ref: f02c92a5fb2d18e1248a67b15cd2ec7dcea2b4d7
dir: /sys/src/ape/lib/ap/amd64/strchr.s/
TEXT strchr(SB), $0 MOVQ RARG, DI MOVB c+8(FP), AX CMPB AX, $0 JEQ l2 /**/ /* * char is not null */ l1: MOVB (DI), BX CMPB BX, $0 JEQ ret0 ADDQ $1, DI CMPB AX, BX JNE l1 MOVQ DI, AX SUBQ $1, AX RET /* * char is null */ l2: MOVQ $-1, CX CLD REPN; SCASB MOVQ DI, AX SUBQ $1, AX RET ret0: MOVQ $0, AX RET