Valu("bool1", OpIsNonNil, c.config.Types.Bool, 0, nil, "ptr1"),
			If("bool1", "differentCheck", "exit")),
		Bloc("differentCheck",
			Valu("ptr2", OpLoad, ptrType, 0, nil, "sb", "mem"),
			Valu("bool2", OpIsNonNil, c.config.Types.Bool, 0, nil, "ptr2"),
			If("bool2", "secondCheck", "exit")),
		Bloc("secondCheck",
			Valu("bool3", OpIsNonNil, c.config.Types.Bool, 0, nil, "ptr1"),

		switch node.op {
		case Work:
			b := node.block

			// First, see if we're dominated by an explicit nil check.
			if len(b.Preds) == 1 {
				p := b.Preds[0].b
				if p.Kind == BlockIf && p.Controls[0].Op == OpIsNonNil && p.Succs[0].b == b {
					if ptr := p.Controls[0].Args[0]; nonNilValues[ptr.ID] == nil {
						nonNilValues[ptr.ID] = ptr
						work = append(work, bp{op: ClearPtr, ptr: ptr})
					}
				}
			}

		OpSignExt8to64, OpSignExt16to32, OpSignExt16to64, OpSignExt32to64,
		// bit
		OpCtz8, OpCtz16, OpCtz32, OpCtz64,
		// mask
		OpSlicemask,
		// safety check
		OpIsNonNil,
		// not
		OpNot:
		return true
	case
		// add
		OpAdd64, OpAdd32, OpAdd16, OpAdd8,
		OpAdd32F, OpAdd64F,
		// sub
		OpSub64, OpSub32, OpSub16, OpSub8,
		OpSub32F, OpSub64F,
		// mul