pc, Qpc

Enables control of floating-point significand precision.

IDE Equivalent

None

Architectures

IA-32, Intel® EM64T

Syntax

Linux and Mac OS:	-pcn
Windows:	/Qpcn

Arguments

n	Is the floating-point significand precision. Possible values are:
	32	Rounds the significand to 24 bits (single precision).
	64	Rounds the significand to 53 bits (double precision).
	80	Rounds the significand to 64 bits (extended precision).

Default

-pc80 or
/Qpc64

On Linux* and Mac OS* systems, the floating-point significand is rounded to 64 bits. On Windows* systems, the floating-point significand is rounded to 53 bits.

Description

This option enables control of floating-point significand precision.

Some floating-point algorithms are sensitive to the accuracy of the significand, or fractional part of the floating-point value. For example, iterative operations like division and finding the square root can run faster if you lower the precision with the this option.

Note that a change of the default precision control or rounding mode, for example, by using the -pc32 (Linux and Mac OS) or /Qpc32 (Windows) option or by user intervention, may affect the results returned by some of the mathematical functions.

Alternate Options