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Diffstat (limited to 'libc/arch-arm/bionic/strcpy.S')
-rw-r--r-- | libc/arch-arm/bionic/strcpy.S | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/libc/arch-arm/bionic/strcpy.S b/libc/arch-arm/bionic/strcpy.S new file mode 100644 index 0000000..70c353f --- /dev/null +++ b/libc/arch-arm/bionic/strcpy.S @@ -0,0 +1,138 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * Copyright (c) 2008 ARM Ltd + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the company may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Android adaptation and tweak by Jim Huang <jserv@0xlab.org>. + */ + +#include <machine/cpu-features.h> + + .text + + .global strcpy + .type strcpy, %function + .align 4 + +strcpy: + .fnstart + PLD(r1, #0) + eor r2, r0, r1 + mov ip, r0 + tst r2, #3 + bne 4f + tst r1, #3 + bne 3f +5: + str r5, [sp, #-4]! + mov r5, #0x01 + orr r5, r5, r5, lsl #8 + orr r5, r5, r5, lsl #16 + + str r4, [sp, #-4]! + tst r1, #4 + ldr r3, [r1], #4 + beq 2f + sub r2, r3, r5 + bics r2, r2, r3 + tst r2, r5, lsl #7 + itt eq + streq r3, [ip], #4 + ldreq r3, [r1], #4 + bne 1f + /* Inner loop. We now know that r1 is 64-bit aligned, so we + can safely fetch up to two words. This allows us to avoid + load stalls. */ + .p2align 2 +2: + PLD(r1, #8) + ldr r4, [r1], #4 + sub r2, r3, r5 + bics r2, r2, r3 + tst r2, r5, lsl #7 + sub r2, r4, r5 + bne 1f + str r3, [ip], #4 + bics r2, r2, r4 + tst r2, r5, lsl #7 + itt eq + ldreq r3, [r1], #4 + streq r4, [ip], #4 + beq 2b + mov r3, r4 +1: +#ifdef __ARMEB__ + rors r3, r3, #24 +#endif + strb r3, [ip], #1 + tst r3, #0xff +#ifdef __ARMEL__ + ror r3, r3, #8 +#endif + bne 1b + ldr r4, [sp], #4 + ldr r5, [sp], #4 + bx lr + + /* Strings have the same offset from word alignment, but it's + not zero. */ +3: + tst r1, #1 + beq 1f + ldrb r2, [r1], #1 + strb r2, [ip], #1 + cmp r2, #0 + it eq + bxeq lr +1: + tst r1, #2 + beq 5b + ldrh r2, [r1], #2 +#ifdef __ARMEB__ + tst r2, #0xff00 + iteet ne + strneh r2, [ip], #2 + lsreq r2, r2, #8 + streqb r2, [ip] + tstne r2, #0xff +#else + tst r2, #0xff + itet ne + strneh r2, [ip], #2 + streqb r2, [ip] + tstne r2, #0xff00 +#endif + bne 5b + bx lr + + /* src and dst do not have a common word-alignement. Fall back to + byte copying. */ +4: + ldrb r2, [r1], #1 + strb r2, [ip], #1 + cmp r2, #0 + bne 4b + bx lr |