Changeset 147658 in webkit for trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

Timestamp:

Apr 4, 2013, 11:31:37 AM (12 years ago)

Author:

[email protected]

Message:

Simplified bytecode generation by merging prefix and postfix nodes
​https://bugs.webkit.org/show_bug.cgi?id=113925

Reviewed by Filip Pizlo.

PostfixNode now inherits from PrefixNode, so when we detect that we're
in a context where postifx and prefix are equivalent, PostFixNode can
just call through to PrefixNode codegen, instead of duplicating the
logic.

• bytecompiler/NodesCodegen.cpp:

(JSC::PostfixNode::emitResolve):
(JSC::PostfixNode::emitBracket):
(JSC::PostfixNode::emitDot):

• parser/NodeConstructors.h:

(JSC::PostfixNode::PostfixNode):

• parser/Nodes.h:

(JSC):
(PrefixNode):
(PostfixNode):

File:

• trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp (modified) (7 diffs)

trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

@@ -625 +625 @@
 RegisterID* PostfixNode::emitResolve(BytecodeGenerator& generator, RegisterID* dst)
 {
+    if (dst == generator.ignoredResult())
+        return PrefixNode::emitResolve(generator, dst);
+
     ASSERT(m_expr->isResolveNode());
     ResolveNode* resolve = static_cast<ResolveNode*>(m_expr);
@@ -636 +639 @@
             return generator.emitToJSNumber(generator.finalDestination(dst), local);
         }
-        if (dst == generator.ignoredResult())
-            return emitPreIncOrDec(generator, local, m_operator);
         return emitPostIncOrDec(generator, generator.finalDestination(dst), local, m_operator);
     }
@@ -643 +644 @@
     if (resolveResult.isStatic() && !resolveResult.isReadOnly()) {
         RefPtr<RegisterID> value = generator.emitGetStaticVar(generator.newTemporary(), resolveResult, ident);
-        RegisterID* oldValue;
-        if (dst == generator.ignoredResult()) {
-            oldValue = 0;
-            emitPreIncOrDec(generator, value.get(), m_operator);
-        } else
-            oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), value.get(), m_operator);
+        RefPtr<RegisterID> oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), value.get(), m_operator);
         generator.emitPutStaticVar(resolveResult, ident, value.get());
-        return oldValue;
+        return oldValue.get();
     }
 
@@ -657 +653 @@
     NonlocalResolveInfo resolveInfo;
     RefPtr<RegisterID> base = generator.emitResolveWithBaseForPut(generator.newTemporary(), value.get(), resolveResult, ident, resolveInfo);
-    RegisterID* oldValue;
-    if (dst == generator.ignoredResult()) {
-        oldValue = 0;
-        emitPreIncOrDec(generator, value.get(), m_operator);
-    } else
-        oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), value.get(), m_operator);
+    RefPtr<RegisterID> oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), value.get(), m_operator);
     generator.emitPutToBase(base.get(), ident, value.get(), resolveInfo);
-    return oldValue;
+    return oldValue.get();
 }
 
 RegisterID* PostfixNode::emitBracket(BytecodeGenerator& generator, RegisterID* dst)
 {
+    if (dst == generator.ignoredResult())
+        return PrefixNode::emitBracket(generator, dst);
+
     ASSERT(m_expr->isBracketAccessorNode());
     BracketAccessorNode* bracketAccessor = static_cast<BracketAccessorNode*>(m_expr);
@@ -679 +673 @@
     generator.emitExpressionInfo(bracketAccessor->divot(), bracketAccessor->startOffset(), bracketAccessor->endOffset());
     RefPtr<RegisterID> value = generator.emitGetByVal(generator.newTemporary(), base.get(), property.get());
-    if (dst == generator.ignoredResult()) {
-        emitPreIncOrDec(generator, value.get(), m_operator);
-        generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-        generator.emitPutByVal(base.get(), property.get(), value.get());
-        return 0;
-    }
     RegisterID* oldValue = emitPostIncOrDec(generator, generator.tempDestination(dst), value.get(), m_operator);
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
@@ -693 +681 @@
 RegisterID* PostfixNode::emitDot(BytecodeGenerator& generator, RegisterID* dst)
 {
+    if (dst == generator.ignoredResult())
+        return PrefixNode::emitDot(generator, dst);
+
     ASSERT(m_expr->isDotAccessorNode());
     DotAccessorNode* dotAccessor = static_cast<DotAccessorNode*>(m_expr);
@@ -702 +693 @@
     generator.emitExpressionInfo(dotAccessor->divot(), dotAccessor->startOffset(), dotAccessor->endOffset());
     RefPtr<RegisterID> value = generator.emitGetById(generator.newTemporary(), base.get(), ident);
-    if (dst == generator.ignoredResult()) {
-        emitPreIncOrDec(generator, value.get(), m_operator);
-        generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-        generator.emitPutById(base.get(), ident, value.get());
-        return 0;
-    }
     RegisterID* oldValue = emitPostIncOrDec(generator, generator.tempDestination(dst), value.get(), m_operator);
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());