Title: [97928] trunk/Source/_javascript_Core
- Revision
- 97928
- Author
- [email protected]
- Date
- 2011-10-19 20:32:20 -0700 (Wed, 19 Oct 2011)
Log Message
DFG JIT 32_64 - remove unnecessary double unboxings in fillDouble/fillSpeculateDouble
https://bugs.webkit.org/show_bug.cgi?id=70460
Patch by Yuqiang Xian <[email protected]> on 2011-10-19
Reviewed by Filip Pizlo.
As pointed out by Gavin in bug #70418, when a value is already in memory
we can avoid loading it to two GPRs at first and then unboxing them to a FPR.
This gives 9% improvement on Kraken if without the change in bug #70418,
and 1% if based on the code with bug #70418 change.
Performance is neutral in V8 and SunSpider.
* dfg/DFGJITCodeGenerator32_64.cpp:
(JSC::DFG::JITCodeGenerator::fillDouble):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::fillSpeculateDouble):
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (97927 => 97928)
--- trunk/Source/_javascript_Core/ChangeLog 2011-10-20 03:16:29 UTC (rev 97927)
+++ trunk/Source/_javascript_Core/ChangeLog 2011-10-20 03:32:20 UTC (rev 97928)
@@ -1,3 +1,21 @@
+2011-10-19 Yuqiang Xian <[email protected]>
+
+ DFG JIT 32_64 - remove unnecessary double unboxings in fillDouble/fillSpeculateDouble
+ https://bugs.webkit.org/show_bug.cgi?id=70460
+
+ Reviewed by Filip Pizlo.
+
+ As pointed out by Gavin in bug #70418, when a value is already in memory
+ we can avoid loading it to two GPRs at first and then unboxing them to a FPR.
+ This gives 9% improvement on Kraken if without the change in bug #70418,
+ and 1% if based on the code with bug #70418 change.
+ Performance is neutral in V8 and SunSpider.
+
+ * dfg/DFGJITCodeGenerator32_64.cpp:
+ (JSC::DFG::JITCodeGenerator::fillDouble):
+ * dfg/DFGSpeculativeJIT32_64.cpp:
+ (JSC::DFG::SpeculativeJIT::fillSpeculateDouble):
+
2011-10-19 Gavin Barraclough <[email protected]>
Poisoning of strict caller,arguments inappropriately poisoning "in"
Modified: trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator32_64.cpp (97927 => 97928)
--- trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator32_64.cpp 2011-10-20 03:16:29 UTC (rev 97927)
+++ trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator32_64.cpp 2011-10-20 03:32:20 UTC (rev 97928)
@@ -132,14 +132,19 @@
info.fillDouble(fpr);
return fpr;
}
- GPRReg tag = allocate();
- GPRReg payload = allocate();
- m_jit.emitLoad(nodeIndex, tag, payload);
- m_gprs.retain(tag, virtualRegister, SpillOrderSpilled);
- m_gprs.retain(payload, virtualRegister, SpillOrderSpilled);
- info.fillJSValue(tag, payload, spillFormat);
- unlock(tag);
- unlock(payload);
+
+ FPRReg fpr = fprAllocate();
+ JITCompiler::Jump isInteger = m_jit.branch32(MacroAssembler::Equal, JITCompiler::tagFor(virtualRegister), TrustedImm32(JSValue::Int32Tag));
+ m_jit.loadDouble(JITCompiler::addressFor(virtualRegister), fpr);
+ JITCompiler::Jump hasUnboxedDouble = m_jit.jump();
+
+ isInteger.link(&m_jit);
+ m_jit.convertInt32ToDouble(JITCompiler::payloadFor(virtualRegister), fpr);
+
+ hasUnboxedDouble.link(&m_jit);
+ m_fprs.retain(fpr, virtualRegister, SpillOrderSpilled);
+ info.fillDouble(fpr);
+ return fpr;
}
}
Modified: trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT32_64.cpp (97927 => 97928)
--- trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT32_64.cpp 2011-10-20 03:16:29 UTC (rev 97927)
+++ trunk/Source/_javascript_Core/dfg/DFGSpeculativeJIT32_64.cpp 2011-10-20 03:32:20 UTC (rev 97928)
@@ -181,15 +181,21 @@
m_fprs.retain(fpr, virtualRegister, SpillOrderSpilled);
info.fillDouble(fpr);
return fpr;
- }
- GPRReg tag = allocate();
- GPRReg payload = allocate();
- m_jit.emitLoad(nodeIndex, tag, payload);
- m_gprs.retain(tag, virtualRegister, SpillOrderSpilled);
- m_gprs.retain(payload, virtualRegister, SpillOrderSpilled);
- info.fillJSValue(tag, payload, spillFormat);
- unlock(tag);
- unlock(payload);
+ }
+
+ FPRReg fpr = fprAllocate();
+ JITCompiler::Jump isInteger = m_jit.branch32(MacroAssembler::Equal, JITCompiler::tagFor(virtualRegister), TrustedImm32(JSValue::Int32Tag));
+ speculationCheck(m_jit.branch32(MacroAssembler::AboveOrEqual, JITCompiler::tagFor(virtualRegister), TrustedImm32(JSValue::LowestTag)));
+ m_jit.loadDouble(JITCompiler::addressFor(virtualRegister), fpr);
+ JITCompiler::Jump hasUnboxedDouble = m_jit.jump();
+
+ isInteger.link(&m_jit);
+ m_jit.convertInt32ToDouble(JITCompiler::payloadFor(virtualRegister), fpr);
+
+ hasUnboxedDouble.link(&m_jit);
+ m_fprs.retain(fpr, virtualRegister, SpillOrderSpilled);
+ info.fillDouble(fpr);
+ return fpr;
}
}
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