diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power8/strrchr.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power8/strrchr.S | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/power8/strrchr.S b/sysdeps/powerpc/powerpc64/power8/strrchr.S new file mode 100644 index 0000000000..6ff8a528b6 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power8/strrchr.S @@ -0,0 +1,468 @@ +/* Optimized strrchr implementation for PowerPC64/POWER7 using cmpb insn. + Copyright (C) 2017-2018 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] strrchr (char *s [r3], int c [r4]) */ +/* TODO: change these to the actual instructions when the minimum required + binutils allows it. */ +#define MTVRD(v,r) .long (0x7c000167 | ((v)<<(32-11)) | ((r)<<(32-16))) +#define MFVRD(r,v) .long (0x7c000067 | ((v)<<(32-11)) | ((r)<<(32-16))) +#define VBPERMQ(t,a,b) .long (0x1000054c \ + | ((t)<<(32-11)) \ + | ((a)<<(32-16)) \ + | ((b)<<(32-21)) ) +#define VCLZD(r,v) .long (0x100007c2 | ((r)<<(32-11)) | ((v)<<(32-21))) +#define VPOPCNTD(r,v) .long (0x100007c3 | ((r)<<(32-11)) | ((v)<<(32-21))) +#define VADDUQM(t,a,b) .long (0x10000100 \ + | ((t)<<(32-11)) \ + | ((a)<<(32-16)) \ + | ((b)<<(32-21)) ) +#ifdef __LITTLE_ENDIAN__ +/* Find the match position from v6 and place result in r6. */ +# define CALCULATE_MATCH() \ + VBPERMQ(v6, v6, v10); \ + vsldoi v6, v6, v6, 6; \ + MFVRD(r7, v6); \ + cntlzd r6, r7; \ + subfic r6, r6, 15; +/* + * Find the first null position to mask bytes after null. + * (reg): vcmpequb result: v2 for 1st qw v3 for 2nd qw. + * Result placed at v2. + */ +# define FIND_NULL_POS(reg) \ + vspltisb v11, -1; \ + VADDUQM(v11, reg, v11); \ + vandc v11, v11, reg; \ + VPOPCNTD(v2, v11); \ + vspltb v11, v2, 15; \ + vcmpequb. v11, v11, v9; \ + blt cr6, 1f; \ + vsldoi v9, v0, v9, 1; \ + vslo v2, v2, v9; \ +1: \ + vsumsws v2, v2, v0; +#else +# define CALCULATE_MATCH() \ + VBPERMQ(v6, v6, v10); \ + MFVRD(r7, v6); \ + addi r6, r7, -1; \ + andc r6, r6, r7; \ + popcntd r6, r6; \ + subfic r6, r6, 15; +# define FIND_NULL_POS(reg) \ + VCLZD(v2, reg); \ + vspltb v11, v2, 7; \ + vcmpequb. v11, v11, v9; \ + blt cr6, 1f; \ + vsldoi v9, v0, v9, 1; \ + vsro v2, v2, v9; \ +1: \ + vsumsws v2, v2, v0; +#endif /* !__LITTLE_ENDIAN__ */ + +#ifndef STRRCHR +# define STRRCHR strrchr +#endif + .machine power7 +ENTRY_TOCLESS (STRRCHR) + CALL_MCOUNT 2 + dcbt 0,r3 + clrrdi r8,r3,3 /* Align the address to doubleword boundary. */ + cmpdi cr7,r4,0 + ld r12,0(r8) /* Load doubleword from memory. */ + li r9,0 /* Used to store last occurence. */ + li r0,0 /* Doubleword with null chars to use + with cmpb. */ + + rlwinm r6,r3,3,26,28 /* Calculate padding. */ + + beq cr7,L(null_match) + + /* Replicate byte to doubleword. */ + insrdi r4,r4,8,48 + insrdi r4,r4,16,32 + insrdi r4,r4,32,0 + + /* r4 is changed now. If it's passed more chars, then + check for null again. */ + cmpdi cr7,r4,0 + beq cr7,L(null_match) + /* Now r4 has a doubleword of c bytes and r0 has + a doubleword of null bytes. */ + + cmpb r10,r12,r4 /* Compare each byte against c byte. */ + cmpb r11,r12,r0 /* Compare each byte against null byte. */ + + /* Move the doublewords left and right to discard the bits that are + not part of the string and bring them back as zeros. */ +#ifdef __LITTLE_ENDIAN__ + srd r10,r10,r6 + srd r11,r11,r6 + sld r10,r10,r6 + sld r11,r11,r6 +#else + sld r10,r10,r6 + sld r11,r11,r6 + srd r10,r10,r6 + srd r11,r11,r6 +#endif + or r5,r10,r11 /* OR the results to speed things up. */ + cmpdi cr7,r5,0 /* If r5 == 0, no c or null bytes + have been found. */ + bne cr7,L(done) + +L(align): + andi. r12, r8, 15 + + /* Are we now aligned to a doubleword boundary? If so, skip to + the main loop. Otherwise, go through the alignment code. */ + + bne cr0, L(loop) + + /* Handle WORD2 of pair. */ + ldu r12,8(r8) + cmpb r10,r12,r4 + cmpb r11,r12,r0 + or r5,r10,r11 + cmpdi cr7,r5,0 + bne cr7,L(done) + b L(loop) /* We branch here (rather than falling through) + to skip the nops due to heavy alignment + of the loop below. */ + .p2align 5 +L(loop): + /* Load two doublewords, compare and merge in a + single register for speed. This is an attempt + to speed up the null-checking process for bigger strings. */ + ld r12,8(r8) + ldu r7,16(r8) + cmpb r10,r12,r4 + cmpb r11,r12,r0 + cmpb r6,r7,r4 + cmpb r7,r7,r0 + or r12,r10,r11 + or r5,r6,r7 + or r5,r12,r5 + cmpdi cr7,r5,0 + beq cr7,L(vector) + + /* OK, one (or both) of the doublewords contains a c/null byte. Check + the first doubleword and decrement the address in case the first + doubleword really contains a c/null byte. */ + cmpdi cr6,r12,0 + addi r8,r8,-8 + bne cr6,L(done) + + /* The c/null byte must be in the second doubleword. Adjust the + address again and move the result of cmpb to r10 so we can calculate + the pointer. */ + + mr r10,r6 + mr r11,r7 + addi r8,r8,8 + + /* r10/r11 have the output of the cmpb instructions, that is, + 0xff in the same position as the c/null byte in the original + doubleword from the string. Use that to calculate the pointer. */ + +L(done): + /* If there are more than one 0xff in r11, find the first position of + 0xff in r11 and fill r10 with 0 from that position. */ + cmpdi cr7,r11,0 + beq cr7,L(no_null) +#ifdef __LITTLE_ENDIAN__ + addi r3,r11,-1 + andc r3,r3,r11 + popcntd r0,r3 +#else + cntlzd r0,r11 +#endif + subfic r0,r0,63 + li r6,-1 +#ifdef __LITTLE_ENDIAN__ + srd r0,r6,r0 +#else + sld r0,r6,r0 +#endif + and r10,r0,r10 +L(no_null): +#ifdef __LITTLE_ENDIAN__ + cntlzd r0,r10 /* Count leading zeros before c matches. */ + addi r3,r10,-1 + andc r3,r3,r10 + addi r10,r11,-1 + andc r10,r10,r11 + cmpld cr7,r3,r10 + bgt cr7,L(no_match) +#else + addi r3,r10,-1 /* Count trailing zeros before c matches. */ + andc r3,r3,r10 + popcntd r0,r3 + cmpld cr7,r11,r10 + bgt cr7,L(no_match) +#endif + srdi r0,r0,3 /* Convert trailing zeros to bytes. */ + subfic r0,r0,7 + add r9,r8,r0 /* Return address of the matching c byte + or null in case c was not found. */ + li r0,0 + cmpdi cr7,r11,0 /* If r11 == 0, no null's have been found. */ + beq cr7,L(align) + + .align 4 +L(no_match): + mr r3,r9 + blr + +/* Check the first 32B in GPR's and move to vectorized loop. */ + .p2align 5 +L(vector): + addi r3, r8, 8 + /* Make sure 32B aligned. */ + andi. r10, r3, 31 + bne cr0, L(loop) + vspltisb v0, 0 + /* Precompute vbpermq constant. */ + vspltisb v10, 3 + lvsl v11, r0, r0 + vslb v10, v11, v10 + MTVRD(v1, r4) + li r5, 16 + vspltb v1, v1, 7 + /* Compare 32 bytes in each loop. */ +L(continue): + lvx v4, 0, r3 + lvx v5, r3, r5 + vcmpequb v2, v0, v4 + vcmpequb v3, v0, v5 + vcmpequb v6, v1, v4 + vcmpequb v7, v1, v5 + vor v8, v2, v3 + vor v9, v6, v7 + vor v11, v8, v9 + vcmpequb. v11, v0, v11 + addi r3, r3, 32 + blt cr6, L(continue) + vcmpequb. v8, v0, v8 + blt cr6, L(match) + + /* One (or both) of the quadwords contains c/null. */ + vspltisb v8, 2 + vspltisb v9, 5 + /* Precompute values used for comparison. */ + vsl v9, v8, v9 /* v9 = 0x4040404040404040. */ + vaddubm v8, v9, v9 + vsldoi v8, v0, v8, 1 /* v8 = 0x80. */ + + /* Check if null is in second qw. */ + vcmpequb. v11, v0, v2 + blt cr6, L(secondqw) + + /* Null found in first qw. */ + addi r8, r3, -32 + /* Calculate the null position. */ + FIND_NULL_POS(v2) + /* Check if null is in the first byte. */ + vcmpequb. v11, v0, v2 + blt cr6, L(no_match) + vsububm v2, v8, v2 + /* Mask unwanted bytes after null. */ +#ifdef __LITTLE_ENDIAN__ + vslo v6, v6, v2 + vsro v6, v6, v2 +#else + vsro v6, v6, v2 + vslo v6, v6, v2 +#endif + vcmpequb. v11, v0, v6 + blt cr6, L(no_match) + /* Found a match before null. */ + CALCULATE_MATCH() + add r3, r8, r6 + blr + +L(secondqw): + addi r8, r3, -16 + FIND_NULL_POS(v3) + vcmpequb. v11, v0, v2 + blt cr6, L(no_match1) + vsububm v2, v8, v2 + /* Mask unwanted bytes after null. */ +#ifdef __LITTLE_ENDIAN__ + vslo v7, v7, v2 + vsro v7, v7, v2 +#else + vsro v7, v7, v2 + vslo v7, v7, v2 +#endif + vcmpequb. v11, v0, v7 + blt cr6, L(no_match1) + addi r8, r8, 16 + vor v6, v0, v7 +L(no_match1): + addi r8, r8, -16 + vcmpequb. v11, v0, v6 + blt cr6, L(no_match) + /* Found a match before null. */ + CALCULATE_MATCH() + add r3, r8, r6 + blr + +L(match): + /* One (or both) of the quadwords contains a match. */ + mr r8, r3 + vcmpequb. v8, v0, v7 + blt cr6, L(firstqw) + /* Match found in second qw. */ + addi r8, r8, 16 + vor v6, v0, v7 +L(firstqw): + addi r8, r8, -32 + CALCULATE_MATCH() + add r9, r8, r6 /* Compute final length. */ + b L(continue) +/* We are here because strrchr was called with a null byte. */ + .align 4 +L(null_match): + /* r0 has a doubleword of null bytes. */ + + cmpb r5,r12,r0 /* Compare each byte against null bytes. */ + + /* Move the doublewords left and right to discard the bits that are + not part of the string and bring them back as zeros. */ +#ifdef __LITTLE_ENDIAN__ + srd r5,r5,r6 + sld r5,r5,r6 +#else + sld r5,r5,r6 + srd r5,r5,r6 +#endif + cmpdi cr7,r5,0 /* If r5 == 0, no c or null bytes + have been found. */ + bne cr7,L(done_null) + + andi. r12, r8, 15 + + /* Are we now aligned to a quadword boundary? If so, skip to + the main loop. Otherwise, go through the alignment code. */ + + bne cr0, L(loop_null) + + /* Handle WORD2 of pair. */ + ldu r12,8(r8) + cmpb r5,r12,r0 + cmpdi cr7,r5,0 + bne cr7,L(done_null) + b L(loop_null) /* We branch here (rather than falling through) + to skip the nops due to heavy alignment + of the loop below. */ + + /* Main loop to look for the end of the string. Since it's a + small loop (< 8 instructions), align it to 32-bytes. */ + .p2align 5 +L(loop_null): + /* Load two doublewords, compare and merge in a + single register for speed. This is an attempt + to speed up the null-checking process for bigger strings. */ + ld r12,8(r8) + ldu r11,16(r8) + cmpb r5,r12,r0 + cmpb r10,r11,r0 + or r6,r5,r10 + cmpdi cr7,r6,0 + beq cr7,L(vector1) + + /* OK, one (or both) of the doublewords contains a null byte. Check + the first doubleword and decrement the address in case the first + doubleword really contains a null byte. */ + + cmpdi cr6,r5,0 + addi r8,r8,-8 + bne cr6,L(done_null) + + /* The null byte must be in the second doubleword. Adjust the address + again and move the result of cmpb to r10 so we can calculate the + pointer. */ + + mr r5,r10 + addi r8,r8,8 + + /* r5 has the output of the cmpb instruction, that is, it contains + 0xff in the same position as the null byte in the original + doubleword from the string. Use that to calculate the pointer. */ +L(done_null): +#ifdef __LITTLE_ENDIAN__ + addi r0,r5,-1 + andc r0,r0,r5 + popcntd r0,r0 +#else + cntlzd r0,r5 /* Count leading zeros before the match. */ +#endif + srdi r0,r0,3 /* Convert trailing zeros to bytes. */ + add r3,r8,r0 /* Return address of the matching null byte. */ + blr +/* Check the first 32B in GPR's and move to vectorized loop. */ + .p2align 5 +L(vector1): + addi r3, r8, 8 + /* Make sure 32B aligned. */ + andi. r10, r3, 31 + bne cr0, L(loop_null) + vspltisb v0, 0 + /* Precompute vbpermq constant. */ + vspltisb v10, 3 + lvsl v11, r0, r0 + vslb v10, v11, v10 + li r5, 16 + /* Compare 32 bytes in each loop. */ +L(continue1): + lvx v4, 0, r3 + lvx v5, r3, r5 + vcmpequb v2, v0, v4 + vcmpequb v3, v0, v5 + vor v8, v2, v3 + vcmpequb. v11, v0, v8 + addi r3, r3, 32 + blt cr6, L(continue1) + addi r3, r3, -32 + VBPERMQ(v2, v2, v10) + VBPERMQ(v3, v3, v10) + /* Shift each component into its correct position for merging. */ +#ifdef __LITTLE_ENDIAN__ + vsldoi v3, v3, v3, 2 +#else + vsldoi v2, v2, v2, 6 + vsldoi v3, v3, v3, 4 +#endif + /* Merge the results and move to a GPR. */ + vor v4, v3, v2 + MFVRD(r5, v4) +#ifdef __LITTLE_ENDIAN__ + addi r6, r5, -1 + andc r6, r6, r5 + popcntd r6, r6 +#else + cntlzd r6, r5 /* Count leading zeros before the match. */ +#endif + add r3, r3, r6 /* Compute final length. */ + blr +END_GEN_TB (STRRCHR, TB_TOCLESS) +weak_alias (strrchr, rindex) +libc_hidden_builtin_def (strrchr) |