Home | History | Annotate | Download | only in bionic
      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  * Copyright (c) 2008 ARM Ltd
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the company may not be used to endorse or promote
     15  *    products derived from this software without specific prior written
     16  *    permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
     19  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     20  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
     23  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     24  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     25  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     26  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     27  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  *
     29  * Android adaptation and tweak by Jim Huang <jserv (at) 0xlab.org>.
     30  */
     31 
     32 #include <machine/cpu-features.h>
     33 #include <private/bionic_asm.h>
     34 
     35 ENTRY(strcpy)
     36 	pld	[r1, #0]
     37 	eor	r2, r0, r1
     38 	mov	ip, r0
     39 	tst	r2, #3
     40 	bne	4f
     41 	tst	r1, #3
     42 	bne	3f
     43 5:
     44 	str	r5, [sp, #-4]!
     45 	mov	r5, #0x01
     46 	orr	r5, r5, r5, lsl #8
     47 	orr	r5, r5, r5, lsl #16
     48 
     49 	str	r4, [sp, #-4]!
     50 	tst	r1, #4
     51 	ldr	r3, [r1], #4
     52 	beq	2f
     53 	sub	r2, r3, r5
     54 	bics	r2, r2, r3
     55 	tst	r2, r5, lsl #7
     56 	itt	eq
     57 	streq	r3, [ip], #4
     58 	ldreq	r3, [r1], #4
     59 	bne	1f
     60        /* Inner loop.  We now know that r1 is 64-bit aligned, so we
     61 	  can safely fetch up to two words.  This allows us to avoid
     62 	  load stalls.  */
     63 	.p2align 2
     64 2:
     65 	pld	[r1, #8]
     66 	ldr	r4, [r1], #4
     67 	sub	r2, r3, r5
     68 	bics	r2, r2, r3
     69 	tst	r2, r5, lsl #7
     70 	sub	r2, r4, r5
     71 	bne	1f
     72 	str	r3, [ip], #4
     73 	bics	r2, r2, r4
     74 	tst	r2, r5, lsl #7
     75 	itt	eq
     76 	ldreq	r3, [r1], #4
     77 	streq	r4, [ip], #4
     78 	beq	2b
     79 	mov	r3, r4
     80 1:
     81 #ifdef __ARMEB__
     82 	rors	r3, r3, #24
     83 #endif
     84 	strb	r3, [ip], #1
     85 	tst	r3, #0xff
     86 #ifdef __ARMEL__
     87 	ror	r3, r3, #8
     88 #endif
     89 	bne	1b
     90 	ldr	r4, [sp], #4
     91 	ldr	r5, [sp], #4
     92 	bx	lr
     93 
     94        /* Strings have the same offset from word alignment, but it's
     95 	  not zero.  */
     96 3:
     97 	tst	r1, #1
     98 	beq	1f
     99 	ldrb	r2, [r1], #1
    100 	strb	r2, [ip], #1
    101 	cmp	r2, #0
    102 	it	eq
    103 	bxeq	lr
    104 1:
    105 	tst	r1, #2
    106 	beq	5b
    107 	ldrh	r2, [r1], #2
    108 #ifdef __ARMEB__
    109 	tst	r2, #0xff00
    110 	iteet	ne
    111 	strneh	r2, [ip], #2
    112 	lsreq	r2, r2, #8
    113 	streqb	r2, [ip]
    114 	tstne	r2, #0xff
    115 #else
    116 	tst	r2, #0xff
    117 	itet	ne
    118 	strneh	r2, [ip], #2
    119 	streqb	r2, [ip]
    120 	tstne	r2, #0xff00
    121 #endif
    122 	bne	5b
    123 	bx	lr
    124 
    125        /* src and dst do not have a common word-alignement.  Fall back to
    126 	  byte copying.  */
    127 4:
    128 	ldrb	r2, [r1], #1
    129 	strb	r2, [ip], #1
    130 	cmp	r2, #0
    131 	bne	4b
    132 	bx	lr
    133 END(strcpy)
    134