17744, 17745, 17746, 17747, 17748, 17775, 17777, 17780, 17781, 17782,
17791, 17793, 17796, 17797, 17803, 17806, 17834
-* Optimized strcpy, stpcpy, strncpy, stpncpy implementations for
+* Optimized strcpy, stpcpy, strncpy, stpncpy, and strcmp implementations for
powerpc64/powerpc64le.
+ Implemented by Adhemerval Zanella (IBM).
* Added support for TSX lock elision of pthread mutexes on powerpc32, powerpc64
and powerpc64le. This may improve lock scaling of existing programs on
--- /dev/null
+/* Optimized strcmp 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(__strcmp_power8) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strcmp_power8): \
+ cfi_startproc; \
+ LOCALENTRY(__strcmp_power8)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strcmp_power8) \
+ END_2(__strcmp_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/strcmp.S>
--- /dev/null
+/* Optimized strcmp 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>
+
+/* Implements the function
+
+ size_t [r3] strcmp (const char *s1 [r3], const char *s2 [r4])
+
+ 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. */
+
+EALIGN (strcmp, 4, 0)
+ li r0,0
+
+ /* Check if [s1]+32 or [s2]+32 will cross a 4K page boundary using
+ the code:
+
+ (((size_t) s1) % PAGE_SIZE > (PAGE_SIZE - ITER_SIZE))
+
+ with PAGE_SIZE being 4096 and ITER_SIZE begin 32. */
+
+ rldicl r7,r3,0,52
+ rldicl r9,r4,0,52
+ cmpldi cr7,r7,4096-32
+ bgt cr7,L(pagecross_check)
+ cmpldi cr5,r9,4096-32
+ bgt cr5,L(pagecross_check)
+
+ /* For short string up to 32 bytes, load both s1 and s2 using
+ unaligned dwords and compare. */
+ ld r8,0(r3)
+ ld r10,0(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ ld r8,8(r3)
+ ld r10,8(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ ld r8,16(r3)
+ ld r10,16(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ ld r8,24(r3)
+ ld r10,24(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ addi r7,r3,32
+ addi r4,r4,32
+
+L(align_8b):
+ /* Now it has checked for first 32 bytes, align source1 to doubleword
+ and adjust source2 address. */
+ rldicl r9,r7,0,61 /* source1 alignment to doubleword */
+ subf r4,r9,r4 /* Adjust source2 address based on source1
+ alignment. */
+ rldicr r7,r7,0,60 /* Align source1 to doubleword. */
+
+ /* At this point, source1 alignment is 0 and source2 alignment is
+ between 0 and 7. Check is source2 alignment is 0, meaning both
+ sources have the same alignment. */
+ andi. r9,r4,0x7
+ bne cr0,L(loop_diff_align)
+
+ /* If both source1 and source2 are doubleword aligned, there is no
+ need for page boundary cross checks. */
+
+ ld r8,0(r7)
+ ld r10,0(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ .align 4
+L(loop_equal_align):
+ ld r8,8(r7)
+ ld r10,8(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ ld r8,16(r7)
+ ld r10,16(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ ldu r8,24(r7)
+ ldu r10,24(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+
+ b L(loop_equal_align)
+
+ /* A zero byte was found in r8 (s1 dword), r9 contains the cmpb
+ result and r10 the dword from s2. To code isolate the byte
+ up to end (including the '\0'), masking with 0xFF the remaining
+ ones:
+
+ #if __LITTLE_ENDIAN__
+ (__builtin_ffsl (x) - 1) = counting trailing zero bits
+ r9 = (__builtin_ffsl (r9) - 1) + 8;
+ r9 = -1UL << r9
+ #else
+ r9 = __builtin_clzl (r9) + 8;
+ r9 = -1UL >> r9
+ #endif
+ r8 = r8 | r9
+ r10 = r10 | r9 */
+
+#ifdef __LITTLE_ENDIAN__
+ nor r9,r9,r9
+L(different_nocmpb):
+ neg r3,r9
+ and r9,r9,r3
+ cntlzd r9,r9
+ subfic r9,r9,63
+#else
+ not r9,r9
+L(different_nocmpb):
+ cntlzd r9,r9
+ subfic r9,r9,56
+#endif
+ srd r3,r8,r9
+ srd r10,r10,r9
+ rldicl r10,r10,0,56
+ rldicl r3,r3,0,56
+ subf r3,r10,r3
+ extsw r3,r3
+ blr
+
+ .align 4
+L(pagecross_check):
+ subfic r9,r9,4096
+ subfic r7,r7,4096
+ cmpld cr7,r7,r9
+ bge cr7,L(pagecross)
+ mr r7,r9
+
+ /* If unaligned 16 bytes reads across a 4K page boundary, it uses
+ a simple byte a byte comparison until the page alignment for s1
+ is reached. */
+L(pagecross):
+ add r7,r3,r7
+ subf r9,r3,r7
+ mtctr r9
+
+ .align 4
+L(pagecross_loop):
+ /* Loads a byte from s1 and s2, compare if *s1 is equal to *s2
+ and if *s1 is '\0'. */
+ lbz r9,0(r3)
+ lbz r10,0(r4)
+ addi r3,r3,1
+ addi r4,r4,1
+ cmplw cr7,r9,r10
+ cmpdi cr5,r9,r0
+ bne cr7,L(pagecross_ne)
+ beq cr5,L(pagecross_nullfound)
+ bdnz L(pagecross_loop)
+ b L(align_8b)
+
+ .align 4
+ /* The unaligned read of source2 will cross a 4K page boundary,
+ and the different byte or NULL maybe be in the remaining page
+ bytes. Since it can not use the unaligned load, the algorithm
+ reads and compares 8 bytes to keep source1 doubleword aligned. */
+L(check_source2_byte):
+ li r9,8
+ mtctr r9
+
+ .align 4
+L(check_source2_byte_loop):
+ lbz r9,0(r7)
+ lbz r10,0(r4)
+ addi r7,r7,1
+ addi r4,r4,1
+ cmplw cr7,r9,10
+ cmpdi r5,r9,0
+ bne cr7,L(pagecross_ne)
+ beq cr5,L(pagecross_nullfound)
+ bdnz L(check_source2_byte_loop)
+
+ /* If source2 is unaligned to doubleword, the code needs to check
+ on each interation if the unaligned doubleword access will cross
+ a 4k page boundary. */
+ .align 5
+L(loop_unaligned):
+ ld r8,0(r7)
+ ld r10,0(r4)
+ cmpb r12,r8,r0
+ cmpb r11,r8,r10
+ orc. r9,r12,r11
+ bne cr0,L(different_nocmpb)
+ addi r7,r7,8
+ addi r4,r4,8
+
+L(loop_diff_align):
+ /* Check if [src2]+8 cross a 4k page boundary:
+
+ srcin2 % PAGE_SIZE > (PAGE_SIZE - 8)
+
+ with PAGE_SIZE being 4096. */
+ rldicl r9,r4,0,52
+ cmpldi cr7,r9,4088
+ ble cr7,L(loop_unaligned)
+ b L(check_source2_byte)
+
+ .align 4
+L(pagecross_ne):
+ extsw r3,r9
+ mr r9,r10
+L(pagecross_retdiff):
+ subf r9,r9,r3
+ extsw r3,r9
+ blr
+
+ .align 4
+L(pagecross_nullfound):
+ li r3,0
+ b L(pagecross_retdiff)
+END (strcmp)
+libc_hidden_builtin_def (strcmp)
projects / thirdparty / glibc.git / commitdiff
