| /* Optimized stpcpy implementation for PowerPC. |
| Copyright (C) 1997-2014 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> |
| |
| /* See strlen.s for comments on how the end-of-string testing works. */ |
| |
| /* char * [r3] stpcpy (char *dest [r3], const char *src [r4]) */ |
| |
| EALIGN (__stpcpy, 4, 0) |
| |
| #define rTMP r0 |
| #define rRTN r3 |
| #define rDEST r3 /* pointer to previous word in dest */ |
| #define rSRC r4 /* pointer to previous word in src */ |
| #define rWORD r6 /* current word from src */ |
| #define rFEFE r7 /* 0xfefefeff */ |
| #define r7F7F r8 /* 0x7f7f7f7f */ |
| #define rNEG r9 /* ~(word in src | 0x7f7f7f7f) */ |
| #define rALT r10 /* alternate word from src */ |
| |
| |
| or rTMP, rSRC, rDEST |
| clrlwi. rTMP, rTMP, 30 |
| addi rDEST, rDEST, -4 |
| bne L(unaligned) |
| |
| lis rFEFE, -0x101 |
| lis r7F7F, 0x7f7f |
| lwz rWORD, 0(rSRC) |
| addi rFEFE, rFEFE, -0x101 |
| addi r7F7F, r7F7F, 0x7f7f |
| b L(g2) |
| |
| L(g0): lwzu rALT, 4(rSRC) |
| stwu rWORD, 4(rDEST) |
| add rTMP, rFEFE, rALT |
| nor rNEG, r7F7F, rALT |
| and. rTMP, rTMP, rNEG |
| bne- L(g1) |
| lwzu rWORD, 4(rSRC) |
| stwu rALT, 4(rDEST) |
| L(g2): add rTMP, rFEFE, rWORD |
| nor rNEG, r7F7F, rWORD |
| and. rTMP, rTMP, rNEG |
| beq+ L(g0) |
| |
| mr rALT, rWORD |
| /* We've hit the end of the string. Do the rest byte-by-byte. */ |
| L(g1): |
| #ifdef __LITTLE_ENDIAN__ |
| rlwinm. rTMP, rALT, 0, 24, 31 |
| stbu rALT, 4(rDEST) |
| beqlr- |
| rlwinm. rTMP, rALT, 24, 24, 31 |
| stbu rTMP, 1(rDEST) |
| beqlr- |
| rlwinm. rTMP, rALT, 16, 24, 31 |
| stbu rTMP, 1(rDEST) |
| beqlr- |
| rlwinm rTMP, rALT, 8, 24, 31 |
| stbu rTMP, 1(rDEST) |
| blr |
| #else |
| rlwinm. rTMP, rALT, 8, 24, 31 |
| stbu rTMP, 4(rDEST) |
| beqlr- |
| rlwinm. rTMP, rALT, 16, 24, 31 |
| stbu rTMP, 1(rDEST) |
| beqlr- |
| rlwinm. rTMP, rALT, 24, 24, 31 |
| stbu rTMP, 1(rDEST) |
| beqlr- |
| stbu rALT, 1(rDEST) |
| blr |
| #endif |
| |
| /* Oh well. In this case, we just do a byte-by-byte copy. */ |
| .align 4 |
| nop |
| L(unaligned): |
| lbz rWORD, 0(rSRC) |
| addi rDEST, rDEST, 3 |
| cmpwi rWORD, 0 |
| beq- L(u2) |
| |
| L(u0): lbzu rALT, 1(rSRC) |
| stbu rWORD, 1(rDEST) |
| cmpwi rALT, 0 |
| beq- L(u1) |
| nop /* Let 601 load start of loop. */ |
| lbzu rWORD, 1(rSRC) |
| stbu rALT, 1(rDEST) |
| cmpwi rWORD, 0 |
| bne+ L(u0) |
| L(u2): stbu rWORD, 1(rDEST) |
| blr |
| L(u1): stbu rALT, 1(rDEST) |
| blr |
| END (__stpcpy) |
| |
| weak_alias (__stpcpy, stpcpy) |
| libc_hidden_def (__stpcpy) |
| libc_hidden_builtin_def (stpcpy) |
