Changeset 37789 in webkit for trunk/JavaScriptCore/VM/CodeGenerator.cpp

Timestamp:

Oct 22, 2008, 2:06:30 PM (17 years ago)

Author:

[email protected]

Message:

2008-10-22 Cameron Zwarich <​[email protected]>

Reviewed by Geoff Garen.

Bug 21803: Fuse op_jfalse with op_eq_null and op_neq_null
<​https://bugs.webkit.org/show_bug.cgi?id=21803>

Fuse op_jfalse with op_eq_null and op_neq_null to make the new opcodes
op_jeq_null and op_jneq_null.

This is a 2.6% speedup on the V8 Raytrace benchmark, and strangely also
a 4.7% speedup on the V8 Arguments benchmark, even though it uses
neither of the two new opcodes.

• VM/CTI.cpp: (JSC::CTI::privateCompileMainPass):
• VM/CodeBlock.cpp: (JSC::CodeBlock::dump):
• VM/CodeGenerator.cpp: (JSC::CodeGenerator::emitJumpIfTrue): (JSC::CodeGenerator::emitJumpIfFalse):
• VM/Machine.cpp: (JSC::Machine::privateExecute):
• VM/Opcode.h:

File:

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

trunk/JavaScriptCore/VM/CodeGenerator.cpp

@@ -547 +547 @@
             return target;
         }
+    } else if (m_lastOpcodeID == op_eq_null && target->isForwardLabel()) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+            emitOpcode(op_jeq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_neq_null && target->isForwardLabel()) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+            emitOpcode(op_jneq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
     }
 
@@ -586 +612 @@
             instructions().append(target->offsetFrom(instructions().size()));
             return target;
-        }        
+        }
+    } else if (m_lastOpcodeID == op_eq_null) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+            emitOpcode(op_jneq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_neq_null) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+            emitOpcode(op_jeq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
     }