Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

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Document Table of Contents

fp-speculation, Qfp-speculation

Tells the compiler the mode in which to speculate on floating-point operations.

Syntax

Linux:

-fp-speculation=mode

macOS:

-fp-speculation=mode

Windows:

/Qfp-speculation:mode

Arguments

mode

Is the mode for floating-point operations. Possible values are:

fast

Tells the compiler to speculate on floating-point operations.

safe

Tells the compiler to disable speculation if there is a possibility that the speculation may cause a floating-point exception.

strict

Tells the compiler to disable speculation on floating-point operations.

off

This is the same as specifying strict. This feature is only available for ifort.

Default

-fp-speculation=fast
or/Qfp-speculation:fast

The compiler speculates on floating-point operations. This is also the behavior when optimizations are enabled. However, if you specify no optimizations (-O0 on Linux*; /Od on Windows*), the default is -fp-speculation=safe (Linux*) or /Qfp-speculation:safe (Windows*).

Description

This option tells the compiler the mode in which to speculate on floating-point operations.

Disabling speculation may prevent the vectorization of some loops containing conditionals.

IDE Equivalent

Visual Studio: Optimization > Floating-Point Speculation

Eclipse: Floating Point > Floating-Point Speculation

Xcode: Floating Point > Floating-Point Speculation

Alternate Options

None