SUBVU	$1, R14
	BEQ	R16, R17, chunk16_loop
	SUBV	$8, R4
	SUBV	$8, R6

byte_loop:
	BEQ	R4, R12, samebytes
	MOVBU	(R4), R8
	ADDVU	$1, R4
	MOVBU	(R6), R9
	ADDVU	$1, R6
	BEQ	R8, R9, byte_loop

byte_cmp:
	SGTU	R8, R9, R4 // R12 = 1 if (R8 > R9)
	BNE	R0, R4, ret
	MOVV	$-1, R4
	JMP	ret

samebytes:
	SGTU	R5, R7, R8
	SGTU	R7, R5, R9
	SUBV	R9, R8, R4

ret:

	AND	$0xff, R7
	MOVV	R4, R6		// store base for later
	ADDV	R4, R5		// end
	ADDV	$-1, R4

	PCALIGN	$16
loop:
	ADDV	$1, R4
	BEQ	R4, R5, notfound
	MOVBU	(R4), R8
	BNE	R7, R8, loop

	SUBV	R6, R4		// remove base
	RET

notfound:
	MOVV	$-1, R4
	RET

TEXT ·IndexByteString<ABIInternal>(SB),NOSPLIT,$0-32
	// R4 = s_base
	// R5 = s_len
	// R6 = byte to find
	MOVV	R4, R7		// store base for later

	"MOVVL",
	"MOVVR",
	"SLLV",
	"SRAV",
	"SRLV",
	"ROTRV",
	"DIVV",
	"DIVVU",
	"REMV",
	"REMVU",
	"MULV",
	"MULVU",
	"MULHV",
	"MULHVU",
	"ADDV",
	"ADDVU",
	"SUBV",
	"SUBVU",
	"TRUNCFV",
	"TRUNCDV",
	"TRUNCFW",
	"TRUNCDW",
	"MOVWU",
	"MOVFV",
	"MOVDV",
	"MOVVF",
	"MOVVD",
	"AMSWAPB",
	"AMSWAPH",
	"AMSWAPW",
	"AMSWAPV",
	"AMCASB",

	MOVV	$4096, R4		// 24000014
	MOVW	R4, R5			// 85001700
	MOVV	R4, R5			// 85001500
	MOVBU	R4, R5			// 85fc4303
	SUB	R4, R5, R6		// a6101100
	SUBV	R4, R5, R6		// a6901100
	ADD	R4, R5, R6		// a6101000
	ADDV	R4, R5, R6		// a6901000
	AND	R4, R5, R6		// a6901400
	SUB	R4, R5			// a5101100
	SUBV	R4, R5			// a5901100
	ADD	R4, R5			// a5101000
	ADDV	R4, R5			// a5901000
	AND	R4, R5			// a5901400
	NEGW	R4, R5			// 05101100