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Extend optimization ==, !=, ===, !== against null to check null presence on any side of the test.

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This commit is contained in:
igor%mir2.org 2004-04-21 12:00:27 +00:00
parent c27f4d336c
commit a06c84f791
1 changed files with 89 additions and 98 deletions
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187
js/rhino/src/org/mozilla/javascript/optimizer/Codegen.java
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@ -3055,110 +3055,101 @@ class BodyCodegen
int trueGOTO, int falseGOTO)
{
if (trueGOTO == -1 || falseGOTO == -1) throw Codegen.badTree();
int type = node.getType();
Node rightChild = child.getNext();
boolean isStrict = type == Token.SHEQ ||
type == Token.SHNE;
if (rightChild.getType() == Token.NULL) {
if (type != Token.EQ && type != Token.SHEQ) {
// invert true and false.
int temp = trueGOTO;
trueGOTO = falseGOTO;
falseGOTO = temp;
short stackInitial = cfw.getStackTop();
int type = node.getType();
Node rChild = child.getNext();
// Optimize if one of operands is null
if (child.getType() == Token.NULL || rChild.getType() == Token.NULL) {
// eq is symmetric in this case
if (child.getType() == Token.NULL) {
child = rChild;
}
generateCodeFromNode(child, node);
if (type == Token.SHEQ || type == Token.SHNE) {
byte testCode = (type == Token.SHEQ)
? ByteCode.IFNULL : ByteCode.IFNONNULL;
cfw.add(testCode, trueGOTO);
} else {
if (type != Token.EQ) {
// swap false/true targets for !=
if (type != Token.NE) throw Codegen.badTree();
int tmp = trueGOTO;
trueGOTO = falseGOTO;
falseGOTO = tmp;
}
cfw.add(ByteCode.DUP);
int undefCheckLabel = cfw.acquireLabel();
cfw.add(ByteCode.IFNONNULL, undefCheckLabel);
short stack = cfw.getStackTop();
cfw.add(ByteCode.POP);
cfw.add(ByteCode.GOTO, trueGOTO);
cfw.markLabel(undefCheckLabel, stack);
Codegen.pushUndefined(cfw);
cfw.add(ByteCode.IF_ACMPEQ, trueGOTO);
}
cfw.add(ByteCode.GOTO, falseGOTO);
} else {
int child_dcp_register = nodeIsDirectCallParameter(child);
if (child_dcp_register != -1
&& rChild.getType() == Optimizer.TO_OBJECT)
{
Node convertChild = rChild.getFirstChild();
if (convertChild.getType() == Token.NUMBER) {
cfw.addALoad(child_dcp_register);
cfw.add(ByteCode.GETSTATIC,
"java/lang/Void",
"TYPE",
"Ljava/lang/Class;");
int notNumbersLabel = cfw.acquireLabel();
cfw.add(ByteCode.IF_ACMPNE, notNumbersLabel);
cfw.addDLoad(child_dcp_register + 1);
cfw.addPush(convertChild.getDouble());
cfw.add(ByteCode.DCMPL);
if (type == Token.EQ)
cfw.add(ByteCode.IFEQ, trueGOTO);
else
cfw.add(ByteCode.IFNE, trueGOTO);
cfw.add(ByteCode.GOTO, falseGOTO);
cfw.markLabel(notNumbersLabel);
// fall thru into generic handling
}
}
generateCodeFromNode(child, node);
if (isStrict) {
cfw.add(ByteCode.IFNULL, trueGOTO);
cfw.add(ByteCode.GOTO, falseGOTO);
return;
generateCodeFromNode(rChild, node);
String name;
byte testCode;
switch (type) {
case Token.EQ:
name = "eq";
testCode = ByteCode.IFNE;
break;
case Token.NE:
name = "eq";
testCode = ByteCode.IFEQ;
break;
case Token.SHEQ:
name = "shallowEq";
testCode = ByteCode.IFNE;
break;
case Token.SHNE:
name = "shallowEq";
testCode = ByteCode.IFEQ;
break;
default:
throw Codegen.badTree();
}
/*
since we have to test for null && undefined we end up
having to push the operand twice and so have to GOTO to
a pop site if the first test passes.
We can avoid that for operands that are 'simple', i.e.
don't generate a lot of code and don't have side-effects.
For now, 'simple' means GETVAR
*/
boolean simpleChild = (child.getType() == Token.GETVAR);
if (!simpleChild) cfw.add(ByteCode.DUP);
int popGOTO = cfw.acquireLabel();
cfw.add(ByteCode.IFNULL,
(simpleChild) ? trueGOTO : popGOTO);
short popStack = cfw.getStackTop();
if (simpleChild) generateCodeFromNode(child, node);
Codegen.pushUndefined(cfw);
cfw.add(ByteCode.IF_ACMPEQ, trueGOTO);
addScriptRuntimeInvoke(name,
"(Ljava/lang/Object;"
+"Ljava/lang/Object;"
+")Z");
cfw.add(testCode, trueGOTO);
cfw.add(ByteCode.GOTO, falseGOTO);
if (!simpleChild) {
cfw.markLabel(popGOTO, popStack);
cfw.add(ByteCode.POP);
cfw.add(ByteCode.GOTO, trueGOTO);
}
return;
}
Node rChild = child.getNext();
int child_dcp_register = nodeIsDirectCallParameter(child);
if (child_dcp_register != -1
&& rChild.getType() == Optimizer.TO_OBJECT)
{
Node convertChild = rChild.getFirstChild();
if (convertChild.getType() == Token.NUMBER) {
cfw.addALoad(child_dcp_register);
cfw.add(ByteCode.GETSTATIC,
"java/lang/Void",
"TYPE",
"Ljava/lang/Class;");
int notNumbersLabel = cfw.acquireLabel();
cfw.add(ByteCode.IF_ACMPNE, notNumbersLabel);
cfw.addDLoad(child_dcp_register + 1);
cfw.addPush(convertChild.getDouble());
cfw.add(ByteCode.DCMPL);
if (type == Token.EQ)
cfw.add(ByteCode.IFEQ, trueGOTO);
else
cfw.add(ByteCode.IFNE, trueGOTO);
cfw.add(ByteCode.GOTO, falseGOTO);
cfw.markLabel(notNumbersLabel);
// fall thru into generic handling
}
}
generateCodeFromNode(child, node);
generateCodeFromNode(rChild, node);
String name;
byte testCode;
switch (type) {
case Token.EQ:
name = "eq";
testCode = ByteCode.IFNE;
break;
case Token.NE:
name = "eq";
testCode = ByteCode.IFEQ;
break;
case Token.SHEQ:
name = "shallowEq";
testCode = ByteCode.IFNE;
break;
case Token.SHNE:
name = "shallowEq";
testCode = ByteCode.IFEQ;
break;
default:
throw Codegen.badTree();
}
addScriptRuntimeInvoke(name,
"(Ljava/lang/Object;"
+"Ljava/lang/Object;"
+")Z");
cfw.add(testCode, trueGOTO);
cfw.add(ByteCode.GOTO, falseGOTO);
if (stackInitial != cfw.getStackTop()) throw Codegen.badTree();
}
private void visitLiteral(Node node)
@ -3299,7 +3290,7 @@ class BodyCodegen
int isNumberLabel = cfw.acquireLabel();
int beyond = cfw.acquireLabel();
cfw.add(ByteCode.IF_ACMPEQ, isNumberLabel);
short stack = cfw.getStackTop();
short stack = cfw.getStackTop();
addDoubleWrap();
cfw.addAStore(lVar.getJRegister());
cfw.add(ByteCode.GOTO, beyond);