From df380c9a1a74df30968bacb067ed77e583bd960d Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sun, 7 Mar 2021 09:44:18 -0800
Subject: [PATCH] x86-64: Use ZMM16-ZMM31 in AVX512 memset family functions
Update ifunc-memset.h/ifunc-wmemset.h to select the function optimized
with AVX512 instructions using ZMM16-ZMM31 registers to avoid RTM abort
with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at
function exit.
(cherry picked from commit 4e2d8f352774b56078c34648b14a2412c38384f4)
---
sysdeps/x86_64/multiarch/ifunc-impl-list.c | 14 +++++++++-----
sysdeps/x86_64/multiarch/ifunc-memset.h | 13 ++++++++-----
sysdeps/x86_64/multiarch/ifunc-wmemset.h | 12 ++++++------
.../multiarch/memset-avx512-unaligned-erms.S | 16 ++++++++--------
4 files changed, 31 insertions(+), 24 deletions(-)
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index c1efeec0..d969a156 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -211,10 +211,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
&& CPU_FEATURE_USABLE (AVX512BW)),
__memset_chk_evex_unaligned_erms)
IFUNC_IMPL_ADD (array, i, __memset_chk,
- CPU_FEATURE_USABLE (AVX512F),
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
__memset_chk_avx512_unaligned_erms)
IFUNC_IMPL_ADD (array, i, __memset_chk,
- CPU_FEATURE_USABLE (AVX512F),
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
__memset_chk_avx512_unaligned)
IFUNC_IMPL_ADD (array, i, __memset_chk,
CPU_FEATURE_USABLE (AVX512F),
@@ -252,10 +254,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
&& CPU_FEATURE_USABLE (AVX512BW)),
__memset_evex_unaligned_erms)
IFUNC_IMPL_ADD (array, i, memset,
- CPU_FEATURE_USABLE (AVX512F),
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
__memset_avx512_unaligned_erms)
IFUNC_IMPL_ADD (array, i, memset,
- CPU_FEATURE_USABLE (AVX512F),
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
__memset_avx512_unaligned)
IFUNC_IMPL_ADD (array, i, memset,
CPU_FEATURE_USABLE (AVX512F),
@@ -719,7 +723,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
CPU_FEATURE_USABLE (AVX512VL),
__wmemset_evex_unaligned)
IFUNC_IMPL_ADD (array, i, wmemset,
- CPU_FEATURE_USABLE (AVX512F),
+ CPU_FEATURE_USABLE (AVX512VL),
__wmemset_avx512_unaligned))
#ifdef SHARED
diff --git a/sysdeps/x86_64/multiarch/ifunc-memset.h b/sysdeps/x86_64/multiarch/ifunc-memset.h
index 6f3375cc..19795938 100644
--- a/sysdeps/x86_64/multiarch/ifunc-memset.h
+++ b/sysdeps/x86_64/multiarch/ifunc-memset.h
@@ -53,13 +53,16 @@ IFUNC_SELECTOR (void)
if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
&& !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
{
- if (CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
- return OPTIMIZE (avx512_no_vzeroupper);
+ if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
+ && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
+ {
+ if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
+ return OPTIMIZE (avx512_unaligned_erms);
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE (avx512_unaligned_erms);
+ return OPTIMIZE (avx512_unaligned);
+ }
- return OPTIMIZE (avx512_unaligned);
+ return OPTIMIZE (avx512_no_vzeroupper);
}
if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))
diff --git a/sysdeps/x86_64/multiarch/ifunc-wmemset.h b/sysdeps/x86_64/multiarch/ifunc-wmemset.h
index bdc94c6c..98c5d406 100644
--- a/sysdeps/x86_64/multiarch/ifunc-wmemset.h
+++ b/sysdeps/x86_64/multiarch/ifunc-wmemset.h
@@ -33,13 +33,13 @@ IFUNC_SELECTOR (void)
if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
&& CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
{
- if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
- && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512)
- && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
- return OPTIMIZE (avx512_unaligned);
-
if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
- return OPTIMIZE (evex_unaligned);
+ {
+ if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
+ return OPTIMIZE (avx512_unaligned);
+
+ return OPTIMIZE (evex_unaligned);
+ }
if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
return OPTIMIZE (avx2_unaligned_rtm);
diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
index 0783979c..22e7b187 100644
--- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
@@ -1,22 +1,22 @@
#if IS_IN (libc)
# define VEC_SIZE 64
-# define VEC(i) zmm##i
+# define XMM0 xmm16
+# define YMM0 ymm16
+# define VEC0 zmm16
+# define VEC(i) VEC##i
# define VMOVU vmovdqu64
# define VMOVA vmovdqa64
+# define VZEROUPPER
# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
- vmovd d, %xmm0; \
movq r, %rax; \
- vpbroadcastb %xmm0, %xmm0; \
- vpbroadcastq %xmm0, %zmm0
+ vpbroadcastb d, %VEC0
# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
- vmovd d, %xmm0; \
movq r, %rax; \
- vpbroadcastd %xmm0, %xmm0; \
- vpbroadcastq %xmm0, %zmm0
+ vpbroadcastd d, %VEC0
-# define SECTION(p) p##.avx512
+# define SECTION(p) p##.evex512
# define MEMSET_SYMBOL(p,s) p##_avx512_##s
# define WMEMSET_SYMBOL(p,s) p##_avx512_##s
--
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