//      z0   z1
	//       \   /
	//       exit
	fun = c.Fun("entry",
		Bloc("entry",
			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
			Valu("c1", OpArg, c.config.Types.Bool, 0, nil),
			If("c1", "b0", "z0")),
		Bloc("b0",
			Valu("c2", OpArg, c.config.Types.Bool, 0, nil),
			If("c2", "z1", "z0")),
		Bloc("z0",
			Goto("exit")),
		Bloc("z1",
			Goto("exit")),
		Bloc("exit",
			Exit("mem"),

func TestSpillWithLoop(t *testing.T) {
	c := testConfig(t)
	f := c.Fun("entry",
		Bloc("entry",
			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
			Valu("ptr", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Temp(c.config.Types.Int64)),
			Valu("cond", OpArg, c.config.Types.Bool, 0, c.Temp(c.config.Types.Bool)),
			Valu("ld", OpAMD64MOVQload, c.config.Types.Int64, 0, nil, "ptr", "mem"), // this value needs a spill
			Goto("loop"),
		),

			Valu("r7", OpAdd64, c.config.Types.Int64, 0, nil, "arg3", "arg1"),
			Valu("r1", OpAdd64, c.config.Types.Int64, 0, nil, "arg1", "arg2"),
			Valu("arg1", OpArg, c.config.Types.Int64, 0, arg1Aux),
			Valu("arg2", OpArg, c.config.Types.Int64, 0, arg2Aux),
			Valu("arg3", OpArg, c.config.Types.Int64, 0, arg3Aux),
			Valu("r9", OpAdd64, c.config.Types.Int64, 0, nil, "r7", "r8"),
			Valu("r4", OpAdd64, c.config.Types.Int64, 0, nil, "r1", "r2"),

		return k
	}
	panic("Haven't implemented this case yet, do I need to?")
}

// prAssignForArg returns the ABIParamAssignment for v, assumed to be an OpArg.
func (x *expandState) prAssignForArg(v *Value) *abi.ABIParamAssignment {
	if v.Op != OpArg {
		panic(fmt.Errorf("Wanted OpArg, instead saw %s", v.LongString()))
	}
	return ParamAssignmentForArgName(x.f, v.Aux.(*ir.Name))
}

					if f.pass.debug > stackDebug {
						fmt.Printf("stackalloc register arg %s skipping name %s\n", v, name)
					}
					continue
				}
			} else if name.N.Class == ir.PPARAM && v.Op != OpArg {
				// PPARAM's only bind to OpArg
				if f.pass.debug > stackDebug {
					fmt.Printf("stackalloc PPARAM name %s skipping non-Arg %s\n", name, v)
				}
				continue
			}

			if names[v.ID] == empty {

		return v
	}

	// Make a pass through the entry block looking for
	// OpArg{Int,Float}Reg ops. Record the slots they use in a table
	// ("sc"). We use a type-insensitive lookup for the slot table,
	// since the type we get from the ABI analyzer won't always match
	// what the compiler uses when creating OpArg{Int,Float}Reg ops.
	for _, v := range f.Entry.Values {
		if v.Op == OpArgIntReg || v.Op == OpArgFloatReg {

				// In particular, they need to come before regular OpArg operations because
				// of how regalloc places spill code (see regalloc.go:placeSpills:mustBeFirst).
				if b != f.Entry {
					f.Fatalf("%s appeared outside of entry block, b=%s", v.Op, b.String())
				}
				score[v.ID] = ScorePhi
			case v.Op == OpArg || v.Op == OpSP || v.Op == OpSB:

// boundary. Such values don't correspond to a user's understanding of a
// statement boundary.
func notStmtBoundary(op Op) bool {
	switch op {
	case OpCopy, OpPhi, OpVarDef, OpVarLive, OpUnknown, OpFwdRef, OpArg, OpArgIntReg, OpArgFloatReg:
		return true
	}
	return false
}

func (b *Block) FirstPossibleStmtValue() *Value {
	for _, v := range b.Values {
		if notStmtBoundary(v.Op) {
			continue
		}
		return v

		if p2.Op == OpAddr || p2.Op == OpLocalAddr || p2.Op == OpSP {
			return true
		}
		return (p2.Op == OpArg || p2.Op == OpArgIntReg) && p1.Args[0].Op == OpSP
	case OpArg, OpArgIntReg:
		if p2.Op == OpSP || p2.Op == OpLocalAddr {
			return true
		}
	case OpSP:
		return p2.Op == OpAddr || p2.Op == OpLocalAddr || p2.Op == OpArg || p2.Op == OpArgIntReg || p2.Op == OpSP
	}
	return false
}

		}

		// The code below assumes that we have handled all the ops
		// with sym effects already. Sanity check that here.
		// Ignore Args since they can't be autos.
		if v.Op.SymEffect() != SymNone && v.Op != OpArg {
			panic("unhandled op with sym effect")
		}

		if v.Uses == 0 && v.Op != OpNilCheck && !v.Op.IsCall() && !v.Op.HasSideEffects() || len(args) == 0 {
			// We need to keep nil checks even if they have no use.