Visible to Intel only — GUID: GUID-3B73C6C7-C74C-415C-A141-058249F529B0
Visible to Intel only — GUID: GUID-3B73C6C7-C74C-415C-A141-058249F529B0
qopt-zmm-usage, Qopt-zmm-usage
Defines a level of zmm registers usage.
Syntax
Linux: |
-qopt-zmm-usage=keyword |
Windows: |
/Qopt-zmm-usage:keyword |
Arguments
keyword |
Specifies the level of zmm registers usage. Possible values are:
|
Default
varies |
The default is low when you specify [Q]xCORE-AVX512. The default is high when you specify [Q]xCOMMON-AVX512. |
Description
This option may provide better code optimization for Intel® processors that are on the Intel® microarchitecture formerly code-named Skylake.
This option defines a level of zmm registers usage. The low setting causes the compiler to generate code with zmm registers very carefully, only when the gain from their usage is proven. The high setting causes the compiler to use much less restrictive heuristics for zmm code generation.
It is not always easy to predict whether the high or the low setting will yield better performance. Programs that enjoy high performance gains from the use of xmm or ymm registers may expect performance improvement by moving to use zmm registers. However, some programs that use zmm registers may not gain as much or may even lose performance. We recommend that you try both option values to measure the performance of your programs.
This option is ignored if you do not specify an option that enables Intel® AVX-512, such as [Q]xCORE-AVX512 or option [Q]xCOMMON-AVX512.
This option has no effect on loops that use directive SIMD SIMDLEN(n) or on functions that are generated by vector specifications specific to CORE-AVX512.
IDE Equivalent
Alternate Options
None