From 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 Mon Sep 17 00:00:00 2001 From: Zack Weinberg Date: Thu, 8 Jun 2017 15:39:03 -0400 Subject: Prepare for radical source tree reorganization. All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control). --- REORG.TODO/sysdeps/powerpc/powerpc64/strncmp.S | 210 +++++++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 REORG.TODO/sysdeps/powerpc/powerpc64/strncmp.S (limited to 'REORG.TODO/sysdeps/powerpc/powerpc64/strncmp.S') diff --git a/REORG.TODO/sysdeps/powerpc/powerpc64/strncmp.S b/REORG.TODO/sysdeps/powerpc/powerpc64/strncmp.S new file mode 100644 index 0000000000..076599804a --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/powerpc64/strncmp.S @@ -0,0 +1,210 @@ +/* Optimized strcmp implementation for PowerPC64. + Copyright (C) 2003-2017 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 + . */ + +#include + +/* See strlen.s for comments on how the end-of-string testing works. */ + +/* int [r3] strncmp (const char *s1 [r3], const char *s2 [r4], size_t size [r5]) */ + +#ifndef STRNCMP +# define STRNCMP strncmp +#endif + +EALIGN (STRNCMP, 4, 0) + CALL_MCOUNT 3 + +#define rTMP2 r0 +#define rRTN r3 +#define rSTR1 r3 /* first string arg */ +#define rSTR2 r4 /* second string arg */ +#define rN r5 /* max string length */ +#define rWORD1 r6 /* current word in s1 */ +#define rWORD2 r7 /* current word in s2 */ +#define rFEFE r8 /* constant 0xfefefefefefefeff (-0x0101010101010101) */ +#define r7F7F r9 /* constant 0x7f7f7f7f7f7f7f7f */ +#define rNEG r10 /* ~(word in s1 | 0x7f7f7f7f7f7f7f7f) */ +#define rBITDIF r11 /* bits that differ in s1 & s2 words */ +#define rTMP r12 + + dcbt 0,rSTR1 + or rTMP, rSTR2, rSTR1 + lis r7F7F, 0x7f7f + dcbt 0,rSTR2 + clrldi. rTMP, rTMP, 61 + cmpldi cr1, rN, 0 + lis rFEFE, -0x101 + bne L(unaligned) +/* We are doubleword aligned so set up for two loops. first a double word + loop, then fall into the byte loop if any residual. */ + srdi. rTMP, rN, 3 + clrldi rN, rN, 61 + addi rFEFE, rFEFE, -0x101 + addi r7F7F, r7F7F, 0x7f7f + cmpldi cr1, rN, 0 + beq L(unaligned) + + mtctr rTMP /* Power4 wants mtctr 1st in dispatch group. */ + ld rWORD1, 0(rSTR1) + ld rWORD2, 0(rSTR2) + sldi rTMP, rFEFE, 32 + insrdi r7F7F, r7F7F, 32, 0 + add rFEFE, rFEFE, rTMP + b L(g1) + +L(g0): + ldu rWORD1, 8(rSTR1) + bne- cr1, L(different) + ldu rWORD2, 8(rSTR2) +L(g1): add rTMP, rFEFE, rWORD1 + nor rNEG, r7F7F, rWORD1 + bdz L(tail) + and. rTMP, rTMP, rNEG + cmpd cr1, rWORD1, rWORD2 + beq+ L(g0) + +/* OK. We've hit the end of the string. We need to be careful that + we don't compare two strings as different because of gunk beyond + the end of the strings... */ + +#ifdef __LITTLE_ENDIAN__ +L(endstring): + addi rTMP2, rTMP, -1 + beq cr1, L(equal) + andc rTMP2, rTMP2, rTMP + rldimi rTMP2, rTMP2, 1, 0 + and rWORD2, rWORD2, rTMP2 /* Mask off gunk. */ + and rWORD1, rWORD1, rTMP2 + cmpd cr1, rWORD1, rWORD2 + beq cr1, L(equal) + xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */ + neg rNEG, rBITDIF + and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */ + cntlzd rNEG, rNEG /* bitcount of the bit. */ + andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */ + sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */ + sld rWORD2, rWORD2, rNEG + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 /* must return an int. */ + ori rRTN, rRTN, 1 + blr +L(equal): + li rRTN, 0 + blr + +L(different): + ld rWORD1, -8(rSTR1) + xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */ + neg rNEG, rBITDIF + and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */ + cntlzd rNEG, rNEG /* bitcount of the bit. */ + andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */ + sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */ + sld rWORD2, rWORD2, rNEG + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 + ori rRTN, rRTN, 1 + blr +L(highbit): + sradi rRTN, rWORD2, 63 + ori rRTN, rRTN, 1 + blr + +#else +L(endstring): + and rTMP, r7F7F, rWORD1 + beq cr1, L(equal) + add rTMP, rTMP, r7F7F + xor. rBITDIF, rWORD1, rWORD2 + andc rNEG, rNEG, rTMP + blt- L(highbit) + cntlzd rBITDIF, rBITDIF + cntlzd rNEG, rNEG + addi rNEG, rNEG, 7 + cmpd cr1, rNEG, rBITDIF + sub rRTN, rWORD1, rWORD2 + blt- cr1, L(equal) + sradi rRTN, rRTN, 63 /* must return an int. */ + ori rRTN, rRTN, 1 + blr +L(equal): + li rRTN, 0 + blr + +L(different): + ld rWORD1, -8(rSTR1) + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 + ori rRTN, rRTN, 1 + blr +L(highbit): + sradi rRTN, rWORD2, 63 + ori rRTN, rRTN, 1 + blr +#endif + +/* Oh well. In this case, we just do a byte-by-byte comparison. */ + .align 4 +L(tail): + and. rTMP, rTMP, rNEG + cmpd cr1, rWORD1, rWORD2 + bne- L(endstring) + addi rSTR1, rSTR1, 8 + bne- cr1, L(different) + addi rSTR2, rSTR2, 8 + cmpldi cr1, rN, 0 +L(unaligned): + mtctr rN /* Power4 wants mtctr 1st in dispatch group */ + bgt cr1, L(uz) +L(ux): + li rRTN, 0 + blr + .align 4 +L(uz): + lbz rWORD1, 0(rSTR1) + lbz rWORD2, 0(rSTR2) + nop + b L(u1) +L(u0): + lbzu rWORD2, 1(rSTR2) +L(u1): + bdz L(u3) + cmpdi cr1, rWORD1, 0 + cmpd rWORD1, rWORD2 + beq- cr1, L(u3) + lbzu rWORD1, 1(rSTR1) + bne- L(u2) + lbzu rWORD2, 1(rSTR2) + bdz L(u3) + cmpdi cr1, rWORD1, 0 + cmpd rWORD1, rWORD2 + bne- L(u3) + lbzu rWORD1, 1(rSTR1) + bne+ cr1, L(u0) + +L(u2): lbzu rWORD1, -1(rSTR1) +L(u3): sub rRTN, rWORD1, rWORD2 + blr +END (STRNCMP) +libc_hidden_builtin_def (strncmp) -- cgit 1.4.1