// getclosureptr can only be used in an assignment statement
// at the entry of a function. Moreover, go:nosplit directive
// must be specified at the declaration of caller function,
// so that the function prolog does not clobber the closure register.
// for example:
//
//	//go:nosplit
//	func f(arg1, arg2, arg3 int) {
//		dx := getclosureptr()
//	}
//
// The compiler rewrites calls to this function into instructions that fetch the

time.

The GODEBUG variable controls debugging variables within the runtime.
It is a comma-separated list of name=val pairs setting these named variables:

	clobberfree: setting clobberfree=1 causes the garbage collector to
	clobber the memory content of an object with bad content when it frees
	the object.

	cpu.*: cpu.all=off disables the use of all optional instruction set extensions.

	// Reserve space for callee-save registers and arguments.
	MOVM.DB.W [R4-R11], (R13)
	SUB	$16, R13

	// If called from an external code context, g will not be set.
	// Save R0, since runtime·load_g will clobber it.
	MOVW	R0, 4(R13)		// signum
	BL	runtime·load_g(SB)

	MOVW	R1, 8(R13)
	MOVW	R2, 12(R13)
	BL	runtime·sigtrampgo(SB)

	// Restore callee-save registers.
	ADD	$16, R13
	MOVM.IA.W (R13), [R4-R11]

		// find the memory before the WB stores
		mem := stores[0].MemoryArg()
		pos := stores[0].Pos

		// If the source of a MoveWB is volatile (will be clobbered by a
		// function call), we need to copy it to a temporary location, as
		// marshaling the args of wbMove might clobber the value we're
		// trying to move.
		// Look for volatile source, copy it to temporary before we check
		// the write barrier flag.

	f43([]*int{&p, &r, &q})
	f43([]*int{&q, &p, &r})
}

//go:noescape
func f43(a []*int)

// Assigning to a sub-element that makes up an entire local variable
// should clobber that variable.
func f44(f func() [2]*int) interface{} { // ERROR "live at entry to f44: f"
	type T struct {
		s [1][2]*int
	}
	ret := T{} // ERROR "stack object ret T"
	ret.s[0] = f()
	return ret
}

	// result: (MSUBW a x y)
	for {
		a := v_0
		l := v_1
		if l.Op != OpARM64MULW {
			break
		}
		y := l.Args[1]
		x := l.Args[0]
		if !(v.Type.Size() <= 4 && l.Uses == 1 && clobber(l)) {
			break
		}
		v.reset(OpARM64MSUBW)
		v.AddArg3(a, x, y)
		return true
	}
	// match: (SUB a l:(MNEGW x y))
	// cond: v.Type.Size() <= 4 && l.Uses==1 && clobber(l)

		fp1flags  = regInfo{inputs: []regMask{fp}}
		fpgp      = regInfo{inputs: []regMask{fp}, outputs: []regMask{gp}, clobbers: buildReg("F15")} // int-float conversion uses F15 as tmp
		gpfp      = regInfo{inputs: []regMask{gp}, outputs: []regMask{fp}, clobbers: buildReg("F15")}
		fp21      = regInfo{inputs: []regMask{fp, fp}, outputs: []regMask{fp}}

  // Whether to replace quantization params of the first dequantize op
  // after the quantized value is produced.
  // If there is a use other than the requantize states, then we can't clobber.
  bool clobber_first = num_uses <= states.size();
  for (RequantizeState& state : states) {
    Type expressed_type = QuantizedType::castToExpressedType(value.getType());
    if (!expressed_type) continue;

		gp11div   = regInfo{inputs: []regMask{ax, gpsp &^ dx}, outputs: []regMask{ax}, clobbers: dx}
		gp21hmul  = regInfo{inputs: []regMask{ax, gpsp}, outputs: []regMask{dx}, clobbers: ax}
		gp11mod   = regInfo{inputs: []regMask{ax, gpsp &^ dx}, outputs: []regMask{dx}, clobbers: ax}
		gp21mul   = regInfo{inputs: []regMask{ax, gpsp}, outputs: []regMask{dx, ax}}

		xergp       = regInfo{inputs: []regMask{xer}, outputs: []regMask{gp}, clobbers: xer}
		gp11cxer    = regInfo{inputs: []regMask{gp | sp | sb}, outputs: []regMask{gp}, clobbers: xer}
		gp11xer     = regInfo{inputs: []regMask{gp | sp | sb}, outputs: []regMask{gp, xer}}
		gp1xer1xer  = regInfo{inputs: []regMask{gp | sp | sb, xer}, outputs: []regMask{gp, xer}, clobbers: xer}