405 lines
10 KiB
C
405 lines
10 KiB
C
|
/*
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "arm_asm.h"
|
||
|
|
#include <_ansi.h>
|
||
|
|
#include <string.h>
|
||
|
|
|
||
|
|
#ifdef __ARMEB__
|
||
|
|
#define SHFT2LSB "lsl"
|
||
|
|
#define SHFT2MSB "lsr"
|
||
|
|
#define MSB "0x000000ff"
|
||
|
|
#define LSB "0xff000000"
|
||
|
|
#else
|
||
|
|
#define SHFT2LSB "lsr"
|
||
|
|
#define SHFT2MSB "lsl"
|
||
|
|
#define MSB "0xff000000"
|
||
|
|
#define LSB "0x000000ff"
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __thumb2__
|
||
|
|
#define magic1(REG) "#0x01010101"
|
||
|
|
#define magic2(REG) "#0x80808080"
|
||
|
|
#else
|
||
|
|
#define magic1(REG) #REG
|
||
|
|
#define magic2(REG) #REG ", lsl #7"
|
||
|
|
#endif
|
||
|
|
|
||
|
|
int
|
||
|
|
__attribute__((naked)) strcmp (const char* s1, const char* s2)
|
||
|
|
{
|
||
|
|
asm(
|
||
|
|
#if !(defined(__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
|
||
|
|
(defined (__thumb__) && !defined (__thumb2__)))
|
||
|
|
"optpld r0\n\t"
|
||
|
|
"optpld r1\n\t"
|
||
|
|
"eor r2, r0, r1\n\t"
|
||
|
|
"tst r2, #3\n\t"
|
||
|
|
/* Strings not at same byte offset from a word boundary. */
|
||
|
|
"bne strcmp_unaligned\n\t"
|
||
|
|
"ands r2, r0, #3\n\t"
|
||
|
|
"bic r0, r0, #3\n\t"
|
||
|
|
"bic r1, r1, #3\n\t"
|
||
|
|
"ldr ip, [r0], #4\n\t"
|
||
|
|
"it eq\n\t"
|
||
|
|
"ldreq r3, [r1], #4\n\t"
|
||
|
|
"beq 1f\n\t"
|
||
|
|
/* Although s1 and s2 have identical initial alignment, they are
|
||
|
|
not currently word aligned. Rather than comparing bytes,
|
||
|
|
make sure that any bytes fetched from before the addressed
|
||
|
|
bytes are forced to 0xff. Then they will always compare
|
||
|
|
equal. */
|
||
|
|
"eor r2, r2, #3\n\t"
|
||
|
|
"lsl r2, r2, #3\n\t"
|
||
|
|
"mvn r3, #"MSB"\n\t"
|
||
|
|
SHFT2LSB" r2, r3, r2\n\t"
|
||
|
|
"ldr r3, [r1], #4\n\t"
|
||
|
|
"orr ip, ip, r2\n\t"
|
||
|
|
"orr r3, r3, r2\n"
|
||
|
|
"1:\n\t"
|
||
|
|
#ifndef __thumb2__
|
||
|
|
/* Load the 'magic' constant 0x01010101. */
|
||
|
|
"str r4, [sp, #-4]!\n\t"
|
||
|
|
"mov r4, #1\n\t"
|
||
|
|
"orr r4, r4, r4, lsl #8\n\t"
|
||
|
|
"orr r4, r4, r4, lsl #16\n"
|
||
|
|
#endif
|
||
|
|
".p2align 2\n"
|
||
|
|
"4:\n\t"
|
||
|
|
"optpld r0, #8\n\t"
|
||
|
|
"optpld r1, #8\n\t"
|
||
|
|
"sub r2, ip, "magic1(r4)"\n\t"
|
||
|
|
"cmp ip, r3\n\t"
|
||
|
|
"itttt eq\n\t"
|
||
|
|
/* check for any zero bytes in first word */
|
||
|
|
"eoreq r2, r2, ip\n\t"
|
||
|
|
"tsteq r2, "magic2(r4)"\n\t"
|
||
|
|
"ldreq ip, [r0], #4\n\t"
|
||
|
|
"ldreq r3, [r1], #4\n\t"
|
||
|
|
"beq 4b\n"
|
||
|
|
"2:\n\t"
|
||
|
|
/* There's a zero or a different byte in the word */
|
||
|
|
SHFT2MSB" r0, ip, #24\n\t"
|
||
|
|
SHFT2LSB" ip, ip, #8\n\t"
|
||
|
|
"cmp r0, #1\n\t"
|
||
|
|
"it cs\n\t"
|
||
|
|
"cmpcs r0, r3, "SHFT2MSB" #24\n\t"
|
||
|
|
"it eq\n\t"
|
||
|
|
SHFT2LSB"eq r3, r3, #8\n\t"
|
||
|
|
"beq 2b\n\t"
|
||
|
|
"sub r0, r0, r3, "SHFT2MSB" #24\n\t"
|
||
|
|
#ifndef __thumb2__
|
||
|
|
"ldr r4, [sp], #4\n\t"
|
||
|
|
#endif
|
||
|
|
"RETURN"
|
||
|
|
#elif (defined (__thumb__) && !defined (__thumb2__))
|
||
|
|
"1:\n\t"
|
||
|
|
"ldrb r2, [r0]\n\t"
|
||
|
|
"ldrb r3, [r1]\n\t"
|
||
|
|
"add r0, r0, #1\n\t"
|
||
|
|
"add r1, r1, #1\n\t"
|
||
|
|
"cmp r2, #0\n\t"
|
||
|
|
"beq 2f\n\t"
|
||
|
|
"cmp r2, r3\n\t"
|
||
|
|
"beq 1b\n\t"
|
||
|
|
"2:\n\t"
|
||
|
|
"sub r0, r2, r3\n\t"
|
||
|
|
"bx lr"
|
||
|
|
#else
|
||
|
|
"3:\n\t"
|
||
|
|
"ldrb r2, [r0], #1\n\t"
|
||
|
|
"ldrb r3, [r1], #1\n\t"
|
||
|
|
"cmp r2, #1\n\t"
|
||
|
|
"it cs\n\t"
|
||
|
|
"cmpcs r2, r3\n\t"
|
||
|
|
"beq 3b\n\t"
|
||
|
|
"sub r0, r2, r3\n\t"
|
||
|
|
"RETURN"
|
||
|
|
#endif
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
#if !(defined(__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
|
||
|
|
(defined (__thumb__) && !defined (__thumb2__)))
|
||
|
|
static int __attribute__((naked, used))
|
||
|
|
strcmp_unaligned(const char* s1, const char* s2)
|
||
|
|
{
|
||
|
|
#if 0
|
||
|
|
/* The assembly code below is based on the following alogrithm. */
|
||
|
|
#ifdef __ARMEB__
|
||
|
|
#define RSHIFT <<
|
||
|
|
#define LSHIFT >>
|
||
|
|
#else
|
||
|
|
#define RSHIFT >>
|
||
|
|
#define LSHIFT <<
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define body(shift) \
|
||
|
|
mask = 0xffffffffU RSHIFT shift; \
|
||
|
|
w1 = *wp1++; \
|
||
|
|
w2 = *wp2++; \
|
||
|
|
do \
|
||
|
|
{ \
|
||
|
|
t1 = w1 & mask; \
|
||
|
|
if (__builtin_expect(t1 != w2 RSHIFT shift, 0)) \
|
||
|
|
{ \
|
||
|
|
w2 RSHIFT= shift; \
|
||
|
|
break; \
|
||
|
|
} \
|
||
|
|
if (__builtin_expect(((w1 - b1) ^ w1) & (b1 << 7), 0)) \
|
||
|
|
{ \
|
||
|
|
if ((((w1 - b1) ^ w1) & (b1 << 7)) & mask) \
|
||
|
|
w2 RSHIFT= shift; \
|
||
|
|
else \
|
||
|
|
{ \
|
||
|
|
w2 = *wp2; \
|
||
|
|
t1 = w1 RSHIFT (32 - shift); \
|
||
|
|
w2 = (w2 LSHIFT (32 - shift)) RSHIFT (32 - shift); \
|
||
|
|
} \
|
||
|
|
break; \
|
||
|
|
} \
|
||
|
|
w2 = *wp2++; \
|
||
|
|
t1 ^= w1; \
|
||
|
|
if (__builtin_expect(t1 != w2 LSHIFT (32 - shift), 0)) \
|
||
|
|
{ \
|
||
|
|
t1 = w1 >> (32 - shift); \
|
||
|
|
w2 = (w2 << (32 - shift)) RSHIFT (32 - shift); \
|
||
|
|
break; \
|
||
|
|
} \
|
||
|
|
w1 = *wp1++; \
|
||
|
|
} while (1)
|
||
|
|
|
||
|
|
const unsigned* wp1;
|
||
|
|
const unsigned* wp2;
|
||
|
|
unsigned w1, w2;
|
||
|
|
unsigned mask;
|
||
|
|
unsigned shift;
|
||
|
|
unsigned b1 = 0x01010101;
|
||
|
|
char c1, c2;
|
||
|
|
unsigned t1;
|
||
|
|
|
||
|
|
while (((unsigned) s1) & 3)
|
||
|
|
{
|
||
|
|
c1 = *s1++;
|
||
|
|
c2 = *s2++;
|
||
|
|
if (c1 == 0 || c1 != c2)
|
||
|
|
return c1 - (int)c2;
|
||
|
|
}
|
||
|
|
wp1 = (unsigned*) (((unsigned)s1) & ~3);
|
||
|
|
wp2 = (unsigned*) (((unsigned)s2) & ~3);
|
||
|
|
t1 = ((unsigned) s2) & 3;
|
||
|
|
if (t1 == 1)
|
||
|
|
{
|
||
|
|
body(8);
|
||
|
|
}
|
||
|
|
else if (t1 == 2)
|
||
|
|
{
|
||
|
|
body(16);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
body (24);
|
||
|
|
}
|
||
|
|
|
||
|
|
do
|
||
|
|
{
|
||
|
|
#ifdef __ARMEB__
|
||
|
|
c1 = (char) t1 >> 24;
|
||
|
|
c2 = (char) w2 >> 24;
|
||
|
|
#else
|
||
|
|
c1 = (char) t1;
|
||
|
|
c2 = (char) w2;
|
||
|
|
#endif
|
||
|
|
t1 RSHIFT= 8;
|
||
|
|
w2 RSHIFT= 8;
|
||
|
|
} while (c1 != 0 && c1 == c2);
|
||
|
|
return c1 - c2;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
asm("wp1 .req r0\n\t"
|
||
|
|
"wp2 .req r1\n\t"
|
||
|
|
"b1 .req r2\n\t"
|
||
|
|
"w1 .req r4\n\t"
|
||
|
|
"w2 .req r5\n\t"
|
||
|
|
"t1 .req ip\n\t"
|
||
|
|
"@ r3 is scratch\n"
|
||
|
|
|
||
|
|
/* First of all, compare bytes until wp1(sp1) is word-aligned. */
|
||
|
|
"1:\n\t"
|
||
|
|
"tst wp1, #3\n\t"
|
||
|
|
"beq 2f\n\t"
|
||
|
|
"ldrb r2, [wp1], #1\n\t"
|
||
|
|
"ldrb r3, [wp2], #1\n\t"
|
||
|
|
"cmp r2, #1\n\t"
|
||
|
|
"it cs\n\t"
|
||
|
|
"cmpcs r2, r3\n\t"
|
||
|
|
"beq 1b\n\t"
|
||
|
|
"sub r0, r2, r3\n\t"
|
||
|
|
"RETURN\n"
|
||
|
|
|
||
|
|
"2:\n\t"
|
||
|
|
"str r5, [sp, #-4]!\n\t"
|
||
|
|
"str r4, [sp, #-4]!\n\t"
|
||
|
|
// "stmfd sp!, {r4, r5}\n\t"
|
||
|
|
"mov b1, #1\n\t"
|
||
|
|
"orr b1, b1, b1, lsl #8\n\t"
|
||
|
|
"orr b1, b1, b1, lsl #16\n\t"
|
||
|
|
|
||
|
|
"and t1, wp2, #3\n\t"
|
||
|
|
"bic wp2, wp2, #3\n\t"
|
||
|
|
"ldr w1, [wp1], #4\n\t"
|
||
|
|
"ldr w2, [wp2], #4\n\t"
|
||
|
|
"cmp t1, #2\n\t"
|
||
|
|
"beq 2f\n\t"
|
||
|
|
"bhi 3f\n"
|
||
|
|
|
||
|
|
/* Critical inner Loop: Block with 3 bytes initial overlap */
|
||
|
|
".p2align 2\n"
|
||
|
|
"1:\n\t"
|
||
|
|
"bic t1, w1, #"MSB"\n\t"
|
||
|
|
"cmp t1, w2, "SHFT2LSB" #8\n\t"
|
||
|
|
"sub r3, w1, b1\n\t"
|
||
|
|
"eor r3, r3, w1\n\t"
|
||
|
|
"bne 4f\n\t"
|
||
|
|
"ands r3, r3, b1, lsl #7\n\t"
|
||
|
|
"it eq\n\t"
|
||
|
|
"ldreq w2, [wp2], #4\n\t"
|
||
|
|
"bne 5f\n\t"
|
||
|
|
"eor t1, t1, w1\n\t"
|
||
|
|
"cmp t1, w2, "SHFT2MSB" #24\n\t"
|
||
|
|
"bne 6f\n\t"
|
||
|
|
"ldr w1, [wp1], #4\n\t"
|
||
|
|
"b 1b\n"
|
||
|
|
"4:\n\t"
|
||
|
|
SHFT2LSB" w2, w2, #8\n\t"
|
||
|
|
"b 8f\n"
|
||
|
|
|
||
|
|
"5:\n\t"
|
||
|
|
"bics r3, r3, #"MSB"\n\t"
|
||
|
|
"bne 7f\n\t"
|
||
|
|
"ldrb w2, [wp2]\n\t"
|
||
|
|
SHFT2LSB" t1, w1, #24\n\t"
|
||
|
|
#ifdef __ARMEB__
|
||
|
|
SHFT2LSB" w2, w2, #24\n\t"
|
||
|
|
#endif
|
||
|
|
"b 8f\n"
|
||
|
|
|
||
|
|
"6:\n\t"
|
||
|
|
SHFT2LSB" t1, w1, #24\n\t"
|
||
|
|
"and w2, w2, #"LSB"\n\t"
|
||
|
|
"b 8f\n"
|
||
|
|
|
||
|
|
/* Critical inner Loop: Block with 2 bytes initial overlap */
|
||
|
|
".p2align 2\n"
|
||
|
|
"2:\n\t"
|
||
|
|
SHFT2MSB" t1, w1, #16\n\t"
|
||
|
|
"sub r3, w1, b1\n\t"
|
||
|
|
SHFT2LSB" t1, t1, #16\n\t"
|
||
|
|
"eor r3, r3, w1\n\t"
|
||
|
|
"cmp t1, w2, "SHFT2LSB" #16\n\t"
|
||
|
|
"bne 4f\n\t"
|
||
|
|
"ands r3, r3, b1, lsl #7\n\t"
|
||
|
|
"it eq\n\t"
|
||
|
|
"ldreq w2, [wp2], #4\n\t"
|
||
|
|
"bne 5f\n\t"
|
||
|
|
"eor t1, t1, w1\n\t"
|
||
|
|
"cmp t1, w2, "SHFT2MSB" #16\n\t"
|
||
|
|
"bne 6f\n\t"
|
||
|
|
"ldr w1, [wp1], #4\n\t"
|
||
|
|
"b 2b\n"
|
||
|
|
|
||
|
|
"5:\n\t"
|
||
|
|
SHFT2MSB"s r3, r3, #16\n\t"
|
||
|
|
"bne 7f\n\t"
|
||
|
|
"ldrh w2, [wp2]\n\t"
|
||
|
|
SHFT2LSB" t1, w1, #16\n\t"
|
||
|
|
#ifdef __ARMEB__
|
||
|
|
SHFT2LSB" w2, w2, #16\n\t"
|
||
|
|
#endif
|
||
|
|
"b 8f\n"
|
||
|
|
|
||
|
|
"6:\n\t"
|
||
|
|
SHFT2MSB" w2, w2, #16\n\t"
|
||
|
|
SHFT2LSB" t1, w1, #16\n\t"
|
||
|
|
"4:\n\t"
|
||
|
|
SHFT2LSB" w2, w2, #16\n\t"
|
||
|
|
"b 8f\n\t"
|
||
|
|
|
||
|
|
/* Critical inner Loop: Block with 1 byte initial overlap */
|
||
|
|
".p2align 2\n"
|
||
|
|
"3:\n\t"
|
||
|
|
"and t1, w1, #"LSB"\n\t"
|
||
|
|
"cmp t1, w2, "SHFT2LSB" #24\n\t"
|
||
|
|
"sub r3, w1, b1\n\t"
|
||
|
|
"eor r3, r3, w1\n\t"
|
||
|
|
"bne 4f\n\t"
|
||
|
|
"ands r3, r3, b1, lsl #7\n\t"
|
||
|
|
"it eq\n\t"
|
||
|
|
"ldreq w2, [wp2], #4\n\t"
|
||
|
|
"bne 5f\n\t"
|
||
|
|
"eor t1, t1, w1\n\t"
|
||
|
|
"cmp t1, w2, "SHFT2MSB" #8\n\t"
|
||
|
|
"bne 6f\n\t"
|
||
|
|
"ldr w1, [wp1], #4\n\t"
|
||
|
|
"b 3b\n"
|
||
|
|
"4:\n\t"
|
||
|
|
SHFT2LSB" w2, w2, #24\n\t"
|
||
|
|
"b 8f\n"
|
||
|
|
"5:\n\t"
|
||
|
|
"tst r3, #128\n\t"
|
||
|
|
"bne 7f\n\t"
|
||
|
|
"ldr w2, [wp2], #4\n"
|
||
|
|
"6:\n\t"
|
||
|
|
SHFT2LSB" t1, w1, #8\n\t"
|
||
|
|
"bic w2, w2, #"MSB"\n\t"
|
||
|
|
"b 8f\n"
|
||
|
|
"7:\n\t"
|
||
|
|
"mov r0, #0\n\t"
|
||
|
|
// "ldmfd sp!, {r4, r5}\n\t"
|
||
|
|
"ldr r4, [sp], #4\n\t"
|
||
|
|
"ldr r5, [sp], #4\n\t"
|
||
|
|
"RETURN\n"
|
||
|
|
"8:\n\t"
|
||
|
|
"and r2, t1, #"LSB"\n\t"
|
||
|
|
"and r0, w2, #"LSB"\n\t"
|
||
|
|
"cmp r0, #1\n\t"
|
||
|
|
"it cs\n\t"
|
||
|
|
"cmpcs r0, r2\n\t"
|
||
|
|
"itt eq\n\t"
|
||
|
|
SHFT2LSB"eq t1, t1, #8\n\t"
|
||
|
|
SHFT2LSB"eq w2, w2, #8\n\t"
|
||
|
|
"beq 8b\n\t"
|
||
|
|
"sub r0, r2, r0\n\t"
|
||
|
|
// "ldmfd sp!, {r4, r5}\n\t"
|
||
|
|
"ldr r4, [sp], #4\n\t"
|
||
|
|
"ldr r5, [sp], #4\n\t"
|
||
|
|
"RETURN");
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|