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| author | Dmitry Ivanov <ethercrow@gmail.com> | 2018-12-08 16:45:02 +0100 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2019-01-30 10:06:31 -0500 |
| commit | c1d9416f2672b8d844141c0393fe773676749777 (patch) | |
| tree | 30d388f8070e3316e40397293ce4150c24351536 /docs | |
| parent | cc2261d42f6a954d88e355aaad41f001f65c95da (diff) | |
| download | haskell-c1d9416f2672b8d844141c0393fe773676749777.tar.gz | |
Compile count{Leading,Trailing}Zeros to corresponding x86_64 instructions under -mbmi2
This works similarly to existing implementation for popCount.
Trac ticket: #16086.
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/users_guide/using.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/docs/users_guide/using.rst b/docs/users_guide/using.rst index 420e2d3bfc..83eeb51eed 100644 --- a/docs/users_guide/using.rst +++ b/docs/users_guide/using.rst @@ -1088,6 +1088,16 @@ Some flags only make sense for particular target platforms. SSE4.2 if your processor supports it but detects this automatically so no flag is required. +.. ghc-flag:: -mbmi2 + :shortdesc: (x86 only) Use BMI2 for bit manipulation operations + :type: dynamic + :category: platform-options + + (x86 only, added in GHC 7.4.1) Use the BMI2 instruction set to + implement some bit operations when using the + :ref:`native code generator <native-code-gen>`. The resulting compiled + code will only run on processors that support BMI2 (Intel Haswell and newer, AMD Excavator, Zen and newer). + Miscellaneous flags ------------------- |