls with inline fast indirect calls. The +ESfic compiler option affects how function pointers are dereferenced in generated code. The default is to generate low-level millicode calls for function pointer calls.

The +ESfic option generates code that calls function pointers directly, by branching through them.

NOTE: The +ESfic option should only be used in an environment where there are no dependencies on shared libraries. The application must be linked with archive libraries only. Using this option can improve run-time performance.

+ES[no]lit Command Line Option Syntax

Syntax

+ES[no]lit

Description:

Places string literals into read-only memory. This is the default. This option may reduce memory requirements and improve run-time speed in multi-user applications.

In A.03.15, A.01.23, and prior compiler versions, only floating-point constant values were placed in read-only memory. Other constants and literals were placed in read-write memory. This behavior remains available by specifying the +ESnolit option when compiling.

As +ESlit allows the placement of string literals into read-only memory, all users of an application share this data. Whereas, each user is allocated a private copy of the data stored in read-write memory. By moving additional data from read-write storage to read-only storage, overall system memory requirements can be reduced and run-time speed improved. In addition, the compiler may also group identical strings, further reducing memory usage.

NOTE: When +ESlit is in effect, you should not attempt to modify string literals, because all string literals are placed in read-only memory. Particularly, the following C library functions should be used with care, since they can alter the contents of a string literal that is specified as the receiving string.

extern char *strncat(char *, const char *, size_t);
extern void *memmove(void *, const void *, size_t);
extern char *strcpy(char *, const char *);
extern char *strncpy(char *, const char *, size_t);
extern char *strcat(char *, const char *);
extern char *strtok(char *, const char *);
Following is an example of code that attempts to modify read-only memory. A compile-time error is generated unless a cast is done, in which case there is no message. At runtime, a SIGBUS signal is generated.
int main()
{
     static const char *p = "Now is the time";
     char *q;

     // .....

     q = (char*)p;      // cast to q

// OR
//  q = const_cast(p);  // const cast to q

    *q = 'd';           // Very bad! Application core dump

    // .....

}

+ESplabel Command Line Option Syntax

Syntax

+ESplabel

Description:

Replaces millicode calls with inline fast indirect calls. The +ESplabel option affects how function pointers are dereferenced in generated code. The default is to generate low-level millicode calls for function pointer calls (and virtual calls).

+ESplabel generates code that calls function pointers directly by inlining the millicode routine.

Usage:

Using this option can improve run-time performance at the expensive of a slight increase in code size for every call.

The option can only be used:

+ESsfc Command Line Option Syntax

Syntax

+ESsfc

Description:

Replaces millicode calls with inline code when performing simple function pointer comparisons. The +ESsfc compiler option affects how function pointers are compared in generated code. The default is to generate low-level millicode calls for function pointer comparisons.

The +ESsfc option generates code that compares function pointers directly, as if they were simple integers.

NOTE: The +ESsfc option should only be used in an environment where there are no dependencies on shared libraries. The application must be linked with archive libraries only. Using this option can improve run-time performance.

Example:

Following is an example of a code fragment that performs function pointer comparisons:

int (*g)( );
int (*f)( );
int foo ( );
{
    . . .
}
    . . .
  if (f == g)
    . . .
  if (f == foo)
    . . .
  if (f == SIG_ERR) /* SIG_ERR is defined in signal.h */
    . . .

+O[no]all Command Line Option Syntax

+O[no]all

Description:

Use +Oall to obtain the best possible performance.

This option should be used with stable, well-structured code. These optimizations give you the fastest code, but are riskier than the default optimizations.

You can use +Oall at optimization levels 2, 3, and 4. The default is +Onoall.

Examples:

aCC +Oall prog.C
Compiles prog.C and optimizes for best performance.

aCC -O +Oall prog.C
Compiles prog.C and optimizes at level 2 with aggressive optimizations and unrestricted compile time.

For More Information:

The +Oall option without +O2, +O3, or +O4 combines the following options:

+O[no]aggressive Command Line Option Syntax

+O[no]aggressive

Description:

The +Oaggressive option enables aggressive optimizations. The +Onoaggressive option disables aggressive optimizations.

Aggressive optimizations can result in significant performance improvement, but can change program behavior. They can:

Use +Oaggressive with optimization levels 2, 3, or 4. By default, aggressive optimizations are turned off.

Example:

To enable aggressive optimizations at the second, third, or fourth optimization levels, type:

aCC +O2 +Oaggressive sourcefile.C
or:
aCC +O3 +Oaggressive sourcefile.C
or:
aCC +O4 +Oaggressive sourcefile.C

For More Information:

The +Oaggressive option invokes the following advanced optimization options:

+O[no]clone Command Line Option Syntax

+O[no]clone

Description:

This option provides user control to turn on [off] the cloning feature of the optimizer. This option is primarily for users who may see a lot of cloning adversely affecting the performance of their code, and want more control over cloning.

Cloning is on by default, and is valid at optimization levels +O3 and +O4. When inlining is turned off, cloning is turned off too.

+O[no]conservative Command Line Option Syntax

+O[no]conservative

Description:

The +Oconservative option causes the optimizer to make conservative assumptions about application code and enable only conservative optimizations, a subset of basic optimizations.

Use +Oconservative at optimization levels 2, 3, or 4 when your source code is unstructured or you are unfamiliar with the source code being optimized. The default is +Onoconservative.

Example:

To enable conservative optimizations at the second, third, or fourth optimization levels, use the +Oconservative option as follows:

aCC +O2 +Oconservative sourcefile.C
or:
aCC +O3 +Oconservative sourcefile.C
or:
aCC +O4 +Oconservative sourcefile.C

+O[no]exception Command Line Option Syntax

+O[no]exception

Description:

Enable[disable] optimizations of code regions with exception handling code sequences. This option is disabled by default.

+Oexception is allowed to be used at optimization levels 2,3 and 4. The default is +Onoexception

+O[no]memory[=malloc] Command Line Option Syntax

+O[no]memory[=malloc]

Description:

Enable [disable] memory optimizations. Specifying 'malloc' in the list will enable[disable] optimizations which consolidate memory allocation procedure calls. This option is disabled by default. This option is incompatible with +Oopenmp and +Oparallel, and is ignored.

+O[no]limit Command Line Option Syntax

+O[no]limit

Description:

The +Olimit option suppresses optimizations that significantly increase compile-time or that consume a lot of memory.

The +Onolimit option enables optimizations regardless of their effect on compile time or memory consumption.

Use +Onolimit with optimization levels 2, 3, or 4. The default is +Olimit.

Example:

To remove optimization time restrictions at the second, third, or fourth optimization levels, use +Onolimit as follows:

aCC +O2 +Onolimit sourcefile.C
or:
aCC +O3 +Onolimit sourcefile.C
or:
aCC +O4 +Onolimit sourcefile.C

+O[no]ptrs_to_globals(list) Command Line Option Syntax

+O[no]ptrs_to_globals(list)

Description:

This option tells the optimizer whether global variables are accessed [are not accessed] through pointers. The default is +Onoptrs_to_globals.

+O[no]size Command Line Option Syntax

+O[no]size

Description:

While most optimizations reduce code size, the +Osize option suppresses those few optimizations that significantly increase code size. The +Onosize option enables code-expanding optimizations.

Use +Osize at optimization levels 2, 3, or 4. The default is +Onosize.

Example:

To disable code size expanding optimizations at the second, third, and fourth optimization levels, use +Osize as follows:

aCC +O2 +Osize sourcefile.C
or:
aCC +O3 +Osize sourcefile.C
or:
aCC +O4 +Osize sourcefile.C

Advanced +Ooptimization Options

Advanced optimization options provide additional control for special situations.

+O[no]dataprefetch
Enable [disable] optimizations to generate data prefetch instructions for data structures referenced within innermost loops.
+O[no]entrysched
Perform [do not perform] instruction scheduling on a subprogram's entry and exit sequences.
+O[no]extern
Perform [do not perform] optimization for a specified set of symbols.
+O[no]failsafe
Enable [disable] fail-safe optimization.
+O[no]fastaccess
Enable [disable] fast access to global data items.
+O[no]fltacc
Disable [enable] all optimizations that cause imprecise floating-point results.
+O[no]initcheck
Enable [disable] initialization of uninitialized scalar variables to null values.
+O[no]inline
Inline [do not inline] procedure calls.
+Oinlinebudget
Inline aggressively.
+Olevel=name1[,name2,...nameN]
Lower the optimization level for one or more named functions.
+O[no]libcalls
Use [do not use] millicode routines instead of certain math library calls.
+O[no]looptransform
Transform [do not transform] eligible loops for improved cache performance.
+O[no]loopunroll[=unroll factor]
Enable [disable] loop unrolling.
+O[no]moveflops
Move [do not move] conditional floating-point instructions out of loops.
+O[no]multiprocessor
Enable [do not enable] multiple process optimization.
+O[no]parmsoverlap
Assume [do not assume] that arguments of function calls overlap in memory.
+O[no]pipeline
Enable [disable] software pipelining.
+O[no]procelim
Enable [disable] elimination of unreferenced procedures.
+O[no]promote_indirect_calls
Enable [disable] the promotion of indirect calls to direct calls.
+O[no]regionsched
Move [do not move] instructions across branches.
+O[no]regreassoc
Enable [disable] register reassociation.
+Oreusedir=DirectoryPath
Specify a directory in which to save intermediate object code files for reuse.
+O[no]volatile
Assume all global variables are [not] volatile.

+O[no]dataprefetch Command Line Option Syntax

+O[no]dataprefetch

Description:

When +Odataprefetch is enabled, the optimizer inserts instructions within innermost loops to explicitly prefetch data from memory into the data cache. Data prefetch instructions are inserted only for data structures referenced within innermost loops using simple loop varying addresses (that is, in a simple arithmetic progression). It is only available for PA-RISC 2.0 targets.

Use this option for applications that have high data cache miss overhead.

You can use +Odataprefetch at optimization levels 2, 3, and 4. The default is +Onodataprefetch.

+O[no]entrysched Command Line Option Syntax

+O[no]entrysched

Description:

The +Oentrysched option optimizes instruction scheduling on a procedure's entry and exit sequences. Enabling this option can speed up an application. The option has undefined behavior for applications which handle asynchronous interrupts. The option affects unwinding in the entry and exit regions.

At optimization level +O2 and higher (using dataflow information), save and restore operations become more efficient.

This option can change the behavior of programs that perform error handling or that handle asynchronous interrupts. The behavior of setjmp() and longjmp() is not affected.

Use +Oentrysched at optimization levels 2, 3, or 4. The default is +Onoentrysched.

+O[no]extern Command Line Option Syntax

+O[no]extern

Description:

The +O[no]extern option allows you to specify which accesses to symbols in an executable or shared library (a load module) can be optimized.

64-bit Mode Only: Use +Onoextern only with the 64-bit runtime model.

NOTE: Use of +Onoextern creates code that cannot be included in a shared library. Use +Onoextern only to build executables.

Only internal symbols (defined in the load module) can be optimized. If +Onoextern is specified, the compiler assumes that no symbols are external to the load module being compiled, and any symbol can be optimized. If +Oextern is specified, the compiler assumes that all symbols are external to the load module being compiled and thus cannot be optimized; this is the default.

Usage:

Use this option to control which symbols' accesses may be optimized. Knowledge of the shared libraries used by an application, or the exported interface of a shared library is required.

Use +O[no]extern at optimization levels 0, 1, 2, 3, or 4. The default is +Oextern with no name list.

+O[no]failsafe Command Line Option Syntax

+O[no]failsafe

Description:

The +Ofailsafe option allows compilations with internal optimization errors to continue by issuing a warning message and restarting the compilation at a lower optimization level or at +O0, as shown in the following table.

Specified
Optimization Level
Optimization Level when Errors Encountered
1 0
2 0
3 2 (Note that further errors at level 2, cause the optimization level to drop to 0.)
4 2 (Note that further errors at level 2, cause the optimization level to drop to 0.)

You can use +Onofailsafe at optimization levels 1, 2, 3, or 4 when you want the internal optimization errors to abort your build.

The default is +Ofailsafe at levels 1, 2, 3, 4.

+O[no]fastaccess Command Line Option Syntax

+O[no]fastaccess

Description:

The +Ofastaccess option optimizes for fast access to global data items.

Use +Ofastaccess to improve execution speed at the expense of longer compile times.

Use +Ofastaccess at optimization levels 0, 1, 2, 3, or 4. The default is +Onofastaccess at optimization levels 0, 1, 2, and 3, and +Ofastaccess at optimization level 4.

+O[no]fltacc Command Line Option Syntax

+O[no]fltacc

Description:

Disable [enable] floating-point optimizations that can result in numerical differences. +Onofltacc also generates Fused Multiply-Add (FMA) instructions, as does compiling your program at optimization level 2 or higher. FMA instructions can improve performance of floating-point applications and are available only on PA-RISC 2.0 systems or later.

If you specify neither +Ofltacc nor +Onofltacc, less optimization is performed than for +Onofltacc. If you specify neither option at optimization level 2 or higher, the optimizer generates FMA instructions but does not perform any expression-reordering optimizations.

Specifying +Ofltacc insures the same result as in unoptimized code (+O0).

Usage

The +Onofltacc option allows the compiler to make transformations which are algebraically correct, but which may slightly affect the result of computations due to the inherent imperfection of computer floating-point arithmetic. For many programs, the results obtained under +Onofltacc are adequately similar to those obtained without the optimization.

For applications in which roundoff error has been carefully studied, and the order of computation carefully crafted to control error, +Onofltacc may be unsatisfactory. To insure the same result as in unoptimized code, use +Ofltacc.

Use +Onofltacc at optimization levels 2, 3, or 4. The default is to leave this option unspecified.

Example:

+Onofltacc allows the compiler to substitute division by a multiplication using the reciprocal. For example, the following code

for (int j=1;j<5;j++)
    a[j] = b[j] / x;

is transformed as follows (note that x is invariant in the loop):

x_inv = 1.0/x;
for (int j=1;j<5;j++)
    a[j] = b[j] * x_inv;

Since multiplication is considerably faster than division, the optimized program runs faster.

+O[no]initcheck Command Line Option Syntax

+O[no]initcheck

Description:

The initialization checking feature of the optimizer has three possible states: on, off, or unspecified.

Use +Oinitcheck to look for program variables that may not be initialized.

Use +Oinitcheck at any optimization level and +Onoinitcheck at optimization levels 2, 3, or 4.

+O[no]inline Command Line Option Syntax

+O[no]inline

Description:

The +Oinline option indicates that any function can be inlined by the optimizer. +Onoinline disables inlining of functions by the optimizer. (This option does not affect functions inlined at the source code level.

Use +Onoinline at optimization levels 3 or 4. The default is +Onoinline at optimization levels 1 and 2 and +Oinline at levels 3 and 4.

See Also:

+Oinlinebudget Command Line Option Syntax

+Oinlinebudget=n

Description:

The +Oinlinebudget option controls the aggressiveness of inlining according to the value you specify for n where n is an integer in the range 1 - 1000000 that specifies the level of aggressiveness, as follows:

= 100
Default level of inlining.

> 100
More aggressive inlining. The optimizer is less restricted by compilation time and code size when searching for eligible routines to inline.

2 - 99
Less aggressive inlining. The optimizer gives more weight to compilation time and code size when determining whether to inline.

= 1
Only inline if it reduces code size.

The +Onolimit and +Osize options also affect inlining. Specifying the +Onolimit option has the same effect as specifying +Oinlinebudget=200. The +Osize option has the same effect as +Oinlinebudget=1.

Note, however, that the +Oinlinebudget option takes precedence over both of these options. This means that you can override the effect of +Onolimit or +Osize option on inlining by specifying the +Oinlinebudget option on the same compile line.

Use this option at optimization level 3 or higher. The default is +Oinlinebudget=100.

For More Information:

See also the +O[no]inline option.

+Olevel=name1[,name2,...,nameN] Command Line Option Syntax

+Olevel=name1[,name2,...,nameN]

Currently only the C++ mangled name of the function is allowed for name.

Description:

This option lowers optimization to the specified level for one or more named functions. level can be 0, 1, 2, 3, or 4. The name parameters are names of functions in the module being compiled. Use this option when one or more functions do not optimize well or properly. This option must be used with a basic +Olevel or -O option.

This option works as does the OPT_LEVEL pragma. The option overrides the pragma for the specified functions. As with the pragma, you can only lower the level of optimization; you cannot raise it above the level specified by a basic +Olevel or -O option. To avoid confusion, it is best to use either this option or the OPT_LEVEL pragma rather than both.

You can use this option at optimization levels 1, 2, 3, and 4. The default is to optimize all functions at the level specified by the basic +Olevel or -O option.

Examples

The following command optimizes all functions at level 3, except for the functions myfunc1 and myfunc2, which it optimizes at level 1.
aCC +O3 +O1=myfunc1,myfunc2 funcs.c main.c
The following command optimizes all functions at level 2, except for the functions myfunc1 and myfunc2, which it optimizes at level 0.
aCC -O +O0=myfunc1,myfunc2 funcs.c main.c

+O[no]libcalls Command Line Option Syntax

+O[no]libcalls

Description:

A number of math library functions are implemented in a special millicode library as well as in the standard math library. The millicode versions are up to 25 percent faster than the standard versions. However, they do not set errno and do not give an error message in the event of an exception.

The +Olibcalls option provides access to millicode routines for the following math library calls:

sin   cos   tan   atan2   pow   log10   asin   acos   atan   exp   log

Use +Olibcalls to improve the performance of these library routines only when you do not want standard error checking. For example, you might use +Olibcalls with code that has already been debugged and runs without error.

The default is +Onolibcalls.

Use +O[no]libcalls at any optimization level.

See Also:

+O[no]looptransform Command Line Option Syntax

+O[no]looptransform

Description:

The +O[no]looptransform option enables [disables] transformation of eligible loops for improved cache performance. The most important transformation is the reordering of nested loops to make the inner loop unit stride, resulting in fewer cache misses.

The default is +Olooptransform at optimization levels 3 and 4. You cannot use the option at levels 0-2.

+O[no]loopunroll Command Line Option Syntax

+O[no]loopunroll[=unroll factor]

Description:

The +Oloopunroll option turns on loop unrolling. When you use +Oloopunroll, you can also use the unroll factor to control the code expansion. The default unroll factor is 4, that is, four copies of the loop body. By experimenting with different factors, you may improve the performance of your program.

You can use +Oloopunroll at optimization levels 2, 3, and 4. The default is +Oloopunroll.

+O[no]moveflops Command Line Option Syntax

+O[no]moveflops

Description:

The +Omoveflops option allows moving conditional floating-point instructions out of loops. The behavior of floating-point error handling may be altered by this option.

This option also allows you to enable or disable replacing integer divide by a floating-point multiply. This may cause SIGFPE if IEEE inexact is enabled (+FPI).

Usage:

Use +Onomoveflops if floating-point traps are enabled and you do not want the behavior of floating-point errors to be altered by the relocation of floating-point instructions.

Use +Onomoveflops at optimization levels 2, 3, and 4. The default is +Omoveflops.

+O[no]multiprocessor Command Line Option Syntax

+O[no]multiprocessor

Description:

If +Omultiprocessor is specified, the compiler performs optimizations appropriate for executables or shared libraries to be run in several different processes on multiprocessor machines.

Usage:

If you enable this option inappropriately (for example, for an executable only run on a uniprocessor system), performance may be degraded.

Use +O[no]multiprocessor at optimization levels 2, 3, and 4. The default is +Onomultiprocessor.

+O[no]parmsoverlap Command Line Option Syntax

+O[no]parmsoverlap

Description:

The +Oparmsoverlap option optimizes with the assumption that the actual arguments of function calls overlap in memory.

Use +Onoparmsoverlap if C++ programs have been literally translated from FORTRAN programs.

Use +Onoparmsoverlap at optimization levels 2, 3, and 4. The default is +Oparmsoverlap.

+O[no]pipeline Command Line Option Syntax

+O[no]pipeline

Description:

The +Opipeline option enables software pipelining.

Use +Onopipeline to conserve code space.

Use +Onopipeline at optimization levels 2, 3, and 4. The default is +Onopipeline at optimization level 1 and +Opipeline at levels 2, 3, and 4.

+O[no]procelim Command Line Option Syntax

+O[no]procelim

Description:

Enable [or disable] the elimination of dead procedure code.

Used when linking an executable file, +Oprocelim removes functions not referenced by the application. Used when building a shared library, +Oprocelim removes functions not exported and not referenced from within the shared library. This may be especially useful when functions have been inlined.

Note that any function having symbolic debug information associated with it is not removed.

The default is +Onoprocelim at optimization levels 1 through 3 and +Oprocelim at level 4.

Use +O[no]procelim at any optimization level. +O[no]promote_indirect_calls

+O[no]promote_indirect_calls Command Line Option Syntax

+O[no]promote_indirect_calls

Description:

This option uses profile data from profile-based optimization and other information to determine the most likely target of indirect calls and promotes them to direct calls. Indirect calls occur with pointers to functions and virtual calls.

In all cases the optimized code tests to make sure the direct call is being taken and if not, executes the indirect call. If +Oinline is in effect, the optimizer may also inline the promoted calls. +Opromote_indirect_calls is only effective with profile-based optimization.

NOTE: The optimizer tries to determine the most likely target of indirect calls. If the profile data is incomplete or ambiguous, the optimizer may not select the best target. If this happens, your code's performance may decrease.

This option can be used at optimization levels 3 and 4. At +O3, it is only effective if indirect calls from functions within a file are mostly to target functions within the same file. This is because +O3 optimizes only within a file whereas, +O4 optimizes across files.

The default is +Onopromote_indirect_calls.

+O[no]regionsched Command Line Option Syntax

+O[no]regionsched

Description:

The +Oregionsched option applies aggressive scheduling techniques to move instructions across branches.

NOTE: This option is incompatible with the -z option. Using this option with -z may cause a SIGSEGV error at run-time. See signal(2) and signal(5) for more information. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

Use +Oregionsched to improve application run-time speed.

Use +Oregionsched at optimization levels 2, 3, and 4. The default is +Onoregionsched.

+O[no]regreassoc Command Line Option Syntax

+O[no]regreassoc

Description:

The +Onoregreassoc option turns off register reassociation.

Use +Onoregreassoc to disable register reassociation if this optimization hinders application performance.

Use +Onoregreassoc at optimization levels 2, 3, and 4. The default is +Oregreassoc.

+Oreusedir=DirectoryPath Command Line Option Syntax

+Oreusedir=DirectoryPath

Description:

This option specifies a directory for the linker to save object files created from intermediate object files when using +O4 or profile-based optimization. It reduces link time by not recompiling intermediate object files when they don't need to be recompiled.

When you compile with +I, +P, or +O4, the compiler generates intermediate code in the object file. Otherwise, the compiler generates regular object code in the object file. When you link, the linker first compiles the intermediate object code to regular object code, then links the object code. With this option you can reduce link time on subsequent links by not recompiling intermediate object files that have already been compiled to regular object code and have not changed.

NOTE: When you do change a source file or command line options and recompile, a new intermediate object file will be created and compiled to regular object code in the specified directory. The previous object file in the directory will not be removed. You should periodically remove this directory or the old object files since the old object files cannot be reused and will not be automatically removed.

Use +Oreusedir=DirectoryPath at optimization level 4 or with profile-based optimization. The default is to use TMPDIR and remove the temporary objects after each link.

+O[no]volatile Command Line Option Syntax

+O[no]volatile

Description:

The +Ovolatile option implies that memory references to global variables are volatile and cannot be removed during optimization. The +Onovolatile option implies that all globals are not of volatile class. This means that references to global variables can be removed during optimization.

Use this option to control the "volatile" semantics for all global variables.

Use +Ovolatile at optimization levels 1, 2, 3, or 4. The default is +Onovolatile.

Parallel Processing Options

HP aC++ provides the following optimization options for parallel code.

For More Information:

-mt
Automatically selects and sets flags for parallelization.
+O[no]autopar
Parallelize loops that are safe to parallelize.
++O[no]dynsel
Enable workload-based dynamic selection of parallelizable loops.
+O[no]loop_block
Enable [disable] blocking of eligible loops for improved cache performance.
+O[no]loop_unroll_jam
Enable [disable] loop unrolling and jamming.
+O[no]parallel
Transform [do not transform] eligible loops for parallel execution on a multiprocessor system.
+O[no]report[=report_type
Produce a Loop Report.
+O[no]sharedgra
Enable [disable] global register allocation.
+tmtarget
Compile code for optimization with a specific machine architecture.

-mt Command Line Option Syntax

Description:

Easier use of threads with -mt The new -mt option enables multi-threading capability without the need to set any other flags, such as -l and -D. aC++ examines your environment and automatically selects and sets the appropriate flags. There are four possible sets of flags depending on your operating system and which libstd you use. Option matrix for -mt: | OS 10.20 (user thread) | OS 11.x (kernel thread) ---------+--------------------------------+------------------------------- old-lib | -D_REENTRANT | -D_REENTRANT libstd | -DRW_MULTI_THREAD | -DRW_MULTI_THREAD 1.2.1 | -DRWSTD_MULTI_THREAD | -DRWSTD_MULTI_THREAD | -D_THREAD_SAFE | -D_THREAD_SAFE & | | -D_POSIX_C_SOURCE=199506L librwtool| | 7.0.x | -lcma | -lpthread ---------+--------------------------------+-------------------------------- new-lib | -D_REENTRANT | -D_REENTRANT (-AA) | -D_RW_MULTI_THREAD | -D_RW_MULTI_THREAD | -D_RWSTD_MULTI_THREAD | -D_RWSTD_MULTI_THREAD libstd | | -D_POSIX_C_SOURCE=199506L 2.2.1 | | | -lcma | -lpthread ---------+--------------------------------+-------------------------------- Macros used to compile multi-thread source code: _REENTRANT Required by system header files that provide reentrant functions (suffixed by _r). RW_MULTI_THREAD/_RW_MULTI_THREAD Required by Rogue Wave toolsh++ header files and libraries. RW_MULTI_THREAD is used by toolsh++ 7.0.x. _RW_MULTI_THREAD is used by toolsh++ 8.x (not yet available). RWSTD_MULTI_THREAD/_RWSTD_MULTI_THREAD Required by Rogue Wave standard library header files and libraries. RWSTD_MULTI_THREAD is used by libstd 1.2.1. _RWSTD_MULTI_THREAD is used by libstd 2.2.1 when compiling with -AA. _POSIX_C_SOURCE=199506L Required by pthread. Using -D__HPACC_THREAD_SAFE_RB_TREE The Rogue Wave Standard C++ Library 1.2.1 (libstd) and Tools.h++ 7.0.6 (librwtool) are not thread safe if the underlying implementation rb_tree class is involved. In other words, if the tree header file (which includes tree.cc) under /opt/aCC/include/ is used, these libraries are not thread safe. Most likely, it is indirectly referenced by including the standard C++ library container class map or set headers, or by including a RogueWave tools.h++ header like tvset.h, tpmset.h, tpmset.h, tvset.h, tvmset.h, tvmset.h, tpmap.h, Since changing the rb_tree implementation to make it thread safe would break binary compatibility, the preprocessing macro __HPACC_THREAD_SAFE_RB_TREE must be defined. Whether or not this macro is defined when compiling a file that includes the tree header, its use must be consistent. For example, a new object file compiled with the macro defined should not be linked with older ones that were compiled without the macro defined. Library providers whose library is built with the macro defined may need to notify their users to also compile their source with the macro defined when the tree header is included. This macro is not set by -mt, You must set it explicitly on the command line. _THREAD_SAFE Required by thread safe cfront compatible libstream header files and library. For the frequently used objects cout, cin, cerr, and clog, you can specify the -D_THREAD_SAFE compile time flag for any file that includes . In this case, a new instance of the object is transparently created for each thread that uses it. All instances share the same file descriptor. libcma.* User thread library used in 10.20 system. libpthread.* Kernel thread library used on 11.x systems.

+O[no]autopar Command Line Option Syntax

+O[no]autopar

Description:

When used with the +Oparallel option, +Oautopar causes the compiler to parallelize loops that are safe to parallelize. When used with +Oparallel, +Onoautopar causes the compiler not to parallelize any loops.

A loop is safe to parallelize if it has an iteration count that can be determined at runtime before loop invocation; it must contain no loop-carried dependences, procedure calls, or I/O operations. A loop-carried dependence exists when one iteration of a loop assigns a value to an address that is referenced or assigned on another iteration.

+Oautopar is the default for all optimization levels but is useful only at levels 3 and 4.

For More Information:

+O[no]dynsel Command Line Option Syntax

+O[no]dynsel

Description:

When specified with +Oparallel, the +Odynsel option enables workload-based dynamic selection of parallelizable loops. +Odynsel causes the compiler to generate either a parallel or a serial version of the loop. The loop's workload is compared to parallelization overhead, and the parallel version is run only if it is profitable to do so.

The +Onodynsel option disables dynamic selection and tells the compiler that it is profitable to parallelize all parallelizable loops.

If a loop's iteration count is known at compile time, this optimization is performed at compile time. If a loop's iteration count is not known until runtime, the optimization is performed at runtime.

The default is +Odynsel if +Oparallel is enabled at optimization level(s) 3 and 4.

For More Information:

+O[no]loop_block Command Line Option Syntax

+O[no]loop_block

Description:

The +O[no]loop_block option enables [disables] blocking of eligible loops for improved cache performance.

The default is +Onoloop_block at optimization level(s) 3 and 4.

For More Information:

+O[no]loop_unroll_jam Command Line Option Syntax

+O[no]loop_unroll_jam

Description:

The +O[no]loop_unroll_jam option enables [disables] loop unrolling and jamming. Loop unrolling and jamming increase register exploitation.

The default is +Onoloop_unroll_jam at optimization level(s) 3 and 4.

For More Information:

+O[no]parallel Command Line Option Syntax

+O[no]parallel

Description:

Transform [do not transform] eligible loops for parallel execution on a multiprocessor system.

The default is +Onoparallel at optimization level(s) 3 and 4.

NOTE: If you compile one or more files in an application using +Oparallel, the application must be linked (using the aCC compiler driver) with the +Oparallel option in order to link in the proper start-up files and runtime support.

Use the MP_NUMBER_OF_THREADS environment variable, to specify the number of processors used in executing your parallel programs. This variable is read by your program at runtime. If set to a positive integer n, your program executes on n processors. n must be less than or equal to the number of processors on the system where the program is executing.

For introductory examples, see Setting the Number of Threads Used in Parallel and Transforming Loops for Parallel Execution (+Oparallel).

NOTE: +Oparallel disables the +Ofailsafe option.

For More Information:

+O[no]report[=report_type] Command Line Option Syntax

+O[no]report[=report_type]

Description:

This option causes the compiler to display various optimization reports. The value of report_type determines which report is displayed, as described below:

The +Onoreport option does not accept any of the report_type values.

For More Information:

The +Oreport[=report_type] option is active only at optimization levels 3 and above. The default is +Onoreport.

+O[no]sharedgra Command Line Option Syntax

+O[no]sharedgra

Description:

The +Onosharedgra option enables [disables] global register allocation for shared-memory variables that are visible to multiple threads. This option may help if a variable shared among parallel threads is causing wrong answers.

The default is +Osharedgra. This option is available at optimization levels 2 and above.

For More Information:

Profile-Based Optimization Options

Profile-based optimization is a set of performance-improving code transformations based on the run-time characteristics of your application.

+dfname
Specifies the profile database to use with profile-based optimization.
+I
Prepares the object code for profile-based optimization data collection.
+P
Performs profile-based optimization.
+pgmname
Specifies the execution profile data to use with profile-based optimization.

For More Information:

For more information on performing profile-based optimization, see:

+dfname Command Line Option Syntax

+dfname

Description:

Specifies the path name of the profile database to use with profile-based optimization. This option can be used with the +P command line option.

The profile database by default is named flow.data. This file stores profile information for one or more executables. Use +df when the flow.data file has been renamed or is in a different directory than where you are linking.

You can also use the FLOW_DATA environment variable to specify a different path and file name for the profile database file. The +dfname command line option takes precedence over the FLOW_DATA environment variable.

NOTE: The +dfname option cannot be used to redirect the instrumentation output (with the +I option). It is only compatible with the +P option.

Example:

aCC +P +dfpbo.data prog.o -o myapp

Relinks the object file prog.o, optimizes using the run-time profile data in the file pbo.data, and puts the executable code in the file myapp.

name Parameter
This parameter specifies the path name of the profile database to use with profile-based optimization.

+I Command Line Option Syntax

+I

Description:

Instructs the compiler to instrument the object code for collecting run-time profile data. The profiling information can then be used by the linker to perform profile-based optimization. Code generation and optimization phases are delayed until link time by this option.

After compiling and linking with +I, run the resultant program using representative input data to collect execution profile data. Finally, relink with the +P option to perform profile-based optimization.

Profile data is stored in flow.data by default. See the +dfname option for information on controlling the name and location of this data file.

The +I option is incompatible with the -G, +P, and -S options. And it is incompatible with -g0 and -g1 if used to compile.

Example:

aCC +I -O -c prog.C
aCC +I -O -o prog.pbo prog.o

Compiles prog.C with optimization, prepares the object code for data collection, and creates the executable file prog.pbo. Running prog.pbo collects run-time information in the file flow.data in preparation for optimization with +P.

+P Command Line Option Syntax

+P

Description:

Directs the compiler to use profile information to guide code generation and profile-based optimization. The compiler generates intermediate compiler code instead of compiled object code. Code generation is done at link time.

The +P option does not affect the default optimization level, or the optimization level specified by the +O1, +O2, +O3, or +O4 options.

NOTE: Source files that are compiled with the +I option do not need to be recompiled with +P in order to use profile-based optimization. You only need to relink the object files with the +P option after running the instrumented version of the program.

The +P option is incompatible with the +I and -S options. And it is incompatible -g0 and -g1 if used to compile.

Example:

aCC +P -o myapp prog.o

Relinks the object file prog.o and optimizes using the run-time profile data.

+pgmname Command Line Option Syntax

+pgmname

Description:

Specifies a program name to look up in the flow.data file to use with profile-based optimization and the +P option.

The +pgmname option should be used when the name of the profiled executable differs from the name of the current executable specified by the -o option.

Example:

In the following example, the instrumented program file name is sample.inst. The optimized program file name is sample.opt. The +pgmname option is used to pass the instrumented program name, sample.inst, to the optimizer:

aCC -c +I sample.C
aCC -o sample.inst +I -O sample.o
sample.inst < input.file1
aCC -o sample.opt +P +pgm sample.inst sample.o

+pgm name Parameter
The name parameter is the instrumented executable program name that is used when performing profile-based optimization.

Other Options that Affect Optimization

+DA
Generate object code for a particular version of the PA-RISC architecture. Also specifies which version of the HP-UX math library to use.
+DS
Perform instruction scheduling tuned for a particular implementation of the PA-RISC architecture.

+O[no]info Command Line Option Syntax

+O[no]info

Description:

+Oinfo displays informational messages about the optimization process. This option may be helpful in understanding what optimizations are occurring.

You can use the option at levels 0-4. The default is +Onoinfo at levels 0-4.


Performance

HP aC++ provides a variety of options to help improve build and run-time performance. Choose from the following:

-fast
Select a set of options for optimum execution speed for reasonable build times.
+inline_level [i]num
Controls how C++ inlining hints influence HP aC++. Also allows implicit inlining of small functions that are not explicitly tagged with the inline keyword.
+[no]objdebug
Generate debug information in object files and not in the executable.
Precompiled Header File Options
Reduce compilation time by precompiling common include (header) files.
+DAarchitecture
Generate object code for a particular version of the PA-RISC architecture. Also specify a version of the HP-UX math library.
+DSmodel
Perform instruction scheduling tuned for a particular implementation of the PA-RISC architecture.
Optimization Options
Select the appropriate options to improve program execution speed.

-fast Command Line Option Syntax

-fast

Description:

The -fast option selects a combination of optimization options for optimum execution speed for reasonable build times. Currently chosen options are: You can override any of the options in -fast by specifying a subsequent option after it.

Usage:

This option may aid in porting C++ applications compiled on other UNIX operating systems to HP-UX.

NOTE: Do not use this option for programs that depend on IEEE standard floating-point denormalized numbers. Otherwise, different numerical results may occur.


Porting

Use the following options as necessary when porting your code from other operating environments to HP-UX.

-fast
Select a set of options for optimum execution speed for reasonable build times.
+uc
Treat an unqualified (plain) char data type as unsigned char.

+uc Command Line Option Syntax

+uc

Description:

By default, HP aC++ treats all unqualified char data types as signed char. Specifying +uc causes an unqualified (plain) char data type to be treated as unsigned char. (Overloading and mangling are unchanged.)

Usage:

Use this option to help in porting applications from environments where an unqualified (plain) char type is treated as unsigned char.

NOTE: Since all unqualified char types in the compilation unit will be affected by this option (including those headers that define external and system interfaces) it is necessary to compile the interfaces used in a single program uniformly.


Precompiled Header Files

You can reduce compilation time by precompiling common include (header) files. HP aC++ provides two mechanisms, header caching and manual precompiled headers.

Note that the mechanisms cannot be mixed.

Header Caching Options

+hdr_cache
Request header caching.
+hdr_dir DirectoryPath
Specify a location and name for the header caching directory.
+hdr_info
Request information about header cache file creation or use.

Manual Precompiled Header Options

+hdr_create
Create a manual precompiled header file.
+hdr_use
Compile using a manual precompiled header file.
+hdr_v
Lists verbose information when manually precompiling a header or when compiling a manual precompiled header file.

See Also:

+hdr_cache Option Syntax

+hdr_cache

Description:

Turns header caching on.

An aCC_cache subdirectory is created to contain precompiled header files. By default, it is in the source file directory. To specify a different aCC_cache location and/or name, use the +hdr_dir option.

Usage

When used together, the manual precompiled header options (+hdr_create and +hdr_use) override the header caching option (+hdr_cache).

+hdr_cache can only be used when actually compiling a source file. If used with -P or -E, it is turned off.

Example:

aCC -c +hdr_cache header.C main.C
                 // Precompile and cache header.C and main.C
                 // (initial compile).

aCC -c +hdr_cache header.C main.C
                 // header.C and main.C are not precompiled
                     // (if no changes to compilation environment).

Note that the -c option is needed to suppress the link step.

See Also:

+hdr_dir DirectoryPath Option Syntax

+hdr_dir DirectoryPath

Description:

When you use the +hdr_cache option, an aCC_cache subdirectory is automatically created to contain precompiled files. By default, it is in the source file directory. The +hdr_dir option allows you to specify a different directory path and directory name in place of the aCC_cache default.

NOTE: To maximize the efficiency of the cache mechanism, it is recommended that you specify a directory in the compilation directory or in a subdirectory of the compilation directory.

Usage

You might use +hdr_dir to specify different aCC_cache locations for debug builds versus release builds, for instance.

Example:

aCC -c +hdr_cache header.C    // Precompile and cache header.C
                                   // in the aCC_cache directory,
                                   // a subdirectory of that
                                   // in which header.C is located.

aCC -c -Ddebugflag +hdr_cache +hdr_dir ./debug/aCC_debug_cache header.C
                                   // Precompile and cache header.C
                                   // in the ./debug/aCC_debug_cache directory,
                                   // a subdirectory of that
                                   // in which header.C is located.

aCC -c +hdr_cache +hdr_dir ./release/aCC_release_cache header.C
                                   // Precompile and cache header.C
                                   // in the ./release/aCC_release_cache
                                   // directory, a subdirectory of that
                                   // in which header.C is located.

See Also:

+hdr_info Option Syntax

+hdr_info

Description:

Generates a message stating whether a header is being re-used or precompiled. The default is off.

+hdr_create Command Line Option Syntax

+hdr_create

Description:

Creates a manual precompiled header file for subsequent use when compiling an application or a library with the +hdr_use option.

You can reduce compilation time by precompiling common include (header) files into a precompiled header file.

Example:

aCC headers.C -c +hdr_create precomp
>From headers.C, creates a precompiled header file named precomp.

Note that the -c option is needed to suppress the link step.

See Also:

+hdr_use Command Line Option Syntax

+hdr_use

Description:

Compiles a manual precompiled header file and its corresponding object (.o) file. These files must have been created by using the +hdr_create option.

This is known as a load compile.

Example:

aCC main.C +hdr_use precomp
Compiles main.C, including a precompiled header file named precomp.

See Also:

+hdr_v Command Line Option Syntax

+hdr_v

Description:

Provides verbose information when precompiling a header or when compiling a precompiled header file.

Examples:

aCC headers.C -c +hdr_create precomp +hdr_v
Creates a precompiled header file named precomp and displays what is going into the precompiled header file.

aCC main.C +hdr_use precomp +hdr_v
Compiles main.C and displays what is being used from the precompiled header file.

See Also:


Preprocessor Options

The following options are accepted by the preprocessor:

-Dname
Defines name to the preprocessor.
-E
Runs only the preprocessor and sends output to stdout.
+m[d]
Output quote enclosed (" ") make(1) dependency files to stdout or to a .d file.
+M[d]
Output both quote enclosed and angle bracket enclosed (< >) make(1) dependency files to stdout or to a .d file.
-notrigraph
Inhibits the processing of trigraphs.
-P
Runs only the preprocessor and sends output to a corresponding .i file.
-.suffix
Sends preprocessed output to the corresponding output file ending with .suffix.
-Uname
Undefines name in the preprocessor.

See Also:

-Dname Command Line Option Syntax

-Dname[=def]
name is the symbol name that is defined for the preprocessor.

def is the definition of the symbol name (name).

Description:

Defines a symbol name (name) to the preprocessor, as if defined by the preprocessing directive #define.

If no definition (def) is given, the name is defined as "1".

Example:

aCC -DDEBUGFLAG file.C

Defines the preprocessor symbol DEBUGFLAG and gives it the value 1. Following is a program that uses this symbol.

#include <iostream.h>
void main(){
int i, j;
#ifdef DEBUGFLAG
int call_count=0;
#endif
  ...
}

For More Information:

-E Command Line Option Syntax

-E

Description:

Runs only the preprocessor on the named C++ files and sends the result to standard output (stdout). Note an exception to this rule when -E is used with either the +m[d] or +M[d] option, only make(1) dependency information is output.

Unlike the -P option, the output of -E contains #line entries indicating the original file and line numbers.

Redirecting Output From This Option

Use the -.suffix option to redirect the output of this option.

+m[d] Command Line Option Syntax

+m[d]

Description:

Directs a list of the quote enclosed (" ") header files upon which your source code depends to stdout. The list is in a format accepted by the make(1) command.

If +md is specified, the list is directed to a .d file. The .d file name prefix is the same as that of the object file. The .d file is created in the same directory as the object file.

Usage:

Use +m[d] when you also specify the -E or the -P option.

Used with the -E option, only dependency information is generated.

Examples:

command line specified .d file name .d file location preprocessing output
aCC -c +m a.C none stdout none
aCC -c -E -.i +md a.C a.d current directory none
aCC -c -P +md a.C -o b.o b.d current directory b.i
aCC -c -P +md a.C -o /tmp/c c.d /tmp directory a.i

+M[d] Command Line Option Syntax

+M[d]

Description:

Directs a list of both the quote enclosed (" ") and angle bracket enclosed (< >) header files upon which your source code depends to stdout. The list is in a format accepted by the make(1) command.

If +Md is specified, the list is directed to a .d file. The .d file name prefix is the same as that of the object file. The .d file is created in the same directory as the object file.

Usage:

Use +Md when you also specify the -E or the -P option.

Used with the -E option, only dependency information is generated.

Examples:

command line specified .d file name .d file location preprocessing output
aCC -c +M a.C none stdout none
aCC -c -E -.i +Md a.C a.d current directory none
aCC -c -P +Md a.C -o b.o b.d current directory b.i
aCC -c -P +Md a.C -o /tmp/c c.d /tmp directory a.i

-notrigraph Command Line Option Syntax

 -notrigraph

Description:

This option inhibits the processing of trigraphs. The -notrigraph option, in previous versions, caused the legacy preprocessor to be invoked, which ignored trigraphs. These trigraphs were still interpreted by the compiler in the preprocessed source.

In this version of aCC, the -notrigraph option does not invoke the legacy preprocessor and also suppresses the trigraphs from being interpreted.

This option is not recommended. The proper protable solution is to quote the ? as \?.

-P Command Line Option Syntax

-P

Description:

Only preprocesses the files named on the command line without invoking further phases. Leaves the result in corresponding files with the suffix .i.

Example:

aCC -P prog.C
Preprocesses the file prog.C leaving the output in the file prog.i. Does not compile the program.

For More Information:

-Uname Command Line Option Syntax

-Uname
name is the symbol name whose definition is removed from the preprocessor.

Description:

Undefines any name that has initially been defined by the preprocessing stage of compilation.

A name can be a definition set by HP aC++; these are displayed when you specify the -v option. Or a name can be a definition you have specified with the -D option on the aCC command line.

The -D option has lower precedence than the -U option. Thus, if the same name is used in both a -U option and a -D option, the name is undefined regardless of the order of the options on the command line.

For More Information:


Profiling Options

HP aC++ provides the following options for profiling your code.

-G
Prepare an object file for use with gprof.
+pa
Request that an application be compiled for routine-level profiling with CXperf.
+pal
Request that an application be compiled for routine-level and loop-level profiling with CXperf.

See Also:

-G Command Line Option Syntax

-G

Description:

Prepares an object file for use with gprof (to get an execution profile).

Example:

aCC -G file.C
Compiles file.C and creates the executable file a.out instrumented for use with gprof.

For More Information:

Refer to the gprof(1) man page. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

+pa Command Line Option Syntax

+pa

Description:

Prepares an application for routine level profiling with CXperf.

The +pa option is invalid with the +O4 or +O[no]all optimization options. Also, +pal is incompatible with the +A, -G, and -s options.

For More Information:

Refer to the CXperf(1) man page. (If you see the message "Man page could not be formatted," ensure the man page is installed.)

+pal Command Line Option Syntax

+pal

Description:

At +O2 and +O3, prepares an application for routine level and loop-level profiling with CXperf.

The +pal option is invalid with the +O4 or +O[no]all optimization options. Also, +pal is incompatible with the +A, -G, and -s options.

For More Information:

Refer to the CXperf(1) man page. (If you see the message "Man page could not be formatted," ensure the man page is installed.)


Standards Related Options

The following options related to the ANSI/ISO C++ International Standard are accepted by the compiler.

-Aa
Enable the use of standard options (-Wc,-koenig_lookup,on and -Wc,-ansi_for_scope,on).
-AA
Enable Rogue Wave Standard C++ Library 2.2.1 and set all standards related options on.
-Wc,-ansi_for_scope,[on][off]
Enable or disable the scoping rules for init-declarations in for statements.
-Wc,-koenig_lookup,[on][off]
Enable or disable argument-dependent lookup rules (also known as Koenig lookup).

-Aa Command Line Option Syntax

-Aa

Description:

-Aa instructs the compiler to use Koenig lookup and strict ANSI for scope rules. The option is equivalent to specifying -Wc,-koenig_lookup,on and -Wc,-ansi_for_scope,on. The default is off.

Usage

The standard features enabled by -Aa are incompatible with earlier C and C++ features.

For More Information:

-AA Command Line Option Syntax

-AA

Description:

The new -AA command line option enables use of the new 2.0 Standard C++ Library, which includes the new standard conforming ("templatized") iostream library. This is the first release of the 2.0 library. It conforms to the ISO C++ standard.

The 2.0 library is a new addition to the HP C++ runtime is not compatible with the version 1.2.1 Standard C++ Library previously bundled with HP aC++. HP aC++ will continue support for standard C++ library 1.2.1 without name or location change. Customers should not notice any change when -AA is not used. However, the 1.2.1 library is deprecated and will be replaced by the new library eventually.

If you wish to use the new 2.0 library, you must use the -AA option consistently to compile and link all translation units. Mixing object files within an executable is not supported.

In order to use the new 2.0 library, you must recompile using the -AA option and you may need to apply a runtime and/or header file patch appropriate to your operating system (see list below). You do not need to install the header file patch if you use the A.03.30 compiler. The header file patches are needed for A.03.27, A.03.26, A.03.25, and A.01.27.

You can avoid the binary incompatibility simply by not using the -AA option and foregoing use of the 2.0 library. If you don't use -AA, you should still install the patches. If you do use -AA and you are on A.03.30, the header file patches are included in A.03.30 but you must still install the runtime patches. Then you must recompile and relink any previous -AA application.

HP does not take the creation of binary incompatibilities lightly. When one is created, it is only after a careful consideration of options and ramifications. Our customers want to be able to use the new 2.0 library. Doing this also ensures compatibility with the Multibyte Support Extensions made in the 11i (11.11) release of HP-UX. The A.03.25 version (PHSS_21906) had an incorrect size and mangling for mbstate_t. The 11i defined value is 8 bytes, the libstd_v2 version is 4.

In particular the following template classes are now larger:

std::basic_filebuf<>

std::basic_fstream<>

std::basic_ifstream<>

std::basic_ofstream<>

std::fpos

std::mbstate_t

In addition to the possible silent corruption with this above change in size, the mangling was changed to better detect this compatibility problem by changing the name.

std::mbstate_t was changed to just mbstate_t.

std::tm was changed to just tm.

So if you developed on A.03.25 with the beta, A.03.26 on 11i or on 11.0 with the Ecommerce compiler, or A.01.27 for AR1200, or A.03.27 for AR1200, you will have the following problems if you don't install both the following header file and runtime library patches:

PHSS_22867 10.x header file

PHSS_22354 10.x runtime

PHSS_22868 11.x header file

PHSS_22543 11.0 runtime

PHSS_22898 11i runtime

Note applications developed on A.01.27 may not have these problems yet because there never was any runtime patch, except for a beta.

An ordinary program using iostreams experiencing this problem will get the following unsats:

If existing application runs on new runtime patch:

/usr/lib/dld.sl: Unresolved symbol: do_out__Q2_3std14codecvt_bynameXTwTcTQ2_ 3std9mbstate_t_CFRQ2_3std9mbstate_tPCwT2RPCwPcT5RPc (plabel) from a.out_old

/usr/lib/dld.sl: Unresolved symbol: do_in__Q2_3std14codecvt_bynameXTwTcTQ2_ 3std9mbstate_t_CFRQ2_3std9mbstate_tPCcT2RPCcPwT5RPw (plabel) from a.out_old

Trying to link with new runtime without new headers:

/usr/ccs/bin/ld: Unsatisfied symbols: std::codecvt_byname::do_in(std::mbstate_t &,const char *,const char *,const char *&,wchar_t *,wchar_t *,wchar_t *&) const (code)

std::codecvt_byname::do_out(std::mbstate_t &,const wchar_t *,const wchar_t *,const wchar_t *&,char *,char *,char *&) const (code)

Running application linked with new headers on old runtime:

/usr/lib/dld.sl: Unresolved symbol: do_out__Q2_3std14codecvt_ bynameXTwTcT9mbstate_t_CFR9mbstate_tPCwT2RPCwPcT5RPc (code) from a.out_new

/usr/lib/dld.sl: Unresolved symbol: do_in__Q2_3std14codecvt_ bynameXTwTcT9mbstate_t_CFR9mbstate_tPCcT2RPCcPwT5RPw (code) from a.out_new

Trying to link with old runtime with new headers:

/usr/ccs/bin/ld: Unsatisfied symbols: std::codecvt_byname::do_out(mbstate_t &,const wchar_t*,const wchar_t *,const wchar_t *&,char *,char *,char *&) const (code)

std::codecvt_byname::do_in(mbstate_t &,const char *,const char *,const char *&,wchar_t *,wchar_t *,wchar_t *&) const (code)

Usage

The standard features enabled by -AA are incompatible with the older Rogue Wave Standard C++ Library 1.2.1 and Tools.h++ 7.0.6. All modules must be consistent in using -AA . Mixing modules compiled with -AA with ones that are not is not supported.

The -Wc,-koenig_lookup,on and -Wc,-ansi_for_scope,on options are also set.

For More Information:

-Wc,-ansi_for_scope,[on][off] Command Line Option Syntax

-Wc,-ansi_for_scope,[on]
                    [off]

Description:

This option enables or disables the standard scoping rules for init-declarations in for statements; the scope of the declaration then ends with the scope of the loop body. By default, the option is disabled.

Examples:

In the following example, if the option in not enabled (the current default), the scope of k extends to the end of the body of main() and statement (1) is valid (and will return zero). With the option enabled, k is no longer in scope and (1) is an error.
#include 

int main() {
   for (int k = 0; k!=100; ++k) {
      printf("%d\n", k);
   }
   return 100-k; // (1)
}

In the next example, with the option disabled, the code is illegal, because it redefines k in (2) when a previous definition (1) is considered to have occurred in the same scope. With the option enabled (-Wc,-ansi_for_scope,on), the definition in (1) is no longer in scope at (2) and thus the definition in (2) is legal.

int main() {
   int sum = 0;
   for (int k = 0; k!=100; ++k)  // (1)
      sum += k;
   for (int k = 100; k!= 0; ++k) // (2)
      sum += k;
}

-Wc,-koenig_lookup,[on][off] Command Line Option Syntax

-Wc,-koenig_lookup,[on]
                   [off]

Description:

This option enables or disables standard argument-dependent lookup rules (also known as Koenig lookup). It causes functions to be looked up in the namespaces and classes associated with the types of the function-call argument. By default, the option is disabled.

Example:

In the following example, if the option is not enabled (the current default), the call in main() does not consider declaration (1) and selects (2). With the option enabled, both declarations are seen, and in this case overload resolution will select (1).
namespace N {
   struct S {};
   void f(S const&, int);  // (1)
}

void f(N::S const&, long); // (2)

int main() {
   N::S x;
   f(x, 1);
}

For More Information:


Subprocesses of the Compiler

These options allow you to substitute your own processes in place of the default HP aC++ subprocesses, or pass options to HP aC++ subprocesses.

-tx,name
Substitutes name in place of subprocess x.
-Wx,args
Passes the option arg to subprocess x of the HP aC++ compiling system.

-tx,name Command Line Option Syntax

-tx,name

Description:

Substitutes or inserts subprocess x using name.

This option works in two modes:

  1. If x is a single identifier, name represents the full path name of the new subprocess.
  2. If x is a set of identifiers, name represents a prefix to which the standard suffixes are concatenated to construct the full path names of the new subprocesses.

    Example:

    aCC -ta,/users/sjs/myasmb file.s
    
    Invokes the assembler /users/sjs/myasmb instead of the default assembler /usr/ccs/bin/as to assemble and link file.s.

    For More Information:

    More Examples of -t

    Substituting for c++filt

    aCC -tf,/new/bin/c++filt file.C
    
    Compiles file.C and specifies that /new/bin/c++filt should be used rather than the default /opt/aCC/bin/c++filt.

    Substituting for ctcom

    aCC -tC,/users/proj/ctcom file.C
    
    Compiles file.C and specifies that /users/proj/ctcom should be used instead of the default /opt/aCC/lbin/ctcom.

    Substituting for All Subprocesses

    aCC -tx,/new/&driver; file.C
    
    Compiles file.C and specifies that the characters /new/aCC should be used as a prefix to all the subprocesses of HP aC++ For example, /new/aCC/ctcom runs rather than the default /opt/aCC/lbin/ctcom.

    x Parameter
    x is one or more identifiers indicating the subprocess or subprocesses. The value of x can be one or more of the following:

    a
    Assembler (standard suffix is as).
    b
    C compiler driver (cc), used to invoke the assembler.
    C (upper case)
    HP aC++ compiler (standard suffix is ctcom).
    f
    Filter tool (c++filt).
    l
    Linker (standard suffix is ld).
    u
    Code generator when using +O4 or performing profile-based optimization (standard suffix is ucomp).
    x
    All subprocesses.

    name Parameter
    This parameter is either the full path name of the executable file that will be run, or a prefix that will be concatenated to the default path name.

    If x is a single identifier, name represents the full path name of the new subprocess. If x is a set of identifiers, name represents a prefix to which the standard suffixes are concatenated to construct the full path names of the new subprocesses.

    -Wx,args Command Line Option Syntax

    -Wx,arg1[,arg2,..,argn]
    

    Description:

    Passes the arguments arg1 through argn to the subprocess x of the compilation. The arguments are of the form:

    -argoption[,argvalue]
    

    Example1:

    To see which include files led to an error or warning, specify the -Wc,-diagnose_includes,on option.
    aCC -Wc,-diagnose_includes,on file.C
    
    Specify -Wc,-diagnose_includes,off (the default) to turn the option off.

    Example2:

    aCC -Wc,-v file.C
    
    Compiles file.C and passes the option -v to the linker.

    aCC -Wl,-v file.C
    
    Compiles file.C and passes the option -v to the linker.

    For More Information:

    More Examples of -W

    Passing Options to the Linker with -W

    aCC file.o -Wl,-a,archive -lm
    
    Links file.o and passes the option -a archive to the linker, indicating that the archive version of the math library (indicated by -lm) and all other driver supplied libraries should be used rather than the default shared library.

    Passing Multiple Options to the Linker with -W

    aCC -Wl,-a,archive,-m,-v file.o -lm
    
    Links file.o and passes the options -a archive, -m, and -v to the linker.

    This case is similar to the previous example, with additional options. -m indicates that a load map should be produced. -v requests verbose messages from the linker.

    argn Parameters
    Each argument, arg1, arg2, through argn to the -W option takes the form:

    -argoption[,argvalue]
    

    where:

    argoption
    is the name of an option recognized by the subprocess.
    argvalue
    is a separate argument to argoption, where necessary.

    x Parameter
    x is one or more identifiers indicating a subprocess or subprocesses. The value of x can be one or more of the following:

    a
    Assembler (standard suffix is as).
    b
    C compiler driver (cc), used to invoke the assembler.
    C (either upper or lower case)
    HP aC++ compiler (standard suffix is ctcom).
    d
    The driver program, aCC
    f
    Filter tool (c++filt).
    l
    Linker (standard suffix is ld).

    Template Options

    By using a template option on the aCC command line, you can:

    +inst_all
    Requests instantiation of all templates.
    +inst_auto
    Requests automatic instantiation.
    +inst_close
    Requests closure with regard to template instantiation (for libraries that contain templates).
    +inst_directed
    Requests that no templates be instantiated (except explicit instantiations) and suppresses the output of assigner information in object files.
    +inst_implicit_include
    Requests HP C++ style template files.
    +inst_include_suffixes
    Requests HP C++ template definition file name suffixes.
    +inst_none
    For automatic (assigner) instantiation, requests that no templates be instantiated (except explicit instantiations).
    +inst_used
    Requests instantiation of templates that are used.
    +inst_v
    Requests verbose information about template processing.

    Template Usage:

    See Also:

    +inst_all Command Line Option Syntax

    +inst_all
    

    Description:

    Causes the compiler to instantiate all template functions and all static data members and member functions of template classes defined in a translation unit, regardless of whether or not they are used, and to place these instantiations in the resulting object file.

    This option allows existing instantiations in a translation unit to be used by the assigner to satisfy instantiation requests in other translation units.

    NOTE: Because +inst_all instantiates all templates, it is essential to have a thorough understanding of your application and its template usage in order to use +inst_all effectively. Otherwise, duplicate symbols may result.

    Usage:

    This option is useful when you want to insure the file location of all templates defined in a given translation unit (for example, when preparing an object code library for distribution).

    Example:

    The following example compiles file1.C and places instantiations in file1.o.

    aCC -c +inst_all file1.C
    

    //file1.C // Define foo function template. template <class T> T foo (T i) {return i; }; // Define S class template. template <class T> class S { public: int n; static int m; int f(); static int g(); }; template <class T> int S<T>::m = 1; template <class T> int S<T>::f() { return 1; }; template <class T> int S<T>::g() { return 1; }; // Instantiate template class S with int to define object h. S<int> h; // S<int>::m, S<int>::f(), and S<int>::g() // are instantiated and placed in file1.o // Instantiate template function foo with int. int k=foo(1); // foo<int> is instantiated and placed in // file1.o

    Migration Note: Note that the +inst_all option differs from the HP C++ -pta option which instantiates all members of used template classes and all needed template functions.

    For More Information:

    +inst_auto Command Line Option Syntax

    +inst_auto
    

    Description:

    Requests that the automatic instantiation mechanism instantiate every template used if it is listed in the corresponding .I file. All used template functions, all static data members and member functions of template classes, and all explicit instantiations are instantiated.

    When you link or create a shared library, if there is more than one object file on the command line, the assigner determines which object file is to contain a given instantiation.

    To use +inst_auto, you must specify it at both compile-time and when creating an executable or a shared library.

    Usage:

    This option is necessary to insure that an archive library prepared for distribution is compatible with such a library prepared using the prior default (assigner) instantiation mechanism. It also facilitates use of the assigner by the library user. Refer to Deciding which Mechanism to Use.

    Example:

    The following example compiles file1.C and file2.C. Instantiations are placed in either file1.o or file2.o, as determined by the assigner during the closure operation.

    Note the use of the +inst_close option to satisfy all needed template instantiations.

    // initial compile aCC -c +inst_auto file1.C file2.C // closure operation to satisfy all unsatisfied instantiations // in file1.o and file2.o without creating duplicate instantiations aCC -c +inst_auto +inst_close file1.o file2.o

    For More Information:

    +inst_close Command Line Option Syntax

    +inst_close
    

    Description:

    Use +inst_close along with the +inst_auto option to specify that automatic instantiation be used to close a set of link units. This option prevents reinstantiation of any already instantiated templates in the .o files or libraries on the command line.

    Note that the -c option must be used with +inst_close, otherwise an executable file or (with -b) a shared library is created.

    Usage:

    +inst_close is used when closing a set of .o files to create a library.

    If you want to create a template library that uses templates, unlike a non-template library, you must instantiate the templates before linking the library.

    Archive Library Example

    To close and create an archive library containing templates, and then link the library to produce an application, use the following commands:

    aCC -c +inst_auto -Idir mylib*.C
    Compile library source files containing templates.

    aCC -c +inst_auto +inst_close mylib*.o
    Close mylib*.o files to create template instantiations in the .o files. (-c prevents linking.)

    ar cr mylib.a mylib*.o
    Create the mylib.a archive library.

    aCC -Idir myfile.C mylib.a -o application
    Link mylib.a with myfile.C to create application.

    NOTE: If a library is dependent on another template library, that template library must be on the command line when you close the dependent library. If you build an application with the dependent library, the dependee library should also be used in the link.

    Shared Library Example

    To close and create a shared library containing templates, and then link the library to produce an application, use the following commands:

    aCC +z -c +inst_auto -Idir mylib*.C
    Compile library source files containing templates.

    aCC -c +inst_auto +inst_close mylib*.o
    Close mylib*.o files to create template instantiations in the .o files. (-c prevents linking.) Refer to the following NOTE.

    aCC -b +inst_none -o mylib.sl mylib*.o
    Create the mylib.sl shared library.

    aCC -Idir myfile.C mylib.sl -o application
    Link mylib.sl with myfile.C to create application.
    NOTE: If desired, you can append one or more library names to this command line, indicating that you do not want duplicate instantiations between any libraries on the command line.

    For example, you may have many shared libraries attached to an a.out. And you do not want to list all of these libraries on the -b command line when you create a shared library. However, you do want to be sure there are no duplicate symbols.

    For More Information:

    +inst_directed Command Line Option Syntax

    +inst_directed
    

    Description:

    Indicates to the compiler that no templates are to be instantiated (except explicit instantiations) and suppresses assigner output in object files.

    Without the use of +inst_directed, instantiation information needed by the assigner is placed in object files even when you have not requested automatic (assigner) instantiation with +inst_none.

    Usage:

    If you are using only explicit instantiation and have not requested automatic (assigner) instantiation, specify +inst_directed instead of +inst_none.

    Example:

    aCC +inst_directed prog.C
    
    Compiles file.C with the resulting object file containing no template instantiations, except for any explicit instantiations coded in your souce file.

    For More Information:

    +inst_implicit_include Command Line Option Syntax

    +inst_implicit_include
    

    Description:

    Specifies that the compiler use a process similar to that of the cfront source rule for locating template definition files. For the cfront based HP C++ compiler, if you are using default instantiation (that is, you are not using a map file), you must have a template definition file for each template declaration file, and these must have the same file name prefix.

    This restriction does not apply in HP aC++. Therefore, if your code was written for HP C++ and/or you wish to follow this rule when compiling with HP aC++, you need to specify the +inst_implicit_include option.

    Example:

    aCC +inst_implicit_include prog.C
    
    If prog.C includes a template declaration file named template.h, the compiler assumes a template definition file name determined by the +inst_include_suffixes option.

    For More Information:

    +inst_include_suffixes Command Line Option Syntax

    +inst_include_suffixes list"
    
    list is a set of space separated file extensions or suffixes, enclosed in quotes, that template definition files can have.

    Description:

    Specifies which file name extensions the compiler uses to locate template definition files. This option must be used with the +inst_implicit_include option.

    The default extensions in order of precedence are:

    ".c .C .cxx .CXX .cc .CC .cpp"
    

    User specified extensions must begin with a dot and must not exceed four characters in total. Any extension that does not follow these rules causes a warning and is ignored.

    These restrictions do not apply in HP aC++. Therefore, if your code was written for HP C++ and/or you wish to follow the cfront based HP C++ template definition file naming conventions when compiling with HP aC++, you need to specify the +inst_include_suffixes option.

    Example:

    +inst_include_suffixes ".c .C" Specifies that template definition files can have extensions of .c or .C.

    Migration:

    The +inst_include_suffixes option is equivalent to the HP C++ -ptS option.

    For More Information:

    +inst_none Command Line Option Syntax

    +inst_none
    

    Description:

    For automatic (assigner) instantiation, indicates to the compiler that no templates are to be instantiated (except explicit instantiations).

    Usage:

    If you know that templates in a translation unit have been instantiated in another translation unit that will participate in the link, you might want to use +inst_none to prevent unneeded instantiation attempts.

    If you use +inst_auto to create a shared library from .o files that have already been closed, you should use +inst_none.

    Example:

    aCC +inst_none file.C
    
    Compiles file.C with the resulting object file containing no template instantiations, except for any explicit instantiations coded in your souce file.

    For More Information:

    +inst_used Command Line Option Syntax

    +inst_used
    

    Description:

    Causes the compiler to instantiate all template class members and all template functions that are used in a translation unit and to place these instantiations in the resulting object file.

    Template instantiation operates on member functions of template classes and template functions. Use of a template is a call to such a function. For example:

    template <class T> class A { public: void boo(); }; ... A<int> a; ... a.boo(); // a use This option allows existing instantiations in a translation unit to be used by the assigner to satisfy instantiation requests in other translation units.

    NOTE: Because +inst_used instantiates all used templates, it is essential to have a thorough understanding of your application and its template usage in order to use +inst_used effectively. Otherwise, duplicate symbols may result.

    Usage:

    This option may be useful when compiling a large application or library containing many templates, only some of which are used.

    +inst_used is essentially equivalent to default compile-time instantiation. However, if you intend to use the instantiations in a translation unit (X.C) to satisfy instantiation requests in other translation units, using the automatic instantiation mechanism, you should specify +inst_used instead of using the default to compile X.C. For example:

    aCC -c +inst_used X.C
    aCC +inst_auto Y.C X.o
    

    Example:

    aCC -c +inst_used file.C
    
    Compiles file.C and places instantiations for all used members of template classes and all used template functions in file.o.

    For More Information:

    +inst_v Command Line Option Syntax

    +inst_v
    

    Description:

    Enables verbose mode, sending a step-by-step description of template processing to stderr. +inst_v works with all template processing options except the default compile-time instantiation mechanism (+inst_compiletime). Messages are produced when:

    In addition, when the assigner cannot satisfy an instantiation request, a message stating the reason is generated.

    Usage:

    You can use +inst_v to help determine the locations of errors in instantiation. Since verbose output tells you where instantiations have been made, you might also use it to determine the layout of explicit instantiation in applications that have many modules produced by a number of different developers.

    Example:

    aCC +inst_auto +inst_v file.C
    
    Compiles file.C and provides details of template processing.

    Migration:

    The +inst_v option is similar to the HP C++ -ptv option.

    For More Information:


    Requesting Verbose Compile and Link Information

    Use the following options to obtain additional information about:

    +dryrun
    Requests compiler subprocess information without running the subprocesses.
    +inst_v
    Requests verbose information about template processing.
    +Oinfo
    Requests optimization information.
    +time
    Requests execution times.
    -v
    Requests verbose information of the compilation process.
    -V
    Requests the current compiler and linker version numbers.
    -Wl,-v
    Requests verbose messages from the linker.

    +dryrun Command Line Option Syntax

    +dryrun
    

    Description:

    Causes aCC (the driver) to generate subprocess information for a given command line without running the subprocesses.

    Usage:

    Useful in the development process to obtain command lines of compiler subprocesses in order to run the commands manually or to use them with other tools.

    Example:

    aCC +dryrun app.C The above command line gives the same kind of information as the -v option but without running the subprocesses.

    +time Command Line Option Syntax

    +time
    

    Description:

    This option generates timing information for compiler subprocesses. For each subprocess, estimated time is generated in seconds for user processes, system calls, and total processing time.

    Usage:

    Useful in the development process, for example, when tuning an application's compile-time performance.

    Examples:

    The following command line:
    aCC +time app.C
    
    generates information like this:
    process: compiler       0.94/u   0.65/s   4.35/r
    process: ld             0.37/u   0.76/s   3.02/r
    
    The following command line:
    aCC -v +time app.C
    
    generates information like this:
    /opt/aCC/lbin/ctcom -inst compiletime -diags 523 -D __hppa -D __hpux
       -D __unix -D __hp9000s800 -D __STDCPP__ -D __hp9000s700 -D _PA_RISC1_1
       -I /opt/aCC/include -I /opt/aCC/include/iostream -I /usr -I
       /usr/include -I /usr/include -inline_power 0 app.C
    
    file name: app.C
    file size: app.o 444 + 16 + 1 = 461
    process                 user    sys   real
    ------------------------------------------
    process: compiler       0.93   0.13   1.17
    ------------------------------------------
    line numbers: app.C 7
    lines/minute: app.C 396
    
    LPATH=/usr/lib:/usr/lib/pa1.1 :/usr/lib:/opt/langtools/lib:/usr/lib
    /opt/aCC/lbin/ld -o a.out /opt/aCC/lib/crt0.o -u ___exit -u main
      -L /opt/aCC/lib /opt/aCC/lib/cpprt0.o app.o -lstd -lstream -lCsup -lm
      /usr/lib/libcl.a -lc /usr/lib/libdld.sl >/usr/tmp/AAAa28149 2>&1
    
    file size: a.out 42475 + 1676 + 152 = 44303
    process                 user    sys   real
    ------------------------------------------
    process: ld             0.35   0.24   0.82
    ------------------------------------------
    total link time(user+sys):   0.59
     removing /usr/tmp/AAAa28149
     removing app.o
    

    -v Command Line Option Syntax

    -v
    

    Description:

    Enables verbose mode, sending a step-by-step description of the compilation process to stderr.

    Usage:

    This is especially useful for debugging or for learning the appropriate commands for processing a C++ file.

    Example:

    The following compiles file.C and gives extra information about the process of compiling.
    aCC -v file.C
    
    /opt/aCC/lbin/ctcom -inst compiletime -diags 523 -D __hppa -D __hpux
       -D __unix -D __hp9000s800 -D __STDCPP__ -D __hp9000s700 -D _PA_RISC1_1
       -I /opt/aCC/include -I /opt/aCC/include/iostream -I /usr -I /usr/include
       -I /usr/include -inline_power 0 app.C
    LPATH=/usr/lib:/usr/lib/pa1.1
          :/usr/lib:/opt/langtools/lib:/usr/lib
    /opt/aCC/lbin/ld -o a.out /opt/aCC/lib/crt0.o -u ___exit -u main
      -L /opt/aCC/lib /opt/aCC/lib/cpprt0.o app.o -lstd -lstream -lCsup
      -lm /usr/lib/libcl.a -lc /usr/lib/libdld.sl >/usr/tmp/AAAa28149 2>&1
      removing /usr/tmp/AAAa28149
    

    -V Command Line Option Syntax

    -V
    

    Description:

    Displays the version numbers of the current compiler and linker (if the linker is executed).

    Usage:

    Use this option whenever you need to know the current compiler and linker version numbers.

    Example:

    aCC -V app.C
    

    Concatenating Options

    You can concatenate some options to the aCC command under a single prefix. The longest substring that matches an option is used. Only the last option can take an argument. You can concatenate option arguments with their options if the resulting string does not match a longer option.

    Examples:

    Suppose you want to compile my_file.C using the options -v and -g. Below are equivalent command lines you could use:

    aCC my_file.C -v -g1
    aCC my_file.C -vg1
    aCC my_file.C -vg1
    aCC -vg1 my_file.C