// s390x:`MOVHBR\t\(.*\), [R]`,`CMPW\t.*, [$]`
	return s == "xx"
}

func CompareString2(s string) bool {
	// amd64:`CMPL\t\(.*\), [$]`
	// arm64:`MOVWU\t\(.*\), [R]`,`CMPW\t.*, [R]`
	// ppc64le:`MOVWZ\t\(.*\), [R]`,`CMPW\t.*, [R]`
	// s390x:`MOVWBR\t\(.*\), [R]`,`CMPW\t.*, [$]`
	return s == "xxxx"
}

func CompareString3(s string) bool {
	// amd64:`CMPQ\t\(.*\), [A-Z]`
	// arm64:-`CMPW\t`

	LFDUX: "FMOVDU", STFDUX: "FMOVDU",
	LFSX: "FMOVS", STFSX: "FMOVS",
	LFSU: "FMOVSU", STFSU: "FMOVSU",
	LFSUX: "FMOVSU", STFSUX: "FMOVSU",
	CMPD: "CMP", CMPDI: "CMP",
	CMPW: "CMPW", CMPWI: "CMPW",
	CMPLD: "CMPU", CMPLDI: "CMPU",
	CMPLW: "CMPWU", CMPLWI: "CMPWU",
	MTSPR: "MOVD", MFSPR: "MOVD", // the width is ambiguous for SPRs
	B:  "BR",
	BL: "CALL",

	CMP	R1, R2                 // b9200012
	CMP	R3, $32767             // a73f7fff
	CMP	R3, $32768             // c23c00008000
	CMP	R3, $-2147483648       // c23c80000000
	CMPU	R4, R5                 // b9210045
	CMPU	R6, $4294967295        // c26effffffff
	CMPW	R7, R8                 // 1978
	CMPW	R9, $-32768            // a79e8000
	CMPW	R9, $-32769            // c29dffff7fff

	// compared to ARM64 and others.
	CMP	$0, R9
	BEQ	sigtrampnog // g == nil

	// g is not nil. Check further.
	MOVD	g_m(R9), R6
	CMP	$0, R6
	BEQ	sigtramp    // g.m == nil
	MOVW	m_ncgo(R6), R7
	CMPW	$0, R7
	BEQ	sigtramp    // g.m.ncgo = 0
	MOVD	m_curg(R6), R7
	CMP	$0, R7
	BEQ	sigtramp    // g.m.curg == nil
	MOVD	g_syscallsp(R7), R7
	CMP	$0, R7
	BEQ	sigtramp    // g.m.curg.syscallsp == 0

	CALL	libc_mmap(SB)
	MOVD	$0, R4
	CMP	R3, $-1
	BNE	noerr
	CALL	libc_errno(SB)
	MOVW	(R3), R4		// errno
	MOVD	$0, R3
noerr:
	MOVD	R3, 32(R14)
	MOVD	R4, 40(R14)
	RET

TEXT runtime·munmap_trampoline(SB),NOSPLIT,$32
	MOVD	8(R3), R4		// arg 2 - len
	MOVD	0(R3), R3		// arg 1 - addr
	CALL	libc_munmap(SB)
	CMP	R3, $-1
	BNE	3(PC)
	MOVD	$0, R3			// crash on failure

	MOVW	0(R0), R0	// arg 1 fd
	BL	libc_write(SB)
	MOVD	$-1, R1
	CMP	R0, R1
	BNE	noerr
	BL	libc_error(SB)
	MOVW	(R0), R0
	NEG	R0, R0		// caller expects negative errno value
noerr:
	RET

TEXT runtime·read_trampoline(SB),NOSPLIT,$0
	MOVD	8(R0), R1	// arg 2 buf
	MOVW	16(R0), R2	// arg 3 count
	MOVW	0(R0), R0	// arg 1 fd
	BL	libc_read(SB)
	MOVD	$-1, R1
	CMP	R0, R1
	BNE	noerr
	BL	libc_error(SB)
	MOVW	(R0), R0

	CALL	libc_mmap(SB)
	MOVD	$0, R1
	CMP	$-1, R0
	BNE	noerr
	CALL	libc_errno(SB)
	MOVW	(R0), R1		// errno
	MOVD	$0, R0
noerr:
	MOVD	R0, 32(R19)
	MOVD	R1, 40(R19)
	RET

TEXT runtime·munmap_trampoline(SB),NOSPLIT,$0
	MOVD	8(R0), R1		// arg 2 - len
	MOVD	0(R0), R0		// arg 1 - addr
	CALL	libc_munmap(SB)
	CMP	$-1, R0
	BNE	3(PC)
	MOVD	$0, R0			// crash on failure

		{name: "CMPL", argLength: 2, reg: gp2flags, asm: "CMPL", typ: "Flags"},                    // arg0 compare to arg1
		{name: "CMPW", argLength: 2, reg: gp2flags, asm: "CMPW", typ: "Flags"},                    // arg0 compare to arg1
		{name: "CMPB", argLength: 2, reg: gp2flags, asm: "CMPB", typ: "Flags"},                    // arg0 compare to arg1

	v_2 := v.Args[2]
	v_1 := v.Args[1]
	v_0 := v.Args[0]
	b := v.Block
	typ := &b.Func.Config.Types
	// match: (CMPWload {sym} [off] ptr x mem)
	// result: (CMPW (MOVWload {sym} [off] ptr mem) x)
	for {
		off := auxIntToInt32(v.AuxInt)
		sym := auxToSym(v.Aux)
		ptr := v_0
		x := v_1
		mem := v_2
		v.reset(OpAMD64CMPW)

var x32 [2]uint32
var x64 [2]uint64

func compMem1() int {
	// amd64:`CMPB\tcommand-line-arguments.x\+1\(SB\), [$]0`
	if x[1] {
		return 1
	}
	// amd64:`CMPB\tcommand-line-arguments.x8\+1\(SB\), [$]7`
	if x8[1] == 7 {
		return 1
	}
	// amd64:`CMPW\tcommand-line-arguments.x16\+2\(SB\), [$]7`
	if x16[1] == 7 {
		return 1
	}
	// amd64:`CMPL\tcommand-line-arguments.x32\+4\(SB\), [$]7`
	if x32[1] == 7 {
		return 1
	}