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author | Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com> | 2015-06-24 02:08:21 -0400 |
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committer | Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com> | 2015-07-16 13:43:51 -0300 |
commit | b42f8cad52ebfbfd43ebf6e42e606b489ffbd466 (patch) | |
tree | ec8f4655557211a79429140e55b12d100a2745d7 /sysdeps/powerpc/powerpc64/power7 | |
parent | 6b96d6de8ccd1c04f172a43d3785960e0a76be3f (diff) | |
download | glibc-b42f8cad52ebfbfd43ebf6e42e606b489ffbd466.zip glibc-b42f8cad52ebfbfd43ebf6e42e606b489ffbd466.tar.gz glibc-b42f8cad52ebfbfd43ebf6e42e606b489ffbd466.tar.bz2 |
powerpc: strstr optimization
This patch optimizes strstr function for power >= 7 systems. Performance
gain is obtained using aligned memory access and usage of cmpb
instruction for quicker comparison. The average improvement of this
optimization is ~40%. Tested on ppc64 and ppc64le.
2015-07-16 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
* sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strstr().
* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: Likewise.
* sysdeps/powerpc/powerpc64/power7/strstr.S: New File.
* sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S: New File.
* sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c: New File.
* sysdeps/powerpc/powerpc64/multiarch/strstr.c: New File.
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power7')
-rw-r--r-- | sysdeps/powerpc/powerpc64/power7/strstr.S | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/power7/strstr.S b/sysdeps/powerpc/powerpc64/power7/strstr.S new file mode 100644 index 0000000..8dca31c --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power7/strstr.S @@ -0,0 +1,509 @@ +/* Optimized strstr implementation for PowerPC64/POWER7. + 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> + +/* Char * [r3] strstr (char *s [r3], char * pat[r4]) */ + +/* The performance gain is obtained using aligned memory access, load + * doubleword and usage of cmpb instruction for quicker comparison. */ + +#ifndef STRLEN +/* For builds with no IFUNC support, local calls should be made to internal + GLIBC symbol (created by libc_hidden_builtin_def). */ +# ifdef SHARED +# define STRLEN __GI_strlen +# else +# define STRLEN strlen +# endif +#endif + +#ifndef STRNLEN +/* For builds with no IFUNC support, local calls should be made to internal + GLIBC symbol (created by libc_hidden_builtin_def). */ +# ifdef SHARED +# define STRNLEN __GI_strnlen +# else +# define STRNLEN strnlen +# endif +#endif + +#ifndef STRCHR +# ifdef SHARED +# define STRCHR __GI_strchr +# else +# define STRCHR strchr +# endif +#endif + +#define FRAMESIZE (FRAME_MIN_SIZE+32) + .machine power7 +EALIGN (strstr, 4, 0) + CALL_MCOUNT 2 + mflr r0 /* Load link register LR to r0. */ + std r31, -8(r1) /* Save callers register r31. */ + cfi_offset(r31, -8) + std r30, -16(r1) /* Save callers register r30. */ + cfi_offset(r30, -16) + std r29, -24(r1) /* Save callers register r29. */ + cfi_offset(r29, -24) + std r0, 16(r1) /* Store the link register. */ + cfi_offset(lr, 16) + stdu r1, -FRAMESIZE(r1) /* Create the stack frame. */ + cfi_adjust_cfa_offset(FRAMESIZE) + + dcbt 0, r3 + dcbt 0, r4 + + cmpdi cr7, r3, 0 + beq cr7, L(retnull) + cmpdi cr7, r4, 0 + beq cr7, L(retnull) + + mr r29, r3 + mr r30, r4 + mr r3, r4 + bl STRLEN + nop + + cmpdi cr7, r3, 0 /* If search str is null. */ + beq cr7, L(ret_r3) + + /* Call __strstr_ppc if needle len > 2048 */ + cmpdi cr7, r3, 2048 + bgt cr7, L(default) + + mr r31, r3 + mr r4, r3 + mr r3, r29 + bl STRNLEN + nop + + cmpd cr7, r3, r31 /* If len(r3) < len(r4). */ + blt cr7, L(retnull) + mr r3, r29 + lbz r4, 0(r30) + bl STRCHR + nop + + mr r11, r3 + /* If first char of search str is not present. */ + cmpdi cr7, r3, 0 + ble cr7, L(end) + + rldicl r8, r3, 0, 52 /* Page cross check. */ + cmpldi cr7, r8, 4096-16 + bgt cr7, L(bytebybyte) + + rldicl r8, r30, 0, 52 + cmpldi cr7, r8, 4096-16 + bgt cr7, L(bytebybyte) + + /* If len(r4) < 8 handle in a different way. */ + /* Shift position based on null and use cmpb. */ + cmpdi cr7, r31, 8 + blt cr7, L(lessthan8) + + /* Len(r4) >= 8 reaches here. */ + mr r8, r3 /* Save r3 for future use. */ + mr r4, r30 /* Restore r4. */ + li r0, 0 + rlwinm r10, r30, 3, 26, 28 /* Calculate padding in bits. */ + clrrdi r4, r4, 3 /* Make r4 aligned to 8. */ + ld r6, 0(r4) + addi r4, r4, 8 + cmpdi cr7, r10, 0 /* Check if its already aligned? */ + beq cr7, L(begin1) +#ifdef __LITTLE_ENDIAN__ + srd r6, r6, r10 /* Discard unwanted bits. */ +#else + sld r6, r6, r10 +#endif + ld r9, 0(r4) + subfic r10, r10, 64 +#ifdef __LITTLE_ENDIAN__ + sld r9, r9, r10 /* Discard unwanted bits. */ +#else + srd r9, r9, r10 +#endif + or r6, r6, r9 /* Form complete search str. */ +L(begin1): + mr r29, r6 + rlwinm r10, r3, 3, 26, 28 + clrrdi r3, r3, 3 + ld r5, 0(r3) + cmpb r9, r0, r6 /* Check if input has null. */ + cmpdi cr7, r9, 0 + bne cr7, L(return3) + cmpb r9, r0, r5 /* Check if input has null. */ +#ifdef __LITTLE_ENDIAN__ + srd r9, r9, r10 +#else + sld r9, r9, r10 +#endif + cmpdi cr7, r9, 0 + bne cr7, L(retnull) + + li r12, -8 /* Shift values. */ + li r11, 72 /* Shift values. */ + cmpdi cr7, r10, 0 + beq cr7, L(nextbyte1) + mr r12, r10 + addi r12, r12, -8 + subfic r11, r12, 64 + +L(nextbyte1): + ldu r7, 8(r3) /* Load next dw. */ + addi r12, r12, 8 /* Shift one byte and compare. */ + addi r11, r11, -8 +#ifdef __LITTLE_ENDIAN__ + srd r9, r5, r12 /* Rotate based on mask. */ + sld r10, r7, r11 +#else + sld r9, r5, r12 + srd r10, r7, r11 +#endif + /* Form single dw from few bytes on first load and second load. */ + or r10, r9, r10 + /* Check for null in the formed dw. */ + cmpb r9, r0, r10 + cmpdi cr7, r9, 0 + bne cr7, L(retnull) + /* Cmpb search str and input str. */ + cmpb r9, r10, r6 + cmpdi cr7, r9, -1 + beq cr7, L(match) + addi r8, r8, 1 + b L(begin) + + .align 4 +L(match): + /* There is a match of 8 bytes, check next bytes. */ + cmpdi cr7, r31, 8 + beq cr7, L(return) + /* Update next starting point r8. */ + srdi r9, r11, 3 + subf r9, r9, r3 + mr r8, r9 + +L(secondmatch): + mr r5, r7 + rlwinm r10, r30, 3, 26, 28 /* Calculate padding in bits. */ + ld r6, 0(r4) + addi r4, r4, 8 + cmpdi cr7, r10, 0 /* Check if its already aligned? */ + beq cr7, L(proceed3) +#ifdef __LITTLE_ENDIAN__ + srd r6, r6, r10 /* Discard unwanted bits. */ + cmpb r9, r0, r6 + sld r9, r9, r10 +#else + sld r6, r6, r10 + cmpb r9, r0, r6 + srd r9, r9, r10 +#endif + cmpdi cr7, r9, 0 + bne cr7, L(proceed3) + ld r9, 0(r4) + subfic r10, r10, 64 +#ifdef __LITTLE_ENDIAN__ + sld r9, r9, r10 /* Discard unwanted bits. */ +#else + srd r9, r9, r10 +#endif + or r6, r6, r9 /* Form complete search str. */ + +L(proceed3): + li r7, 0 + addi r3, r3, 8 + cmpb r9, r0, r5 + cmpdi cr7, r9, 0 + bne cr7, L(proceed4) + ld r7, 0(r3) +L(proceed4): +#ifdef __LITTLE_ENDIAN__ + srd r9, r5, r12 + sld r10, r7, r11 +#else + sld r9, r5, r12 + srd r10, r7, r11 +#endif + /* Form single dw with few bytes from first and second load. */ + or r10, r9, r10 + cmpb r9, r0, r6 + cmpdi cr7, r9, 0 + bne cr7, L(return4) + /* Check for null in the formed dw. */ + cmpb r9, r0, r10 + cmpdi cr7, r9, 0 + bne cr7, L(retnull) + /* If the next 8 bytes dont match, start search again. */ + cmpb r9, r10, r6 + cmpdi cr7, r9, -1 + bne cr7, L(reset) + /* If the next 8 bytes match, load and compare next 8. */ + b L(secondmatch) + + .align 4 +L(reset): + /* Start the search again. */ + addi r8, r8, 1 + b L(begin) + + .align 4 +L(return3): + /* Count leading zeros and compare partial dw. */ +#ifdef __LITTLE_ENDIAN__ + addi r7, r9, -1 + andc r7, r7, r9 + popcntd r7, r7 + subfic r7, r7, 64 + sld r10, r5, r7 + sld r6, r6, r7 +#else + cntlzd r7, r9 + subfic r7, r7, 64 + srd r10, r5, r7 + srd r6, r6, r7 +#endif + cmpb r9, r10, r6 + cmpdi cr7, r9, -1 + addi r8, r8, 1 + /* Start search again if there is no match. */ + bne cr7, L(begin) + /* If the words match, update return values. */ + subfic r7, r7, 64 + srdi r7, r7, 3 + add r3, r3, r7 + subf r3, r31, r3 + b L(end) + + .align 4 +L(return4): + /* Count leading zeros and compare partial dw. */ +#ifdef __LITTLE_ENDIAN__ + addi r7, r9, -1 + andc r7, r7, r9 + popcntd r7, r7 + subfic r7, r7, 64 + sld r10, r10, r7 + sld r6, r6, r7 +#else + cntlzd r7, r9 + subfic r7, r7, 64 + srd r10, r10, r7 + srd r6, r6, r7 +#endif + cmpb r9, r10, r6 + cmpdi cr7, r9, -1 + addi r8, r8, 1 + bne cr7, L(begin) + subfic r7, r7, 64 + srdi r11, r11, 3 + subf r3, r11, r3 + srdi r7, r7, 3 + add r3, r3, r7 + subf r3, r31, r3 + b L(end) + + .align 4 +L(begin): + mr r3, r8 + lbz r4, 0(r30) + bl STRCHR + nop + /* If first char of search str is not present. */ + cmpdi cr7, r3, 0 + ble cr7, L(end) + mr r8, r3 + mr r4, r30 /* Restore r4. */ + li r0, 0 + mr r6, r29 + clrrdi r4, r4, 3 + addi r4, r4, 8 + b L(begin1) + + /* Handle less than 8 search string. */ + .align 4 +L(lessthan8): + mr r4, r3 + mr r9, r30 + li r0, 0 + + rlwinm r10, r9, 3, 26, 28 /* Calculate padding in bits. */ + srdi r8, r10, 3 /* Padding in bytes. */ + clrrdi r9, r9, 3 /* Make r4 aligned to 8. */ + ld r6, 0(r9) + cmpdi cr7, r10, 0 /* Check if its already aligned? */ + beq cr7, L(proceed2) +#ifdef __LITTLE_ENDIAN__ + srd r6, r6, r10 /* Discard unwanted bits. */ +#else + sld r6, r6, r10 +#endif + subfic r8, r8, 8 + cmpd cr7, r8, r31 /* Next load needed? */ + bge cr7, L(proceed2) + ld r7, 8(r9) + subfic r10, r10, 64 +#ifdef __LITTLE_ENDIAN__ + sld r7, r7, r10 /* Discard unwanted bits. */ +#else + srd r7, r7, r10 +#endif + or r6, r6, r7 /* Form complete search str. */ +L(proceed2): + mr r29, r6 + rlwinm r10, r3, 3, 26, 28 + clrrdi r7, r3, 3 /* Make r3 aligned. */ + ld r5, 0(r7) + sldi r8, r31, 3 + subfic r8, r8, 64 +#ifdef __LITTLE_ENDIAN__ + sld r6, r6, r8 + cmpb r9, r0, r5 + srd r9, r9, r10 +#else + srd r6, r6, r8 + cmpb r9, r0, r5 + sld r9, r9, r10 +#endif + cmpdi cr7, r9, 0 + bne cr7, L(noload) + cmpdi cr7, r10, 0 + beq cr7, L(continue) + ld r7, 8(r7) +L(continue1): + mr r12, r10 + addi r12, r12, -8 + subfic r11, r12, 64 + b L(nextbyte) + + .align 4 +L(continue): + ld r7, 8(r7) + li r12, -8 /* Shift values. */ + li r11, 72 /* Shift values. */ +L(nextbyte): + addi r12, r12, 8 /* Mask for rotation. */ + addi r11, r11, -8 +#ifdef __LITTLE_ENDIAN__ + srd r9, r5, r12 + sld r10, r7, r11 + or r10, r9, r10 + sld r10, r10, r8 + cmpb r9, r0, r10 + srd r9, r9, r8 +#else + sld r9, r5, r12 + srd r10, r7, r11 + or r10, r9, r10 + srd r10, r10, r8 + cmpb r9, r0, r10 + sld r9, r9, r8 +#endif + cmpdi cr7, r9, 0 + bne cr7, L(retnull) + cmpb r9, r10, r6 + cmpdi cr7, r9, -1 + beq cr7, L(end) + addi r3, r4, 1 + lbz r4, 0(r30) + bl STRCHR + nop + /* If first char of search str is not present. */ + cmpdi cr7, r3, 0 + ble cr7, L(end) + mr r4, r3 + mr r6, r29 + li r0, 0 + b L(proceed2) + + .align 4 +L(noload): + /* Reached null in r3, so skip next load. */ + li r7, 0 + b L(continue1) + + .align 4 +L(return): + /* Update return values. */ + srdi r9, r11, 3 + subf r3, r9, r3 + b L(end) + + /* Handling byte by byte. */ + .align 4 +L(bytebybyte): + mr r8, r3 + addi r8, r8, -1 +L(loop1): + addi r8, r8, 1 + mr r3, r8 + mr r4, r30 + lbz r6, 0(r4) + cmpdi cr7, r6, 0 + beq cr7, L(updater3) +L(loop): + lbz r5, 0(r3) + cmpdi cr7, r5, 0 + beq cr7, L(retnull) + cmpld cr7, r6, r5 + bne cr7, L(loop1) + addi r3, r3, 1 + addi r4, r4, 1 + lbz r6, 0(r4) + cmpdi cr7, r6, 0 + beq cr7, L(updater3) + b L(loop) + + /* Handling return values. */ + .align 4 +L(updater3): + subf r3, r31, r3 /* Reduce len of r4 from r3. */ + b L(end) + + .align 4 +L(ret_r3): + mr r3, r29 /* Return r3. */ + b L(end) + + .align 4 +L(retnull): + li r3, 0 /* Return NULL. */ + b L(end) + + .align 4 +L(default): + mr r3, r29 + mr r4, r30 + bl __strstr_ppc + nop + + .align 4 +L(end): + addi r1, r1, FRAMESIZE /* Restore stack pointer. */ + cfi_adjust_cfa_offset(-FRAMESIZE) + ld r0, 16(r1) /* Restore the saved link register. */ + ld r29, -24(r1) /* Restore callers save register r29. */ + ld r30, -16(r1) /* Restore callers save register r30. */ + ld r31, -8(r1) /* Restore callers save register r31. */ + mtlr r0 /* Branch to link register. */ + blr +END (strstr) +libc_hidden_builtin_def (strstr) |