Changeset 49004 in webkit for trunk/JavaScriptCore/jit/JITCall.cpp

Timestamp:

Oct 1, 2009, 4:32:48 PM (16 years ago)

Author:

[email protected]

Message:

Take one branch instead of two to test for JSValue().

Patch by Geoffrey Garen <​[email protected]> on 2009-10-01
Reviewed by Sam Weinig.

1.1% SunSpider speedup.

• jit/JITCall.cpp:

(JSC::JIT::compileOpCall):

• jit/JITOpcodes.cpp:

(JSC::JIT::emit_op_to_jsnumber):
(JSC::JIT::emit_op_create_arguments):

• jit/JITPropertyAccess.cpp:

(JSC::JIT::emitSlow_op_get_by_val):
(JSC::JIT::emit_op_put_by_val): Test for the empty value tag, instead
of testing for the cell tag with a 0 payload.

• runtime/JSValue.cpp:

(JSC::JSValue::description): Added support for dumping the new empty value,
and deleted values, in debug builds.

• runtime/JSValue.h:

(JSC::JSValue::JSValue()): Construct JSValue() with the empty value tag.

(JSC::JSValue::JSValue(JSCell*)): Convert null pointer to the empty value
tag, to avoid having two different c++ versions of null / empty.

(JSC::JSValue::operator bool): Test for the empty value tag, instead
of testing for the cell tag with a 0 payload.

File:

• trunk/JavaScriptCore/jit/JITCall.cpp (modified) (6 diffs)

trunk/JavaScriptCore/jit/JITCall.cpp

@@ -237 +237 @@
     int registerOffset = instruction[4].u.operand;
 
-    Jump wasEval1;
-    Jump wasEval2;
+    Jump wasEval;
     if (opcodeID == op_call_eval) {
         JITStubCall stubCall(this, cti_op_call_eval);
@@ -245 +244 @@
         stubCall.addArgument(JIT::Imm32(argCount));
         stubCall.call();
-        wasEval1 = branchTest32(NonZero, regT0);
-        wasEval2 = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
+        wasEval = branch32(Equal, regT1, Imm32(JSValue::EmptyValueTag));
     }
 
@@ -272 +270 @@
     emitNakedCall(m_globalData->jitStubs.ctiVirtualCall());
 
-    if (opcodeID == op_call_eval) {
-        wasEval1.link(this);
-        wasEval2.link(this);
-    }
+    if (opcodeID == op_call_eval)
+        wasEval.link(this);
 
     emitStore(dst, regT1, regT0);;
@@ -307 +303 @@
     int registerOffset = instruction[4].u.operand;
 
-    Jump wasEval1;
-    Jump wasEval2;
+    Jump wasEval;
     if (opcodeID == op_call_eval) {
         JITStubCall stubCall(this, cti_op_call_eval);
@@ -315 +310 @@
         stubCall.addArgument(JIT::Imm32(argCount));
         stubCall.call();
-        wasEval1 = branchTest32(NonZero, regT0);
-        wasEval2 = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
+        wasEval = branch32(NotEqual, regT1, Imm32(JSValue::EmptyValueTag));
     }
 
@@ -360 +354 @@
     m_callStructureStubCompilationInfo[callLinkInfoIndex].hotPathOther = emitNakedCall();
     
-    if (opcodeID == op_call_eval) {
-        wasEval1.link(this);
-        wasEval2.link(this);
-    }
+    if (opcodeID == op_call_eval)
+        wasEval.link(this);
 
     // Put the return value in dst. In the interpreter, op_ret does this.