536 lines
11 KiB
ArmAsm
536 lines
11 KiB
ArmAsm
/* Optimized strstr implementation for PowerPC64/POWER7.
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Copyright (C) 2015-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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/* Char * [r3] strstr (char *s [r3], char * pat[r4]) */
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/* The performance gain is obtained using aligned memory access, load
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* doubleword and usage of cmpb instruction for quicker comparison. */
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#define ITERATIONS 64
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#ifndef STRSTR
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# define STRSTR strstr
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#endif
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#ifndef STRLEN
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/* For builds with no IFUNC support, local calls should be made to internal
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GLIBC symbol (created by libc_hidden_builtin_def). */
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# ifdef SHARED
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# define STRLEN __GI_strlen
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# define STRLEN_is_local
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# else
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# define STRLEN strlen
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# endif
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#endif
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#ifndef STRNLEN
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/* For builds with no IFUNC support, local calls should be made to internal
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GLIBC symbol (created by libc_hidden_builtin_def). */
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# ifdef SHARED
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# define STRNLEN __GI_strnlen
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# define STRNLEN_is_local
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# else
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# define STRNLEN __strnlen
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# endif
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#endif
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#ifndef STRCHR
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# ifdef SHARED
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# define STRCHR __GI_strchr
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# define STRCHR_is_local
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# else
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# define STRCHR strchr
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# endif
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#endif
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#define FRAMESIZE (FRAME_MIN_SIZE+32)
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.machine power7
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/* Can't be ENTRY_TOCLESS due to calling __strstr_ppc which uses r2. */
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ENTRY (STRSTR, 4)
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CALL_MCOUNT 2
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mflr r0 /* Load link register LR to r0. */
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std r31, -8(r1) /* Save callers register r31. */
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std r30, -16(r1) /* Save callers register r30. */
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std r29, -24(r1) /* Save callers register r29. */
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std r28, -32(r1) /* Save callers register r28. */
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std r0, 16(r1) /* Store the link register. */
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cfi_offset(r31, -8)
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cfi_offset(r30, -16)
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cfi_offset(r28, -32)
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cfi_offset(r29, -24)
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cfi_offset(lr, 16)
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stdu r1, -FRAMESIZE(r1) /* Create the stack frame. */
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cfi_adjust_cfa_offset(FRAMESIZE)
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dcbt 0, r3
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dcbt 0, r4
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cmpdi cr7, r3, 0
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beq cr7, L(retnull)
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cmpdi cr7, r4, 0
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beq cr7, L(retnull)
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mr r29, r3
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mr r30, r4
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mr r3, r4
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bl STRLEN
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#ifndef STRLEN_is_local
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nop
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#endif
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cmpdi cr7, r3, 0 /* If search str is null. */
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beq cr7, L(ret_r3)
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mr r31, r3
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mr r4, r3
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mr r3, r29
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bl STRNLEN
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#ifndef STRNLEN_is_local
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nop
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#endif
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cmpd cr7, r3, r31 /* If len(r3) < len(r4). */
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blt cr7, L(retnull)
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mr r3, r29
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lbz r4, 0(r30)
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bl STRCHR
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#ifndef STRCHR_is_local
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nop
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#endif
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mr r11, r3
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/* If first char of search str is not present. */
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cmpdi cr7, r3, 0
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ble cr7, L(end)
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/* Reg r28 is used to count the number of iterations. */
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li r28, 0
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rldicl r8, r3, 0, 52 /* Page cross check. */
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cmpldi cr7, r8, 4096-16
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bgt cr7, L(bytebybyte)
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rldicl r8, r30, 0, 52
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cmpldi cr7, r8, 4096-16
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bgt cr7, L(bytebybyte)
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/* If len(r4) < 8 handle in a different way. */
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/* Shift position based on null and use cmpb. */
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cmpdi cr7, r31, 8
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blt cr7, L(lessthan8)
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/* Len(r4) >= 8 reaches here. */
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mr r8, r3 /* Save r3 for future use. */
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mr r4, r30 /* Restore r4. */
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li r0, 0
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rlwinm r10, r30, 3, 26, 28 /* Calculate padding in bits. */
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clrrdi r4, r4, 3 /* Make r4 aligned to 8. */
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ld r6, 0(r4)
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addi r4, r4, 8
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cmpdi cr7, r10, 0 /* Check if its already aligned? */
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beq cr7, L(begin1)
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#ifdef __LITTLE_ENDIAN__
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srd r6, r6, r10 /* Discard unwanted bits. */
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#else
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sld r6, r6, r10
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#endif
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ld r9, 0(r4)
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subfic r10, r10, 64
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#ifdef __LITTLE_ENDIAN__
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sld r9, r9, r10 /* Discard unwanted bits. */
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#else
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srd r9, r9, r10
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#endif
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or r6, r6, r9 /* Form complete search str. */
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L(begin1):
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mr r29, r6
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rlwinm r10, r3, 3, 26, 28
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clrrdi r3, r3, 3
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ld r5, 0(r3)
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cmpb r9, r0, r6 /* Check if input has null. */
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cmpdi cr7, r9, 0
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bne cr7, L(return3)
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cmpb r9, r0, r5 /* Check if input has null. */
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#ifdef __LITTLE_ENDIAN__
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srd r9, r9, r10
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#else
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sld r9, r9, r10
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#endif
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cmpdi cr7, r9, 0
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bne cr7, L(retnull)
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li r12, -8 /* Shift values. */
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li r11, 72 /* Shift values. */
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cmpdi cr7, r10, 0
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beq cr7, L(nextbyte1)
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mr r12, r10
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addi r12, r12, -8
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subfic r11, r12, 64
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L(nextbyte1):
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ldu r7, 8(r3) /* Load next dw. */
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addi r12, r12, 8 /* Shift one byte and compare. */
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addi r11, r11, -8
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#ifdef __LITTLE_ENDIAN__
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srd r9, r5, r12 /* Rotate based on mask. */
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sld r10, r7, r11
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#else
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sld r9, r5, r12
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srd r10, r7, r11
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#endif
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/* Form single dw from few bytes on first load and second load. */
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or r10, r9, r10
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/* Check for null in the formed dw. */
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cmpb r9, r0, r10
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cmpdi cr7, r9, 0
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bne cr7, L(retnull)
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/* Cmpb search str and input str. */
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cmpb r9, r10, r6
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cmpdi cr7, r9, -1
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beq cr7, L(match)
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addi r8, r8, 1
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b L(begin)
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.align 4
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L(match):
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/* There is a match of 8 bytes, check next bytes. */
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cmpdi cr7, r31, 8
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beq cr7, L(return)
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/* Update next starting point r8. */
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srdi r9, r11, 3
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subf r9, r9, r3
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mr r8, r9
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L(secondmatch):
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mr r5, r7
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rlwinm r10, r30, 3, 26, 28 /* Calculate padding in bits. */
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ld r6, 0(r4)
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addi r4, r4, 8
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cmpdi cr7, r10, 0 /* Check if its already aligned? */
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beq cr7, L(proceed3)
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#ifdef __LITTLE_ENDIAN__
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srd r6, r6, r10 /* Discard unwanted bits. */
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cmpb r9, r0, r6
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sld r9, r9, r10
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#else
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sld r6, r6, r10
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cmpb r9, r0, r6
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srd r9, r9, r10
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#endif
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cmpdi cr7, r9, 0
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bne cr7, L(proceed3)
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ld r9, 0(r4)
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subfic r10, r10, 64
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#ifdef __LITTLE_ENDIAN__
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sld r9, r9, r10 /* Discard unwanted bits. */
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#else
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srd r9, r9, r10
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#endif
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or r6, r6, r9 /* Form complete search str. */
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L(proceed3):
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li r7, 0
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addi r3, r3, 8
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cmpb r9, r0, r5
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cmpdi cr7, r9, 0
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bne cr7, L(proceed4)
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ld r7, 0(r3)
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L(proceed4):
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#ifdef __LITTLE_ENDIAN__
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srd r9, r5, r12
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sld r10, r7, r11
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#else
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sld r9, r5, r12
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srd r10, r7, r11
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#endif
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/* Form single dw with few bytes from first and second load. */
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or r10, r9, r10
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cmpb r9, r0, r6
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cmpdi cr7, r9, 0
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bne cr7, L(return4)
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/* Check for null in the formed dw. */
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cmpb r9, r0, r10
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cmpdi cr7, r9, 0
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bne cr7, L(retnull)
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/* If the next 8 bytes dont match, start search again. */
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cmpb r9, r10, r6
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cmpdi cr7, r9, -1
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bne cr7, L(reset)
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/* If the next 8 bytes match, load and compare next 8. */
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b L(secondmatch)
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.align 4
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L(reset):
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/* Start the search again. */
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addi r8, r8, 1
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b L(begin)
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.align 4
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L(return3):
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/* Count leading zeros and compare partial dw. */
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#ifdef __LITTLE_ENDIAN__
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addi r7, r9, -1
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andc r7, r7, r9
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popcntd r7, r7
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subfic r7, r7, 64
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sld r10, r5, r7
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sld r6, r6, r7
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#else
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cntlzd r7, r9
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subfic r7, r7, 64
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srd r10, r5, r7
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srd r6, r6, r7
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#endif
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cmpb r9, r10, r6
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cmpdi cr7, r9, -1
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addi r8, r8, 1
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/* Start search again if there is no match. */
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bne cr7, L(begin)
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/* If the words match, update return values. */
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subfic r7, r7, 64
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srdi r7, r7, 3
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add r3, r3, r7
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subf r3, r31, r3
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b L(end)
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.align 4
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L(return4):
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/* Count leading zeros and compare partial dw. */
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#ifdef __LITTLE_ENDIAN__
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addi r7, r9, -1
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andc r7, r7, r9
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popcntd r7, r7
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subfic r7, r7, 64
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sld r10, r10, r7
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sld r6, r6, r7
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#else
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cntlzd r7, r9
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subfic r7, r7, 64
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srd r10, r10, r7
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srd r6, r6, r7
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#endif
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cmpb r9, r10, r6
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cmpdi cr7, r9, -1
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addi r8, r8, 1
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bne cr7, L(begin)
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subfic r7, r7, 64
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srdi r11, r11, 3
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subf r3, r11, r3
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srdi r7, r7, 3
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add r3, r3, r7
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subf r3, r31, r3
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b L(end)
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.align 4
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L(begin):
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mr r3, r8
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/* When our iterations exceed ITERATIONS,fall back to default. */
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addi r28, r28, 1
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cmpdi cr7, r28, ITERATIONS
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beq cr7, L(default)
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lbz r4, 0(r30)
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bl STRCHR
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#ifndef STRCHR_is_local
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nop
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#endif
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/* If first char of search str is not present. */
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cmpdi cr7, r3, 0
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ble cr7, L(end)
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mr r8, r3
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mr r4, r30 /* Restore r4. */
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li r0, 0
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mr r6, r29
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clrrdi r4, r4, 3
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addi r4, r4, 8
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b L(begin1)
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/* Handle less than 8 search string. */
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.align 4
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L(lessthan8):
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mr r4, r3
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mr r9, r30
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li r0, 0
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rlwinm r10, r9, 3, 26, 28 /* Calculate padding in bits. */
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srdi r8, r10, 3 /* Padding in bytes. */
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clrrdi r9, r9, 3 /* Make r4 aligned to 8. */
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ld r6, 0(r9)
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cmpdi cr7, r10, 0 /* Check if its already aligned? */
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beq cr7, L(proceed2)
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#ifdef __LITTLE_ENDIAN__
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srd r6, r6, r10 /* Discard unwanted bits. */
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#else
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sld r6, r6, r10
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#endif
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subfic r8, r8, 8
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cmpd cr7, r8, r31 /* Next load needed? */
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bge cr7, L(proceed2)
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ld r7, 8(r9)
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subfic r10, r10, 64
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#ifdef __LITTLE_ENDIAN__
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sld r7, r7, r10 /* Discard unwanted bits. */
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#else
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srd r7, r7, r10
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#endif
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or r6, r6, r7 /* Form complete search str. */
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L(proceed2):
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mr r29, r6
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rlwinm r10, r3, 3, 26, 28
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clrrdi r7, r3, 3 /* Make r3 aligned. */
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ld r5, 0(r7)
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sldi r8, r31, 3
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subfic r8, r8, 64
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#ifdef __LITTLE_ENDIAN__
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sld r6, r6, r8
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cmpb r9, r0, r5
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srd r9, r9, r10
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#else
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srd r6, r6, r8
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cmpb r9, r0, r5
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sld r9, r9, r10
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#endif
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cmpdi cr7, r9, 0
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bne cr7, L(noload)
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cmpdi cr7, r10, 0
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beq cr7, L(continue)
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ld r7, 8(r7)
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L(continue1):
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mr r12, r10
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addi r12, r12, -8
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subfic r11, r12, 64
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b L(nextbyte)
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.align 4
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L(continue):
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ld r7, 8(r7)
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li r12, -8 /* Shift values. */
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li r11, 72 /* Shift values. */
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L(nextbyte):
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addi r12, r12, 8 /* Mask for rotation. */
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addi r11, r11, -8
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#ifdef __LITTLE_ENDIAN__
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srd r9, r5, r12
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sld r10, r7, r11
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or r10, r9, r10
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sld r10, r10, r8
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cmpb r9, r0, r10
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srd r9, r9, r8
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#else
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sld r9, r5, r12
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srd r10, r7, r11
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or r10, r9, r10
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srd r10, r10, r8
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cmpb r9, r0, r10
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sld r9, r9, r8
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#endif
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cmpdi cr7, r9, 0
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bne cr7, L(retnull)
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cmpb r9, r10, r6
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cmpdi cr7, r9, -1
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beq cr7, L(end)
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addi r3, r4, 1
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/* When our iterations exceed ITERATIONS,fall back to default. */
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addi r28, r28, 1
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cmpdi cr7, r28, ITERATIONS
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beq cr7, L(default)
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lbz r4, 0(r30)
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bl STRCHR
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#ifndef STRCHR_is_local
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nop
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#endif
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/* If first char of search str is not present. */
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cmpdi cr7, r3, 0
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ble cr7, L(end)
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mr r4, r3
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mr r6, r29
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li r0, 0
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b L(proceed2)
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.align 4
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L(noload):
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/* Reached null in r3, so skip next load. */
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li r7, 0
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b L(continue1)
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.align 4
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L(return):
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/* Update return values. */
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srdi r9, r11, 3
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subf r3, r9, r3
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b L(end)
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/* Handling byte by byte. */
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.align 4
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L(bytebybyte):
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mr r8, r3
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addi r8, r8, -1
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L(loop1):
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addi r8, r8, 1
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mr r3, r8
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mr r4, r30
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lbz r6, 0(r4)
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cmpdi cr7, r6, 0
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beq cr7, L(updater3)
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L(loop):
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lbz r5, 0(r3)
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cmpdi cr7, r5, 0
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beq cr7, L(retnull)
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cmpld cr7, r6, r5
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bne cr7, L(loop1)
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addi r3, r3, 1
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addi r4, r4, 1
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lbz r6, 0(r4)
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cmpdi cr7, r6, 0
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beq cr7, L(updater3)
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b L(loop)
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/* Handling return values. */
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.align 4
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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 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 r28, -32(r1) /* Restore callers save register r28. */
|
|
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)
|