~linaro-toolchain-dev/cortex-strings/trunk

7 by Michael Hope
Pulled in the routines and packaged them up.
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/*
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 * Copyright (c) 2008 ARM Ltd
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. The name of the company may not be used to endorse or promote
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 *    products derived from this software without specific prior written
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 *    permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
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 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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11 by Michael Hope
Added GLIBC add-on support
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/* For GLIBC:
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#include <string.h>
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#include <memcopy.h>
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#undef strcmp
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*/
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7 by Michael Hope
Pulled in the routines and packaged them up.
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#ifdef __thumb2__
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#define magic1(REG) "#0x01010101"
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#define magic2(REG) "#0x80808080"
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#else
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#define magic1(REG) #REG
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#define magic2(REG) #REG ", lsl #7"
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#endif
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char* __attribute__((naked))
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strcpy (char* dst, const char* src)
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{
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  asm (
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#if !(defined(__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
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      (defined (__thumb__) && !defined (__thumb2__)))
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       "pld	[r1, #0]\n\t"
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       "eor	r2, r0, r1\n\t"
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       "mov	ip, r0\n\t"
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       "tst	r2, #3\n\t"
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       "bne	4f\n\t"
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       "tst	r1, #3\n\t"
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       "bne	3f\n"
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  "5:\n\t"
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#ifndef __thumb2__
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       "str	r5, [sp, #-4]!\n\t"
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       "mov	r5, #0x01\n\t"
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       "orr	r5, r5, r5, lsl #8\n\t"
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       "orr	r5, r5, r5, lsl #16\n\t"
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#endif
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       "str	r4, [sp, #-4]!\n\t"
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       "tst	r1, #4\n\t"
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       "ldr	r3, [r1], #4\n\t"
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       "beq	2f\n\t"
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       "sub	r2, r3, "magic1(r5)"\n\t"
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       "bics	r2, r2, r3\n\t"
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       "tst	r2, "magic2(r5)"\n\t"
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       "itt	eq\n\t"
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       "streq	r3, [ip], #4\n\t"
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       "ldreq	r3, [r1], #4\n"
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       "bne	1f\n\t"
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       /* Inner loop.  We now know that r1 is 64-bit aligned, so we
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	  can safely fetch up to two words.  This allows us to avoid
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	  load stalls.  */
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       ".p2align 2\n"
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  "2:\n\t"
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       "pld	[r1, #8]\n\t"
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       "ldr	r4, [r1], #4\n\t"
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       "sub	r2, r3, "magic1(r5)"\n\t"
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       "bics	r2, r2, r3\n\t"
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       "tst	r2, "magic2(r5)"\n\t"
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       "sub	r2, r4, "magic1(r5)"\n\t"
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       "bne	1f\n\t"
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       "str	r3, [ip], #4\n\t"
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       "bics	r2, r2, r4\n\t"
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       "tst	r2, "magic2(r5)"\n\t"
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       "itt	eq\n\t"
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       "ldreq	r3, [r1], #4\n\t"
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       "streq	r4, [ip], #4\n\t"
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       "beq	2b\n\t"
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       "mov	r3, r4\n"
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  "1:\n\t"
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#ifdef __ARMEB__
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       "rors	r3, r3, #24\n\t"
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#endif
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       "strb	r3, [ip], #1\n\t"
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       "tst	r3, #0xff\n\t"
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#ifdef __ARMEL__
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       "ror	r3, r3, #8\n\t"
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#endif
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       "bne	1b\n\t"
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       "ldr	r4, [sp], #4\n\t"
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#ifndef __thumb2__
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       "ldr	r5, [sp], #4\n\t"
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#endif
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       "BX LR\n"
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       /* Strings have the same offset from word alignment, but it's
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	  not zero.  */
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  "3:\n\t"
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       "tst	r1, #1\n\t"
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       "beq	1f\n\t"
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       "ldrb	r2, [r1], #1\n\t"
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       "strb	r2, [ip], #1\n\t"
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       "cmp	r2, #0\n\t"
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       "it	eq\n"
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       "BXEQ LR\n"
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  "1:\n\t"
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       "tst	r1, #2\n\t"
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       "beq	5b\n\t"
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       "ldrh	r2, [r1], #2\n\t"
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#ifdef __ARMEB__
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       "tst	r2, #0xff00\n\t"
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       "iteet	ne\n\t"
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       "strneh	r2, [ip], #2\n\t"
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       "lsreq	r2, r2, #8\n\t"
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       "streqb	r2, [ip]\n\t"
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       "tstne	r2, #0xff\n\t"
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#else
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       "tst	r2, #0xff\n\t"
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       "itet	ne\n\t"
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       "strneh	r2, [ip], #2\n\t"
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       "streqb	r2, [ip]\n\t"
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       "tstne	r2, #0xff00\n\t"
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#endif
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       "bne	5b\n\t"
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       "BX LR\n"
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       /* src and dst do not have a common word-alignement.  Fall back to
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	  byte copying.  */
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  "4:\n\t"
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       "ldrb	r2, [r1], #1\n\t"
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       "strb	r2, [ip], #1\n\t"
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       "cmp	r2, #0\n\t"
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       "bne	4b\n\t"
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       "BX LR"
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#elif !defined (__thumb__) || defined (__thumb2__)
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       "mov	r3, r0\n\t"
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  "1:\n\t"
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       "ldrb	r2, [r1], #1\n\t"
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       "strb	r2, [r3], #1\n\t"
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       "cmp	r2, #0\n\t"
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       "bne	1b\n\t"
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       "BX LR"
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#else
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       "mov	r3, r0\n\t"
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  "1:\n\t"
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       "ldrb	r2, [r1]\n\t"
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       "add	r1, r1, #1\n\t"
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       "strb	r2, [r3]\n\t"
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       "add	r3, r3, #1\n\t"
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       "cmp	r2, #0\n\t"
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       "bne	1b\n\t"
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       "BX LR"
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#endif
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       );
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}
11 by Michael Hope
Added GLIBC add-on support
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/* For GLIBC: libc_hidden_builtin_def (strcpy) */