Implement try/catch in the DFG.
[WebKit-https.git] / Source / JavaScriptCore / jit / AssemblyHelpers.h
index 381189f..0c2daaa 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011, 2013, 2014 Apple Inc. All rights reserved.
+ * Copyright (C) 2011, 2013-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
 #include "CodeBlock.h"
 #include "FPRInfo.h"
 #include "GPRInfo.h"
+#include "InlineCallFrame.h"
 #include "JITCode.h"
 #include "MacroAssembler.h"
+#include "RegisterAtOffsetList.h"
+#include "RegisterSet.h"
+#include "TypeofType.h"
 #include "VM.h"
 
 namespace JSC {
@@ -88,6 +92,16 @@ public:
 #endif
     }
     
+    void storeValue(JSValueRegs regs, BaseIndex address)
+    {
+#if USE(JSVALUE64)
+        store64(regs.gpr(), address);
+#else
+        store32(regs.payloadGPR(), address.withOffset(PayloadOffset));
+        store32(regs.tagGPR(), address.withOffset(TagOffset));
+#endif
+    }
+    
     void storeValue(JSValueRegs regs, void* address)
     {
 #if USE(JSVALUE64)
@@ -113,6 +127,26 @@ public:
 #endif
     }
     
+    void loadValue(BaseIndex address, JSValueRegs regs)
+    {
+#if USE(JSVALUE64)
+        load64(address, regs.gpr());
+#else
+        if (address.base == regs.payloadGPR() || address.index == regs.payloadGPR()) {
+            // We actually could handle the case where the registers are aliased to both
+            // tag and payload, but we don't for now.
+            RELEASE_ASSERT(address.base != regs.tagGPR());
+            RELEASE_ASSERT(address.index != regs.tagGPR());
+            
+            load32(address.withOffset(TagOffset), regs.tagGPR());
+            load32(address.withOffset(PayloadOffset), regs.payloadGPR());
+        } else {
+            load32(address.withOffset(PayloadOffset), regs.payloadGPR());
+            load32(address.withOffset(TagOffset), regs.tagGPR());
+        }
+#endif
+    }
+    
     void moveTrustedValue(JSValue value, JSValueRegs regs)
     {
 #if USE(JSVALUE64)
@@ -122,6 +156,179 @@ public:
         move(TrustedImm32(value.payload()), regs.payloadGPR());
 #endif
     }
+    
+    void storeTrustedValue(JSValue value, Address address)
+    {
+#if USE(JSVALUE64)
+        store64(TrustedImm64(JSValue::encode(value)), address);
+#else
+        store32(TrustedImm32(value.tag()), address.withOffset(TagOffset));
+        store32(TrustedImm32(value.payload()), address.withOffset(PayloadOffset));
+#endif
+    }
+
+    void storeTrustedValue(JSValue value, BaseIndex address)
+    {
+#if USE(JSVALUE64)
+        store64(TrustedImm64(JSValue::encode(value)), address);
+#else
+        store32(TrustedImm32(value.tag()), address.withOffset(TagOffset));
+        store32(TrustedImm32(value.payload()), address.withOffset(PayloadOffset));
+#endif
+    }
+
+    void emitSaveCalleeSavesFor(CodeBlock* codeBlock, VirtualRegister offsetVirtualRegister = static_cast<VirtualRegister>(0))
+    {
+        ASSERT(codeBlock);
+
+        RegisterAtOffsetList* calleeSaves = codeBlock->calleeSaveRegisters();
+        RegisterSet dontSaveRegisters = RegisterSet(RegisterSet::stackRegisters(), RegisterSet::allFPRs());
+        unsigned registerCount = calleeSaves->size();
+
+        for (unsigned i = 0; i < registerCount; i++) {
+            RegisterAtOffset entry = calleeSaves->at(i);
+            if (dontSaveRegisters.get(entry.reg()))
+                continue;
+            storePtr(entry.reg().gpr(), Address(framePointerRegister, offsetVirtualRegister.offsetInBytes() + entry.offset()));
+        }
+    }
+
+    void emitRestoreCalleeSavesFor(CodeBlock* codeBlock)
+    {
+        ASSERT(codeBlock);
+
+        RegisterAtOffsetList* calleeSaves = codeBlock->calleeSaveRegisters();
+        RegisterSet dontRestoreRegisters = RegisterSet(RegisterSet::stackRegisters(), RegisterSet::allFPRs());
+        unsigned registerCount = calleeSaves->size();
+        
+        for (unsigned i = 0; i < registerCount; i++) {
+            RegisterAtOffset entry = calleeSaves->at(i);
+            if (dontRestoreRegisters.get(entry.reg()))
+                continue;
+            loadPtr(Address(framePointerRegister, entry.offset()), entry.reg().gpr());
+        }
+    }
+
+    void emitSaveCalleeSaves()
+    {
+        emitSaveCalleeSavesFor(codeBlock());
+    }
+
+    void emitRestoreCalleeSaves()
+    {
+        emitRestoreCalleeSavesFor(codeBlock());
+    }
+
+    void copyCalleeSavesToVMCalleeSavesBuffer(const TempRegisterSet& usedRegisters = { RegisterSet::stubUnavailableRegisters() })
+    {
+#if NUMBER_OF_CALLEE_SAVES_REGISTERS > 0
+        GPRReg temp1 = usedRegisters.getFreeGPR(0);
+
+        move(TrustedImmPtr(m_vm->calleeSaveRegistersBuffer), temp1);
+
+        RegisterAtOffsetList* allCalleeSaves = m_vm->getAllCalleeSaveRegisterOffsets();
+        RegisterSet dontCopyRegisters = RegisterSet::stackRegisters();
+        unsigned registerCount = allCalleeSaves->size();
+        
+        for (unsigned i = 0; i < registerCount; i++) {
+            RegisterAtOffset entry = allCalleeSaves->at(i);
+            if (dontCopyRegisters.get(entry.reg()))
+                continue;
+            if (entry.reg().isGPR())
+                storePtr(entry.reg().gpr(), Address(temp1, entry.offset()));
+            else
+                storeDouble(entry.reg().fpr(), Address(temp1, entry.offset()));
+        }
+#else
+        UNUSED_PARAM(usedRegisters);
+#endif
+    }
+
+    void restoreCalleeSavesFromVMCalleeSavesBuffer(const TempRegisterSet& usedRegisters = { RegisterSet::stubUnavailableRegisters() })
+    {
+#if NUMBER_OF_CALLEE_SAVES_REGISTERS > 0
+        GPRReg temp1 = usedRegisters.getFreeGPR(0);
+        
+        move(TrustedImmPtr(m_vm->calleeSaveRegistersBuffer), temp1);
+
+        RegisterAtOffsetList* allCalleeSaves = m_vm->getAllCalleeSaveRegisterOffsets();
+        RegisterSet dontRestoreRegisters = RegisterSet::stackRegisters();
+        unsigned registerCount = allCalleeSaves->size();
+        
+        for (unsigned i = 0; i < registerCount; i++) {
+            RegisterAtOffset entry = allCalleeSaves->at(i);
+            if (dontRestoreRegisters.get(entry.reg()))
+                continue;
+            if (entry.reg().isGPR())
+                loadPtr(Address(temp1, entry.offset()), entry.reg().gpr());
+            else
+                loadDouble(Address(temp1, entry.offset()), entry.reg().fpr());
+        }
+#else
+        UNUSED_PARAM(usedRegisters);
+#endif
+    }
+    
+    void copyCalleeSavesFromFrameOrRegisterToVMCalleeSavesBuffer(const TempRegisterSet& usedRegisters = { RegisterSet::stubUnavailableRegisters() })
+    {
+#if NUMBER_OF_CALLEE_SAVES_REGISTERS > 0
+        GPRReg temp1 = usedRegisters.getFreeGPR(0);
+        GPRReg temp2 = usedRegisters.getFreeGPR(1);
+        FPRReg fpTemp = usedRegisters.getFreeFPR();
+        ASSERT(temp2 != InvalidGPRReg);
+
+        ASSERT(codeBlock());
+
+        // Copy saved calleeSaves on stack or unsaved calleeSaves in register to vm calleeSave buffer
+        move(TrustedImmPtr(m_vm->calleeSaveRegistersBuffer), temp1);
+
+        RegisterAtOffsetList* allCalleeSaves = m_vm->getAllCalleeSaveRegisterOffsets();
+        RegisterAtOffsetList* currentCalleeSaves = codeBlock()->calleeSaveRegisters();
+        RegisterSet dontCopyRegisters = RegisterSet::stackRegisters();
+        unsigned registerCount = allCalleeSaves->size();
+
+        for (unsigned i = 0; i < registerCount; i++) {
+            RegisterAtOffset vmEntry = allCalleeSaves->at(i);
+            if (dontCopyRegisters.get(vmEntry.reg()))
+                continue;
+            RegisterAtOffset* currentFrameEntry = currentCalleeSaves->find(vmEntry.reg());
+
+            if (vmEntry.reg().isGPR()) {
+                GPRReg regToStore;
+                if (currentFrameEntry) {
+                    // Load calleeSave from stack into temp register
+                    regToStore = temp2;
+                    loadPtr(Address(framePointerRegister, currentFrameEntry->offset()), regToStore);
+                } else
+                    // Just store callee save directly
+                    regToStore = vmEntry.reg().gpr();
+
+                storePtr(regToStore, Address(temp1, vmEntry.offset()));
+            } else {
+                FPRReg fpRegToStore;
+                if (currentFrameEntry) {
+                    // Load calleeSave from stack into temp register
+                    fpRegToStore = fpTemp;
+                    loadDouble(Address(framePointerRegister, currentFrameEntry->offset()), fpRegToStore);
+                } else
+                    // Just store callee save directly
+                    fpRegToStore = vmEntry.reg().fpr();
+
+                storeDouble(fpRegToStore, Address(temp1, vmEntry.offset()));
+            }
+        }
+#else
+        UNUSED_PARAM(usedRegisters);
+#endif
+    }
+
+    void emitMaterializeTagCheckRegisters()
+    {
+#if USE(JSVALUE64)
+        move(MacroAssembler::TrustedImm64(TagTypeNumber), GPRInfo::tagTypeNumberRegister);
+        orPtr(MacroAssembler::TrustedImm32(TagBitTypeOther), GPRInfo::tagTypeNumberRegister, GPRInfo::tagMaskRegister);
+#endif
+    }
 
 #if CPU(X86_64) || CPU(X86)
     static size_t prologueStackPointerDelta()
@@ -253,10 +460,20 @@ public:
     }
 #endif
 
-    void emitGetFromCallFrameHeaderPtr(JSStack::CallFrameHeaderEntry entry, GPRReg to)
+    void emitGetFromCallFrameHeaderPtr(JSStack::CallFrameHeaderEntry entry, GPRReg to, GPRReg from = GPRInfo::callFrameRegister)
+    {
+        loadPtr(Address(from, entry * sizeof(Register)), to);
+    }
+    void emitGetFromCallFrameHeader32(JSStack::CallFrameHeaderEntry entry, GPRReg to, GPRReg from = GPRInfo::callFrameRegister)
     {
-        loadPtr(Address(GPRInfo::callFrameRegister, entry * sizeof(Register)), to);
+        load32(Address(from, entry * sizeof(Register)), to);
     }
+#if USE(JSVALUE64)
+    void emitGetFromCallFrameHeader64(JSStack::CallFrameHeaderEntry entry, GPRReg to, GPRReg from = GPRInfo::callFrameRegister)
+    {
+        load64(Address(from, entry * sizeof(Register)), to);
+    }
+#endif // USE(JSVALUE64)
     void emitPutToCallFrameHeader(GPRReg from, JSStack::CallFrameHeaderEntry entry)
     {
         storePtr(from, Address(GPRInfo::callFrameRegister, entry * sizeof(Register)));
@@ -307,6 +524,36 @@ public:
         storePtr(tag, Address(stackPointerRegister, entry * static_cast<ptrdiff_t>(sizeof(Register)) - prologueStackPointerDelta() + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.tag)));
     }
 #endif
+    
+    JumpList branchIfNotEqual(JSValueRegs regs, JSValue value)
+    {
+#if USE(JSVALUE64)
+        return branch64(NotEqual, regs.gpr(), TrustedImm64(JSValue::encode(value)));
+#else
+        JumpList result;
+        result.append(branch32(NotEqual, regs.tagGPR(), TrustedImm32(value.tag())));
+        if (value.isEmpty() || value.isUndefinedOrNull())
+            return result; // These don't have anything interesting in the payload.
+        result.append(branch32(NotEqual, regs.payloadGPR(), TrustedImm32(value.payload())));
+        return result;
+#endif
+    }
+    
+    Jump branchIfEqual(JSValueRegs regs, JSValue value)
+    {
+#if USE(JSVALUE64)
+        return branch64(Equal, regs.gpr(), TrustedImm64(JSValue::encode(value)));
+#else
+        Jump notEqual;
+        // These don't have anything interesting in the payload.
+        if (!value.isEmpty() && !value.isUndefinedOrNull())
+            notEqual = branch32(NotEqual, regs.payloadGPR(), TrustedImm32(value.payload()));
+        Jump result = branch32(Equal, regs.tagGPR(), TrustedImm32(value.tag()));
+        if (notEqual.isSet())
+            notEqual.link(this);
+        return result;
+#endif
+    }
 
     Jump branchIfNotCell(GPRReg reg)
     {
@@ -316,6 +563,171 @@ public:
         return branch32(MacroAssembler::NotEqual, reg, TrustedImm32(JSValue::CellTag));
 #endif
     }
+    Jump branchIfNotCell(JSValueRegs regs)
+    {
+#if USE(JSVALUE64)
+        return branchIfNotCell(regs.gpr());
+#else
+        return branchIfNotCell(regs.tagGPR());
+#endif
+    }
+    
+    Jump branchIfCell(GPRReg reg)
+    {
+#if USE(JSVALUE64)
+        return branchTest64(MacroAssembler::Zero, reg, GPRInfo::tagMaskRegister);
+#else
+        return branch32(MacroAssembler::Equal, reg, TrustedImm32(JSValue::CellTag));
+#endif
+    }
+    Jump branchIfCell(JSValueRegs regs)
+    {
+#if USE(JSVALUE64)
+        return branchIfCell(regs.gpr());
+#else
+        return branchIfCell(regs.tagGPR());
+#endif
+    }
+    
+    Jump branchIfOther(JSValueRegs regs, GPRReg tempGPR)
+    {
+#if USE(JSVALUE64)
+        move(regs.gpr(), tempGPR);
+        and64(TrustedImm32(~TagBitUndefined), tempGPR);
+        return branch64(Equal, tempGPR, TrustedImm64(ValueNull));
+#else
+        or32(TrustedImm32(1), regs.tagGPR(), tempGPR);
+        return branch32(Equal, tempGPR, TrustedImm32(JSValue::NullTag));
+#endif
+    }
+    
+    Jump branchIfNotOther(JSValueRegs regs, GPRReg tempGPR)
+    {
+#if USE(JSVALUE64)
+        move(regs.gpr(), tempGPR);
+        and64(TrustedImm32(~TagBitUndefined), tempGPR);
+        return branch64(NotEqual, tempGPR, TrustedImm64(ValueNull));
+#else
+        or32(TrustedImm32(1), regs.tagGPR(), tempGPR);
+        return branch32(NotEqual, tempGPR, TrustedImm32(JSValue::NullTag));
+#endif
+    }
+    
+    Jump branchIfInt32(JSValueRegs regs)
+    {
+#if USE(JSVALUE64)
+        return branch64(AboveOrEqual, regs.gpr(), GPRInfo::tagTypeNumberRegister);
+#else
+        return branch32(Equal, regs.tagGPR(), TrustedImm32(JSValue::Int32Tag));
+#endif
+    }
+    
+    Jump branchIfNotInt32(JSValueRegs regs)
+    {
+#if USE(JSVALUE64)
+        return branch64(Below, regs.gpr(), GPRInfo::tagTypeNumberRegister);
+#else
+        return branch32(NotEqual, regs.tagGPR(), TrustedImm32(JSValue::Int32Tag));
+#endif
+    }
+
+    // Note that the tempGPR is not used in 64-bit mode.
+    Jump branchIfNumber(JSValueRegs regs, GPRReg tempGPR)
+    {
+#if USE(JSVALUE64)
+        UNUSED_PARAM(tempGPR);
+        return branchTest64(NonZero, regs.gpr(), GPRInfo::tagTypeNumberRegister);
+#else
+        add32(TrustedImm32(1), regs.tagGPR(), tempGPR);
+        return branch32(Below, tempGPR, TrustedImm32(JSValue::LowestTag + 1));
+#endif
+    }
+    
+    // Note that the tempGPR is not used in 64-bit mode.
+    Jump branchIfNotNumber(JSValueRegs regs, GPRReg tempGPR)
+    {
+#if USE(JSVALUE64)
+        UNUSED_PARAM(tempGPR);
+        return branchTest64(Zero, regs.gpr(), GPRInfo::tagTypeNumberRegister);
+#else
+        add32(TrustedImm32(1), regs.tagGPR(), tempGPR);
+        return branch32(AboveOrEqual, tempGPR, TrustedImm32(JSValue::LowestTag + 1));
+#endif
+    }
+
+    // Note that the tempGPR is not used in 32-bit mode.
+    Jump branchIfBoolean(JSValueRegs regs, GPRReg tempGPR)
+    {
+#if USE(JSVALUE64)
+        move(regs.gpr(), tempGPR);
+        xor64(TrustedImm32(static_cast<int32_t>(ValueFalse)), tempGPR);
+        return branchTest64(Zero, tempGPR, TrustedImm32(static_cast<int32_t>(~1)));
+#else
+        UNUSED_PARAM(tempGPR);
+        return branch32(Equal, regs.tagGPR(), TrustedImm32(JSValue::BooleanTag));
+#endif
+    }
+    
+    // Note that the tempGPR is not used in 32-bit mode.
+    Jump branchIfNotBoolean(JSValueRegs regs, GPRReg tempGPR)
+    {
+#if USE(JSVALUE64)
+        move(regs.gpr(), tempGPR);
+        xor64(TrustedImm32(static_cast<int32_t>(ValueFalse)), tempGPR);
+        return branchTest64(NonZero, tempGPR, TrustedImm32(static_cast<int32_t>(~1)));
+#else
+        UNUSED_PARAM(tempGPR);
+        return branch32(NotEqual, regs.tagGPR(), TrustedImm32(JSValue::BooleanTag));
+#endif
+    }
+    
+    Jump branchIfObject(GPRReg cellGPR)
+    {
+        return branch8(
+            AboveOrEqual, Address(cellGPR, JSCell::typeInfoTypeOffset()), TrustedImm32(ObjectType));
+    }
+    
+    Jump branchIfNotObject(GPRReg cellGPR)
+    {
+        return branch8(
+            Below, Address(cellGPR, JSCell::typeInfoTypeOffset()), TrustedImm32(ObjectType));
+    }
+    
+    Jump branchIfType(GPRReg cellGPR, JSType type)
+    {
+        return branch8(Equal, Address(cellGPR, JSCell::typeInfoTypeOffset()), TrustedImm32(type));
+    }
+    
+    Jump branchIfNotType(GPRReg cellGPR, JSType type)
+    {
+        return branch8(NotEqual, Address(cellGPR, JSCell::typeInfoTypeOffset()), TrustedImm32(type));
+    }
+    
+    Jump branchIfString(GPRReg cellGPR) { return branchIfType(cellGPR, StringType); }
+    Jump branchIfNotString(GPRReg cellGPR) { return branchIfNotType(cellGPR, StringType); }
+    Jump branchIfSymbol(GPRReg cellGPR) { return branchIfType(cellGPR, SymbolType); }
+    Jump branchIfNotSymbol(GPRReg cellGPR) { return branchIfNotType(cellGPR, SymbolType); }
+    Jump branchIfFunction(GPRReg cellGPR) { return branchIfType(cellGPR, JSFunctionType); }
+    Jump branchIfNotFunction(GPRReg cellGPR) { return branchIfNotType(cellGPR, JSFunctionType); }
+    
+    Jump branchIfEmpty(JSValueRegs regs)
+    {
+#if USE(JSVALUE64)
+        return branchTest64(Zero, regs.gpr());
+#else
+        return branch32(Equal, regs.tagGPR(), TrustedImm32(JSValue::EmptyValueTag));
+#endif
+    }
+
+    template<typename T>
+    Jump branchStructure(RelationalCondition condition, T leftHandSide, Structure* structure)
+    {
+#if USE(JSVALUE64)
+        return branch32(condition, leftHandSide, TrustedImm32(structure->id()));
+#else
+        return branchPtr(condition, leftHandSide, TrustedImmPtr(structure));
+#endif
+    }
     
     static Address addressForByteOffset(ptrdiff_t byteOffset)
     {
@@ -328,6 +740,10 @@ public:
     }
     static Address addressFor(VirtualRegister virtualRegister)
     {
+        // NB. It's tempting on some architectures to sometimes use an offset from the stack
+        // register because for some offsets that will encode to a smaller instruction. But we
+        // cannot do this. We use this in places where the stack pointer has been moved to some
+        // unpredictable location.
         ASSERT(virtualRegister.isValid());
         return Address(GPRInfo::callFrameRegister, virtualRegister.offset() * sizeof(Register));
     }
@@ -356,26 +772,62 @@ public:
         return payloadFor(static_cast<VirtualRegister>(operand));
     }
 
-    Jump branchIfCellNotObject(GPRReg cellReg)
+    // Access to our fixed callee CallFrame.
+    static Address calleeFrameSlot(int slot)
+    {
+        ASSERT(slot >= JSStack::CallerFrameAndPCSize);
+        return Address(stackPointerRegister, sizeof(Register) * (slot - JSStack::CallerFrameAndPCSize));
+    }
+
+    // Access to our fixed callee CallFrame.
+    static Address calleeArgumentSlot(int argument)
     {
-        return branch8(Below, Address(cellReg, JSCell::typeInfoTypeOffset()), TrustedImm32(ObjectType));
+        return calleeFrameSlot(virtualRegisterForArgument(argument).offset());
     }
 
-    static GPRReg selectScratchGPR(GPRReg preserve1 = InvalidGPRReg, GPRReg preserve2 = InvalidGPRReg, GPRReg preserve3 = InvalidGPRReg, GPRReg preserve4 = InvalidGPRReg)
+    static Address calleeFrameTagSlot(int slot)
     {
-        if (preserve1 != GPRInfo::regT0 && preserve2 != GPRInfo::regT0 && preserve3 != GPRInfo::regT0 && preserve4 != GPRInfo::regT0)
+        return calleeFrameSlot(slot).withOffset(TagOffset);
+    }
+
+    static Address calleeFramePayloadSlot(int slot)
+    {
+        return calleeFrameSlot(slot).withOffset(PayloadOffset);
+    }
+
+    static Address calleeArgumentTagSlot(int argument)
+    {
+        return calleeArgumentSlot(argument).withOffset(TagOffset);
+    }
+
+    static Address calleeArgumentPayloadSlot(int argument)
+    {
+        return calleeArgumentSlot(argument).withOffset(PayloadOffset);
+    }
+
+    static Address calleeFrameCallerFrame()
+    {
+        return calleeFrameSlot(0).withOffset(CallFrame::callerFrameOffset());
+    }
+
+    static GPRReg selectScratchGPR(GPRReg preserve1 = InvalidGPRReg, GPRReg preserve2 = InvalidGPRReg, GPRReg preserve3 = InvalidGPRReg, GPRReg preserve4 = InvalidGPRReg, GPRReg preserve5 = InvalidGPRReg)
+    {
+        if (preserve1 != GPRInfo::regT0 && preserve2 != GPRInfo::regT0 && preserve3 != GPRInfo::regT0 && preserve4 != GPRInfo::regT0 && preserve5 != GPRInfo::regT0)
             return GPRInfo::regT0;
 
-        if (preserve1 != GPRInfo::regT1 && preserve2 != GPRInfo::regT1 && preserve3 != GPRInfo::regT1 && preserve4 != GPRInfo::regT1)
+        if (preserve1 != GPRInfo::regT1 && preserve2 != GPRInfo::regT1 && preserve3 != GPRInfo::regT1 && preserve4 != GPRInfo::regT1 && preserve5 != GPRInfo::regT1)
             return GPRInfo::regT1;
 
-        if (preserve1 != GPRInfo::regT2 && preserve2 != GPRInfo::regT2 && preserve3 != GPRInfo::regT2 && preserve4 != GPRInfo::regT2)
+        if (preserve1 != GPRInfo::regT2 && preserve2 != GPRInfo::regT2 && preserve3 != GPRInfo::regT2 && preserve4 != GPRInfo::regT2 && preserve5 != GPRInfo::regT2)
             return GPRInfo::regT2;
 
-        if (preserve1 != GPRInfo::regT3 && preserve2 != GPRInfo::regT3 && preserve3 != GPRInfo::regT3 && preserve4 != GPRInfo::regT3)
+        if (preserve1 != GPRInfo::regT3 && preserve2 != GPRInfo::regT3 && preserve3 != GPRInfo::regT3 && preserve4 != GPRInfo::regT3 && preserve5 != GPRInfo::regT3)
             return GPRInfo::regT3;
 
-        return GPRInfo::regT4;
+        if (preserve1 != GPRInfo::regT4 && preserve2 != GPRInfo::regT4 && preserve3 != GPRInfo::regT4 && preserve4 != GPRInfo::regT4 && preserve5 != GPRInfo::regT4)
+            return GPRInfo::regT4;
+
+        return GPRInfo::regT5;
     }
 
     // Add a debug call. This call has no effect on JIT code execution state.
@@ -445,6 +897,7 @@ public:
     void jitAssertIsNull(GPRReg);
     void jitAssertTagsInPlace();
     void jitAssertArgumentCountSane();
+    void jitAssertNoException();
 #else
     void jitAssertIsInt32(GPRReg) { }
     void jitAssertIsJSInt32(GPRReg) { }
@@ -455,6 +908,7 @@ public:
     void jitAssertIsNull(GPRReg) { }
     void jitAssertTagsInPlace() { }
     void jitAssertArgumentCountSane() { }
+    void jitAssertNoException() { }
 #endif
     
     void purifyNaN(FPRReg);
@@ -468,13 +922,17 @@ public:
         jitAssertIsJSDouble(gpr);
         return gpr;
     }
-    FPRReg unboxDouble(GPRReg gpr, FPRReg fpr)
+    FPRReg unboxDoubleWithoutAssertions(GPRReg gpr, FPRReg fpr)
     {
-        jitAssertIsJSDouble(gpr);
         add64(GPRInfo::tagTypeNumberRegister, gpr);
         move64ToDouble(gpr, fpr);
         return fpr;
     }
+    FPRReg unboxDouble(GPRReg gpr, FPRReg fpr)
+    {
+        jitAssertIsJSDouble(gpr);
+        return unboxDoubleWithoutAssertions(gpr, fpr);
+    }
     
     void boxDouble(FPRReg fpr, JSValueRegs regs)
     {
@@ -520,10 +978,50 @@ public:
     }
 #endif
     
+    void boxBooleanPayload(GPRReg boolGPR, GPRReg payloadGPR)
+    {
+#if USE(JSVALUE64)
+        add32(TrustedImm32(ValueFalse), boolGPR, payloadGPR);
+#else
+        move(boolGPR, payloadGPR);
+#endif
+    }
+
+    void boxBooleanPayload(bool value, GPRReg payloadGPR)
+    {
+#if USE(JSVALUE64)
+        move(TrustedImm32(ValueFalse + value), payloadGPR);
+#else
+        move(TrustedImm32(value), payloadGPR);
+#endif
+    }
+
+    void boxBoolean(GPRReg boolGPR, JSValueRegs boxedRegs)
+    {
+        boxBooleanPayload(boolGPR, boxedRegs.payloadGPR());
+#if USE(JSVALUE32_64)
+        move(TrustedImm32(JSValue::BooleanTag), boxedRegs.tagGPR());
+#endif
+    }
+
+    void boxInt32(GPRReg intGPR, JSValueRegs boxedRegs)
+    {
+#if USE(JSVALUE64)
+        move(intGPR, boxedRegs.gpr());
+        or64(TrustedImm64(TagTypeNumber), boxedRegs.gpr());
+#else
+        move(intGPR, boxedRegs.payloadGPR());
+        move(TrustedImm32(JSValue::Int32Tag), boxedRegs.tagGPR());
+#endif
+    }
+    
     void callExceptionFuzz();
     
     enum ExceptionCheckKind { NormalExceptionCheck, InvertedExceptionCheck };
-    Jump emitExceptionCheck(ExceptionCheckKind kind = NormalExceptionCheck);
+    enum ExceptionJumpWidth { NormalJumpWidth, FarJumpWidth };
+    Jump emitExceptionCheck(
+        ExceptionCheckKind = NormalExceptionCheck, ExceptionJumpWidth = NormalJumpWidth);
+    Jump emitNonPatchableExceptionCheck();
 
 #if ENABLE(SAMPLING_COUNTERS)
     static void emitCount(MacroAssembler& jit, AbstractSamplingCounter& counter, int32_t increment = 1)
@@ -577,46 +1075,20 @@ public:
         return m_baselineCodeBlock;
     }
     
-    VirtualRegister baselineArgumentsRegisterFor(InlineCallFrame* inlineCallFrame)
-    {
-        if (!inlineCallFrame)
-            return baselineCodeBlock()->argumentsRegister();
-        
-        return VirtualRegister(baselineCodeBlockForInlineCallFrame(
-            inlineCallFrame)->argumentsRegister().offset() + inlineCallFrame->stackOffset);
-    }
-    
-    VirtualRegister baselineArgumentsRegisterFor(const CodeOrigin& codeOrigin)
-    {
-        return baselineArgumentsRegisterFor(codeOrigin.inlineCallFrame);
-    }
-    
-    SymbolTable* symbolTableFor(const CodeOrigin& codeOrigin)
-    {
-        return baselineCodeBlockFor(codeOrigin)->symbolTable();
-    }
-
-    int offsetOfLocals(const CodeOrigin& codeOrigin)
-    {
-        if (!codeOrigin.inlineCallFrame)
-            return 0;
-        return codeOrigin.inlineCallFrame->stackOffset * sizeof(Register);
-    }
-
-    int offsetOfArguments(InlineCallFrame* inlineCallFrame)
+    static VirtualRegister argumentsStart(InlineCallFrame* inlineCallFrame)
     {
         if (!inlineCallFrame)
-            return CallFrame::argumentOffset(0) * sizeof(Register);
+            return VirtualRegister(CallFrame::argumentOffset(0));
         if (inlineCallFrame->arguments.size() <= 1)
-            return 0;
+            return virtualRegisterForLocal(0);
         ValueRecovery recovery = inlineCallFrame->arguments[1];
         RELEASE_ASSERT(recovery.technique() == DisplacedInJSStack);
-        return recovery.virtualRegister().offset() * sizeof(Register);
+        return recovery.virtualRegister();
     }
     
-    int offsetOfArguments(const CodeOrigin& codeOrigin)
+    static VirtualRegister argumentsStart(const CodeOrigin& codeOrigin)
     {
-        return offsetOfArguments(codeOrigin.inlineCallFrame);
+        return argumentsStart(codeOrigin.inlineCallFrame);
     }
     
     void emitLoadStructure(RegisterID source, RegisterID dest, RegisterID scratch)
@@ -675,6 +1147,82 @@ public:
         uint8_t* address = reinterpret_cast<uint8_t*>(cell) + JSCell::gcDataOffset();
         return branchTest8(MacroAssembler::NonZero, MacroAssembler::AbsoluteAddress(address));
     }
+    
+    // Emits the branch structure for typeof. The code emitted by this doesn't fall through. The
+    // functor is called at those points where we have pinpointed a type. One way to use this is to
+    // have the functor emit the code to put the type string into an appropriate register and then
+    // jump out. A secondary functor is used for the call trap and masquerades-as-undefined slow
+    // case. It is passed the unlinked jump to the slow case.
+    template<typename Functor, typename SlowPathFunctor>
+    void emitTypeOf(
+        JSValueRegs regs, GPRReg tempGPR, const Functor& functor,
+        const SlowPathFunctor& slowPathFunctor)
+    {
+        // Implements the following branching structure:
+        //
+        // if (is cell) {
+        //     if (is object) {
+        //         if (is function) {
+        //             return function;
+        //         } else if (doesn't have call trap and doesn't masquerade as undefined) {
+        //             return object
+        //         } else {
+        //             return slowPath();
+        //         }
+        //     } else if (is string) {
+        //         return string
+        //     } else {
+        //         return symbol
+        //     }
+        // } else if (is number) {
+        //     return number
+        // } else if (is null) {
+        //     return object
+        // } else if (is boolean) {
+        //     return boolean
+        // } else {
+        //     return undefined
+        // }
+        
+        Jump notCell = branchIfNotCell(regs);
+        
+        GPRReg cellGPR = regs.payloadGPR();
+        Jump notObject = branchIfNotObject(cellGPR);
+        
+        Jump notFunction = branchIfNotFunction(cellGPR);
+        functor(TypeofType::Function, false);
+        
+        notFunction.link(this);
+        slowPathFunctor(
+            branchTest8(
+                NonZero,
+                Address(cellGPR, JSCell::typeInfoFlagsOffset()),
+                TrustedImm32(MasqueradesAsUndefined | TypeOfShouldCallGetCallData)));
+        functor(TypeofType::Object, false);
+        
+        notObject.link(this);
+        
+        Jump notString = branchIfNotString(cellGPR);
+        functor(TypeofType::String, false);
+        notString.link(this);
+        functor(TypeofType::Symbol, false);
+        
+        notCell.link(this);
+
+        Jump notNumber = branchIfNotNumber(regs, tempGPR);
+        functor(TypeofType::Number, false);
+        notNumber.link(this);
+        
+        JumpList notNull = branchIfNotEqual(regs, jsNull());
+        functor(TypeofType::Object, false);
+        notNull.link(this);
+        
+        Jump notBoolean = branchIfNotBoolean(regs, tempGPR);
+        functor(TypeofType::Boolean, false);
+        notBoolean.link(this);
+        
+        functor(TypeofType::Undefined, true);
+    }
 
     Vector<BytecodeAndMachineOffset>& decodedCodeMapFor(CodeBlock*);