[PATCH] x86: Install <cpu-features.h> [BZ #26124]
H.J. Lu
hjl.tools@gmail.com
Wed Jun 17 19:31:00 GMT 2020
Install <cpu-features.h> so that programmers can do
#if __has_include(<cpu-features.h>)
#include <cpu-features.h>
#endif
...
if (HAS_CPU_FEATURE (SSE3))
...
if (CPU_FEATURE_USABLE (SSE3))
...
<cpu-features.h> exports only:
struct cpu_features
{
struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
unsigned int feature[FEATURE_INDEX_MAX];
struct cpu_features_basic basic;
};
/* Get a pointer to the CPU features structure. */
extern const struct cpu_features *__get_cpu_features (void)
__attribute__ ((const));
Since all feature checks are done through macros, programs compiled with
a newer <cpu-features.h> header are compatible with the older ones as
long as the layout of struct cpu_features is identical.
Note: Although GCC has __builtin_cpu_supports, it only supports a subset
of <cpu-features.h>.
---
sysdeps/unix/sysv/linux/i386/ld.abilist | 1 +
sysdeps/unix/sysv/linux/x86_64/64/ld.abilist | 1 +
sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist | 1 +
sysdeps/x86/Makefile | 1 +
sysdeps/x86/Versions | 2 +-
sysdeps/x86/cpu-features.h | 58 ++---------
sysdeps/x86/include/cpu-features.h | 95 +++++++++++++++++++
7 files changed, 106 insertions(+), 53 deletions(-)
create mode 100644 sysdeps/x86/include/cpu-features.h
diff --git a/sysdeps/unix/sysv/linux/i386/ld.abilist b/sysdeps/unix/sysv/linux/i386/ld.abilist
index 0478e22071..2f522173b4 100644
--- a/sysdeps/unix/sysv/linux/i386/ld.abilist
+++ b/sysdeps/unix/sysv/linux/i386/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.1 __libc_stack_end D 0x4
GLIBC_2.1 _dl_mcount F
GLIBC_2.3 ___tls_get_addr F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.32 __get_cpu_features F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
index d3cdf7611e..5a6abd4da0 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.2.5 __libc_stack_end D 0x8
GLIBC_2.2.5 _dl_mcount F
GLIBC_2.2.5 _r_debug D 0x28
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.32 __get_cpu_features F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
index c70bccf782..1169d8135d 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.16 __libc_stack_end D 0x4
GLIBC_2.16 __tls_get_addr F
GLIBC_2.16 _dl_mcount F
GLIBC_2.16 _r_debug D 0x14
+GLIBC_2.32 __get_cpu_features F
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index beab426f67..47051a3c82 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -4,6 +4,7 @@ endif
ifeq ($(subdir),elf)
sysdep-dl-routines += dl-get-cpu-features
+sysdep_headers += cpu-features.h
tests += tst-get-cpu-features tst-get-cpu-features-static
tests-static += tst-get-cpu-features-static
diff --git a/sysdeps/x86/Versions b/sysdeps/x86/Versions
index e02923708e..04596dd688 100644
--- a/sysdeps/x86/Versions
+++ b/sysdeps/x86/Versions
@@ -1,5 +1,5 @@
ld {
- GLIBC_PRIVATE {
+ GLIBC_2.32 {
__get_cpu_features;
}
}
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index de20044417..5c4e1a726a 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -1,4 +1,5 @@
-/* This file is part of the GNU C Library.
+/* Data structure for x86 CPU features.
+ This file is part of the GNU C Library.
Copyright (C) 2008-2020 Free Software Foundation, Inc.
The GNU C Library is free software; you can redistribute it and/or
@@ -15,8 +16,8 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#ifndef cpu_features_h
-#define cpu_features_h
+#ifndef _CPU_FEATURES_H
+#define _CPU_FEATURES_H
enum
{
@@ -72,34 +73,12 @@ struct cpu_features
struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
unsigned int feature[FEATURE_INDEX_MAX];
struct cpu_features_basic basic;
- /* The state size for XSAVEC or XSAVE. The type must be unsigned long
- int so that we use
-
- sub xsave_state_size_offset(%rip) %RSP_LP
-
- in _dl_runtime_resolve. */
- unsigned long int xsave_state_size;
- /* The full state size for XSAVE when XSAVEC is disabled by
-
- GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVEC_Usable
- */
- unsigned int xsave_state_full_size;
- /* Data cache size for use in memory and string routines, typically
- L1 size. */
- unsigned long int data_cache_size;
- /* Shared cache size for use in memory and string routines, typically
- L2 or L3 size. */
- unsigned long int shared_cache_size;
- /* Threshold to use non temporal store. */
- unsigned long int non_temporal_threshold;
};
-/* Used from outside of glibc to get access to the CPU features
- structure. */
+/* Get a pointer to the CPU features structure. */
extern const struct cpu_features *__get_cpu_features (void)
__attribute__ ((const));
-/* Only used directly in cpu-features.c. */
# define CPU_FEATURES_CPU_P(ptr, name) \
((ptr->cpuid[index_cpu_##name].reg_##name & (bit_cpu_##name)) != 0)
# define CPU_FEATURES_ARCH_P(ptr, name) \
@@ -976,29 +955,4 @@ extern const struct cpu_features *__get_cpu_features (void)
#define bit_ZMM0_15_state (1u << 6)
#define bit_ZMM16_31_state (1u << 7)
-# if defined (_LIBC) && !IS_IN (nonlib)
-/* Unused for x86. */
-# define INIT_ARCH()
-# define __get_cpu_features() (&GLRO(dl_x86_cpu_features))
-# define x86_get_cpuid_registers(i) \
- (&(GLRO(dl_x86_cpu_features).cpuid[i]))
-# endif
-
-#ifdef __x86_64__
-# define HAS_CPUID 1
-#elif (defined __i586__ || defined __pentium__ \
- || defined __geode__ || defined __k6__)
-# define HAS_CPUID 1
-# define HAS_I586 1
-# define HAS_I686 HAS_ARCH_FEATURE (I686)
-#elif defined __i486__
-# define HAS_CPUID 0
-# define HAS_I586 HAS_ARCH_FEATURE (I586)
-# define HAS_I686 HAS_ARCH_FEATURE (I686)
-#else
-# define HAS_CPUID 1
-# define HAS_I586 1
-# define HAS_I686 1
-#endif
-
-#endif /* cpu_features_h */
+#endif /* _CPU_FEATURES_H */
diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
new file mode 100644
index 0000000000..e2a303dc1f
--- /dev/null
+++ b/sysdeps/x86/include/cpu-features.h
@@ -0,0 +1,95 @@
+/* Data structure for x86 CPU features.
+ Copyright (C) 2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _PRIVATE_CPU_FEATURES_H
+#define _PRIVATE_CPU_FEATURES_H 1
+
+#ifdef _CPU_FEATURES_H
+# error this should be impossible
+#endif
+
+#ifndef _ISOMAC
+/* Get most of the contents from the public header, but we define a
+ different `struct cpu_features' type for private use. */
+# define cpu_features cpu_features_public
+# define __get_cpu_features __get_cpu_features_public
+#endif
+
+#include <sysdeps/x86/cpu-features.h>
+
+#ifndef _ISOMAC
+
+# undef cpu_features
+# undef __get_cpu_features
+
+/* Forward declaration. */
+struct cpu_features
+{
+ struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
+ unsigned int feature[FEATURE_INDEX_MAX];
+ struct cpu_features_basic basic;
+ /* The state size for XSAVEC or XSAVE. The type must be unsigned long
+ int so that we use
+
+ sub xsave_state_size_offset(%rip) %RSP_LP
+
+ in _dl_runtime_resolve. */
+ unsigned long int xsave_state_size;
+ /* The full state size for XSAVE when XSAVEC is disabled by
+
+ GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVEC_Usable
+ */
+ unsigned int xsave_state_full_size;
+ /* Data cache size for use in memory and string routines, typically
+ L1 size. */
+ unsigned long int data_cache_size;
+ /* Shared cache size for use in memory and string routines, typically
+ L2 or L3 size. */
+ unsigned long int shared_cache_size;
+ /* Threshold to use non temporal store. */
+ unsigned long int non_temporal_threshold;
+};
+
+# if defined (_LIBC) && !IS_IN (nonlib)
+/* Unused for x86. */
+# define INIT_ARCH()
+# define __get_cpu_features() (&GLRO(dl_x86_cpu_features))
+# define x86_get_cpuid_registers(i) \
+ (&(GLRO(dl_x86_cpu_features).cpuid[i]))
+# endif
+
+# ifdef __x86_64__
+# define HAS_CPUID 1
+# elif (defined __i586__ || defined __pentium__ \
+ || defined __geode__ || defined __k6__)
+# define HAS_CPUID 1
+# define HAS_I586 1
+# define HAS_I686 HAS_ARCH_FEATURE (I686)
+# elif defined __i486__
+# define HAS_CPUID 0
+# define HAS_I586 HAS_ARCH_FEATURE (I586)
+# define HAS_I686 HAS_ARCH_FEATURE (I686)
+# else
+# define HAS_CPUID 1
+# define HAS_I586 1
+# define HAS_I686 1
+# endif
+
+#endif /* !_ISOMAC */
+
+#endif /* include/link.h */
--
2.26.2
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