[webkit-changes] [198057] trunk/Source/JavaScriptCore

[commit-queue]

Title: [198057] trunk/Source/_javascript_Core

Revision

198057

Author

commit-qu...@webkit.org

Date

2016-03-11 19:28:32 -0800 (Fri, 11 Mar 2016)

Log Message

[JSC] Remove a few jumps from DFG
https://bugs.webkit.org/show_bug.cgi?id=155347

Patch by Benjamin Poulain <bpoul...@apple.com> on 2016-03-11
Reviewed by Mark Lam.

Usually, setting ValueTrue or ValueFalse is set
by Compare+Or. There are 3 places in DFG with branches instead.

This patch changes them to the usual pattern.

* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compileObjectEquality):
(JSC::DFG::SpeculativeJIT::compileObjectToObjectOrOtherEquality):

Modified Paths

• trunk/Source/_javascript_Core/ChangeLog
• trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT64.cpp

Diff

Modified: trunk/Source/_javascript_Core/ChangeLog (198056 => 198057)

--- trunk/Source/_javascript_Core/ChangeLog	2016-03-12 03:11:04 UTC (rev 198056)
+++ trunk/Source/_javascript_Core/ChangeLog	2016-03-12 03:28:32 UTC (rev 198057)
@@ -1,3 +1,19 @@
+2016-03-11  Benjamin Poulain  <bpoul...@apple.com>
+
+        [JSC] Remove a few jumps from DFG
+        https://bugs.webkit.org/show_bug.cgi?id=155347
+
+        Reviewed by Mark Lam.
+
+        Usually, setting ValueTrue or ValueFalse is set
+        by Compare+Or. There are 3 places in DFG with branches instead.
+
+        This patch changes them to the usual pattern.
+
+        * dfg/DFGSpeculativeJIT64.cpp:
+        (JSC::DFG::SpeculativeJIT::compileObjectEquality):
+        (JSC::DFG::SpeculativeJIT::compileObjectToObjectOrOtherEquality):
+
 2016-03-11  Saam barati  <sbar...@apple.com>
 
         [ES6] Make Object.assign spec compliant

Modified: trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT64.cpp (198056 => 198057)

--- trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT64.cpp	2016-03-12 03:11:04 UTC (rev 198056)
+++ trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT64.cpp	2016-03-12 03:28:32 UTC (rev 198057)
@@ -1369,14 +1369,9 @@
                 MacroAssembler::Address(op2GPR, JSCell::typeInfoFlagsOffset()), 
                 MacroAssembler::TrustedImm32(MasqueradesAsUndefined)));
     }
-    
-    MacroAssembler::Jump falseCase = m_jit.branch64(MacroAssembler::NotEqual, op1GPR, op2GPR);
-    m_jit.move(TrustedImm32(ValueTrue), resultGPR);
-    MacroAssembler::Jump done = m_jit.jump();
-    falseCase.link(&m_jit);
-    m_jit.move(TrustedImm32(ValueFalse), resultGPR);
-    done.link(&m_jit);
 
+    m_jit.compare64(MacroAssembler::Equal, op1GPR, op2GPR, resultGPR);
+    m_jit.or32(TrustedImm32(ValueFalse), resultGPR);
     jsValueResult(resultGPR, m_currentNode, DataFormatJSBoolean);
 }
 
@@ -1468,8 +1463,8 @@
     // At this point we know that we can perform a straight-forward equality comparison on pointer
     // values because both left and right are pointers to objects that have no special equality
     // protocols.
-    MacroAssembler::Jump falseCase = m_jit.branch64(MacroAssembler::NotEqual, op1GPR, op2GPR);
-    MacroAssembler::Jump trueCase = m_jit.jump();
+    m_jit.compare64(MacroAssembler::Equal, op1GPR, op2GPR, resultGPR);
+    MacroAssembler::Jump done = m_jit.jump();
     
     rightNotCell.link(&m_jit);
     
@@ -1485,14 +1480,10 @@
                 MacroAssembler::NotEqual, resultGPR,
                 MacroAssembler::TrustedImm64(ValueNull)));
     }
-    
-    falseCase.link(&m_jit);
-    m_jit.move(TrustedImm32(ValueFalse), resultGPR);
-    MacroAssembler::Jump done = m_jit.jump();
-    trueCase.link(&m_jit);
-    m_jit.move(TrustedImm32(ValueTrue), resultGPR);
+    m_jit.move(TrustedImm32(0), result.gpr());
+
     done.link(&m_jit);
-    
+    m_jit.or32(TrustedImm32(ValueFalse), resultGPR);
     jsValueResult(resultGPR, m_currentNode, DataFormatJSBoolean);
 }
 

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