Chapter 3 Factors that Affect the Results of Floating-Point Computations

Table of Contents

How Basic Operations Affect Application Results

How Mathematical Library Functions Affect Application Results

How Exceptions and Library Errors Affect Application Results

Conversions Between Binary and Decimal
Compiler Behavior and Compiler Version
Compiler Options
Architecture Type of Run-Time System
Operating System Release of Build-Time System
Operating System Release of Run-Time System
Values of Certain Modifiable Hardware Status Register Fields

Floating-Point Coding Practices that Affect Application Results

Testing Floating-Point Values for Equality
Taking the Difference of Similar Values
Adding Values with Very Different Magnitudes
Unintentional Underflow
Truncation to an Integer Value
Ill-Conditioned Computations

When a floating-point application executes, the results it yields may be different from those of previous executions, or the results may be inaccurate. A great many factors can contribute to such differences or inaccuracies. This chapter describes these factors.

We've divided the factors that can affect application results into the following general categories:

Basic operations
Mathematical library functions
Exception conditions and library errors
Other system-related factors, which usually affect the three preceding factors
Floating-point coding practices that lead to inaccurate results

Chapter 3 Factors that Affect the Results of Floating-Point Computations

Technical documentation

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