This patch adds an optimized POWER8 strcpy using unaligned accesses.
For strings up to 16 bytes the implementation first calculate the
string size, like strlen, and issues a memcpy. For larger strings,
source is first aligned to 16 bytes and then tested over a loop that
reads 16 bytes am combine the cmpb results for speedup. Special case is
added for page cross reads.
It shows 30%-60% improvement over the optimized POWER7 one that uses
only aligned accesses.
+2015-01-13 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
+
+ * sysdeps/powerpc/powerpc64/multiarch/Makefile [sysdep_routines]: Add
+ strcpy-power8 and stpcpy-power8 objects.
+ * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+ (__libc_ifunc_impl_list): Add __strcpy_power8 and __stpcpy_power8
+ implementations.
+ * sysdeps/powerpc/powerpc64/multiarch/stpcpy-power8.S: New file:
+ multiarch stpcpy implementation for POWER8.
+ * sysdeps/powerpc/powerpc64/multiarch/strcpy-power8.S: New file;
+ multiarch strcpy implementation for POWER8.
+ * sysdeps/powerpc/powerpc64/multiarch/strcpy.c (strcpy): Add
+ __strcpy_power8 function.
+ * sysdeps/powerpc/powerpc64/power8/stpcpy.S: New file: optimized
+ stpcpy for POWER8.
+ * sysdeps/powerpc/powerpc64/power8/strcpy.S: New file: optimized
+ strcpy for POWER8.
+ * NEWS: Update.
+
2015-01-13 Leonhard Holz <leonhard.holz@web.de>
[BZ #16009]
17744, 17745, 17746, 17747, 17748, 17775, 17777, 17780, 17781, 17782,
17791, 17793, 17796, 17797, 17803, 17806, 17834
+* Optimized strcpy and stpcpy implementations for powerpc64/powerpc64le.
+
* Added support for TSX lock elision of pthread mutexes on powerpc32, powerpc64
and powerpc64le. This may improve lock scaling of existing programs on
HTM capable systems. The lock elision code is only enabled with
wcschr-power6 wcschr-ppc64 wcsrchr-power7 wcsrchr-power6 \
wcsrchr-ppc64 wcscpy-power7 wcscpy-power6 wcscpy-ppc64 \
wordcopy-power7 wordcopy-power6 wordcopy-ppc64 \
- strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
+ strcpy-power8 strcpy-power7 strcpy-ppc64 stpcpy-power8 \
+ stpcpy-power7 stpcpy-ppc64 \
strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
strncpy-power7 strncpy-ppc64 \
stpncpy-power7 stpncpy-ppc64 strcmp-power7 strcmp-ppc64 \
/* Support sysdeps/powerpc/powerpc64/multiarch/strcpy.c. */
IFUNC_IMPL (i, name, strcpy,
+ IFUNC_IMPL_ADD (array, i, strcpy, hwcap2 & PPC_FEATURE2_ARCH_2_07,
+ __strcpy_power8)
IFUNC_IMPL_ADD (array, i, strcpy, hwcap & PPC_FEATURE_HAS_VSX,
__strcpy_power7)
IFUNC_IMPL_ADD (array, i, strcpy, 1,
/* Support sysdeps/powerpc/powerpc64/multiarch/stpcpy.c. */
IFUNC_IMPL (i, name, stpcpy,
+ IFUNC_IMPL_ADD (array, i, stpcpy, hwcap2 & PPC_FEATURE2_ARCH_2_07,
+ __stpcpy_power8)
IFUNC_IMPL_ADD (array, i, stpcpy, hwcap & PPC_FEATURE_HAS_VSX,
__stpcpy_power7)
IFUNC_IMPL_ADD (array, i, stpcpy, 1,
--- /dev/null
+/* Optimized stpcpy implementation for POWER8/PPC64.
+ Copyright (C) 2015 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>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__stpcpy_power8) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__stpcpy_power8): \
+ cfi_startproc; \
+ LOCALENTRY(__stpcpy_power8)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__stpcpy_power8) \
+ END_2(__stpcpy_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/stpcpy.S>
--- /dev/null
+/* Optimized strcpy implementation for POWER8/PPC64.
+ Copyright (C) 2015 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>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__strcpy_power8) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strcpy_power8): \
+ cfi_startproc; \
+ LOCALENTRY(__strcpy_power8)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strcpy_power8) \
+ END_2(__strcpy_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/strcpy.S>
extern __typeof (strcpy) __strcpy_ppc attribute_hidden;
extern __typeof (strcpy) __strcpy_power7 attribute_hidden;
+extern __typeof (strcpy) __strcpy_power8 attribute_hidden;
libc_ifunc (strcpy,
- (hwcap & PPC_FEATURE_HAS_VSX)
- ? __strcpy_power7
+ (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+ ? __strcpy_power8 :
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __strcpy_power7
: __strcpy_ppc);
#endif
--- /dev/null
+/* Optimized stpcpy implementation for PowerPC64/POWER8.
+ Copyright (C) 2015 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/>. */
+
+#define USE_AS_STPCPY
+#include <sysdeps/powerpc/powerpc64/power8/strcpy.S>
+
+weak_alias (__stpcpy, stpcpy)
+libc_hidden_def (__stpcpy)
+libc_hidden_builtin_def (stpcpy)
--- /dev/null
+/* Optimized strcpy/stpcpy implementation for PowerPC64/POWER8.
+ Copyright (C) 2015 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>
+
+#ifdef USE_AS_STPCPY
+# define FUNC_NAME __stpcpy
+#else
+# define FUNC_NAME strcpy
+#endif
+
+/* Implements the function
+
+ char * [r3] strcpy (char *dest [r3], const char *src [r4])
+
+ or
+
+ char * [r3] stpcpy (char *dest [r3], const char *src [r4])
+
+ if USE_AS_STPCPY is defined.
+
+ The implementation uses unaligned doubleword access to avoid specialized
+ code paths depending of data alignment. Although recent powerpc64 uses
+ 64K as default, the page cross handling assumes minimum page size of
+ 4k. */
+
+ .machine power7
+EALIGN (FUNC_NAME, 4, 0)
+ li r0,0 /* Doubleword with null chars to use
+ with cmpb. */
+
+ /* Check if the [src]+15 will cross a 4K page by checking if the bit
+ indicating the page size changes. Basically:
+
+ uint64_t srcin = (uint64_t)src;
+ uint64_t ob = srcin & 4096UL;
+ uint64_t nb = (srcin+15UL) & 4096UL;
+ if (ob ^ nb)
+ goto pagecross; */
+
+ addi r9,r4,15
+ xor r9,r9,r4
+ rlwinm. r9,r9,0,19,19
+ bne L(pagecross)
+
+ /* For short string (less than 16 bytes), just calculate its size as
+ strlen and issues a memcpy if null is found. */
+ mr r7,r4
+ ld r12,0(r7) /* Load doubleword from memory. */
+ cmpb r10,r12,r0 /* Check for null bytes in DWORD1. */
+ cmpdi cr7,r10,0 /* If r10 == 0, no null's have been found. */
+ bne cr7,L(done)
+
+ ldu r8,8(r7)
+ cmpb r10,r8,r0
+ cmpdi cr7,r10,0
+ bne cr7,L(done)
+
+ b L(loop_before)
+
+ .align 4
+L(pagecross):
+ clrrdi r7,r4,3 /* Align the address to doubleword boundary. */
+ rlwinm r6,r4,3,26,28 /* Calculate padding. */
+ li r5,-1 /* MASK = 0xffffffffffffffff. */
+ ld r12,0(r7) /* Load doubleword from memory. */
+#ifdef __LITTLE_ENDIAN__
+ sld r5,r5,r6
+#else
+ srd r5,r5,r6 /* MASK = MASK >> padding. */
+#endif
+ orc r9,r12,r5 /* Mask bits that are not part of the string. */
+ cmpb r10,r9,r0 /* Check for null bytes in DWORD1. */
+ cmpdi cr7,r10,0 /* If r10 == 0, no null's have been found. */
+ bne cr7,L(done)
+
+ ldu r6,8(r7)
+ cmpb r10,r6,r0
+ cmpdi cr7,r10,0
+ bne cr7,L(done)
+
+ ld r12,0(r7)
+ cmpb r10,r12,r0
+ cmpdi cr7,r10,0
+ bne cr7,L(done)
+
+ ldu r6,8(r7)
+ cmpb r10,r6,r0
+ cmpdi cr7,r10,0
+ bne cr7,L(done)
+
+ /* We checked for 24 - x bytes, with x being the source alignment
+ (0 <= x <= 16), and no zero has been found. Start the loop
+ copy with doubleword aligned address. */
+ mr r7,r4
+ ld r12, 0(r7)
+ ldu r8, 8(r7)
+
+L(loop_before):
+ /* Save the two doublewords readed from source and align the source
+ to 16 bytes for the loop. */
+ mr r11,r3
+ std r12,0(r11)
+ std r8,8(r11)
+ addi r11,r11,16
+ rldicl r9,r4,0,60
+ subf r7,r9,r7
+ subf r11,r9,r11
+ b L(loop_start)
+
+ .align 5
+L(loop):
+ std r12, 0(r11)
+ std r6, 8(r11)
+ addi r11,r11,16
+L(loop_start):
+ /* Load two doublewords, compare and merge in a
+ single register for speed. This is an attempt
+ to speed up the null-checking process for bigger strings. */
+
+ ld r12, 8(r7)
+ ldu r6, 16(r7)
+ cmpb r10,r12,r0
+ cmpb r9,r6,r0
+ or r8,r9,r10 /* Merge everything in one doubleword. */
+ cmpdi cr7,r8,0
+ beq cr7,L(loop)
+
+
+ /* OK, one (or both) of the doublewords contains a null byte. Check
+ the first doubleword and decrement the address in case the first
+ doubleword really contains a null byte. */
+
+ addi r4,r7,-8
+ cmpdi cr6,r10,0
+ addi r7,r7,-8
+ bne cr6,L(done2)
+
+ /* The null byte must be in the second doubleword. Adjust the address
+ again and move the result of cmpb to r10 so we can calculate the
+ length. */
+
+ mr r10,r9
+ addi r7,r7,8
+ b L(done2)
+
+ /* r10 has the output of the cmpb instruction, that is, it contains
+ 0xff in the same position as the null byte in the original
+ doubleword from the string. Use that to calculate the length. */
+L(done):
+ mr r11,r3
+L(done2):
+#ifdef __LITTLE_ENDIAN__
+ addi r9, r10, -1 /* Form a mask from trailing zeros. */
+ andc r9, r9, r10
+ popcntd r6, r9 /* Count the bits in the mask. */
+#else
+ cntlzd r6,r10 /* Count leading zeros before the match. */
+#endif
+ subf r5,r4,r7
+ srdi r6,r6,3 /* Convert leading/trailing zeros to bytes. */
+ add r8,r5,r6 /* Compute final length. */
+#ifdef USE_AS_STPCPY
+ /* stpcpy returns the dest address plus the size not counting the
+ final '\0'. */
+ add r3,r11,r8
+#endif
+ addi r8,r8,1 /* Final '/0'. */
+
+ cmpldi cr6,r8,8
+ mtocrf 0x01,r8
+ ble cr6,L(copy_LE_8)
+
+ cmpldi cr1,r8,16
+ blt cr1,8f
+
+ /* Handle copies of 0~31 bytes. */
+ .align 4
+L(copy_LT_32):
+ /* At least 6 bytes to go. */
+ blt cr1,8f
+
+ /* Copy 16 bytes. */
+ ld r6,0(r4)
+ ld r8,8(r4)
+ addi r4,r4,16
+ std r6,0(r11)
+ std r8,8(r11)
+ addi r11,r11,16
+8: /* Copy 8 bytes. */
+ bf 28,L(tail4)
+ ld r6,0(r4)
+ addi r4,r4,8
+ std r6,0(r11)
+ addi r11,r11,8
+
+ .align 4
+/* Copies 4~7 bytes. */
+L(tail4):
+ bf 29,L(tail2)
+ lwz r6,0(r4)
+ stw r6,0(r11)
+ bf 30,L(tail5)
+ lhz r7,4(r4)
+ sth r7,4(r11)
+ bflr 31
+ lbz r8,6(r4)
+ stb r8,6(r11)
+ blr
+
+ .align 4
+/* Copies 2~3 bytes. */
+L(tail2):
+ bf 30,1f
+ lhz r6,0(r4)
+ sth r6,0(r11)
+ bflr 31
+ lbz r7,2(r4)
+ stb r7,2(r11)
+ blr
+
+ .align 4
+L(tail5):
+ bf 31,1f
+ lbz r6,4(r4)
+ stb r6,4(r11)
+ blr
+
+ .align 4
+1:
+ bflr 31
+ lbz r6,0(r4)
+ stb r6,0(r11)
+ blr
+
+/* Handles copies of 0~8 bytes. */
+ .align 4
+L(copy_LE_8):
+ bne cr6,L(tail4)
+ ld r6,0(r4)
+ std r6,0(r11)
+ blr
+END (FUNC_NAME)
+
+#ifndef USE_AS_STPCPY
+libc_hidden_builtin_def (strcpy)
+#endif
projects / platform / upstream / glibc.git / commitdiff