/* Optimized strcpy implementation for PowerPC. Copyright (C) 1997, 1999, 2000 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <sysdep.h> #include <bp-sym.h> #include <bp-asm.h> /* See strlen.s for comments on how the end-of-string testing works. */ /* char * [r3] strcpy (char *dest [r3], const char *src [r4]) */ EALIGN (BP_SYM (strcpy), 4, 0) #define rTMP r0 #define rRTN r3 /* incoming DEST arg preserved as result */ #if __BOUNDED_POINTERS__ # define rDEST r4 /* pointer to previous word in dest */ # define rSRC r5 /* pointer to previous word in src */ # define rLOW r11 # define rHIGH r12 #else # define rSRC r4 /* pointer to previous word in src */ # define rDEST r5 /* pointer to previous word in dest */ #endif #define rWORD r6 /* current word from src */ #define rFEFE r7 /* constant 0xfefefeff (-0x01010101) */ #define r7F7F r8 /* constant 0x7f7f7f7f */ #define rNEG r9 /* ~(word in s1 | 0x7f7f7f7f) */ #define rALT r10 /* alternate word from src */ CHECK_BOUNDS_LOW (rSRC, rLOW, rHIGH) CHECK_BOUNDS_LOW (rDEST, rLOW, rHIGH) STORE_RETURN_BOUNDS (rLOW, rHIGH) or rTMP, rSRC, rRTN clrlwi. rTMP, rTMP, 30 #if __BOUNDED_POINTERS__ addi rDEST, rDEST, -4 #else addi rDEST, rRTN, -4 #endif 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): rlwinm. rTMP, rALT, 8, 24, 31 stb rTMP, 4(rDEST) beqlr- rlwinm. rTMP, rALT, 16, 24, 31 stb rTMP, 5(rDEST) beqlr- rlwinm. rTMP, rALT, 24, 24, 31 stb rTMP, 6(rDEST) beqlr- stb rALT, 7(rDEST) /* GKM FIXME: check high bound. */ blr /* Oh well. In this case, we just do a byte-by-byte copy. */ .align 4 nop L(unaligned): lbz rWORD, 0(rSRC) addi rDEST, rRTN, -1 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): stb rWORD, 1(rDEST) /* GKM FIXME: check high bound. */ blr L(u1): stb rALT, 1(rDEST) /* GKM FIXME: check high bound. */ blr END (BP_SYM (strcpy))