66 return canonical(null, op, stamp, x, y, view);
67 }
68
69 @Override
70 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
71 NodeView view = NodeView.from(tool);
72 ValueNode ret = super.canonical(tool, forX, forY);
73 if (ret != this) {
74 return ret;
75 }
76
77 return canonical(this, getArithmeticOp(), stamp(view), forX, forY, view);
78 }
79
80 private static ValueNode canonical(RightShiftNode rightShiftNode, ArithmeticOpTable.ShiftOp<Shr> op, Stamp stamp, ValueNode forX, ValueNode forY, NodeView view) {
81 RightShiftNode self = rightShiftNode;
82 if (forX.stamp(view) instanceof IntegerStamp && ((IntegerStamp) forX.stamp(view)).isPositive()) {
83 return new UnsignedRightShiftNode(forX, forY);
84 }
85
86 if (forY.isConstant()) {
87 int amount = forY.asJavaConstant().asInt();
88 int originalAmout = amount;
89 int mask = op.getShiftAmountMask(stamp);
90 amount &= mask;
91 if (amount == 0) {
92 return forX;
93 }
94 if (forX instanceof ShiftNode) {
95 ShiftNode<?> other = (ShiftNode<?>) forX;
96 if (other.getY().isConstant()) {
97 int otherAmount = other.getY().asJavaConstant().asInt() & mask;
98 if (other instanceof RightShiftNode) {
99 int total = amount + otherAmount;
100 if (total != (total & mask)) {
101 assert other.getX().stamp(view) instanceof IntegerStamp;
102 IntegerStamp istamp = (IntegerStamp) other.getX().stamp(view);
103
104 if (istamp.isPositive()) {
105 return ConstantNode.forIntegerKind(stamp.getStackKind(), 0);
106 }
107 if (istamp.isStrictlyNegative()) {
108 return ConstantNode.forIntegerKind(stamp.getStackKind(), -1L);
109 }
110
111 /*
112 * if we cannot replace both shifts with a constant, replace them by a
113 * full shift for this kind
|
66 return canonical(null, op, stamp, x, y, view);
67 }
68
69 @Override
70 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
71 NodeView view = NodeView.from(tool);
72 ValueNode ret = super.canonical(tool, forX, forY);
73 if (ret != this) {
74 return ret;
75 }
76
77 return canonical(this, getArithmeticOp(), stamp(view), forX, forY, view);
78 }
79
80 private static ValueNode canonical(RightShiftNode rightShiftNode, ArithmeticOpTable.ShiftOp<Shr> op, Stamp stamp, ValueNode forX, ValueNode forY, NodeView view) {
81 RightShiftNode self = rightShiftNode;
82 if (forX.stamp(view) instanceof IntegerStamp && ((IntegerStamp) forX.stamp(view)).isPositive()) {
83 return new UnsignedRightShiftNode(forX, forY);
84 }
85
86 Stamp xStampGeneric = forX.stamp(view);
87 if (xStampGeneric instanceof IntegerStamp) {
88 IntegerStamp xStamp = (IntegerStamp) xStampGeneric;
89 if (xStamp.lowerBound() >= -1 && xStamp.upperBound() <= 0) {
90 // Right shift by any amount does not change any bit.
91 return forX;
92 }
93 }
94
95 if (forY.isConstant()) {
96 int amount = forY.asJavaConstant().asInt();
97 int originalAmout = amount;
98 int mask = op.getShiftAmountMask(stamp);
99 amount &= mask;
100 if (amount == 0) {
101 return forX;
102 }
103
104 if (xStampGeneric instanceof IntegerStamp) {
105 IntegerStamp xStamp = (IntegerStamp) xStampGeneric;
106
107 if (xStamp.lowerBound() >> amount == xStamp.upperBound() >> amount) {
108 // Right shift turns the result of the expression into a constant.
109 return ConstantNode.forIntegerKind(stamp.getStackKind(), xStamp.lowerBound() >> amount);
110 }
111 }
112
113 if (forX instanceof ShiftNode) {
114 ShiftNode<?> other = (ShiftNode<?>) forX;
115 if (other.getY().isConstant()) {
116 int otherAmount = other.getY().asJavaConstant().asInt() & mask;
117 if (other instanceof RightShiftNode) {
118 int total = amount + otherAmount;
119 if (total != (total & mask)) {
120 assert other.getX().stamp(view) instanceof IntegerStamp;
121 IntegerStamp istamp = (IntegerStamp) other.getX().stamp(view);
122
123 if (istamp.isPositive()) {
124 return ConstantNode.forIntegerKind(stamp.getStackKind(), 0);
125 }
126 if (istamp.isStrictlyNegative()) {
127 return ConstantNode.forIntegerKind(stamp.getStackKind(), -1L);
128 }
129
130 /*
131 * if we cannot replace both shifts with a constant, replace them by a
132 * full shift for this kind
|