Changeset 89956 in webkit

Timestamp:

Jun 28, 2011, 1:47:58 PM (15 years ago)

Author:

barraclough@apple.com

Message:

Make constant array optimisation less strict about what constitutes a constant
​https://bugs.webkit.org/show_bug.cgi?id=63554

Patch by Oliver Hunt <​oliver@apple.com> on 2011-06-28
Reviewed by Gavin Barraclough.

Now allow string constants in array literals to actually be considered constant,
and so avoid codegen in array literals with strings in them.

• bytecode/CodeBlock.h:

(JSC::CodeBlock::addConstantBuffer):
(JSC::CodeBlock::constantBuffer):

• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::addConstantBuffer):
(JSC::BytecodeGenerator::addStringConstant):
(JSC::BytecodeGenerator::emitNewArray):

• bytecompiler/BytecodeGenerator.h:
• interpreter/Interpreter.cpp:

(JSC::Interpreter::privateExecute):

• jit/JITStubs.cpp:

(JSC::DEFINE_STUB_FUNCTION):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• dfg/DFGJITCodeGenerator.cpp (modified) (1 diff)
• dfg/DFGJITCodeGenerator.h (modified) (4 diffs)
• dfg/DFGRegisterBank.h (modified) (1 diff)
• dfg/DFGSpeculativeJIT.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ -21 +21 @@
         * jit/JITStubs.cpp:
         (JSC::DEFINE_STUB_FUNCTION):
+
+2011-06-28  Gavin Barraclough  <barraclough@apple.com>
+
+        Reviewed by Oliver Hunt.
+
+        https://bugs.webkit.org/show_bug.cgi?id=63560
+        DFG_JIT allow allocation of specific machine registers
+
+        This allow us to allocate the registers necessary to perform x86
+        idiv instructions for div/mod, and may be useful for shifts, too.
+
+        * dfg/DFGJITCodeGenerator.cpp:
+        (JSC::DFG::GPRTemporary::GPRTemporary):
+        * dfg/DFGJITCodeGenerator.h:
+        (JSC::DFG::JITCodeGenerator::allocate):
+        (JSC::DFG::GPRResult::GPRResult):
+        * dfg/DFGRegisterBank.h:
+        (JSC::DFG::RegisterBank::allocateSpecific):
+        * dfg/DFGSpeculativeJIT.h:
+        (JSC::DFG::SpeculativeJIT::isInteger):
 
 2011-06-28  Gavin Barraclough  <barraclough@apple.com>

trunk/Source/JavaScriptCore/dfg/DFGJITCodeGenerator.cpp

@@ -537 +537 @@
 }
 
+GPRTemporary::GPRTemporary(JITCodeGenerator* jit, GPRReg specific)
+    : m_jit(jit)
+    , m_gpr(InvalidGPRReg)
+{
+    m_gpr = m_jit->allocate(specific);
+}
+
 GPRTemporary::GPRTemporary(JITCodeGenerator* jit, SpeculateIntegerOperand& op1)
     : m_jit(jit)

trunk/Source/JavaScriptCore/dfg/DFGJITCodeGenerator.h

@@ -117 +117 @@
         return gpr;
     }
+    GPRReg allocate(GPRReg specific)
+    {
+        VirtualRegister spillMe = m_gprs.allocateSpecific(specific);
+        if (spillMe != InvalidVirtualRegister)
+            spill(spillMe);
+        return specific;
+    }
     FPRReg fprAllocate()
     {
@@ -1000 +1007 @@
 public:
     GPRTemporary(JITCodeGenerator*);
+    GPRTemporary(JITCodeGenerator*, GPRReg specific);
     GPRTemporary(JITCodeGenerator*, SpeculateIntegerOperand&);
     GPRTemporary(JITCodeGenerator*, SpeculateIntegerOperand&, SpeculateIntegerOperand&);
@@ -1018 +1026 @@
     }
 
-protected:
-    GPRTemporary(JITCodeGenerator* jit, GPRReg lockedGPR)
-        : m_jit(jit)
-        , m_gpr(lockedGPR)
-    {
-    }
-
 private:
     JITCodeGenerator* m_jit;
@@ -1067 +1068 @@
 public:
     GPRResult(JITCodeGenerator* jit)
-        : GPRTemporary(jit, lockedResult(jit))
-    {
-    }
-
-private:
-    static GPRReg lockedResult(JITCodeGenerator* jit)
-    {
-        jit->lock(GPRInfo::returnValueGPR);
-        return GPRInfo::returnValueGPR;
+        : GPRTemporary(jit, GPRInfo::returnValueGPR)
+    {
     }
 };

trunk/Source/JavaScriptCore/dfg/DFGRegisterBank.h

@@ -140 +140 @@
     }
 
+    // Allocates the given register, even if this will force a spill.
+    VirtualRegister allocateSpecific(RegID reg)
+    {
+        unsigned index = BankInfo::toIndex(reg);
+
+        ++m_data[index].lockCount;
+        VirtualRegister name = nameAtIndex(index);
+        if (name != InvalidVirtualRegister)
+            releaseAtIndex(index);
+        
+        return name;
+    }
+
     // retain/release - these methods are used to associate/disassociate names
     // with values in registers. retain should only be called on locked registers.

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.h

@@ -161 +161 @@
             return true;
 
+        if (isInt32Constant(nodeIndex))
+            return true;
+
         VirtualRegister virtualRegister = node.virtualRegister();
         GenerationInfo& info = m_generationInfo[virtualRegister];