Development Reference Guides

Contents

pc, Qpc

Enables control of floating-point significand precision.

Syntax

Linux:
-pc
n
Windows:
/Qpc
n
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* 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 this option.
Note that a change of the default precision control or rounding mode, for example, by using the
[Q]pc32
option or by user intervention, may affect the results returned by some of the mathematical functions.
IDE Equivalent
None
Alternate Options
None

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.