1 /* Optimized strcpy implementation for PowerPC64.
2 Copyright (C) 1997, 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 /* See strlen.s for comments on how the end-of-string testing works. */
26 /* char * [r3] strcpy (char *dest [r3], const char *src [r4]) */
28 EALIGN (BP_SYM (strcpy), 4, 0)
31 #define rRTN r3 /* incoming DEST arg preserved as result */
32 /* Note. The Bounded pointer support in this code is broken. This code
33 was inherited from PPC32 and and that support was never completed.
34 Current PPC gcc does not support -fbounds-check or -fbounded-pointers.
35 These artifacts are left in the code as a reminder in case we need
36 bounded pointer support in the future. */
37 #if __BOUNDED_POINTERS__
38 # define rDEST r4 /* pointer to previous word in dest */
39 # define rSRC r5 /* pointer to previous word in src */
43 # define rSRC r4 /* pointer to previous word in src */
44 # define rDEST r5 /* pointer to previous word in dest */
46 #define rWORD r6 /* current word from src */
47 #define rFEFE r7 /* constant 0xfefefefefefefeff (-0x0101010101010101) */
48 #define r7F7F r8 /* constant 0x7f7f7f7f7f7f7f7f */
49 #define rNEG r9 /* ~(word in s1 | 0x7f7f7f7f7f7f7f7f) */
50 #define rALT r10 /* alternate word from src */
52 CHECK_BOUNDS_LOW (rSRC, rLOW, rHIGH)
53 CHECK_BOUNDS_LOW (rDEST, rLOW, rHIGH)
54 STORE_RETURN_BOUNDS (rLOW, rHIGH)
58 clrldi. rTMP, rTMP, 61
59 #if __BOUNDED_POINTERS__
70 addi rFEFE, rFEFE, -0x101
71 addi r7F7F, r7F7F, 0x7f7f
73 insrdi r7F7F, r7F7F, 32, 0
74 add rFEFE, rFEFE, rTMP
77 L(g0): ldu rALT, 8(rSRC)
85 L(g2): add rTMP, rFEFE, rWORD
86 nor rNEG, r7F7F, rWORD
91 /* We've hit the end of the string. Do the rest byte-by-byte. */
93 extrdi. rTMP, rALT, 8, 0
96 extrdi. rTMP, rALT, 8, 8
99 extrdi. rTMP, rALT, 8, 16
102 extrdi. rTMP, rALT, 8, 24
105 extrdi. rTMP, rALT, 8, 32
108 extrdi. rTMP, rALT, 8, 40
111 extrdi. rTMP, rALT, 8, 48
115 /* GKM FIXME: check high bound. */
118 /* Oh well. In this case, we just do a byte-by-byte copy. */
127 L(u0): lbzu rALT, 1(rSRC)
131 nop /* Let 601 load start of loop. */
136 L(u2): stb rWORD, 1(rDEST)
137 /* GKM FIXME: check high bound. */
139 L(u1): stb rALT, 1(rDEST)
140 /* GKM FIXME: check high bound. */
143 END (BP_SYM (strcpy))
144 libc_hidden_builtin_def (strcpy)