mirror of git://sourceware.org/git/glibc.git
9620398097
Install <sys/platform/x86.h> so that programmers can do
#if __has_include(<sys/platform/x86.h>)
#include <sys/platform/x86.h>
#endif
...
if (CPU_FEATURE_USABLE (SSE2))
...
if (CPU_FEATURE_USABLE (AVX2))
...
<sys/platform/x86.h> exports only:
enum
{
COMMON_CPUID_INDEX_1 = 0,
COMMON_CPUID_INDEX_7,
COMMON_CPUID_INDEX_80000001,
COMMON_CPUID_INDEX_D_ECX_1,
COMMON_CPUID_INDEX_80000007,
COMMON_CPUID_INDEX_80000008,
COMMON_CPUID_INDEX_7_ECX_1,
/* Keep the following line at the end. */
COMMON_CPUID_INDEX_MAX
};
struct cpuid_features
{
struct cpuid_registers cpuid;
struct cpuid_registers usable;
};
struct cpu_features
{
struct cpu_features_basic basic;
struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
};
/* Get a pointer to the CPU features structure. */
extern const struct cpu_features *__x86_get_cpu_features
(unsigned int max) __attribute__ ((const));
Since all feature checks are done through macros, programs compiled with
a newer <sys/platform/x86.h> are compatible with the older glibc binaries
as long as the layout of struct cpu_features is identical. The features
array can be expanded with backward binary compatibility for both .o and
.so files. When COMMON_CPUID_INDEX_MAX is increased to support new
processor features, __x86_get_cpu_features in the older glibc binaries
returns NULL and HAS_CPU_FEATURE/CPU_FEATURE_USABLE return false on the
new processor feature. No new symbol version is neeeded.
Both CPU_FEATURE_USABLE and HAS_CPU_FEATURE are provided. HAS_CPU_FEATURE
can be used to identify processor features.
Note: Although GCC has __builtin_cpu_supports, it only supports a subset
of <sys/platform/x86.h> and it is equivalent to CPU_FEATURE_USABLE. It
doesn't support HAS_CPU_FEATURE.
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|---|---|---|
| .. | ||
| bits | ||
| fpu | ||
| include | ||
| nptl | ||
| sys/platform | ||
| Makeconfig | ||
| Makefile | ||
| Versions | ||
| __longjmp_cancel.S | ||
| atomic-machine.h | ||
| cacheinfo.c | ||
| cet-control.h | ||
| check-cet.awk | ||
| configure | ||
| configure.ac | ||
| cpu-features-offsets.sym | ||
| cpu-features.c | ||
| cpu-tunables.c | ||
| dl-cet.c | ||
| dl-get-cpu-features.c | ||
| dl-hwcap.h | ||
| dl-lookupcfg.h | ||
| dl-procinfo.c | ||
| dl-procinfo.h | ||
| dl-procruntime.c | ||
| dl-prop.h | ||
| dl-tunables.list | ||
| elf-initfini.h | ||
| elide.h | ||
| float128-abi.h | ||
| fpu_control.h | ||
| hp-timing.h | ||
| init-arch.h | ||
| jmp_buf-ssp.sym | ||
| ldsodefs.h | ||
| libc-start.c | ||
| libc-start.h | ||
| link_map.h | ||
| linkmap.h | ||
| longjmp.c | ||
| string_private.h | ||
| sysdep.h | ||
| tininess.h | ||
| tst-cet-legacy-1.c | ||
| tst-cet-legacy-1a.c | ||
| tst-cet-legacy-2.c | ||
| tst-cet-legacy-2a.c | ||
| tst-cet-legacy-3.c | ||
| tst-cet-legacy-4.c | ||
| tst-cet-legacy-4a.c | ||
| tst-cet-legacy-4b.c | ||
| tst-cet-legacy-4c.c | ||
| tst-cet-legacy-5.c | ||
| tst-cet-legacy-5a.c | ||
| tst-cet-legacy-5b.c | ||
| tst-cet-legacy-6.c | ||
| tst-cet-legacy-6a.c | ||
| tst-cet-legacy-6b.c | ||
| tst-cet-legacy-7.c | ||
| tst-cet-legacy-8.c | ||
| tst-cet-legacy-mod-1.c | ||
| tst-cet-legacy-mod-2.c | ||
| tst-cet-legacy-mod-4.c | ||
| tst-cet-legacy-mod-5.c | ||
| tst-cet-legacy-mod-5a.c | ||
| tst-cet-legacy-mod-5b.c | ||
| tst-cet-legacy-mod-5c.c | ||
| tst-cet-legacy-mod-6.c | ||
| tst-cet-legacy-mod-6a.c | ||
| tst-cet-legacy-mod-6b.c | ||
| tst-cet-legacy-mod-6c.c | ||
| tst-cet-legacy-mod-6d.c | ||
| tst-cpu-features-cpuinfo.c | ||
| tst-cpu-features-supports.c | ||
| tst-get-cpu-features-static.c | ||
| tst-get-cpu-features.c | ||