#if defined __thumb__ #include "../../string/memset.c" #else #include #include "xscale.h" void * memset (void *dst, int c, size_t len) { int dummy; asm volatile ("tst %0, #0x3" #ifndef __OPTIMIZE_SIZE__ " beq 1f b 2f 0: strb %1, [%0], #1 tst %0, #0x3 beq 1f 2: movs r3, %2 sub %2, %2, #1 bne 0b # At this point we know that %2 == len == -1 (since the SUB has already taken # place). If we fall through to the 1: label (as the code used to do), the # CMP will detect this negative value and branch to the 2: label. This will # test %2 again, but this time against 0. The test will fail and the loop # at 2: will go on for (almost) ever. Hence the explicit branch to the end # of the hand written assembly code. b 4f 1: cmp %2, #0x3 bls 2f and %1, %1, #0xff orr lr, %1, %1, asl #8 cmp %2, #0xf orr lr, lr, lr, asl #16 bls 1f mov r3, lr mov r4, lr mov r5, lr 0: sub %2, %2, #16 stmia %0!, { r3, r4, r5, lr } cmp %2, #0xf bhi 0b 1: cmp %2, #0x7 bls 1f mov r3, lr 0: sub %2, %2, #8 stmia %0!, { r3, lr } cmp %2, #0x7 bhi 0b 1: cmp %2, #0x3 bls 2f 0: sub %2, %2, #4 str lr, [%0], #4 cmp %2, #0x3 bhi 0b " #endif /* !__OPTIMIZE_SIZE__ */ " 2: movs r3, %2 sub %2, %2, #1 beq 4f 0: movs r3, %2 sub %2, %2, #1 strb %1, [%0], #1 bne 0b 4:" : "=&r" (dummy), "=&r" (c), "=&r" (len) : "0" (dst), "1" (c), "2" (len) : "memory", "r3", "r4", "r5", "lr"); return dst; } #endif