// rewrite mem for each call,
	// rewrite each OpSelectNAddr.
	for _, b := range f.Blocks {
		for _, v := range b.Values {
			switch v.Op {
			case OpInitMem:
				m0 = v

			case OpClosureLECall, OpInterLECall, OpStaticLECall, OpTailLECall:
				calls = append(calls, v)

			case OpArg:
				args = append(args, v)

			case OpStore:
				if a := v.Args[1]; a.Op == OpSelectN && !CanSSA(a.Type) {
					if a.Uses > 1 {

				return false
			case OpPanicBounds, OpPanicExtend:
				// Note: these are panic generators that are ok (like the static calls above).
			case OpClosureCall, OpInterCall, OpClosureLECall, OpInterLECall:
				// We must keep the race functions if there are any other call types.
				return false
			}
		}
	}
	if isSameCall(sym, "runtime.racefuncenter") {

	case ir.OADDR:
		n := n.(*ir.AddrExpr)
		return s.addr(n.X)

	case ir.ORESULT:
		n := n.(*ir.ResultExpr)
		if s.prevCall == nil || s.prevCall.Op != ssa.OpStaticLECall && s.prevCall.Op != ssa.OpInterLECall && s.prevCall.Op != ssa.OpClosureLECall {
			panic("Expected to see a previous call")
		}
		which := n.Index
		if which == -1 {
			panic(fmt.Errorf("ORESULT %v does not match call %s", n, s.prevCall))
		}

	case OpEqSlice:
		return rewriteValuegeneric_OpEqSlice(v)
	case OpFloor:
		return rewriteValuegeneric_OpFloor(v)
	case OpIMake:
		return rewriteValuegeneric_OpIMake(v)
	case OpInterLECall:
		return rewriteValuegeneric_OpInterLECall(v)
	case OpIsInBounds:
		return rewriteValuegeneric_OpIsInBounds(v)
	case OpIsNonNil:
		return rewriteValuegeneric_OpIsNonNil(v)
	case OpIsSliceInBounds:

	OpZeroWB
	OpWBend
	OpWB
	OpHasCPUFeature
	OpPanicBounds
	OpPanicExtend
	OpClosureCall
	OpStaticCall
	OpInterCall
	OpTailCall
	OpClosureLECall
	OpStaticLECall
	OpInterLECall
	OpTailLECall
	OpSignExt8to16
	OpSignExt8to32
	OpSignExt8to64
	OpSignExt16to32
	OpSignExt16to64
	OpSignExt32to64
	OpZeroExt8to16
	OpZeroExt8to32
	OpZeroExt8to64