ref: 314faec39447f98c0dfd96a91dbd25fd757d106d
dir: /sys/src/libc/sparc/memset.s/
TEXT memset(SB),$0 /* * performance: * (tba) */ MOVW R7, 0(FP) MOVW n+8(FP), R9 /* R9 is count */ MOVW p+0(FP), R10 /* R10 is pointer */ MOVW c+4(FP), R11 /* R11 is char */ ADD R9,R10, R12 /* R12 is end pointer */ /* * if not at least 4 chars, * dont even mess around. * 3 chars to guarantee any * rounding up to a word * boundary and 4 characters * to get at least maybe one * full word store. */ SUBCC $4,R9, R0 BL out /* * turn R11 into a word of characters */ AND $0xff, R11 SLL $8,R11, R7 OR R7, R11 SLL $16,R11, R7 OR R7, R11 /* * store one byte at a time until pointer * is alligned on a word boundary */ l1: ANDCC $3,R10, R0 BE l2 MOVB R11, 0(R10) ADD $1, R10 JMP l1 /* * turn R9 into end pointer-15 * store 16 at a time while theres room */ l2: ADD $-15,R12, R9 SUBCC R10,R9, R0 BLEU l4 l3: MOVW R11, 0(R10) MOVW R11, 4(R10) ADD $16, R10 SUBCC R10,R9, R0 MOVW R11, -8(R10) MOVW R11, -4(R10) BGU l3 /* * turn R9 into end pointer-3 * store 4 at a time while theres room */ l4: ADD $-3,R12, R9 l5: SUBCC R10,R9, R0 BLEU out MOVW R11, 0(R10) ADD $4, R10 JMP l5 /* * last loop, store byte at a time */ out: SUBCC R10,R12, R0 BLEU ret MOVB R11, 0(R10) ADD $1, R10 JMP out ret: MOVW s1+0(FP), R7 RETURN