prec-div, Qprec-div

Improves precision of floating-point divides.

IDE Equivalent

None

Architectures

IA-32, Intel® EM64T

Syntax

Linux:	-prec-div -no-prec-div
Windows:	/Qprec-div /Qprec-div-

Arguments

None

Default

ON	The compiler uses this method for floating-point divides.

Description

This option improves precision of floating-point divides. It has a slight impact on speed.

With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

If you specify -no-prec-div (Linux) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

Alternate Options

Linux: -prec_div

Windows: /Qprec_div