ref: 2e9835e771c54cb9a0c9cd81012e7b4b75f878f7
dir: /sys/src/libc/68000/memset.s/
TEXT memset(SB), $0 MOVL n+8(FP), R0 BLE return MOVL s1+0(FP), A1 CLRL R1 MOVB c+7(FP), R1 BEQ l1 /* * create 4 replicated copies * of the byte in R1 */ MOVL R1, R2 ASLL $8, R2 ORL R2, R1 MOVL R1, R2 SWAP R2 ORL R2, R1 /* * byte-at-a-time until alligned */ l1: MOVL A1, R1 ANDL $3, R1 BEQ l2 SUBL $1, R0 BLT return MOVB R1, (A1)+ BRA l1 /* * quad-long-at-a-time set */ l2: SUBL $16, R0 BLT l3 MOVL R1, (A1)+ MOVL R1, (A1)+ MOVL R1, (A1)+ MOVL R1, (A1)+ BRA l2 /* * cleanup byte-at-a-time */ l3: ADDL $15, R0 BLT return l4: MOVB R1, (A1)+ SUBL $1, R0 BGE l4 return: MOVL s1+0(FP),R0 RTS