From 3d5101ddb7a4004459ca3f894caa47cfe9208be6 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 5 Mar 2021 07:15:03 -0800
Subject: [PATCH] x86-64: Add memset family functions with 256-bit EVEX
Update ifunc-memset.h/ifunc-wmemset.h to select the function optimized
with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM
abort with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at
function exit.
(cherry picked from commit 1b968b6b9b3aac702ac2f133e0dd16cfdbb415ee)
---
sysdeps/x86_64/multiarch/Makefile | 1 +
sysdeps/x86_64/multiarch/ifunc-impl-list.c | 22 +++++++++++++++++
sysdeps/x86_64/multiarch/ifunc-memset.h | 24 +++++++++++++++----
sysdeps/x86_64/multiarch/ifunc-wmemset.h | 13 ++++++----
.../multiarch/memset-evex-unaligned-erms.S | 24 +++++++++++++++++++
.../multiarch/memset-vec-unaligned-erms.S | 20 +++++++++++-----
6 files changed, 90 insertions(+), 14 deletions(-)
create mode 100644 sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
index 4563fc56..1cc0a10e 100644
--- a/sysdeps/x86_64/multiarch/Makefile
+++ b/sysdeps/x86_64/multiarch/Makefile
@@ -43,6 +43,7 @@ sysdep_routines += strncat-c stpncpy-c strncpy-c \
memchr-evex \
memmove-evex-unaligned-erms \
memrchr-evex \
+ memset-evex-unaligned-erms \
rawmemchr-evex \
stpcpy-evex \
stpncpy-evex \
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index 6bd3abfc..7cf83485 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -160,6 +160,14 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, __memset_chk,
CPU_FEATURE_USABLE (AVX2),
__memset_chk_avx2_unaligned_erms)
+ IFUNC_IMPL_ADD (array, i, __memset_chk,
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
+ __memset_chk_evex_unaligned)
+ IFUNC_IMPL_ADD (array, i, __memset_chk,
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
+ __memset_chk_evex_unaligned_erms)
IFUNC_IMPL_ADD (array, i, __memset_chk,
CPU_FEATURE_USABLE (AVX512F),
__memset_chk_avx512_unaligned_erms)
@@ -185,6 +193,14 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, memset,
CPU_FEATURE_USABLE (AVX2),
__memset_avx2_unaligned_erms)
+ IFUNC_IMPL_ADD (array, i, memset,
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
+ __memset_evex_unaligned)
+ IFUNC_IMPL_ADD (array, i, memset,
+ (CPU_FEATURE_USABLE (AVX512VL)
+ && CPU_FEATURE_USABLE (AVX512BW)),
+ __memset_evex_unaligned_erms)
IFUNC_IMPL_ADD (array, i, memset,
CPU_FEATURE_USABLE (AVX512F),
__memset_avx512_unaligned_erms)
@@ -555,6 +571,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, wmemset,
CPU_FEATURE_USABLE (AVX2),
__wmemset_avx2_unaligned)
+ IFUNC_IMPL_ADD (array, i, wmemset,
+ CPU_FEATURE_USABLE (AVX512VL),
+ __wmemset_evex_unaligned)
IFUNC_IMPL_ADD (array, i, wmemset,
CPU_FEATURE_USABLE (AVX512F),
__wmemset_avx512_unaligned))
@@ -723,6 +742,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, __wmemset_chk,
CPU_FEATURE_USABLE (AVX2),
__wmemset_chk_avx2_unaligned)
+ IFUNC_IMPL_ADD (array, i, __wmemset_chk,
+ CPU_FEATURE_USABLE (AVX512VL),
+ __wmemset_chk_evex_unaligned)
IFUNC_IMPL_ADD (array, i, __wmemset_chk,
CPU_FEATURE_USABLE (AVX512F),
__wmemset_chk_avx512_unaligned))
diff --git a/sysdeps/x86_64/multiarch/ifunc-memset.h b/sysdeps/x86_64/multiarch/ifunc-memset.h
index 708bd72e..6f31f4dc 100644
--- a/sysdeps/x86_64/multiarch/ifunc-memset.h
+++ b/sysdeps/x86_64/multiarch/ifunc-memset.h
@@ -27,6 +27,10 @@ extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned_erms)
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned) attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_erms)
attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned)
+ attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned_erms)
+ attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned)
attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned_erms)
@@ -56,10 +60,22 @@ IFUNC_SELECTOR (void)
if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))
{
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE (avx2_unaligned_erms);
- else
- return OPTIMIZE (avx2_unaligned);
+ 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 (evex_unaligned_erms);
+
+ return OPTIMIZE (evex_unaligned);
+ }
+
+ if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
+ {
+ if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
+ return OPTIMIZE (avx2_unaligned_erms);
+
+ return OPTIMIZE (avx2_unaligned);
+ }
}
if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
diff --git a/sysdeps/x86_64/multiarch/ifunc-wmemset.h b/sysdeps/x86_64/multiarch/ifunc-wmemset.h
index eb242210..9290c4bf 100644
--- a/sysdeps/x86_64/multiarch/ifunc-wmemset.h
+++ b/sysdeps/x86_64/multiarch/ifunc-wmemset.h
@@ -20,6 +20,7 @@
extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned) attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned) attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned) attribute_hidden;
static inline void *
@@ -27,14 +28,18 @@ IFUNC_SELECTOR (void)
{
const struct cpu_features* cpu_features = __get_cpu_features ();
- if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER)
- && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
+ 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_AVX512)
+ && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
return OPTIMIZE (avx512_unaligned);
- else
+
+ if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
+ return OPTIMIZE (evex_unaligned);
+
+ if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
return OPTIMIZE (avx2_unaligned);
}
diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
new file mode 100644
index 00000000..ae0a4d6e
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
@@ -0,0 +1,24 @@
+#if IS_IN (libc)
+# define VEC_SIZE 32
+# define XMM0 xmm16
+# define YMM0 ymm16
+# define VEC0 ymm16
+# define VEC(i) VEC##i
+# define VMOVU vmovdqu64
+# define VMOVA vmovdqa64
+# define VZEROUPPER
+
+# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
+ movq r, %rax; \
+ vpbroadcastb d, %VEC0
+
+# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
+ movq r, %rax; \
+ vpbroadcastd d, %VEC0
+
+# define SECTION(p) p##.evex
+# define MEMSET_SYMBOL(p,s) p##_evex_##s
+# define WMEMSET_SYMBOL(p,s) p##_evex_##s
+
+# include "memset-vec-unaligned-erms.S"
+#endif
diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
index 9a0fd818..71e91a8f 100644
--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
@@ -34,6 +34,14 @@
# define WMEMSET_CHK_SYMBOL(p,s) WMEMSET_SYMBOL(p, s)
#endif
+#ifndef XMM0
+# define XMM0 xmm0
+#endif
+
+#ifndef YMM0
+# define YMM0 ymm0
+#endif
+
#ifndef VZEROUPPER
# if VEC_SIZE > 16
# define VZEROUPPER vzeroupper
@@ -67,7 +75,7 @@
ENTRY (__bzero)
mov %RDI_LP, %RAX_LP /* Set return value. */
mov %RSI_LP, %RDX_LP /* Set n. */
- pxor %xmm0, %xmm0
+ pxor %XMM0, %XMM0
jmp L(entry_from_bzero)
END (__bzero)
weak_alias (__bzero, bzero)
@@ -223,7 +231,7 @@ L(less_vec):
cmpb $16, %dl
jae L(between_16_31)
# endif
- MOVQ %xmm0, %rcx
+ MOVQ %XMM0, %rcx
cmpb $8, %dl
jae L(between_8_15)
cmpb $4, %dl
@@ -238,16 +246,16 @@ L(less_vec):
# if VEC_SIZE > 32
/* From 32 to 63. No branch when size == 32. */
L(between_32_63):
- vmovdqu %ymm0, -32(%rdi,%rdx)
- vmovdqu %ymm0, (%rdi)
+ VMOVU %YMM0, -32(%rdi,%rdx)
+ VMOVU %YMM0, (%rdi)
VZEROUPPER
ret
# endif
# if VEC_SIZE > 16
/* From 16 to 31. No branch when size == 16. */
L(between_16_31):
- vmovdqu %xmm0, -16(%rdi,%rdx)
- vmovdqu %xmm0, (%rdi)
+ VMOVU %XMM0, -16(%rdi,%rdx)
+ VMOVU %XMM0, (%rdi)
VZEROUPPER
ret
# endif
--
GitLab