X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/b80e619319b1def83d1e8b4f84042b661be1be7f..14957cd040308e3eeec43d26bae5d76da13fcd85:/dfg/DFGSpeculativeJIT.cpp

diff --git a/dfg/DFGSpeculativeJIT.cpp b/dfg/DFGSpeculativeJIT.cpp
new file mode 100644
index 0000000..71004fe
--- /dev/null
+++ b/dfg/DFGSpeculativeJIT.cpp
@@ -0,0 +1,956 @@
+/*
+ * Copyright (C) 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "DFGSpeculativeJIT.h"
+
+#if ENABLE(DFG_JIT)
+
+namespace JSC { namespace DFG {
+
+template<bool strict>
+GPRReg SpeculativeJIT::fillSpeculateIntInternal(NodeIndex nodeIndex, DataFormat& returnFormat)
+{
+    Node& node = m_jit.graph()[nodeIndex];
+    VirtualRegister virtualRegister = node.virtualRegister();
+    GenerationInfo& info = m_generationInfo[virtualRegister];
+
+    switch (info.registerFormat()) {
+    case DataFormatNone: {
+        GPRReg gpr = allocate();
+
+        if (node.isConstant()) {
+            m_gprs.retain(gpr, virtualRegister, SpillOrderConstant);
+            if (isInt32Constant(nodeIndex)) {
+                m_jit.move(MacroAssembler::Imm32(valueOfInt32Constant(nodeIndex)), gpr);
+                info.fillInteger(gpr);
+                returnFormat = DataFormatInteger;
+                return gpr;
+            }
+            m_jit.move(constantAsJSValueAsImmPtr(nodeIndex), gpr);
+        } else {
+            DataFormat spillFormat = info.spillFormat();
+            ASSERT(spillFormat & DataFormatJS);
+
+            m_gprs.retain(gpr, virtualRegister, SpillOrderSpilled);
+
+            if (spillFormat == DataFormatJSInteger) {
+                // If we know this was spilled as an integer we can fill without checking.
+                if (strict) {
+                    m_jit.load32(JITCompiler::addressFor(virtualRegister), gpr);
+                    info.fillInteger(gpr);
+                    returnFormat = DataFormatInteger;
+                    return gpr;
+                }
+                m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), gpr);
+                info.fillJSValue(gpr, DataFormatJSInteger);
+                returnFormat = DataFormatJSInteger;
+                return gpr;
+            }
+            m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), gpr);
+        }
+
+        // Fill as JSValue, and fall through.
+        info.fillJSValue(gpr, DataFormatJSInteger);
+        m_gprs.unlock(gpr);
+    }
+
+    case DataFormatJS: {
+        // Check the value is an integer.
+        GPRReg gpr = info.gpr();
+        m_gprs.lock(gpr);
+        speculationCheck(m_jit.branchPtr(MacroAssembler::Below, gpr, GPRInfo::tagTypeNumberRegister));
+        info.fillJSValue(gpr, DataFormatJSInteger);
+        // If !strict we're done, return.
+        if (!strict) {
+            returnFormat = DataFormatJSInteger;
+            return gpr;
+        }
+        // else fall through & handle as DataFormatJSInteger.
+        m_gprs.unlock(gpr);
+    }
+
+    case DataFormatJSInteger: {
+        // In a strict fill we need to strip off the value tag.
+        if (strict) {
+            GPRReg gpr = info.gpr();
+            GPRReg result;
+            // If the register has already been locked we need to take a copy.
+            // If not, we'll zero extend in place, so mark on the info that this is now type DataFormatInteger, not DataFormatJSInteger.
+            if (m_gprs.isLocked(gpr))
+                result = allocate();
+            else {
+                m_gprs.lock(gpr);
+                info.fillInteger(gpr);
+                result = gpr;
+            }
+            m_jit.zeroExtend32ToPtr(gpr, result);
+            returnFormat = DataFormatInteger;
+            return result;
+        }
+
+        GPRReg gpr = info.gpr();
+        m_gprs.lock(gpr);
+        returnFormat = DataFormatJSInteger;
+        return gpr;
+    }
+
+    case DataFormatInteger: {
+        GPRReg gpr = info.gpr();
+        m_gprs.lock(gpr);
+        returnFormat = DataFormatInteger;
+        return gpr;
+    }
+
+    case DataFormatDouble:
+    case DataFormatCell:
+    case DataFormatJSDouble:
+    case DataFormatJSCell: {
+        terminateSpeculativeExecution();
+        returnFormat = DataFormatInteger;
+        return allocate();
+    }
+    }
+
+    ASSERT_NOT_REACHED();
+    return InvalidGPRReg;
+}
+
+SpeculationCheck::SpeculationCheck(MacroAssembler::Jump check, SpeculativeJIT* jit, unsigned recoveryIndex)
+    : m_check(check)
+    , m_nodeIndex(jit->m_compileIndex)
+    , m_recoveryIndex(recoveryIndex)
+{
+    for (gpr_iterator iter = jit->m_gprs.begin(); iter != jit->m_gprs.end(); ++iter) {
+        if (iter.name() != InvalidVirtualRegister) {
+            GenerationInfo& info =  jit->m_generationInfo[iter.name()];
+            m_gprInfo[iter.index()].nodeIndex = info.nodeIndex();
+            m_gprInfo[iter.index()].format = info.registerFormat();
+        } else
+            m_gprInfo[iter.index()].nodeIndex = NoNode;
+    }
+    for (fpr_iterator iter = jit->m_fprs.begin(); iter != jit->m_fprs.end(); ++iter) {
+        if (iter.name() != InvalidVirtualRegister) {
+            GenerationInfo& info =  jit->m_generationInfo[iter.name()];
+            ASSERT(info.registerFormat() == DataFormatDouble);
+            m_fprInfo[iter.index()] = info.nodeIndex();
+        } else
+            m_fprInfo[iter.index()] = NoNode;
+    }
+}
+
+GPRReg SpeculativeJIT::fillSpeculateInt(NodeIndex nodeIndex, DataFormat& returnFormat)
+{
+    return fillSpeculateIntInternal<false>(nodeIndex, returnFormat);
+}
+
+GPRReg SpeculativeJIT::fillSpeculateIntStrict(NodeIndex nodeIndex)
+{
+    DataFormat mustBeDataFormatInteger;
+    GPRReg result = fillSpeculateIntInternal<true>(nodeIndex, mustBeDataFormatInteger);
+    ASSERT(mustBeDataFormatInteger == DataFormatInteger);
+    return result;
+}
+
+GPRReg SpeculativeJIT::fillSpeculateCell(NodeIndex nodeIndex)
+{
+    Node& node = m_jit.graph()[nodeIndex];
+    VirtualRegister virtualRegister = node.virtualRegister();
+    GenerationInfo& info = m_generationInfo[virtualRegister];
+
+    switch (info.registerFormat()) {
+    case DataFormatNone: {
+        GPRReg gpr = allocate();
+
+        if (node.isConstant()) {
+            m_gprs.retain(gpr, virtualRegister, SpillOrderConstant);
+            JSValue jsValue = constantAsJSValue(nodeIndex);
+            if (jsValue.isCell()) {
+                m_jit.move(MacroAssembler::TrustedImmPtr(jsValue.asCell()), gpr);
+                info.fillJSValue(gpr, DataFormatJSCell);
+                return gpr;
+            }
+            terminateSpeculativeExecution();
+            return gpr;
+        }
+        ASSERT(info.spillFormat() & DataFormatJS);
+        m_gprs.retain(gpr, virtualRegister, SpillOrderSpilled);
+        m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), gpr);
+
+        if (info.spillFormat() != DataFormatJSCell)
+            speculationCheck(m_jit.branchTestPtr(MacroAssembler::NonZero, gpr, GPRInfo::tagMaskRegister));
+        info.fillJSValue(gpr, DataFormatJSCell);
+        return gpr;
+    }
+
+    case DataFormatCell:
+    case DataFormatJSCell: {
+        GPRReg gpr = info.gpr();
+        m_gprs.lock(gpr);
+        return gpr;
+    }
+
+    case DataFormatJS: {
+        GPRReg gpr = info.gpr();
+        m_gprs.lock(gpr);
+        speculationCheck(m_jit.branchTestPtr(MacroAssembler::NonZero, gpr, GPRInfo::tagMaskRegister));
+        info.fillJSValue(gpr, DataFormatJSCell);
+        return gpr;
+    }
+
+    case DataFormatJSInteger:
+    case DataFormatInteger:
+    case DataFormatJSDouble:
+    case DataFormatDouble: {
+        terminateSpeculativeExecution();
+        return allocate();
+    }
+    }
+
+    ASSERT_NOT_REACHED();
+    return InvalidGPRReg;
+}
+
+void SpeculativeJIT::compilePeepHoleBranch(Node& node, JITCompiler::RelationalCondition condition)
+{
+    Node& branchNode = m_jit.graph()[m_compileIndex + 1];
+    BlockIndex taken = m_jit.graph().blockIndexForBytecodeOffset(branchNode.takenBytecodeOffset());
+    BlockIndex notTaken = m_jit.graph().blockIndexForBytecodeOffset(branchNode.notTakenBytecodeOffset());
+
+    // The branch instruction will branch to the taken block.
+    // If taken is next, switch taken with notTaken & invert the branch condition so we can fall through.
+    if (taken == (m_block + 1)) {
+        condition = JITCompiler::invert(condition);
+        BlockIndex tmp = taken;
+        taken = notTaken;
+        notTaken = tmp;
+    }
+
+    int32_t imm;
+    if (isJSConstantWithInt32Value(node.child1, imm)) {
+        SpeculateIntegerOperand op2(this, node.child2);
+        addBranch(m_jit.branch32(condition, JITCompiler::Imm32(imm), op2.gpr()), taken);
+    } else if (isJSConstantWithInt32Value(node.child2, imm)) {
+        SpeculateIntegerOperand op1(this, node.child1);
+        addBranch(m_jit.branch32(condition, op1.gpr(), JITCompiler::Imm32(imm)), taken);
+    } else {
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        addBranch(m_jit.branch32(condition, op1.gpr(), op2.gpr()), taken);
+    }
+
+    // Check for fall through, otherwise we need to jump.
+    if (notTaken != (m_block + 1))
+        addBranch(m_jit.jump(), notTaken);
+}
+
+void SpeculativeJIT::compile(Node& node)
+{
+    NodeType op = node.op;
+
+    switch (op) {
+    case Int32Constant:
+    case DoubleConstant:
+    case JSConstant:
+        initConstantInfo(m_compileIndex);
+        break;
+
+    case GetLocal: {
+        GPRTemporary result(this);
+        PredictedType prediction = m_jit.graph().getPrediction(node.local());
+        if (prediction == PredictInt32) {
+            m_jit.load32(JITCompiler::payloadFor(node.local()), result.gpr());
+
+            // Like integerResult, but don't useChildren - our children are phi nodes,
+            // and don't represent values within this dataflow with virtual registers.
+            VirtualRegister virtualRegister = node.virtualRegister();
+            m_gprs.retain(result.gpr(), virtualRegister, SpillOrderInteger);
+            m_generationInfo[virtualRegister].initInteger(m_compileIndex, node.refCount(), result.gpr());
+        } else {
+            m_jit.loadPtr(JITCompiler::addressFor(node.local()), result.gpr());
+
+            // Like jsValueResult, but don't useChildren - our children are phi nodes,
+            // and don't represent values within this dataflow with virtual registers.
+            VirtualRegister virtualRegister = node.virtualRegister();
+            m_gprs.retain(result.gpr(), virtualRegister, SpillOrderJS);
+            m_generationInfo[virtualRegister].initJSValue(m_compileIndex, node.refCount(), result.gpr(), (prediction == PredictArray) ? DataFormatJSCell : DataFormatJS);
+        }
+        break;
+    }
+
+    case SetLocal: {
+        switch (m_jit.graph().getPrediction(node.local())) {
+        case PredictInt32: {
+            SpeculateIntegerOperand value(this, node.child1);
+            m_jit.store32(value.gpr(), JITCompiler::payloadFor(node.local()));
+            noResult(m_compileIndex);
+            break;
+        }
+        case PredictArray: {
+            SpeculateCellOperand cell(this, node.child1);
+            m_jit.storePtr(cell.gpr(), JITCompiler::addressFor(node.local()));
+            noResult(m_compileIndex);
+            break;
+        }
+
+        default: {
+            JSValueOperand value(this, node.child1);
+            m_jit.storePtr(value.gpr(), JITCompiler::addressFor(node.local()));
+            noResult(m_compileIndex);
+            break;
+        }
+        }
+        break;
+    }
+
+    case BitAnd:
+    case BitOr:
+    case BitXor:
+        if (isInt32Constant(node.child1)) {
+            SpeculateIntegerOperand op2(this, node.child2);
+            GPRTemporary result(this, op2);
+
+            bitOp(op, valueOfInt32Constant(node.child1), op2.gpr(), result.gpr());
+
+            integerResult(result.gpr(), m_compileIndex);
+        } else if (isInt32Constant(node.child2)) {
+            SpeculateIntegerOperand op1(this, node.child1);
+            GPRTemporary result(this, op1);
+
+            bitOp(op, valueOfInt32Constant(node.child2), op1.gpr(), result.gpr());
+
+            integerResult(result.gpr(), m_compileIndex);
+        } else {
+            SpeculateIntegerOperand op1(this, node.child1);
+            SpeculateIntegerOperand op2(this, node.child2);
+            GPRTemporary result(this, op1, op2);
+
+            GPRReg reg1 = op1.gpr();
+            GPRReg reg2 = op2.gpr();
+            bitOp(op, reg1, reg2, result.gpr());
+
+            integerResult(result.gpr(), m_compileIndex);
+        }
+        break;
+
+    case BitRShift:
+    case BitLShift:
+    case BitURShift:
+        if (isInt32Constant(node.child2)) {
+            SpeculateIntegerOperand op1(this, node.child1);
+            GPRTemporary result(this, op1);
+
+            shiftOp(op, op1.gpr(), valueOfInt32Constant(node.child2) & 0x1f, result.gpr());
+
+            integerResult(result.gpr(), m_compileIndex);
+        } else {
+            // Do not allow shift amount to be used as the result, MacroAssembler does not permit this.
+            SpeculateIntegerOperand op1(this, node.child1);
+            SpeculateIntegerOperand op2(this, node.child2);
+            GPRTemporary result(this, op1);
+
+            GPRReg reg1 = op1.gpr();
+            GPRReg reg2 = op2.gpr();
+            shiftOp(op, reg1, reg2, result.gpr());
+
+            integerResult(result.gpr(), m_compileIndex);
+        }
+        break;
+
+    case UInt32ToNumber: {
+        IntegerOperand op1(this, node.child1);
+        GPRTemporary result(this, op1);
+
+        // Test the operand is positive.
+        speculationCheck(m_jit.branch32(MacroAssembler::LessThan, op1.gpr(), TrustedImm32(0)));
+
+        m_jit.move(op1.gpr(), result.gpr());
+        integerResult(result.gpr(), m_compileIndex, op1.format());
+        break;
+    }
+
+    case NumberToInt32: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        GPRTemporary result(this, op1);
+        m_jit.move(op1.gpr(), result.gpr());
+        integerResult(result.gpr(), m_compileIndex, op1.format());
+        break;
+    }
+
+    case Int32ToNumber: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        GPRTemporary result(this, op1);
+        m_jit.move(op1.gpr(), result.gpr());
+        integerResult(result.gpr(), m_compileIndex, op1.format());
+        break;
+    }
+
+    case ValueToInt32: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        GPRTemporary result(this, op1);
+        m_jit.move(op1.gpr(), result.gpr());
+        integerResult(result.gpr(), m_compileIndex, op1.format());
+        break;
+    }
+
+    case ValueToNumber: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        GPRTemporary result(this, op1);
+        m_jit.move(op1.gpr(), result.gpr());
+        integerResult(result.gpr(), m_compileIndex, op1.format());
+        break;
+    }
+
+    case ValueAdd:
+    case ArithAdd: {
+        int32_t imm1;
+        if (isDoubleConstantWithInt32Value(node.child1, imm1)) {
+            SpeculateIntegerOperand op2(this, node.child2);
+            GPRTemporary result(this);
+
+            speculationCheck(m_jit.branchAdd32(MacroAssembler::Overflow, op2.gpr(), Imm32(imm1), result.gpr()));
+
+            integerResult(result.gpr(), m_compileIndex);
+            break;
+        }
+            
+        int32_t imm2;
+        if (isDoubleConstantWithInt32Value(node.child2, imm2)) {
+            SpeculateIntegerOperand op1(this, node.child1);
+            GPRTemporary result(this);
+
+            speculationCheck(m_jit.branchAdd32(MacroAssembler::Overflow, op1.gpr(), Imm32(imm2), result.gpr()));
+
+            integerResult(result.gpr(), m_compileIndex);
+            break;
+        }
+            
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        GPRReg gpr1 = op1.gpr();
+        GPRReg gpr2 = op2.gpr();
+        GPRReg gprResult = result.gpr();
+        MacroAssembler::Jump check = m_jit.branchAdd32(MacroAssembler::Overflow, gpr1, gpr2, gprResult);
+
+        if (gpr1 == gprResult)
+            speculationCheck(check, SpeculationRecovery(SpeculativeAdd, gprResult, gpr2));
+        else if (gpr2 == gprResult)
+            speculationCheck(check, SpeculationRecovery(SpeculativeAdd, gprResult, gpr1));
+        else
+            speculationCheck(check);
+
+        integerResult(gprResult, m_compileIndex);
+        break;
+    }
+
+    case ArithSub: {
+        int32_t imm2;
+        if (isDoubleConstantWithInt32Value(node.child2, imm2)) {
+            SpeculateIntegerOperand op1(this, node.child1);
+            GPRTemporary result(this);
+
+            speculationCheck(m_jit.branchSub32(MacroAssembler::Overflow, op1.gpr(), Imm32(imm2), result.gpr()));
+
+            integerResult(result.gpr(), m_compileIndex);
+            break;
+        }
+            
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this);
+
+        speculationCheck(m_jit.branchSub32(MacroAssembler::Overflow, op1.gpr(), op2.gpr(), result.gpr()));
+
+        integerResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case ArithMul: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this);
+
+        GPRReg reg1 = op1.gpr();
+        GPRReg reg2 = op2.gpr();
+        speculationCheck(m_jit.branchMul32(MacroAssembler::Overflow, reg1, reg2, result.gpr()));
+
+        MacroAssembler::Jump resultNonZero = m_jit.branchTest32(MacroAssembler::NonZero, result.gpr());
+        speculationCheck(m_jit.branch32(MacroAssembler::LessThan, reg1, TrustedImm32(0)));
+        speculationCheck(m_jit.branch32(MacroAssembler::LessThan, reg2, TrustedImm32(0)));
+        resultNonZero.link(&m_jit);
+
+        integerResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case ArithDiv: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        op1.gpr();
+        op2.gpr();
+        terminateSpeculativeExecution();
+
+        integerResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case ArithMod: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        op1.gpr();
+        op2.gpr();
+        terminateSpeculativeExecution();
+
+        integerResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case LogicalNot: {
+        JSValueOperand value(this, node.child1);
+        GPRTemporary result(this); // FIXME: We could reuse, but on speculation fail would need recovery to restore tag (akin to add).
+
+        m_jit.move(value.gpr(), result.gpr());
+        m_jit.xorPtr(TrustedImm32(static_cast<int32_t>(ValueFalse)), result.gpr());
+        speculationCheck(m_jit.branchTestPtr(JITCompiler::NonZero, result.gpr(), TrustedImm32(static_cast<int32_t>(~1))));
+        m_jit.xorPtr(TrustedImm32(static_cast<int32_t>(ValueTrue)), result.gpr());
+
+        // If we add a DataFormatBool, we should use it here.
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case CompareLess: {
+        // Fused compare & branch.
+        if (detectPeepHoleBranch()) {
+            // detectPeepHoleBranch currently only permits the branch to be the very next node,
+            // so can be no intervening nodes to also reference the compare. 
+            ASSERT(node.adjustedRefCount() == 1);
+
+            compilePeepHoleBranch(node, JITCompiler::LessThan);
+
+            use(node.child1);
+            use(node.child2);
+            ++m_compileIndex;
+            return;
+        }
+
+        // Normal case, not fused to branch.
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        m_jit.compare32(JITCompiler::LessThan, op1.gpr(), op2.gpr(), result.gpr());
+
+        // If we add a DataFormatBool, we should use it here.
+        m_jit.or32(TrustedImm32(ValueFalse), result.gpr());
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case CompareLessEq: {
+        // Fused compare & branch.
+        if (detectPeepHoleBranch()) {
+            // detectPeepHoleBranch currently only permits the branch to be the very next node,
+            // so can be no intervening nodes to also reference the compare. 
+            ASSERT(node.adjustedRefCount() == 1);
+
+            compilePeepHoleBranch(node, JITCompiler::LessThanOrEqual);
+
+            use(node.child1);
+            use(node.child2);
+            ++m_compileIndex;
+            return;
+        }
+
+        // Normal case, not fused to branch.
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        m_jit.compare32(JITCompiler::LessThanOrEqual, op1.gpr(), op2.gpr(), result.gpr());
+
+        // If we add a DataFormatBool, we should use it here.
+        m_jit.or32(TrustedImm32(ValueFalse), result.gpr());
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case CompareEq: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        m_jit.compare32(JITCompiler::Equal, op1.gpr(), op2.gpr(), result.gpr());
+
+        // If we add a DataFormatBool, we should use it here.
+        m_jit.or32(TrustedImm32(ValueFalse), result.gpr());
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case CompareStrictEq: {
+        SpeculateIntegerOperand op1(this, node.child1);
+        SpeculateIntegerOperand op2(this, node.child2);
+        GPRTemporary result(this, op1, op2);
+
+        m_jit.compare32(JITCompiler::Equal, op1.gpr(), op2.gpr(), result.gpr());
+
+        // If we add a DataFormatBool, we should use it here.
+        m_jit.or32(TrustedImm32(ValueFalse), result.gpr());
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case GetByVal: {
+        NodeIndex alias = node.child3;
+        if (alias != NoNode) {
+            // FIXME: result should be able to reuse child1, child2. Should have an 'UnusedOperand' type.
+            JSValueOperand aliasedValue(this, node.child3);
+            GPRTemporary result(this, aliasedValue);
+            m_jit.move(aliasedValue.gpr(), result.gpr());
+            jsValueResult(result.gpr(), m_compileIndex);
+            break;
+        }
+
+        SpeculateCellOperand base(this, node.child1);
+        SpeculateStrictInt32Operand property(this, node.child2);
+        GPRTemporary storage(this);
+
+        GPRReg baseReg = base.gpr();
+        GPRReg propertyReg = property.gpr();
+        GPRReg storageReg = storage.gpr();
+
+        // Get the array storage. We haven't yet checked this is a JSArray, so this is only safe if
+        // an access with offset JSArray::storageOffset() is valid for all JSCells!
+        m_jit.loadPtr(MacroAssembler::Address(baseReg, JSArray::storageOffset()), storageReg);
+
+        // Check that base is an array, and that property is contained within m_vector (< m_vectorLength).
+        // If we have predicted the base to be type array, we can skip the check.
+        Node& baseNode = m_jit.graph()[node.child1];
+        if (baseNode.op != GetLocal || m_jit.graph().getPrediction(baseNode.local()) != PredictArray)
+            speculationCheck(m_jit.branchPtr(MacroAssembler::NotEqual, MacroAssembler::Address(baseReg), MacroAssembler::TrustedImmPtr(m_jit.globalData()->jsArrayVPtr)));
+        speculationCheck(m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, MacroAssembler::Address(baseReg, JSArray::vectorLengthOffset())));
+
+        // FIXME: In cases where there are subsequent by_val accesses to the same base it might help to cache
+        // the storage pointer - especially if there happens to be another register free right now. If we do so,
+        // then we'll need to allocate a new temporary for result.
+        GPRTemporary& result = storage;
+        m_jit.loadPtr(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])), result.gpr());
+        speculationCheck(m_jit.branchTestPtr(MacroAssembler::Zero, result.gpr()));
+
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case PutByVal: {
+        SpeculateCellOperand base(this, node.child1);
+        SpeculateStrictInt32Operand property(this, node.child2);
+        JSValueOperand value(this, node.child3);
+        GPRTemporary storage(this);
+
+        // Map base, property & value into registers, allocate a register for storage.
+        GPRReg baseReg = base.gpr();
+        GPRReg propertyReg = property.gpr();
+        GPRReg valueReg = value.gpr();
+        GPRReg storageReg = storage.gpr();
+
+        // Check that base is an array, and that property is contained within m_vector (< m_vectorLength).
+        // If we have predicted the base to be type array, we can skip the check.
+        Node& baseNode = m_jit.graph()[node.child1];
+        if (baseNode.op != GetLocal || m_jit.graph().getPrediction(baseNode.local()) != PredictArray)
+            speculationCheck(m_jit.branchPtr(MacroAssembler::NotEqual, MacroAssembler::Address(baseReg), MacroAssembler::TrustedImmPtr(m_jit.globalData()->jsArrayVPtr)));
+        speculationCheck(m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, MacroAssembler::Address(baseReg, JSArray::vectorLengthOffset())));
+
+        // Get the array storage.
+        m_jit.loadPtr(MacroAssembler::Address(baseReg, JSArray::storageOffset()), storageReg);
+
+        // Check if we're writing to a hole; if so increment m_numValuesInVector.
+        MacroAssembler::Jump notHoleValue = m_jit.branchTestPtr(MacroAssembler::NonZero, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));
+        m_jit.add32(TrustedImm32(1), MacroAssembler::Address(storageReg, OBJECT_OFFSETOF(ArrayStorage, m_numValuesInVector)));
+
+        // If we're writing to a hole we might be growing the array; 
+        MacroAssembler::Jump lengthDoesNotNeedUpdate = m_jit.branch32(MacroAssembler::Below, propertyReg, MacroAssembler::Address(storageReg, OBJECT_OFFSETOF(ArrayStorage, m_length)));
+        m_jit.add32(TrustedImm32(1), propertyReg);
+        m_jit.store32(propertyReg, MacroAssembler::Address(storageReg, OBJECT_OFFSETOF(ArrayStorage, m_length)));
+        m_jit.sub32(TrustedImm32(1), propertyReg);
+
+        lengthDoesNotNeedUpdate.link(&m_jit);
+        notHoleValue.link(&m_jit);
+
+        // Store the value to the array.
+        m_jit.storePtr(valueReg, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));
+
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case PutByValAlias: {
+        SpeculateCellOperand base(this, node.child1);
+        SpeculateStrictInt32Operand property(this, node.child2);
+        JSValueOperand value(this, node.child3);
+        GPRTemporary storage(this, base); // storage may overwrite base.
+
+        // Get the array storage.
+        GPRReg storageReg = storage.gpr();
+        m_jit.loadPtr(MacroAssembler::Address(base.gpr(), JSArray::storageOffset()), storageReg);
+
+        // Map property & value into registers.
+        GPRReg propertyReg = property.gpr();
+        GPRReg valueReg = value.gpr();
+
+        // Store the value to the array.
+        m_jit.storePtr(valueReg, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));
+
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case DFG::Jump: {
+        BlockIndex taken = m_jit.graph().blockIndexForBytecodeOffset(node.takenBytecodeOffset());
+        if (taken != (m_block + 1))
+            addBranch(m_jit.jump(), taken);
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case Branch: {
+        JSValueOperand value(this, node.child1);
+        GPRReg valueReg = value.gpr();
+
+        BlockIndex taken = m_jit.graph().blockIndexForBytecodeOffset(node.takenBytecodeOffset());
+        BlockIndex notTaken = m_jit.graph().blockIndexForBytecodeOffset(node.notTakenBytecodeOffset());
+
+        // Integers
+        addBranch(m_jit.branchPtr(MacroAssembler::Equal, valueReg, MacroAssembler::ImmPtr(JSValue::encode(jsNumber(0)))), notTaken);
+        MacroAssembler::Jump isNonZeroInteger = m_jit.branchPtr(MacroAssembler::AboveOrEqual, valueReg, GPRInfo::tagTypeNumberRegister);
+
+        // Booleans
+        addBranch(m_jit.branchPtr(MacroAssembler::Equal, valueReg, MacroAssembler::ImmPtr(JSValue::encode(jsBoolean(false)))), notTaken);
+        speculationCheck(m_jit.branchPtr(MacroAssembler::NotEqual, valueReg, MacroAssembler::ImmPtr(JSValue::encode(jsBoolean(true)))));
+
+        if (taken == (m_block + 1))
+            isNonZeroInteger.link(&m_jit);
+        else {
+            addBranch(isNonZeroInteger, taken);
+            addBranch(m_jit.jump(), taken);
+        }
+
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case Return: {
+        ASSERT(GPRInfo::callFrameRegister != GPRInfo::regT1);
+        ASSERT(GPRInfo::regT1 != GPRInfo::returnValueGPR);
+        ASSERT(GPRInfo::returnValueGPR != GPRInfo::callFrameRegister);
+
+#if DFG_SUCCESS_STATS
+        static SamplingCounter counter("SpeculativeJIT");
+        m_jit.emitCount(counter);
+#endif
+
+        // Return the result in returnValueGPR.
+        JSValueOperand op1(this, node.child1);
+        m_jit.move(op1.gpr(), GPRInfo::returnValueGPR);
+
+        // Grab the return address.
+        m_jit.emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, GPRInfo::regT1);
+        // Restore our caller's "r".
+        m_jit.emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, GPRInfo::callFrameRegister);
+        // Return.
+        m_jit.restoreReturnAddressBeforeReturn(GPRInfo::regT1);
+        m_jit.ret();
+        
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case ConvertThis: {
+        SpeculateCellOperand thisValue(this, node.child1);
+        GPRTemporary temp(this);
+
+        m_jit.loadPtr(JITCompiler::Address(thisValue.gpr(), JSCell::structureOffset()), temp.gpr());
+        speculationCheck(m_jit.branchTest8(JITCompiler::NonZero, JITCompiler::Address(temp.gpr(), Structure::typeInfoFlagsOffset()), JITCompiler::TrustedImm32(NeedsThisConversion)));
+
+        cellResult(thisValue.gpr(), m_compileIndex);
+        break;
+    }
+
+    case GetById: {
+        JSValueOperand base(this, node.child1);
+        GPRReg baseGPR = base.gpr();
+        flushRegisters();
+
+        GPRResult result(this);
+        callOperation(operationGetById, result.gpr(), baseGPR, identifier(node.identifierNumber()));
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case PutById: {
+        JSValueOperand base(this, node.child1);
+        JSValueOperand value(this, node.child2);
+        GPRReg valueGPR = value.gpr();
+        GPRReg baseGPR = base.gpr();
+        flushRegisters();
+
+        callOperation(m_jit.codeBlock()->isStrictMode() ? operationPutByIdStrict : operationPutByIdNonStrict, valueGPR, baseGPR, identifier(node.identifierNumber()));
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case PutByIdDirect: {
+        JSValueOperand base(this, node.child1);
+        JSValueOperand value(this, node.child2);
+        GPRReg valueGPR = value.gpr();
+        GPRReg baseGPR = base.gpr();
+        flushRegisters();
+
+        callOperation(m_jit.codeBlock()->isStrictMode() ? operationPutByIdDirectStrict : operationPutByIdDirectNonStrict, valueGPR, baseGPR, identifier(node.identifierNumber()));
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case GetGlobalVar: {
+        GPRTemporary result(this);
+
+        JSVariableObject* globalObject = m_jit.codeBlock()->globalObject();
+        m_jit.loadPtr(globalObject->addressOfRegisters(), result.gpr());
+        m_jit.loadPtr(JITCompiler::addressForGlobalVar(result.gpr(), node.varNumber()), result.gpr());
+
+        jsValueResult(result.gpr(), m_compileIndex);
+        break;
+    }
+
+    case PutGlobalVar: {
+        JSValueOperand value(this, node.child1);
+        GPRTemporary temp(this);
+
+        JSVariableObject* globalObject = m_jit.codeBlock()->globalObject();
+        m_jit.loadPtr(globalObject->addressOfRegisters(), temp.gpr());
+        m_jit.storePtr(value.gpr(), JITCompiler::addressForGlobalVar(temp.gpr(), node.varNumber()));
+
+        noResult(m_compileIndex);
+        break;
+    }
+
+    case Phi:
+        ASSERT_NOT_REACHED();
+    }
+
+    if (node.hasResult() && node.mustGenerate())
+        use(m_compileIndex);
+}
+
+void SpeculativeJIT::compile(BasicBlock& block)
+{
+    ASSERT(m_compileIndex == block.begin);
+    m_blockHeads[m_block] = m_jit.label();
+#if DFG_JIT_BREAK_ON_EVERY_BLOCK
+    m_jit.breakpoint();
+#endif
+
+    for (; m_compileIndex < block.end; ++m_compileIndex) {
+        Node& node = m_jit.graph()[m_compileIndex];
+        if (!node.shouldGenerate())
+            continue;
+
+#if DFG_DEBUG_VERBOSE
+        fprintf(stderr, "SpeculativeJIT generating Node @%d at JIT offset 0x%x\n", (int)m_compileIndex, m_jit.debugOffset());
+#endif
+#if DFG_JIT_BREAK_ON_EVERY_NODE
+        m_jit.breakpoint();
+#endif
+        checkConsistency();
+        compile(node);
+        if (!m_compileOkay)
+            return;
+        checkConsistency();
+    }
+}
+
+// If we are making type predictions about our arguments then
+// we need to check that they are correct on function entry.
+void SpeculativeJIT::checkArgumentTypes()
+{
+    ASSERT(!m_compileIndex);
+    for (int i = 0; i < m_jit.codeBlock()->m_numParameters; ++i) {
+        VirtualRegister virtualRegister = (VirtualRegister)(m_jit.codeBlock()->thisRegister() + i);
+        switch (m_jit.graph().getPrediction(virtualRegister)) {
+        case PredictInt32:
+            speculationCheck(m_jit.branchPtr(MacroAssembler::Below, JITCompiler::addressFor(virtualRegister), GPRInfo::tagTypeNumberRegister));
+            break;
+
+        case PredictArray: {
+            GPRTemporary temp(this);
+            m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), temp.gpr());
+            speculationCheck(m_jit.branchTestPtr(MacroAssembler::NonZero, temp.gpr(), GPRInfo::tagMaskRegister));
+            speculationCheck(m_jit.branchPtr(MacroAssembler::NotEqual, MacroAssembler::Address(temp.gpr()), MacroAssembler::TrustedImmPtr(m_jit.globalData()->jsArrayVPtr)));
+            break;
+        }
+
+        default:
+            break;
+        }
+    }
+}
+
+// For any vars that we will be treating as numeric, write 0 to
+// the var on entry. Throughout the block we will only read/write
+// to the payload, by writing the tag now we prevent the GC from
+// misinterpreting values as pointers.
+void SpeculativeJIT::initializeVariableTypes()
+{
+    ASSERT(!m_compileIndex);
+    for (int var = 0; var < m_jit.codeBlock()->m_numVars; ++var) {
+        if (m_jit.graph().getPrediction(var) == PredictInt32)
+            m_jit.storePtr(GPRInfo::tagTypeNumberRegister, JITCompiler::addressFor((VirtualRegister)var));
+    }
+}
+
+bool SpeculativeJIT::compile()
+{
+    checkArgumentTypes();
+    initializeVariableTypes();
+
+    ASSERT(!m_compileIndex);
+    for (m_block = 0; m_block < m_jit.graph().m_blocks.size(); ++m_block) {
+        compile(*m_jit.graph().m_blocks[m_block]);
+        if (!m_compileOkay)
+            return false;
+    }
+    linkBranches();
+    return true;
+}
+
+} } // namespace JSC::DFG
+
+#endif