[GitHub] [arrow] jianxind commented on a change in pull request #8071: ARROW-9877: [C++] Fix homebrew-cpp build fail on AVX512

[GitBox]

jianxind commented on a change in pull request #8071:
URL: https://github.com/apache/arrow/pull/8071#discussion_r478941556



##
File path: cpp/src/arrow/util/cpu_info.h
##
@@ -71,8 +78,8 @@ class ARROW_EXPORT CpuInfo {
   /// Returns all the flags for this cpu
   int64_t hardware_flags();
 
-  /// Returns whether of not the cpu supports this flag
-  bool IsSupported(int64_t flag) const { return (hardware_flags_ & flag) != 0; 
}
+  /// Returns whether of not the cpu supports the flags

Review comment:
   done





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[GitHub] [arrow] jianxind commented on a change in pull request #8071: ARROW-9877: [C++] Fix homebrew-cpp build fail on AVX512

[GitBox]

jianxind commented on a change in pull request #8071:
URL: https://github.com/apache/arrow/pull/8071#discussion_r478897639



##
File path: cpp/cmake_modules/SetupCxxFlags.cmake
##
@@ -47,8 +47,8 @@ if(ARROW_CPU_FLAG STREQUAL "x86")
   else()
 set(ARROW_SSE4_2_FLAG "-msse4.2")
 set(ARROW_AVX2_FLAG "-mavx2")
-# skylake-avx512 consists of AVX512F,AVX512BW,AVX512VL,AVX512CD,AVX512DQ
-set(ARROW_AVX512_FLAG "-march=skylake-avx512 -mbmi2")
+# Typical AVX512 subsets consists of AVX512F, AVX512BW, AVX512VL, 
AVX512CD, AVX512DQ
+set(ARROW_AVX512_FLAG "-mavx512f -mavx512cd -mavx512vl -mavx512dq 
-mavx512bw -mbmi2")

Review comment:
   Yes. Most build use "-march=haswell" for AVX2, "-march=skylake-avx512" 
for AVX512.
   
   Thus we has to use "-mavx512f -mavx512cd -mavx512vl -mavx512dq -mavx512bw 
-march=skylake-avx512" for this issue, a little duplicated...





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