func sbfx8(x int8) int64 {
	return int64(x >> 5) // arm64:"SBFX\t[$]5, R[0-9]+, [$]3"
}

// sbfx combinations.
// merge shifts with sbfiz into sbfx.
func sbfx9(x int32) int32 {
	return (x << 3) >> 4 // arm64:"SBFX\t[$]1, R[0-9]+, [$]28",-"LSL",-"ASR"
}

// merge sbfx and sign-extension into sbfx.
func sbfx10(x int32) int64 {
	c := x + 5
	return int64(c >> 20) // arm64"SBFX\t[$]20, R[0-9]+, [$]12",-"MOVW\tR[0-9]+, R[0-9]+"
}

	"REMW",
	"REV",
	"REV16",
	"REV16W",
	"REV32",
	"REVW",
	"ROR",
	"RORW",
	"SBC",
	"SBCS",
	"SBCSW",
	"SBCW",
	"SBFIZ",
	"SBFIZW",
	"SBFM",
	"SBFMW",
	"SBFX",
	"SBFXW",
	"SCVTFD",
	"SCVTFS",
	"SCVTFWD",
	"SCVTFWS",
	"SDIV",
	"SDIVW",
	"SEV",
	"SEVL",
	"SHA1C",
	"SHA1H",
	"SHA1M",
	"SHA1P",
	"SHA1SU0",
	"SHA1SU1",
	"SHA256H",

Examples:

	FMADDD F30, F20, F3, F29    <=>    fmadd d29, d3, d30, d20
	FNMSUBS F7, F25, F7, F22    <=>    fnmsub s22, s7, s7, s25

(4) BFI, BFXIL, SBFIZ, SBFX, UBFIZ, UBFX $<lsb>, <Rn>, $<width>, <Rd>

Examples:

	BFIW $16, R20, $6, R0      <=>    bfi w0, w20, #16, #6
	UBFIZ $34, R26, $5, R20    <=>    ubfiz x20, x26, #34, #5