ref: bafc196c4b07261923d4f197659a26d0919cdeae
dir: /sys/src/libc/386/strcpy.s/
TEXT strcpy(SB),$0 MOVL $0, AX MOVL $-1, CX CLD /* * find end of second string */ MOVL p2+4(FP), DI REPN; SCASB MOVL DI, BX SUBL p2+4(FP), BX /* * copy the memory */ MOVL p1+0(FP), DI MOVL p2+4(FP), SI /* * copy whole longs */ MOVL BX, CX SHRL $2, CX REP; MOVSL /* * copy the rest, by bytes */ ANDL $3, BX MOVL BX, CX REP; MOVSB MOVL p1+0(FP), AX RET