diff options
Diffstat (limited to 'newlib/libc/machine/xscale/memcmp.c')
| -rw-r--r-- | newlib/libc/machine/xscale/memcmp.c | 176 |
1 files changed, 88 insertions, 88 deletions
diff --git a/newlib/libc/machine/xscale/memcmp.c b/newlib/libc/machine/xscale/memcmp.c index 1eba4b8dd..1b85af45d 100644 --- a/newlib/libc/machine/xscale/memcmp.c +++ b/newlib/libc/machine/xscale/memcmp.c @@ -13,96 +13,96 @@ memcmp (const void * s1, const void * s2, size_t len) int result; asm ( #ifndef __OPTIMIZE_SIZE__ -"\n\ - cmp %2, #0x3 @ Is the length a multiple of four ?\n\ - bls 6f @ no = goto SLOW CHECK\n\ - and r2, %0, #0x3 @ get alignment of first pointer\n\ - and r3, %1, #0x3 @ get alignment of second pointer\n\ - cmp r2, r3 @ Do the two pointers share the same alignment ?\n\ - bne 6f @ no = goto SLOW CHECK\n\ - mov lr, %0 @ copy first pointer into LR\n\ - mov r4, %1 @ copy second pointer into R4\n\ - cmp r2, #0x0 @ Are we comparing word aligned pointers ?\n\ - beq 3f @ yes = goto START WORD CHECK LOOP\n\ - b 1f @ jump to LOOP TEST\n\ -0: @ LOOP START\n\ - ldrb r2, [lr], #1 @ load byte from LR, post inc.\n\ -" PRELOADSTR("lr") " @ preload\n\ - ldrb r3, [r4], #1 @ load byte from R4, post inc.\n\ -" PRELOADSTR("r4") " @ preload\n\ - cmp r2, r3 @ are the two bytes the same ?\n\ - bne 5f @ no = goto EXIT\n\ - tst lr, #0x3 @ has the LR become word aligned ?\n\ - bne 1f @ no = skip the next test\n\ - cmp %2, #4 @ is the count >= 4 ?\n\ - bhs 3f @ yes = goto START WORD CHECK LOOP\n\ -1: @ LOOP TEST\n\ - sub %2, %2, #1 @ decrement count by one\n\ - cmn %2, #0x1 @ has the count reached -1 ?\n\ - bne 0b @ no = loop back to LOOP START\n\ - b 4f @ goto PASS END\n\ -\n\ -0: @ ??\n\ - cmp %2, #0x7 @ Is the count a multiple of 8 ?\n\ - bls 3f @ no = goto ???\n\ - ldmia lr,{r2, r3} @ get two words from first pointer, post inc\n\ - ldmia r4,{r5, r6} @ get two words from second pointer, post inc\n\ - sub %2, %2, #0x4 @ decrement count by 4\n\ - cmp r2, r5 @ has the count reached ????\n\ - bne 1f @ no = goto\n\ - sub %2, %2, #0x4 @ decrement the count by 4\n\ - add lr, lr, #0x4 @ add 4 to first pointer\n\ - add r4, r4, #0x4 @ add 4 to second pointer\n\ - cmp r3, r6 @ ???\n\ - beq 0b @ goto ???\n\ -1: @ ??\n\ - add %2, %2, #0x4 @ Add four to count\n\ - sub %0, lr, #0x4 @ decrement first pointer by 4\n\ - sub %1, r4, #0x4 @ decrement second pointer by 4\n\ - b 6f @ goto SLOW CHECK\n\ -\n\ -3: @ START WORD CHECK LOOP\n\ - cmp %2, #0x3 @ is the count <= 3 ?\n\ - bls 1f @ yes = goto CHECK BYTES BY HAND\n\ - ldr r2, [lr], #4 @ get word from LR, post inc\n\ - ldr r3, [r4], #4 @ get word from R4, post inc\n\ - sub %2, %2, #4 @ decrement count by 4\n\ - cmp r2, r3 @ are the two words the same ?\n\ - bne 1f @ no = goto CHECK WORD CONTENTS\n\ -0: @ WORD CHECK LOOP\n\ - cmp %2, #0x3 @ is the count <= 3 ?\n\ - bls 1f @ yes = goto CHECK BYTES BY HAND\n\ - ldr r2, [lr], #4 @ load word from LR, post inc\n\ -" PRELOADSTR("lr") " @ preload\n\ - ldr r3, [r4], #4 @ load word from R4, post inc\n\ -" PRELOADSTR("r4") " @ preload\n\ - sub %2, %2, #4 @ decrement count by 4\n\ - cmp r2, r3 @ are the two words the same ?\n\ - beq 0b @ yes = goto WORD CHECK LOOP\n\ -1: @ CHECK BYTES BY HAND\n\ - sub %0, lr, #0x4 @ move LR back a word and put into first pointer\n\ - sub %1, r4, #0x4 @ move R4 back a word and put into second pointer\n\ - add %2, %2, #4 @ increment the count by 4\n\ +" + cmp %2, #0x3 @ Is the length a multiple of four ? + bls 6f @ no = goto SLOW CHECK + and r2, %0, #0x3 @ get alignment of first pointer + and r3, %1, #0x3 @ get alignment of second pointer + cmp r2, r3 @ Do the two pointers share the same alignment ? + bne 6f @ no = goto SLOW CHECK + mov lr, %0 @ copy first pointer into LR + mov r4, %1 @ copy second pointer into R4 + cmp r2, #0x0 @ Are we comparing word aligned pointers ? + beq 3f @ yes = goto START WORD CHECK LOOP + b 1f @ jump to LOOP TEST +0: @ LOOP START + ldrb r2, [lr], #1 @ load byte from LR, post inc. +" PRELOADSTR("lr") " @ preload + ldrb r3, [r4], #1 @ load byte from R4, post inc. +" PRELOADSTR("r4") " @ preload + cmp r2, r3 @ are the two bytes the same ? + bne 5f @ no = goto EXIT + tst lr, #0x3 @ has the LR become word aligned ? + bne 1f @ no = skip the next test + cmp %2, #4 @ is the count >= 4 ? + bhs 3f @ yes = goto START WORD CHECK LOOP +1: @ LOOP TEST + sub %2, %2, #1 @ decrement count by one + cmn %2, #0x1 @ has the count reached -1 ? + bne 0b @ no = loop back to LOOP START + b 4f @ goto PASS END + +0: @ ?? + cmp %2, #0x7 @ Is the count a multiple of 8 ? + bls 3f @ no = goto ??? + ldmia lr,{r2, r3} @ get two words from first pointer, post inc + ldmia r4,{r5, r6} @ get two words from second pointer, post inc + sub %2, %2, #0x4 @ decrement count by 4 + cmp r2, r5 @ has the count reached ???? + bne 1f @ no = goto + sub %2, %2, #0x4 @ decrement the count by 4 + add lr, lr, #0x4 @ add 4 to first pointer + add r4, r4, #0x4 @ add 4 to second pointer + cmp r3, r6 @ ??? + beq 0b @ goto ??? +1: @ ?? + add %2, %2, #0x4 @ Add four to count + sub %0, lr, #0x4 @ decrement first pointer by 4 + sub %1, r4, #0x4 @ decrement second pointer by 4 + b 6f @ goto SLOW CHECK + +3: @ START WORD CHECK LOOP + cmp %2, #0x3 @ is the count <= 3 ? + bls 1f @ yes = goto CHECK BYTES BY HAND + ldr r2, [lr], #4 @ get word from LR, post inc + ldr r3, [r4], #4 @ get word from R4, post inc + sub %2, %2, #4 @ decrement count by 4 + cmp r2, r3 @ are the two words the same ? + bne 1f @ no = goto CHECK WORD CONTENTS +0: @ WORD CHECK LOOP + cmp %2, #0x3 @ is the count <= 3 ? + bls 1f @ yes = goto CHECK BYTES BY HAND + ldr r2, [lr], #4 @ load word from LR, post inc +" PRELOADSTR("lr") " @ preload + ldr r3, [r4], #4 @ load word from R4, post inc +" PRELOADSTR("r4") " @ preload + sub %2, %2, #4 @ decrement count by 4 + cmp r2, r3 @ are the two words the same ? + beq 0b @ yes = goto WORD CHECK LOOP +1: @ CHECK BYTES BY HAND + sub %0, lr, #0x4 @ move LR back a word and put into first pointer + sub %1, r4, #0x4 @ move R4 back a word and put into second pointer + add %2, %2, #4 @ increment the count by 4 @ fall through into SLOW CHECK" #endif /* !__OPTIMIZE_SIZE__ */ -"\n\ -6: @ SLOW CHECK\n\ - sub %2, %2, #1 @ Decrement the count by one\n\ - cmn %2, #0x1 @ Has the count reached -1 ?\n\ - beq 4f @ Yes - we are finished, goto PASS END\n\ -0: @ LOOP1\n\ - ldrb r2, [%0], #1 @ get byte from first pointer\n\ -" PRELOADSTR("%0") " @ preload first pointer\n\ - ldrb r3, [%1], #1 @ get byte from second pointer\n\ -" PRELOADSTR("%1") " @ preload second pointer\n\ - cmp r2, r3 @ compare the two loaded bytes\n\ - bne 5f @ if they are not equal goto EXIT\n\ - sub %2, %2, #1 @ decremented count by 1\n\ - cmn %2, #0x1 @ has the count reached -1 ?\n\ - bne 0b @ no = then go back to LOOP1\n\ -4: @ PASS END\n\ - mov r3, r2 @ Default return value is 0\n\ -5: @ EXIT\n\ +" +6: @ SLOW CHECK + sub %2, %2, #1 @ Decrement the count by one + cmn %2, #0x1 @ Has the count reached -1 ? + beq 4f @ Yes - we are finished, goto PASS END +0: @ LOOP1 + ldrb r2, [%0], #1 @ get byte from first pointer +" PRELOADSTR("%0") " @ preload first pointer + ldrb r3, [%1], #1 @ get byte from second pointer +" PRELOADSTR("%1") " @ preload second pointer + cmp r2, r3 @ compare the two loaded bytes + bne 5f @ if they are not equal goto EXIT + sub %2, %2, #1 @ decremented count by 1 + cmn %2, #0x1 @ has the count reached -1 ? + bne 0b @ no = then go back to LOOP1 +4: @ PASS END + mov r3, r2 @ Default return value is 0 +5: @ EXIT rsb %0, r3, r2 @ return difference between last two bytes loaded" : "=r" (result), "=&r" (s2), "=&r" (len) : "0" (s1), "1" (s2), "2" (len) |