// cond: x.Uses == 1 && clobber(x)
	// result: @x.Block (MOVBUload <t> [off] {sym} ptr mem)
	for {
		t := v.Type
		x := v_0
		if x.Op != OpRISCV64MOVBload {
			break
		}
		off := auxIntToInt32(x.AuxInt)
		sym := auxToSym(x.Aux)
		mem := x.Args[1]
		ptr := x.Args[0]
		if !(x.Uses == 1 && clobber(x)) {
			break
		}
		b = x.Block

				// during the execution of the function prologue, the traceback
				// code will not see a half-updated stack frame.
				// This sequence is not async preemptible, as if we open a frame
				// at the current SP, it will clobber the saved LR.
				q = c.ctxt.StartUnsafePoint(q, c.newprog)

				q = obj.Appendp(q, newprog)
				q.As = mov
				q.Pos = p.Pos
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REGLINK

	} else {
		lea = ALEAL
		mov = AMOVL
		reg = REG_CX
		if p.As == ALEAL && p.To.Reg != p.From.Reg && p.To.Reg != p.From.Index {
			// Special case: clobber the destination register with
			// the PC so we don't have to clobber CX.
			// The SSA backend depends on CX not being clobbered across LEAL.
			// See cmd/compile/internal/ssa/gen/386.rules (search for Flag_shared).
			reg = p.To.Reg
		}
	}

		// It saves all GP registers if necessary,
		// but clobbers R14 (LR) because it's a call,
		// and also clobbers R1 as the PLT stub does.
		// Returns a pointer to a write barrier buffer in R9.
		{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ gpg) | buildReg("R14") | r1, outputs: []regMask{r9}}, clobberFlags: true, aux: "Int64"},

	if n&(n-1) != 0 {
		throw("stack not a power of 2")
	}
	if stk.lo+n < stk.hi {
		throw("bad stack size")
	}
	if stackDebug >= 1 {
		println("stackfree", v, n)
		memclrNoHeapPointers(v, n) // for testing, clobber stack data
	}
	if debug.efence != 0 || stackFromSystem != 0 {
		if debug.efence != 0 || stackFaultOnFree != 0 {
			sysFault(v, n)
		} else {
			sysFree(v, n, &memstats.stacks_sys)
		}
		return
	}

		fp2gp   = regInfo{inputs: []regMask{fpMask, fpMask}, outputs: []regMask{gpMask}}

		call        = regInfo{clobbers: callerSave}
		callClosure = regInfo{inputs: []regMask{gpspMask, regCtxt, 0}, clobbers: callerSave}
		callInter   = regInfo{inputs: []regMask{gpMask}, clobbers: callerSave}
	)

	RISCV64ops := []opData{
		{name: "ADD", argLength: 2, reg: gp21, asm: "ADD", commutative: true}, // arg0 + arg1

// gcWriteBarrier does NOT follow the Go ABI. It accepts the
// number of bytes of buffer needed in DI, and returns a pointer
// to the buffer space in DI.
// It clobbers FLAGS. It does not clobber any general-purpose registers,
// but may clobber others (e.g., SSE registers).
// Typical use would be, when doing *(CX+88) = AX
//     CMPL    $0, runtime.writeBarrier(SB)
//     JEQ     dowrite

	BL	racecall<>(SB)
	MOVD	R15, R8	// restore the original function
	MOVD	R17, R6 // restore arg list addr
	// Call the atomic function.
	// racecall will call LLVM race code which might clobber r30 (g)
	MOVD	runtime·tls_g(SB), R10
	MOVD	0(R10), g

	MOVD	g_racectx(g), R3
	MOVD	R8, R4		// pc being called same TODO as above
	MOVD	(R1), R5	// caller pc from latest LR
	BL	racecall<>(SB)

	// Please refer to https://golang.org/issue/31827 .
	SAVE_R19_TO_R28(8*4)
	SAVE_F8_TO_F15(8*14)

	// If called from an external code context, g will not be set.
	// Save R0, since runtime·load_g will clobber it.
	MOVW	R0, 8(RSP)		// signum
	BL	runtime·load_g(SB)

	// Restore signum to R0.
	MOVW	8(RSP), R0
	// R1 and R2 already contain info and ctx, respectively.
	BL	runtime·sigtrampgo<ABIInternal>(SB)

	// cond: x.Uses == 1 && clobber(x)
	// result: @x.Block (MOVBUload <t> [off] {sym} ptr mem)
	for {
		t := v.Type
		x := v_0
		if x.Op != OpMIPSMOVBload {
			break
		}
		off := auxIntToInt32(x.AuxInt)
		sym := auxToSym(x.Aux)
		mem := x.Args[1]
		ptr := x.Args[0]
		if !(x.Uses == 1 && clobber(x)) {
			break
		}
		b = x.Block