ref: 4ddd74becb975b678d89c5d738e701b235607c5b
dir: /builtins.amd64.s/
TEXT memcpyf(SB),1,$0 MOVQ RARG, DI MOVQ DI, AX MOVQ p2+8(FP), SI MOVL n+16(FP), CX CLD; REP; MOVSB RET TEXT __builtin_clz(SB),1,$0 BSRL RARG, AX XORL $31, AX RET TEXT __builtin_bswap32(SB),1,$0 MOVL RARG, AX BYTE $0x0F; BYTE $0xC8 /* BSWAP32 AX */ RET