diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power8/strncmp.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power8/strncmp.S | 327 |
1 files changed, 0 insertions, 327 deletions
diff --git a/sysdeps/powerpc/powerpc64/power8/strncmp.S b/sysdeps/powerpc/powerpc64/power8/strncmp.S deleted file mode 100644 index 3d8df90538..0000000000 --- a/sysdeps/powerpc/powerpc64/power8/strncmp.S +++ /dev/null @@ -1,327 +0,0 @@ -/* Optimized strncmp implementation for PowerPC64/POWER8. - Copyright (C) 2015-2017 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 STRNCMP -# define STRNCMP strncmp -#endif - -/* Implements the function - - int [r3] strncmp (const char *s1 [r3], const char *s2 [r4], size_t [r5] n) - - 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 (STRNCMP, 4, 0) - /* Check if size is 0. */ - mr. r10,r5 - beq cr0,L(ret0) - - /* Check if [s1]+16 or [s2]+16 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 16. */ - rldicl r8,r3,0,52 - cmpldi cr7,r8,4096-16 - bgt cr7,L(pagecross) - rldicl r9,r4,0,52 - cmpldi cr7,r9,4096-16 - bgt cr7,L(pagecross) - - /* For short string up to 16 bytes, load both s1 and s2 using - unaligned dwords and compare. */ - ld r7,0(r3) - ld r9,0(r4) - li r8,0 - cmpb r8,r7,r8 - cmpb r6,r7,r9 - orc. r8,r8,r6 - bne cr0,L(different1) - - /* If the string compared are equal, but size is less or equal - to 8, return 0. */ - cmpldi cr7,r10,8 - li r9,0 - ble cr7,L(ret1) - addi r5,r10,-8 - - ld r7,8(r3) - ld r9,8(r4) - cmpb r8,r7,r8 - cmpb r6,r7,r9 - orc. r8,r8,r6 - bne cr0,L(different0) - - cmpldi cr7,r5,8 - mr r9,r8 - ble cr7,L(ret1) - - /* Update pointers and size. */ - addi r10,r10,-16 - addi r3,r3,16 - addi r4,r4,16 - - /* Now it has checked for first 16 bytes, align source1 to doubleword - and adjust source2 address. */ -L(align_8b): - rldicl r5,r3,0,61 - rldicr r3,r3,0,60 - subf r4,r5,r4 - add r10,r10,r5 - - /* 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. r8,r4,0x7 - beq cr0,L(loop_eq_align_0) - - li r5,0 - b L(loop_ne_align_1) - - /* 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 4 -L(loop_ne_align_0): - ld r7,0(r3) - ld r9,0(r4) - cmpb r8,r7,r5 - cmpb r6,r7,r9 - orc. r8,r8,r6 - bne cr0,L(different1) - - cmpldi cr7,r10,8 - ble cr7,L(ret0) - addi r10,r10,-8 - addi r3,r3,8 - addi r4,r4,8 -L(loop_ne_align_1): - rldicl r9,r4,0,52 - cmpldi r7,r9,4088 - ble cr7,L(loop_ne_align_0) - cmpdi cr7,r10,0 - beq cr7,L(ret0) - - lbz r9,0(r3) - lbz r8,0(r4) - cmplw cr7,r9,r8 - bne cr7,L(byte_ne_4) - cmpdi cr7,r9,0 - beq cr7,L(size_reached_0) - - li r9,r7 - addi r8,r3,1 - mtctr r9 - addi r4,r4,1 - addi r10,r10,-1 - addi r3,r3,8 - - /* 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. */ - .align 4 -L(loop_ne_align_byte): - cmpdi cr7,r10,0 - addi r10,r10,-1 - beq cr7,L(ret0) - lbz r9,0(r8) - lbz r7,0(r4) - addi r8,r8,1 - addi r4,r4,1 - cmplw cr7,r9,r7 - cmpdi cr5,r9,0 - bne cr7,L(size_reached_2) - beq cr5,L(size_reached_0) - bdnz L(loop_ne_align_byte) - - cmpdi cr7,r10,0 - bne+ cr7,L(loop_ne_align_0) - - .align 4 -L(ret0): - li r9,0 -L(ret1): - mr r3,r9 - blr - - /* The code now check if r8 and r10 are different by issuing a - cmpb and shift the result based on its output: - - #ifdef __LITTLE_ENDIAN__ - leadzero = (__builtin_ffsl (z1) - 1); - leadzero = leadzero > (n-1)*8 ? (n-1)*8 : leadzero; - r1 = (r1 >> leadzero) & 0xFFUL; - r2 = (r2 >> leadzero) & 0xFFUL; - #else - leadzero = __builtin_clzl (z1); - leadzero = leadzero > (n-1)*8 ? (n-1)*8 : leadzero; - r1 = (r1 >> (56 - leadzero)) & 0xFFUL; - r2 = (r2 >> (56 - leadzero)) & 0xFFUL; - #endif - return r1 - r2; */ - - .align 4 -L(different0): - mr r10,r5 -#ifdef __LITTLE_ENDIAN__ -L(different1): - neg r11,r8 - sldi r10,r10,3 - and r8,r11,r8 - addi r10,r10,-8 - cntlzd r8,r8 - subfic r8,r8,63 - extsw r8,r8 - cmpld cr7,r8,r10 - ble cr7,L(different2) - mr r8,r10 -L(different2): - extsw r8,r8 -#else -L(different1): - addi r10,r10,-1 - cntlzd r8,r8 - sldi r10,r10,3 - cmpld cr7,r8,r10 - blt cr7,L(different2) - mr r8,r10 -L(different2): - subfic r8,r8,56 -#endif - srd r7,r7,r8 - srd r9,r9,r8 - rldicl r3,r7,0,56 - rldicl r9,r9,0,56 - subf r9,r9,3 - extsw r9,r9 - mr r3,r9 - blr - - /* 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. */ - .align 4 -L(pagecross): - lbz r7,0(r3) - lbz r9,0(r4) - subfic r8,r8,4095 - cmplw cr7,r9,r7 - bne cr7,L(byte_ne_3) - cmpdi cr7,r9,0 - beq cr7,L(byte_ne_0) - addi r10,r10,-1 - subf r7,r8,r10 - subf r9,r7,r10 - addi r9,r9,1 - mtctr r9 - b L(pagecross_loop1) - - .align 4 -L(pagecross_loop0): - beq cr7,L(ret0) - lbz r9,0(r3) - lbz r8,0(r4) - addi r10,r10,-1 - cmplw cr7,r9,r8 - cmpdi cr5,r9,0 - bne r7,L(byte_ne_2) - beq r5,L(byte_ne_0) -L(pagecross_loop1): - cmpdi cr7,r10,0 - addi r3,r3,1 - addi r4,r4,1 - bdnz L(pagecross_loop0) - cmpdi cr7,r7,0 - li r9,0 - bne+ cr7,L(align_8b) - b L(ret1) - - /* If both source1 and source2 are doubleword aligned, there is no - need for page boundary cross checks. */ - .align 4 -L(loop_eq_align_0): - ld r7,0(r3) - ld r9,0(r4) - cmpb r8,r7,r8 - cmpb r6,r7,r9 - orc. r8,r8,r6 - bne cr0,L(different1) - - cmpldi cr7,r10,8 - ble cr7,L(ret0) - addi r9,r10,-9 - - li r5,0 - srdi r9,r9,3 - addi r9,r9,1 - mtctr r9 - b L(loop_eq_align_2) - - .align 4 -L(loop_eq_align_1): - bdz L(ret0) -L(loop_eq_align_2): - ldu r7,8(r3) - addi r10,r10,-8 - ldu r9,8(r4) - cmpb r8,r7,r5 - cmpb r6,r7,r9 - orc. r8,r8,r6 - beq cr0,L(loop_eq_align_1) - b L(different1) - - .align 4 -L(byte_ne_0): - li r7,0 -L(byte_ne_1): - subf r9,r9,r7 - extsw r9,r9 - b L(ret1) - - .align 4 -L(byte_ne_2): - extsw r7,r9 - mr r9,r8 - b L(byte_ne_1) -L(size_reached_0): - li r10,0 -L(size_reached_1): - subf r9,r9,r10 - extsw r9,r9 - b L(ret1) -L(size_reached_2): - extsw r10,r9 - mr r9,r7 - b L(size_reached_1) -L(byte_ne_3): - extsw r7,r7 - b L(byte_ne_1) -L(byte_ne_4): - extsw r10,r9 - mr r9,r8 - b L(size_reached_1) -END(STRNCMP) -libc_hidden_builtin_def(strncmp) |