ref: ddaaf65efe197dafd7ca9175debb075dca0ce49b
dir: /sys/src/ape/lib/ap/68020/strchr.s/
TEXT strchr(SB), $0 MOVL s+0(FP), A0 MOVB c+7(FP), R2 BEQ null l: MOVB (A0)+, R1 BEQ out CMPB R1, R2 BNE l MOVL A0, R0 ADDL $-1, R0 RTS out: CLRL R0 RTS null: TSTB (A0)+ BNE null MOVL A0, R0 ADDL $-1, R0 RTS