[llvm] 5ac144f - [X86] Calculate the needed size of the feature arrays in _cpu_indicator_init and getHostCPUName using the size of the feature enum.

[Hans Wennborg via llvm-commits]

This seems to be breaking the build: http://45.33.8.238/linux/20972/step_4.txt

On Mon, Jun 22, 2020 at 9:07 PM Craig Topper via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
>
>
> Author: Craig Topper
> Date: 2020-06-22T11:46:20-07:00
> New Revision: 5ac144fe64c6911b5b6011cac1d61e0f82562e7f
>
> URL: https://github.com/llvm/llvm-project/commit/5ac144fe64c6911b5b6011cac1d61e0f82562e7f
> DIFF: https://github.com/llvm/llvm-project/commit/5ac144fe64c6911b5b6011cac1d61e0f82562e7f.diff
>
> LOG: [X86] Calculate the needed size of the feature arrays in _cpu_indicator_init and getHostCPUName using the size of the feature enum.
>
> Move 0 initialization up to the caller so we don't need to know
> the size.
>
> Added:
>
>
> Modified:
>     compiler-rt/lib/builtins/cpu_model.c
>     llvm/include/llvm/Support/X86TargetParser.h
>     llvm/lib/Support/Host.cpp
>
> Removed:
>
>
>
> ################################################################################
> diff  --git a/compiler-rt/lib/builtins/cpu_model.c b/compiler-rt/lib/builtins/cpu_model.c
> index 59c6974207c7..3207f1449e00 100644
> --- a/compiler-rt/lib/builtins/cpu_model.c
> +++ b/compiler-rt/lib/builtins/cpu_model.c
> @@ -125,7 +125,8 @@ enum ProcessorFeatures {
>    FEATURE_AVX512VNNI,
>    FEATURE_AVX512BITALG,
>    FEATURE_AVX512BF16,
> -  FEATURE_AVX512VP2INTERSECT
> +  FEATURE_AVX512VP2INTERSECT,
> +  CPU_FEATURE_MAX
>  };
>
>  // The check below for i386 was copied from clang's cpuid.h (__get_cpuid_max).
> @@ -493,8 +494,6 @@ static void getAMDProcessorTypeAndSubtype(unsigned Family, unsigned Model,
>
>  static void getAvailableFeatures(unsigned ECX, unsigned EDX, unsigned MaxLeaf,
>                                   unsigned *Features) {
> -  Features[0] = 0;
> -  Features[1] = 0;
>    unsigned EAX, EBX;
>
>  #define setFeature(F)                                                          \
> @@ -653,7 +652,8 @@ int CONSTRUCTOR_ATTRIBUTE __cpu_indicator_init(void) {
>    unsigned MaxLeaf = 5;
>    unsigned Vendor;
>    unsigned Model, Family;
> -  unsigned Features[2];
> +  const unsigned SIZE_OF_FEATURES = (CPU_FEATURE_MAX + 31) / 32;
> +  unsigned Features[SIZE_OF_FEATURES] = {0};
>
>    // This function needs to run just once.
>    if (__cpu_model.__cpu_vendor)
> @@ -670,6 +670,8 @@ int CONSTRUCTOR_ATTRIBUTE __cpu_indicator_init(void) {
>
>    // Find available features.
>    getAvailableFeatures(ECX, EDX, MaxLeaf, &Features[0]);
> +
> +  assert(SIZE_OF_FEATURES == 2);
>    __cpu_model.__cpu_features[0] = Features[0];
>    __cpu_features2 = Features[1];
>
>
> diff  --git a/llvm/include/llvm/Support/X86TargetParser.h b/llvm/include/llvm/Support/X86TargetParser.h
> index 7cdf1c532814..e357d11a6615 100644
> --- a/llvm/include/llvm/Support/X86TargetParser.h
> +++ b/llvm/include/llvm/Support/X86TargetParser.h
> @@ -56,7 +56,7 @@ enum ProcessorFeatures {
>  #define X86_FEATURE(VAL, ENUM) \
>    ENUM = VAL,
>  #include "llvm/Support/X86TargetParser.def"
> -
> +  CPU_FEATURE_MAX
>  };
>
>  enum CPUKind {
>
> diff  --git a/llvm/lib/Support/Host.cpp b/llvm/lib/Support/Host.cpp
> index c6b12e6516a4..e4c6b879884a 100644
> --- a/llvm/lib/Support/Host.cpp
> +++ b/llvm/lib/Support/Host.cpp
> @@ -582,7 +582,7 @@ static void detectX86FamilyModel(unsigned EAX, unsigned *Family,
>
>  static void
>  getIntelProcessorTypeAndSubtype(unsigned Family, unsigned Model,
> -                                const unsigned (&Features)[3],
> +                                const unsigned *Features,
>                                  unsigned *Type, unsigned *Subtype) {
>    auto testFeature = [&](unsigned F) {
>      return (Features[F / 32] & (1U << (F % 32))) != 0;
> @@ -910,7 +910,7 @@ getIntelProcessorTypeAndSubtype(unsigned Family, unsigned Model,
>  }
>
>  static void getAMDProcessorTypeAndSubtype(unsigned Family, unsigned Model,
> -                                          const unsigned (&Features)[3],
> +                                          const unsigned *Features,
>                                            unsigned *Type, unsigned *Subtype) {
>    auto testFeature = [&](unsigned F) {
>      return (Features[F / 32] & (1U << (F % 32))) != 0;
> @@ -1012,10 +1012,7 @@ static void getAMDProcessorTypeAndSubtype(unsigned Family, unsigned Model,
>  }
>
>  static void getAvailableFeatures(unsigned ECX, unsigned EDX, unsigned MaxLeaf,
> -                                 unsigned (&Features)[3]) {
> -  Features[0] = 0;
> -  Features[1] = 0;
> -  Features[2] = 0;
> +                                 unsigned *Features) {
>    unsigned EAX, EBX;
>
>    auto setFeature = [&](unsigned F) {
> @@ -1157,7 +1154,7 @@ StringRef sys::getHostCPUName() {
>    getX86CpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX);
>
>    unsigned Family = 0, Model = 0;
> -  unsigned Features[3] = {0, 0, 0};
> +  unsigned Features[(X86::CPU_FEATURE_MAX + 31) / 32] = {0};
>    detectX86FamilyModel(EAX, &Family, &Model);
>    getAvailableFeatures(ECX, EDX, MaxLeaf, Features);
>
>
>
>
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