/* Optimized strstr implementation for PowerPC64/POWER7.
Copyright (C) 2015-2022 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
. */
#include
/* 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. */
#define ITERATIONS 64
#ifndef STRSTR
# define STRSTR strstr
#endif
#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
# define STRLEN_is_local
# 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
# define STRNLEN_is_local
# else
# define STRNLEN __strnlen
# endif
#endif
#ifndef STRCHR
# ifdef SHARED
# define STRCHR __GI_strchr
# define STRCHR_is_local
# else
# define STRCHR strchr
# endif
#endif
#define FRAMESIZE (FRAME_MIN_SIZE+32)
.machine power7
/* Can't be ENTRY_TOCLESS due to calling __strstr_ppc which uses r2. */
ENTRY (STRSTR, 4)
CALL_MCOUNT 2
mflr r0 /* Load link register LR to r0. */
std r31, -8(r1) /* Save callers register r31. */
std r30, -16(r1) /* Save callers register r30. */
std r29, -24(r1) /* Save callers register r29. */
std r28, -32(r1) /* Save callers register r28. */
std r0, 16(r1) /* Store the link register. */
cfi_offset(r31, -8)
cfi_offset(r30, -16)
cfi_offset(r28, -32)
cfi_offset(r29, -24)
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
#ifndef STRLEN_is_local
nop
#endif
cmpdi cr7, r3, 0 /* If search str is null. */
beq cr7, L(ret_r3)
mr r31, r3
mr r4, r3
mr r3, r29
bl STRNLEN
#ifndef STRNLEN_is_local
nop
#endif
cmpd cr7, r3, r31 /* If len(r3) < len(r4). */
blt cr7, L(retnull)
mr r3, r29
lbz r4, 0(r30)
bl STRCHR
#ifndef STRCHR_is_local
nop
#endif
mr r11, r3
/* If first char of search str is not present. */
cmpdi cr7, r3, 0
ble cr7, L(end)
/* Reg r28 is used to count the number of iterations. */
li r28, 0
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
/* When our iterations exceed ITERATIONS,fall back to default. */
addi r28, r28, 1
cmpdi cr7, r28, ITERATIONS
beq cr7, L(default)
lbz r4, 0(r30)
bl STRCHR
#ifndef STRCHR_is_local
nop
#endif
/* 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
/* When our iterations exceed ITERATIONS,fall back to default. */
addi r28, r28, 1
cmpdi cr7, r28, ITERATIONS
beq cr7, L(default)
lbz r4, 0(r30)
bl STRCHR
#ifndef STRCHR_is_local
nop
#endif
/* 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 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)