// R20 changed as side effect
		// R16 and R17 may be clobbered by linker trampoline.
		{
			name:      "DUFFZERO",
			aux:       "Int64",
			argLength: 2,
			reg: regInfo{
				inputs:   []regMask{buildReg("R20")},
				clobbers: buildReg("R16 R17 R20 R30"),
			},
			faultOnNilArg0: true,
			unsafePoint:    true, // FP maintenance around DUFFZERO can be clobbered by interrupts
		},

		// large zeroing

			}

			// Dump any registers which will be clobbered
			if s.doClobber && v.Op.IsCall() {
				// clobber registers that are marked as clobber in regmask, but
				// don't clobber inputs.
				s.clobberRegs(regspec.clobbers &^ s.tmpused &^ s.nospill)
			}
			s.freeRegs(regspec.clobbers)
			s.tmpused |= regspec.clobbers

			// Pick registers for outputs.
			{

// gcWriteBarrier does NOT follow the Go ABI. It accepts the
// number of bytes of buffer needed in R11, and returns a pointer
// to the buffer space in R11.
// 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

	return nil // too far away
}

// clobber invalidates values. Returns true.
// clobber is used by rewrite rules to:
//
//	A) make sure the values are really dead and never used again.
//	B) decrement use counts of the values' args.
func clobber(vv ...*Value) bool {
	for _, v := range vv {
		v.reset(OpInvalid)
		// Note: leave v.Block intact.  The Block field is used after clobber.
	}
	return true
}

	}

	// Handle any register clobbering. Call operations, for example,
	// clobber all registers even though they don't explicitly write to
	// them.
	clobbers := uint64(opcodeTable[v.Op].reg.clobbers)
	for {
		if clobbers == 0 {
			break
		}
		reg := uint8(bits.TrailingZeros64(clobbers))
		clobbers &^= 1 << reg

		for _, slot := range locs.registers[reg] {
			if state.loggingLevel > 1 {

X- ;  Y- ;  MUL;T3=T // T3 = T3*T2         T2   T3   T4
X=T4; Y=Y1; MUL;T-   // T4 = T4*Y1              T3   T4
SUB(T<T3-T) Y3:=T    // Y3 = T3-T4              T3   T4

	*/
//
// V27 is clobbered by p256MulInternal so must be
// saved in a temp.
//
// func p256PointAddAffineAsm(res, in1 *P256Point, in2 *p256AffinePoint, sign, sel, zero int)
TEXT ·p256PointAddAffineAsm(SB), NOSPLIT, $16-48

		m.mask = 1
	} else {
		m.mask = m.mask << 1
	}
	m.index++
}

// clobberdeadPtr is a special value that is used by the compiler to
// clobber dead stack slots, when -clobberdead flag is set.
const clobberdeadPtr = uintptr(0xdeaddead | 0xdeaddead<<((^uintptr(0)>>63)*32))

// badPointer throws bad pointer in heap panic.
func badPointer(s *mspan, p, refBase, refOff uintptr) {

		// Remainder after the loop
		rem := v.AuxInt % bytesPerLoop

		dstReg := v.Args[0].Reg()
		srcReg := v.Args[1].Reg()

		// The set of registers used here, must match the clobbered reg list
		// in PPC64Ops.go.
		offset := int64(0)

		// top of the loop
		var top *obj.Prog
		// Only generate looping code when loop counter is > 1 for >= 64 bytes
		if ctr > 1 {

		p.As = ABLTU
		p.From.Type = obj.TYPE_REG
		p.From.Reg = REG_X6
		p.Reg = REG_X7
		p.To.Type = obj.TYPE_BRANCH
		to_done = p
	}

	// Spill the register args that could be clobbered by the
	// morestack code
	p = ctxt.EmitEntryStackMap(cursym, p, newprog)
	p = cursym.Func().SpillRegisterArgs(p, newprog)

	// CALL runtime.morestack(SB)
	p = obj.Appendp(p, newprog)
	p.As = obj.ACALL

		// 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"},