commit e941e0ae80626b7661c1db8953a673cafd3b8b19
Author: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Date: Fri Apr 30 18:12:08 2021 -0300
powerpc64le: Optimize memcpy for POWER10
This implementation is based on __memcpy_power8_cached and integrates
suggestions from Anton Blanchard.
It benefits from loads and stores with length for short lengths and for
tail code, simplifying the code.
All unaligned memory accesses use instructions that do not generate
alignment interrupts on POWER10, making it safe to use on
caching-inhibited memory.
The main loop has also been modified in order to increase instruction
throughput by reducing the dependency on updates from previous iterations.
On average, this implementation provides around 30% improvement when
compared to __memcpy_power7 and 10% improvement in comparison to
__memcpy_power8_cached.
diff --git a/sysdeps/powerpc/powerpc64/le/power10/memcpy.S b/sysdeps/powerpc/powerpc64/le/power10/memcpy.S
new file mode 100644
index 0000000000000000..ad1414db4a3a8b9f
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/le/power10/memcpy.S
@@ -0,0 +1,198 @@
+/* Optimized memcpy implementation for POWER10.
+ Copyright (C) 2021 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+
+#ifndef MEMCPY
+# define MEMCPY memcpy
+#endif
+
+/* __ptr_t [r3] memcpy (__ptr_t dst [r3], __ptr_t src [r4], size_t len [r5]);
+ Returns 'dst'. */
+
+ .machine power9
+ENTRY_TOCLESS (MEMCPY, 5)
+ CALL_MCOUNT 3
+
+ /* Copy up to 16 bytes. */
+ sldi r6,r5,56 /* Prepare [l|st]xvl counter. */
+ lxvl v10,r4,r6
+ stxvl v10,r3,r6
+ subic. r6,r5,16 /* Return if len <= 16. */
+ blelr
+
+ /* If len >= 256, assume nothing got copied before and copy
+ again. This might cause issues with overlapped memory, but memcpy
+ is not expected to treat overlapped memory. */
+ cmpdi r5,256
+ bge L(copy_ge_256)
+ /* 16 < len < 256 and the first 16 bytes have already been copied. */
+ addi r10,r3,16 /* Keep r3 intact as return value. */
+ addi r4,r4,16
+ subi r5,r5,16
+ b L(copy_lt_256) /* Avoid the main loop if len < 256. */
+
+ .p2align 5
+L(copy_ge_256):
+ mr r10,r3 /* Keep r3 intact as return value. */
+ /* Align dst to 16 bytes. */
+ andi. r9,r10,0xf
+ beq L(dst_is_align_16)
+ lxv v10,0(r4)
+ subfic r12,r9,16
+ subf r5,r12,r5
+ add r4,r4,r12
+ stxv v10,0(r3)
+ add r10,r3,r12
+
+L(dst_is_align_16):
+ srdi r9,r5,7 /* Divide by 128. */
+ mtctr r9
+ addi r6,r4,64
+ addi r7,r10,64
+
+
+ /* Main loop, copy 128 bytes per iteration.
+ Use r6=src+64 and r7=dest+64 in order to reduce the dependency on
+ r4 and r10. */
+ .p2align 5
+L(copy_128):
+
+ lxv v10, 0(r4)
+ lxv v11, 16(r4)
+ lxv v12, 32(r4)
+ lxv v13, 48(r4)
+
+ addi r4,r4,128
+
+ stxv v10, 0(r10)
+ stxv v11, 16(r10)
+ stxv v12, 32(r10)
+ stxv v13, 48(r10)
+
+ addi r10,r10,128
+
+ lxv v10, 0(r6)
+ lxv v11, 16(r6)
+ lxv v12, 32(r6)
+ lxv v13, 48(r6)
+
+ addi r6,r6,128
+
+ stxv v10, 0(r7)
+ stxv v11, 16(r7)
+ stxv v12, 32(r7)
+ stxv v13, 48(r7)
+
+ addi r7,r7,128
+
+ bdnz L(copy_128)
+
+ clrldi. r5,r5,64-7 /* Have we copied everything? */
+ beqlr
+
+ .p2align 5
+L(copy_lt_256):
+ cmpdi r5,16
+ ble L(copy_le_16)
+ srdi. r9,r5,5 /* Divide by 32. */
+ beq L(copy_lt_32)
+ mtctr r9
+ /* Use r6=src+32, r7=dest+32, r8=src+64, r9=dest+64 in order to reduce
+ the dependency on r4 and r10. */
+ addi r6,r4,32
+ addi r7,r10,32
+ addi r8,r4,64
+ addi r9,r10,64
+
+ .p2align 5
+ /* Copy 32 bytes at a time, unaligned.
+ The loop is unrolled 3 times in order to reduce the dependency on
+ r4 and r10, copying up-to 96 bytes per iteration. */
+L(copy_32):
+ lxv v10, 0(r4)
+ lxv v11, 16(r4)
+ stxv v10, 0(r10)
+ stxv v11, 16(r10)
+ bdz L(end_copy_32a)
+ addi r4,r4,96
+ addi r10,r10,96
+
+ lxv v10, 0(r6)
+ lxv v11, 16(r6)
+ addi r6,r6,96
+ stxv v10, 0(r7)
+ stxv v11, 16(r7)
+ bdz L(end_copy_32b)
+ addi r7,r7,96
+
+ lxv v12, 0(r8)
+ lxv v13, 16(r8)
+ addi r8,r8,96
+ stxv v12, 0(r9)
+ stxv v13, 16(r9)
+ addi r9,r9,96
+ bdnz L(copy_32)
+
+ clrldi. r5,r5,64-5 /* Have we copied everything? */
+ beqlr
+ cmpdi r5,16
+ ble L(copy_le_16)
+ b L(copy_lt_32)
+
+ .p2align 5
+L(end_copy_32a):
+ clrldi. r5,r5,64-5 /* Have we copied everything? */
+ beqlr
+ /* 32 bytes have been copied since the last update of r4 and r10. */
+ addi r4,r4,32
+ addi r10,r10,32
+ cmpdi r5,16
+ ble L(copy_le_16)
+ b L(copy_lt_32)
+
+ .p2align 5
+L(end_copy_32b):
+ clrldi. r5,r5,64-5 /* Have we copied everything? */
+ beqlr
+ /* The last iteration of the loop copied 64 bytes. Update r4 and r10
+ accordingly. */
+ addi r4,r4,-32
+ addi r10,r10,-32
+ cmpdi r5,16
+ ble L(copy_le_16)
+
+ .p2align 5
+L(copy_lt_32):
+ lxv v10, 0(r4)
+ stxv v10, 0(r10)
+ addi r4,r4,16
+ addi r10,r10,16
+ subi r5,r5,16
+
+ .p2align 5
+L(copy_le_16):
+ sldi r6,r5,56
+ lxvl v10,r4,r6
+ stxvl v10,r10,r6
+ blr
+
+
+END_GEN_TB (MEMCPY,TB_TOCLESS)
+libc_hidden_builtin_def (memcpy)
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 66f8c6ace9824d4a..2e3c8f2e8a81cda4 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -32,7 +32,7 @@ sysdep_routines += memcpy-power8-cached memcpy-power7 memcpy-a2 memcpy-power6 \
strncase-power8
ifneq (,$(filter %le,$(config-machine)))
-sysdep_routines += memmove-power10 \
+sysdep_routines += memcpy-power10 memmove-power10 \
strcmp-power9 strncmp-power9 strcpy-power9 stpcpy-power9 \
rawmemchr-power9 strlen-power9 strncpy-power9 stpncpy-power9 \
strlen-power10
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index 4ce04bc51574cca1..9d5a14e480c02171 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -51,6 +51,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
#ifdef SHARED
/* Support sysdeps/powerpc/powerpc64/multiarch/memcpy.c. */
IFUNC_IMPL (i, name, memcpy,
+#ifdef __LITTLE_ENDIAN__
+ IFUNC_IMPL_ADD (array, i, memcpy,
+ hwcap2 & PPC_FEATURE2_ARCH_3_1
+ && hwcap & PPC_FEATURE_HAS_VSX,
+ __memcpy_power10)
+#endif
IFUNC_IMPL_ADD (array, i, memcpy, hwcap2 & PPC_FEATURE2_ARCH_2_07,
__memcpy_power8_cached)
IFUNC_IMPL_ADD (array, i, memcpy, hwcap & PPC_FEATURE_HAS_VSX,
diff --git a/sysdeps/powerpc/powerpc64/multiarch/memcpy-power10.S b/sysdeps/powerpc/powerpc64/multiarch/memcpy-power10.S
new file mode 100644
index 0000000000000000..70e0fc3ed610cdc3
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/memcpy-power10.S
@@ -0,0 +1,26 @@
+/* Optimized memcpy implementation for POWER10.
+ Copyright (C) 2021 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/>. */
+
+#if defined __LITTLE_ENDIAN__ && IS_IN (libc)
+#define MEMCPY __memcpy_power10
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/le/power10/memcpy.S>
+#endif
diff --git a/sysdeps/powerpc/powerpc64/multiarch/memcpy.c b/sysdeps/powerpc/powerpc64/multiarch/memcpy.c
index 44dea594f3770673..be0e47f32dde2ccf 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/memcpy.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/memcpy.c
@@ -36,8 +36,15 @@ extern __typeof (__redirect_memcpy) __memcpy_power6 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_a2 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_power7 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_power8_cached attribute_hidden;
+# if defined __LITTLE_ENDIAN__
+extern __typeof (__redirect_memcpy) __memcpy_power10 attribute_hidden;
+# endif
libc_ifunc (__libc_memcpy,
+# if defined __LITTLE_ENDIAN__
+ (hwcap2 & PPC_FEATURE2_ARCH_3_1 && hwcap & PPC_FEATURE_HAS_VSX)
+ ? __memcpy_power10 :
+# endif
((hwcap2 & PPC_FEATURE2_ARCH_2_07) && use_cached_memopt)
? __memcpy_power8_cached :
(hwcap & PPC_FEATURE_HAS_VSX)