// RegArgs is a slice of register-memory pairs that must be spilled and unspilled in the uncommon path of function entry.
	RegArgs []Spill
	// OwnAux describes parameters and results for this function.
	OwnAux *AuxCall
	// CloSlot holds the compiler-synthesized name (".closureptr")
	// where we spill the closure pointer for range func bodies.
	CloSlot *ir.Name

mapreduce.reduce.shuffle.merge.percent=0.9 # Minimum % merges in RAM
mapreduce.reduce.speculative=false # Disable speculation for reducing
mapreduce.task.io.sort.factor=999 # Threshold before writing to disk
mapreduce.task.sort.spill.percent=0.9 # Minimum % before spilling to disk
```

			if v.Op == OpSPanchored {
				// Free this value
				if v.Uses != 0 {
					base.Fatalf("SPAnchored still has %d uses", v.Uses)
				}
				v.resetArgs()
				f.freeValue(v)
			} else {
				if opcodeTable[v.Op].nilCheck {
					if v.Uses != 0 {
						base.Fatalf("nilcheck still has %d uses", v.Uses)
					}
					// We can't delete the nil check, but we mark
					// it as having void type so regalloc won't

}
func cmpstring2(x, y string) int {
	// We want to fail if there are two calls to cmpstring.
	// They will both have the same line number, so a test
	// like in cmpstring1 will not work. Instead, we
	// look for spill/restore instructions, which only
	// need to exist if there are 2 calls.
	//amd64:-`MOVQ\t.*\(SP\)`
	return cmp.Compare(x, y)

	// Transition from C ABI to Go ABI.
	PUSH_REGS_HOST_TO_ABI0()

	// Set up ABIInternal environment: g in R14, cleared X15.
	get_tls(R12)
	MOVQ	g(R12), R14
	PXOR	X15, X15

	// Reserve space for spill slots.
	NOP	SP		// disable vet stack checking
	ADJSP   $24

	// Call into the Go signal handler
	MOVQ	DI, AX	// sig
	MOVQ	SI, BX	// info
	MOVQ	DX, CX	// ctx
	CALL	·sigtrampgo<ABIInternal>(SB)

	ADJSP	$-24

	return c.registers[m].objNum
}

// ArgWidth returns the amount of stack needed for all the inputs
// and outputs of a function or method, including ABI-defined parameter
// slots and ABI-defined spill slots for register-resident parameters.
//
// The name is taken from the types package's ArgWidth(<function type>),
// which predated changes to the ABI; this version handles those changes.
func (a *AuxCall) ArgWidth() int64 {

// therefore be >= stackArgsSize. It must include additional space for spilling
// register arguments for stack growth and preemption.
//
// TODO(mknyszek): Once we don't need the additional spill space, remove frameSize,
// since frameSize will be redundant with stackArgsSize.
//
// Arguments passed in registers must be laid out in regArgs according to the ABI.

	// Transition from C ABI to Go ABI.
	PUSH_REGS_HOST_TO_ABI0()

	// Set up ABIInternal environment: g in R14, cleared X15.
	get_tls(R12)
	MOVQ	g(R12), R14
	PXOR	X15, X15

	// Reserve space for spill slots.
	NOP	SP		// disable vet stack checking
	ADJSP   $24

	// Call into the Go signal handler
	MOVQ	DI, AX	// sig
	MOVQ	SI, BX	// info
	MOVQ	DX, CX	// ctx
	CALL	·sigtrampgo<ABIInternal>(SB)

	nodes.Append(nif)

	// Index to start copying into s.
	//   idx = newLen - len(l2)
	// We use this expression instead of oldLen because it avoids
	// a spill/restore of oldLen.
	// Note: this doesn't work optimally currently because
	// the compiler optimizer undoes this arithmetic.
	idx := ir.NewBinaryExpr(base.Pos, ir.OSUB, newLen, ir.NewUnaryExpr(base.Pos, ir.OLEN, l2))

		// any pointers we must get into the write barrier buffer still make it,
		// possibly in a different order and possibly a different (but definitely
		// more than 0) number of times.
		// In light of that, we process all the OpStoreWBs first. This minimizes
		// the amount of spill/restore code we need around the Zero/Move calls.