Changeset 34883 in webkit for trunk/JavaScriptCore/VM/CodeGenerator.cpp

Timestamp:

Jun 29, 2008, 11:17:01 PM (17 years ago)

Author:

[email protected]

Message:

2008-06-29 Cameron Zwarich <​[email protected]>

Reviewed by Oliver.

Bug 19821: Merge the instruction pair (less, jfalse)
<​https://bugs.webkit.org/show_bug.cgi?id=19821>

This is a 2.4% win on SunSpider. I needed to add an ALWAYS_INLINE
intrinisc to CodeGenerator::rewindBinaryOp() to avoid a massive
regression in regexp-dna.

• VM/CodeBlock.cpp: (KJS::CodeBlock::dump):
• VM/CodeGenerator.cpp: (KJS::CodeGenerator::rewindBinaryOp): (KJS::CodeGenerator::emitJumpIfFalse):
• VM/Machine.cpp: (KJS::Machine::privateExecute):
• VM/Opcode.cpp: (KJS::):
• VM/Opcode.h:

File:

• trunk/JavaScriptCore/VM/CodeGenerator.cpp (modified) (2 diffs)

trunk/JavaScriptCore/VM/CodeGenerator.cpp

@@ -430 +430 @@
 }
 
-void CodeGenerator::rewindBinaryOp()
+void ALWAYS_INLINE CodeGenerator::rewindBinaryOp()
 {
     ASSERT(instructions().size() >= 4);
@@ -471 +471 @@
 {
     ASSERT(target->isForwardLabel());
+    
+    if (m_lastOpcodeID == op_less) {
+        int dstIndex;
+        int src1Index;
+        int src2Index;
+        
+        retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
+        
+        if (cond->index() == dstIndex && !cond->refCount()) {
+            rewindBinaryOp();
+            emitOpcode(op_jnless);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    }
+    
     emitOpcode(op_jfalse);
     instructions().append(cond->index());