Developer Guide and Reference

Contents

qsimd-serialize-fp-reduction, Qsimd-serialize-fp-reduction

Tells the compiler to serialize floating-point reduction when vectorizing SIMD loops.

Syntax

Linux:
-qsimd-serialize-fp-reduction
-qno-simd-serialize-fp-reduction
macOS:
-qsimd-serialize-fp-reduction
-qno-simd-serialize-fp-reduction
Windows:
/Qsimd-serialize-fp-reduction
/Qsimd-serialize-fp-reduction-
Arguments
None
Default
-qno-simd-serialize-fp-reduction
or
/Qsimd-serialize-fp-reduction-
The compiler does not attempt to serialize floating-point reduction in SIMD loops.
Description
The OpenMP* SIMD reduction specification and the setting of compiler option
-fp-model
(Linux* and
macOS*
) or
/fp
(Windows*) can contradict in requirements. When contradiction occurs, the default behavior of the compiler is to follow OpenMP* specification and therefore vectorize the loop, including floating-point reduction.
This option lets you override this default behavior - it causes the compiler to follow the
-fp-model
(or
/fp
) specification. This means that the compiler will serialize the floating-point reduction while vectorizing the rest of the loop.
When
[q or Q]simd-honor-fp-model
is specified and OpenMP* SIMD reduction specification is the only thing causing serialization of the entire loop, addition of option
[q or Q]simd-serialize-fp-reduction
will result in vectorization of the entire loop except for reduction calculation, which will be serialized.
This option does not affect automatic vectorization of loops. By default, the compiler uses
-fp-model
(Linux*
and
macOS*
) or
/fp
(Windows*) settings for this.
Alternate Options
None

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804