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* x86: Install <sys/platform/x86.h> [BZ #26124]H.J. Lu2020-09-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Add _dl_x86_cpu_features to rtld_globalH.J. Lu2015-08-131-0/+5
This patch adds _dl_x86_cpu_features to rtld_global in x86 ld.so and initializes it early before __libc_start_main is called so that cpu_features is always available when it is used and we can avoid calling __init_cpu_features in IFUNC selectors. * sysdeps/i386/dl-machine.h: Include <cpu-features.c>. (dl_platform_init): Call init_cpu_features. * sysdeps/i386/dl-procinfo.c (_dl_x86_cpu_features): New. * sysdeps/i386/i686/cacheinfo.c (DISABLE_PREFERRED_MEMORY_INSTRUCTION): Removed. * sysdeps/i386/i686/multiarch/Makefile (aux): Remove init-arch. * sysdeps/i386/i686/multiarch/Versions: Removed. * sysdeps/i386/i686/multiarch/ifunc-defines.sym (KIND_OFFSET): Removed. * sysdeps/i386/ldsodefs.h: Include <cpu-features.h>. * sysdeps/unix/sysv/linux/x86/Makefile (libpthread-sysdep_routines): Remove init-arch. * sysdeps/unix/sysv/linux/x86_64/dl-procinfo.c: Include <sysdeps/x86_64/dl-procinfo.c> instead of sysdeps/generic/dl-procinfo.c>. * sysdeps/x86/Makefile [$(subdir) == csu] (gen-as-const-headers): Add cpu-features-offsets.sym and rtld-global-offsets.sym. [$(subdir) == elf] (sysdep-dl-routines): Add dl-get-cpu-features. [$(subdir) == elf] (tests): Add tst-get-cpu-features. [$(subdir) == elf] (tests-static): Add tst-get-cpu-features-static. * sysdeps/x86/Versions: New file. * sysdeps/x86/cpu-features-offsets.sym: Likewise. * sysdeps/x86/cpu-features.c: Likewise. * sysdeps/x86/cpu-features.h: Likewise. * sysdeps/x86/dl-get-cpu-features.c: Likewise. * sysdeps/x86/libc-start.c: Likewise. * sysdeps/x86/rtld-global-offsets.sym: Likewise. * sysdeps/x86/tst-get-cpu-features-static.c: Likewise. * sysdeps/x86/tst-get-cpu-features.c: Likewise. * sysdeps/x86_64/dl-procinfo.c: Likewise. * sysdeps/x86_64/cacheinfo.c (__cpuid_count): Removed. Assume USE_MULTIARCH is defined and don't check it. (is_intel): Replace __cpu_features with GLRO(dl_x86_cpu_features). (is_amd): Likewise. (max_cpuid): Likewise. (intel_check_word): Likewise. (__cache_sysconf): Don't call __init_cpu_features. (__x86_preferred_memory_instruction): Removed. (init_cacheinfo): Don't call __init_cpu_features. Replace __cpu_features with GLRO(dl_x86_cpu_features). * sysdeps/x86_64/dl-machine.h: <cpu-features.c>. (dl_platform_init): Call init_cpu_features. * sysdeps/x86_64/ldsodefs.h: Include <cpu-features.h>. * sysdeps/x86_64/multiarch/Makefile (aux): Remove init-arch. * sysdeps/x86_64/multiarch/Versions: Removed. * sysdeps/x86_64/multiarch/cacheinfo.c: Likewise. * sysdeps/x86_64/multiarch/init-arch.c: Likewise. * sysdeps/x86_64/multiarch/ifunc-defines.sym (KIND_OFFSET): Removed. * sysdeps/x86_64/multiarch/init-arch.h: Rewrite.