1. Factor out some of the ISA level defines in isa-level.c to
standalone header isa-level.h
2. Add new headers with ISA level dependent macros for handling
ifuncs.
Note, this file does not change any code.
Tested with and without multiarch on x86_64 for ISA levels:
{generic, x86-64-v2, x86-64-v3, x86-64-v4}
---
sysdeps/generic/ifunc-init.h | 8 ++
sysdeps/x86/init-arch.h | 4 +
sysdeps/x86/isa-cpu-feature-checks.h | 55 +++++++++++++
sysdeps/x86/isa-ifunc-macros.h | 117 +++++++++++++++++++++++++++
sysdeps/x86/isa-level.c | 17 ++--
sysdeps/x86/isa-level.h | 67 +++++++++++++++
sysdeps/x86_64/isa-default-impl.h | 49 +++++++++++
7 files changed, 305 insertions(+), 12 deletions(-)
create mode 100644 sysdeps/x86/isa-cpu-feature-checks.h
create mode 100644 sysdeps/x86/isa-ifunc-macros.h
create mode 100644 sysdeps/x86/isa-level.h
create mode 100644 sysdeps/x86_64/isa-default-impl.h
@@ -55,3 +55,11 @@
#define OPTIMIZE2(name) EVALUATOR2 (SYMBOL_NAME, name)
/* Default is to use OPTIMIZE2. */
#define OPTIMIZE(name) OPTIMIZE2(name)
+
+/* Syntactic sugar for common usage of the OPTIMIZE and OPTIMIZE1 macros
+ respectively. */
+#define OPTIMIZE_DECL(...) \
+ extern __typeof (REDIRECT_NAME) OPTIMIZE (__VA_ARGS__) attribute_hidden;
+
+#define OPTIMIZE_DECL1(...) \
+ extern __typeof (REDIRECT_NAME) OPTIMIZE1 (__VA_ARGS__) attribute_hidden;
@@ -27,6 +27,10 @@
# define USE_I586 0
# define USE_I686 1
# else
+
+# include <isa-ifunc-macros.h>
+# include <isa-cpu-feature-checks.h>
+
# define USE_I586 (HAS_ARCH_FEATURE (I586) && !HAS_ARCH_FEATURE (I686))
# define USE_I686 HAS_ARCH_FEATURE (I686)
# endif
new file mode 100644
@@ -0,0 +1,55 @@
+/* Common ifunc selection utils
+ All versions must be listed in ifunc-impl-list.c.
+ Copyright (C) 2017-2022 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 _ISA_CPU_FEATURE_CHECKS_H
+#define _ISA_CPU_FEATURE_CHECKS_H 1
+
+#include <isa-level.h>
+
+/* ISA level >= 4 guaranteed includes. */
+#define X86_FEATURE_USABLE_P_AVX512VL \
+ (MINIMUM_X86_ISA_LEVEL >= 4 || CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
+
+#define X86_FEATURE_USABLE_P_AVX512BW \
+ (MINIMUM_X86_ISA_LEVEL >= 4 || CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
+
+/* ISA level >= 3 guaranteed includes. */
+#define X86_FEATURE_USABLE_P_AVX2 \
+ (MINIMUM_X86_ISA_LEVEL >= 3 || CPU_FEATURE_USABLE_P (cpu_features, AVX2))
+
+#define X86_FEATURE_USABLE_P_BMI2 \
+ (MINIMUM_X86_ISA_LEVEL >= 3 || CPU_FEATURE_USABLE_P (cpu_features, BMI2))
+
+/*
+ * NB: This may not be fully assumable for ISA level >= 3. From looking over
+ * the architectures supported in cpu-features.h the following CPUs may have an
+ * issue with this being default set:
+ * - AMD Excavator
+ */
+#define X86_FEATURE_ARCH_P_AVX_Fast_Unaligned_Load \
+ (MINIMUM_X86_ISA_LEVEL >= 3 \
+ || CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
+
+/* ISA independent non-guaranteed includes. */
+#define X86_FEATURE_USABLE_P_RTM CPU_FEATURE_USABLE_P (cpu_features, RTM)
+
+#define X86_FEATURE_ARCH_P_Prefer_No_VZEROUPPER \
+ CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER)
+
+#endif
new file mode 100644
@@ -0,0 +1,117 @@
+/* Common ifunc selection utils
+ All versions must be listed in ifunc-impl-list.c.
+ Copyright (C) 2017-2022 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 _ISA_IFUNC_MACROS_H
+#define _ISA_IFUNC_MACROS_H 1
+
+#include <isa-level.h>
+#include <sys/cdefs.h>
+
+/* Only include at the level of the minimum build ISA or higher. I.e
+ if built with ISA=V1, then include all implementations. On the
+ other hand if built with ISA=V3 only include V3/V4
+ implementations. If there is no implementation at or above the
+ minimum build ISA level, then include the highest ISA level
+ implementation. */
+#if MINIMUM_X86_ISA_LEVEL <= 4
+# define X86_IFUNC_IMPL_ADD_V4(...) IFUNC_IMPL_ADD (__VA_ARGS__)
+# define return_X86_OPTIMIZE_V4(...) return OPTIMIZE (__VA_ARGS__)
+# define return_X86_OPTIMIZE1_V4(...) return OPTIMIZE1 (__VA_ARGS__)
+#endif
+#if MINIMUM_X86_ISA_LEVEL <= 3
+# define X86_IFUNC_IMPL_ADD_V3(...) IFUNC_IMPL_ADD (__VA_ARGS__)
+# define return_X86_OPTIMIZE_V3(...) return OPTIMIZE (__VA_ARGS__)
+# define return_X86_OPTIMIZE1_V3(...) return OPTIMIZE1 (__VA_ARGS__)
+#endif
+#if MINIMUM_X86_ISA_LEVEL <= 2
+# define X86_IFUNC_IMPL_ADD_V2(...) IFUNC_IMPL_ADD (__VA_ARGS__)
+# define return_X86_OPTIMIZE_V2(...) return OPTIMIZE (__VA_ARGS__)
+# define return_X86_OPTIMIZE1_V2(...) return OPTIMIZE1 (__VA_ARGS__)
+#endif
+#if MINIMUM_X86_ISA_LEVEL <= 1
+# define X86_IFUNC_IMPL_ADD_V1(...) IFUNC_IMPL_ADD (__VA_ARGS__)
+# define return_X86_OPTIMIZE_V1(...) return OPTIMIZE (__VA_ARGS__)
+# define return_X86_OPTIMIZE1_V1(...) return OPTIMIZE1 (__VA_ARGS__)
+#endif
+
+#ifndef return_X86_OPTIMIZE_V4
+# define X86_IFUNC_IMPL_ADD_V4(...)
+# define return_X86_OPTIMIZE_V4(...) (void) (0)
+# define return_X86_OPTIMIZE1_V4(...) (void) (0)
+#endif
+#ifndef return_X86_OPTIMIZE_V3
+# define X86_IFUNC_IMPL_ADD_V3(...)
+# define return_X86_OPTIMIZE_V3(...) (void) (0)
+# define return_X86_OPTIMIZE1_V3(...) (void) (0)
+#endif
+#ifndef return_X86_OPTIMIZE_V2
+# define X86_IFUNC_IMPL_ADD_V2(...)
+# define return_X86_OPTIMIZE_V2(...) (void) (0)
+# define return_X86_OPTIMIZE1_V2(...) (void) (0)
+#endif
+#ifndef return_X86_OPTIMIZE_V1
+# define X86_IFUNC_IMPL_ADD_V1(...)
+# define return_X86_OPTIMIZE_V1(...) (void) (0)
+# define return_X86_OPTIMIZE1_V1(...) (void) (0)
+#endif
+
+#if MINIMUM_X86_ISA_LEVEL == 1
+# define X86_OPTIMIZE_FALLBACK(v1, ...) OPTIMIZE (v1)
+#elif MINIMUM_X86_ISA_LEVEL == 2
+# define X86_OPTIMIZE_FALLBACK(v1, v2, ...) OPTIMIZE (v2)
+#elif MINIMUM_X86_ISA_LEVEL == 3
+# define X86_OPTIMIZE_FALLBACK(v1, v2, v3, ...) OPTIMIZE (v3)
+#elif MINIMUM_X86_ISA_LEVEL == 4
+# define X86_OPTIMIZE_FALLBACK(v1, v2, v3, v4) OPTIMIZE (v4)
+#else
+# error "Unsupported ISA Level"
+#endif
+
+
+#if MINIMUM_X86_ISA_LEVEL >= 4
+__errordecl (__unreachable_isa_above_4,
+ "This code should be unreachable if ISA level >= 4 build ");
+# define X86_ERROR_IF_REACHABLE_V4() \
+ __unreachable_isa_above_4 (); \
+ __builtin_unreachable ();
+#else
+# define X86_ERROR_IF_REACHABLE_V4()
+#endif
+
+#if MINIMUM_X86_ISA_LEVEL >= 3
+__errordecl (__unreachable_isa_above_3,
+ "This code should be unreachable if ISA level >= 3 build");
+# define X86_ERROR_IF_REACHABLE_V3() \
+ __unreachable_isa_above_3 (); \
+ __builtin_unreachable ();
+#else
+# define X86_ERROR_IF_REACHABLE_V3()
+#endif
+
+#if MINIMUM_X86_ISA_LEVEL >= 2
+__errordecl (__unreachable_isa_above_2,
+ "This code should be unreachable if ISA level >= 2 build");
+# define X86_ERROR_IF_REACHABLE_V2() \
+ __unreachable_isa_above_2 (); \
+ __builtin_unreachable ();
+#else
+# define X86_ERROR_IF_REACHABLE_V2()
+#endif
+
+#endif
@@ -26,38 +26,31 @@
<https://www.gnu.org/licenses/>. */
#include <elf.h>
-
+#include <sysdeps/x86/isa-level.h>
/* ELF program property for x86 ISA level. */
#ifdef INCLUDE_X86_ISA_LEVEL
-# if defined __SSE__ && defined __SSE2__
+# if MINIMUM_X86_ISA_LEVEL >= 1
/* NB: ISAs, excluding MMX, in x86-64 ISA level baseline are used. */
# define ISA_BASELINE GNU_PROPERTY_X86_ISA_1_BASELINE
# else
# define ISA_BASELINE 0
# endif
-# if ISA_BASELINE && defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
- && defined HAVE_X86_LAHF_SAHF && defined __POPCNT__ \
- && defined __SSE3__ && defined __SSSE3__ && defined __SSE4_1__ \
- && defined __SSE4_2__
+# if MINIMUM_X86_ISA_LEVEL >= 2
/* NB: ISAs in x86-64 ISA level v2 are used. */
# define ISA_V2 GNU_PROPERTY_X86_ISA_1_V2
# else
# define ISA_V2 0
# endif
-# if ISA_V2 && defined __AVX__ && defined __AVX2__ && defined __F16C__ \
- && defined __FMA__ && defined __LZCNT__ && defined HAVE_X86_MOVBE \
- && defined __BMI__ && defined __BMI2__
+# if MINIMUM_X86_ISA_LEVEL >= 3
/* NB: ISAs in x86-64 ISA level v3 are used. */
# define ISA_V3 GNU_PROPERTY_X86_ISA_1_V3
# else
# define ISA_V3 0
# endif
-# if ISA_V3 && defined __AVX512F__ && defined __AVX512BW__ \
- && defined __AVX512CD__ && defined __AVX512DQ__ \
- && defined __AVX512VL__
+# if MINIMUM_X86_ISA_LEVEL >= 4
/* NB: ISAs in x86-64 ISA level v4 are used. */
# define ISA_V4 GNU_PROPERTY_X86_ISA_1_V4
# else
new file mode 100644
@@ -0,0 +1,67 @@
+/* Header defining the minimum x86 ISA level
+ Copyright (C) 2022 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.
+
+ In addition to the permissions in the GNU Lesser General Public
+ License, the Free Software Foundation gives you unlimited
+ permission to link the compiled version of this file with other
+ programs, and to distribute those programs without any restriction
+ coming from the use of this file. (The Lesser General Public
+ License restrictions do apply in other respects; for example, they
+ cover modification of the file, and distribution when not linked
+ into another program.)
+
+ 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 _ISA_LEVEL_H
+#define _ISA_LEVEL_H
+
+#if defined __SSE__ && defined __SSE2__
+/* NB: ISAs, excluding MMX, in x86-64 ISA level baseline are used. */
+# define __X86_ISA_V1 1
+#else
+# define __X86_ISA_V1 0
+#endif
+
+#if __X86_ISA_V1 && defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
+ && defined HAVE_X86_LAHF_SAHF && defined __POPCNT__ && defined __SSE3__ \
+ && defined __SSSE3__ && defined __SSE4_1__ && defined __SSE4_2__
+/* NB: ISAs in x86-64 ISA level v2 are used. */
+# define __X86_ISA_V2 1
+#else
+# define __X86_ISA_V2 0
+#endif
+
+#if __X86_ISA_V2 && defined __AVX__ && defined __AVX2__ && defined __F16C__ \
+ && defined __FMA__ && defined __LZCNT__ && defined HAVE_X86_MOVBE \
+ && defined __BMI__ && defined __BMI2__
+/* NB: ISAs in x86-64 ISA level v3 are used. */
+# define __X86_ISA_V3 1
+#else
+# define __X86_ISA_V3 0
+#endif
+
+#if __X86_ISA_V3 && defined __AVX512F__ && defined __AVX512BW__ \
+ && defined __AVX512CD__ && defined __AVX512DQ__ && defined __AVX512VL__
+/* NB: ISAs in x86-64 ISA level v4 are used. */
+# define __X86_ISA_V4 1
+#else
+# define __X86_ISA_V4 0
+#endif
+
+#define MINIMUM_X86_ISA_LEVEL \
+ (__X86_ISA_V1 + __X86_ISA_V2 + __X86_ISA_V3 + __X86_ISA_V4)
+
+#endif
new file mode 100644
@@ -0,0 +1,49 @@
+/* Utility for including proper default function based on ISA level
+ Copyright (C) 2022 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/>. */
+
+#include <isa-level.h>
+
+#ifndef DEFAULT_IMPL_V1
+# error "Must have at least ISA V1 Version"
+#endif
+
+#ifndef DEFAULT_IMPL_V2
+# define DEFAULT_IMPL_V2 DEFAULT_IMPL_V1
+#endif
+
+#ifndef DEFAULT_IMPL_V3
+# define DEFAULT_IMPL_V3 DEFAULT_IMPL_V2
+#endif
+
+#ifndef DEFAULT_IMPL_V4
+# define DEFAULT_IMPL_V4 DEFAULT_IMPL_V3
+#endif
+
+#if MINIMUM_X86_ISA_LEVEL == 1
+# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V1
+#elif MINIMUM_X86_ISA_LEVEL == 2
+# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V2
+#elif MINIMUM_X86_ISA_LEVEL == 3
+# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V3
+#elif MINIMUM_X86_ISA_LEVEL == 4
+# define ISA_DEFAULT_IMPL DEFAULT_IMPL_V4
+#else
+# error "Unsupport ISA Level!"
+#endif
+
+#include ISA_DEFAULT_IMPL