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authorH.J. Lu <hjl.tools@gmail.com>2020-06-17 06:34:46 -0700
committerH.J. Lu <hjl.tools@gmail.com>2020-06-22 13:09:33 -0700
commitecbbadbf107ea1155ae5b71a8b7bd48f38c76731 (patch)
treeedc19a18074492532661cf40364d633ac39e75b8 /sysdeps/unix/sysv/linux/clock_gettime.c
parentea04f0213135b13d80f568ca2c4127c2ec112537 (diff)
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x86: Update CPU feature detection [BZ #26149]
1. Divide architecture features into the usable features and the preferred
features.  The usable features are for correctness and can be exported in
a stable ABI.  The preferred features are for performance and only for
glibc internal use.
2. Change struct cpu_features to

struct cpu_features
{
  struct cpu_features_basic basic;
  unsigned int *usable_p;
  struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
  unsigned int usable[USABLE_FEATURE_INDEX_MAX];
  unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
  ...
};

and initialize usable_p to pointer to the usable arary so that

struct cpu_features
{
  struct cpu_features_basic basic;
  unsigned int *usable_p;
  struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
};

can be exported via a stable ABI.  The cpuid and usable arrays can be
expanded with backward binary compatibility for both .o and .so files.
3. Add COMMON_CPUID_INDEX_7_ECX_1 for AVX512_BF16.
4. Detect ENQCMD, PKS, AVX512_VP2INTERSECT, MD_CLEAR, SERIALIZE, HYBRID,
TSXLDTRK, L1D_FLUSH, CORE_CAPABILITIES and AVX512_BF16.
5. Rename CAPABILITIES to ARCH_CAPABILITIES.
6. Check if AVX512_VP2INTERSECT, AVX512_BF16 and PKU are usable.
7. Update CPU feature detection test.
Diffstat (limited to 'sysdeps/unix/sysv/linux/clock_gettime.c')
0 files changed, 0 insertions, 0 deletions