V4: Split arguments/locals from temps.

There are a couple of reasons to split the temporaries off from the
arguments and locals:

Temporaries are invisible, and changes to them cannot be observed.
On the other hand, arguments and locals are visible, and writes to them
can be seen from other places (nested functions), or by using the
arguments array. So, in practice these correspond to memory locations.
(One could argue that if neither nested functions, nor eval(), nor
arguments[] is used, the loads/stores are invisible too. But that's an
optimization, and changing locals/arguments to temporaries can be done
in a separate pass.)

Because of the "volatile" nature of arguments and locals, their usage
cannot be optimized. All optimizations (SSA construction, register
allocation, copy elimination, etc.) work on temporaries. Being able to
easily ignore all non-temporaries has the benefit that optimizations can
be faster.

Previously, Temps were not uniquely numbered: argument 1, local 1, and
temporary 1 all had the same number and were distinguishable by their
type. So, for any mapping from Temp to something else, a QHash was used.
Now that Temps only hold proper temporaries, the indexes do uniquely
identify them. Add to that the fact that after transforming to SSA form
all temporaries are renumbered starting from 0 and without any holes in
the numbering, many of those datastructures can be changed to simple
vectors. That change gives a noticeable performance improvement.

One implication of this change is that a number of functions that took
a Temp as their argument, now need to take Temp-or-ArgLocal, so Expr.
However, it turns out that there are very few places where that applies,
as many of those places also need to take constants or names. However,
explicitly separating memory loads/stores for arguments/locals from
temporaries adds the benefit that it's now easier to do a peep-hole
optimizer for those load/store operations in the future: when a load is
directly preceded by a store, it can be eliminated if the value is
still available in a temporary.

Change-Id: I4114006b076795d9ea9fe3649cdb3b9d7b7508f0
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

9 files changed, 529 insertions, 429 deletions

diff --git a/src/qml/jit/qv4assembler.cpp b/src/qml/jit/qv4assembler.cpp
index cd44b537df..f090e7d506 100644
--- a/src/qml/jit/qv4assembler.cpp
+++ b/src/qml/jit/qv4assembler.cpp
@@ -223,10 +223,27 @@ void Assembler::generateCJumpOnCompare(RelationalCondition cond, RegisterID left
     }
 }
 
-Assembler::Pointer Assembler::loadTempAddress(RegisterID baseReg, IR::Temp *t)
+Assembler::Pointer Assembler::loadAddress(RegisterID tmp, IR::Expr *e)
+{
+    IR::Temp *t = e->asTemp();
+    if (t)
+        return loadTempAddress(t);
+    else
+        return loadArgLocalAddress(tmp, e->asArgLocal());
+}
+
+Assembler::Pointer Assembler::loadTempAddress(IR::Temp *t)
+{
+    if (t->kind == IR::Temp::StackSlot)
+        return stackSlotPointer(t);
+    else
+        Q_UNREACHABLE();
+}
+
+Assembler::Pointer Assembler::loadArgLocalAddress(RegisterID baseReg, IR::ArgLocal *al)
 {
     int32_t offset = 0;
-    int scope = t->scope;
+    int scope = al->scope;
     RegisterID context = ContextRegister;
     if (scope) {
         loadPtr(Address(ContextRegister, qOffsetOf(ExecutionContext, outer)), baseReg);
@@ -237,19 +254,16 @@ Assembler::Pointer Assembler::loadTempAddress(RegisterID baseReg, IR::Temp *t)
             --scope;
         }
     }
-    switch (t->kind) {
-    case IR::Temp::Formal:
-    case IR::Temp::ScopedFormal: {
+    switch (al->kind) {
+    case IR::ArgLocal::Formal:
+    case IR::ArgLocal::ScopedFormal: {
         loadPtr(Address(context, qOffsetOf(ExecutionContext, callData)), baseReg);
-        offset = sizeof(CallData) + (t->index - 1) * sizeof(Value);
+        offset = sizeof(CallData) + (al->index - 1) * sizeof(Value);
     } break;
-    case IR::Temp::Local:
-    case IR::Temp::ScopedLocal: {
+    case IR::ArgLocal::Local:
+    case IR::ArgLocal::ScopedLocal: {
         loadPtr(Address(context, qOffsetOf(CallContext, locals)), baseReg);
-        offset = t->index * sizeof(Value);
-    } break;
-    case IR::Temp::StackSlot: {
-        return stackSlotPointer(t);
+        offset = al->index * sizeof(Value);
     } break;
     default:
         Q_UNREACHABLE();
@@ -273,9 +287,9 @@ void Assembler::loadStringRef(RegisterID reg, const QString &string)
     addPtr(TrustedImmPtr(id * sizeof(QV4::StringValue)), reg);
 }
 
-void Assembler::storeValue(QV4::Primitive value, IR::Temp* destination)
+void Assembler::storeValue(QV4::Primitive value, IR::Expr *destination)
 {
-    Address addr = loadTempAddress(ScratchRegister, destination);
+    Address addr = loadAddress(ScratchRegister, destination);
     storeValue(value, addr);
 }
 
@@ -347,13 +361,12 @@ Assembler::Jump Assembler::genTryDoubleConversion(IR::Expr *src, Assembler::FPRe
         break;
     }
 
-    IR::Temp *sourceTemp = src->asTemp();
-    Q_ASSERT(sourceTemp);
+    Q_ASSERT(src->asTemp() || src->asArgLocal());
 
     // It's not a number type, so it cannot be in a register.
-    Q_ASSERT(sourceTemp->kind != IR::Temp::PhysicalRegister || sourceTemp->type == IR::BoolType);
+    Q_ASSERT(src->asArgLocal() || src->asTemp()->kind != IR::Temp::PhysicalRegister || src->type == IR::BoolType);
 
-    Assembler::Pointer tagAddr = loadTempAddress(Assembler::ScratchRegister, sourceTemp);
+    Assembler::Pointer tagAddr = loadAddress(Assembler::ScratchRegister, src);
     tagAddr.offset += 4;
     load32(tagAddr, Assembler::ScratchRegister);
 
diff --git a/src/qml/jit/qv4assembler_p.h b/src/qml/jit/qv4assembler_p.h
index 6fde517e1f..90387dcf79 100644
--- a/src/qml/jit/qv4assembler_p.h
+++ b/src/qml/jit/qv4assembler_p.h
@@ -460,8 +460,10 @@ public:
         QString string;
     };
     struct Reference {
-        Reference(IR::Temp *value) : value(value) {}
-        IR::Temp *value;
+        Reference(IR::Expr *value) : value(value) {
+            Q_ASSERT(value->asTemp() || value->asArgLocal());
+        }
+        IR::Expr *value;
     };
 
     struct ReentryBlock {
@@ -504,13 +506,14 @@ public:
     Jump genTryDoubleConversion(IR::Expr *src, Assembler::FPRegisterID dest);
     Assembler::Jump branchDouble(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
 
-    Pointer loadTempAddress(RegisterID baseReg, IR::Temp *t);
+    Pointer loadAddress(RegisterID tmp, IR::Expr *t);
+    Pointer loadTempAddress(IR::Temp *t);
+    Pointer loadArgLocalAddress(RegisterID baseReg, IR::ArgLocal *al);
     Pointer loadStringAddress(RegisterID reg, const QString &string);
     void loadStringRef(RegisterID reg, const QString &string);
     Pointer stackSlotPointer(IR::Temp *t) const
     {
         Q_ASSERT(t->kind == IR::Temp::StackSlot);
-        Q_ASSERT(t->scope == 0);
 
         return Pointer(_stackLayout.stackSlotPointer(t->index));
     }
@@ -585,7 +588,7 @@ public:
     void loadArgumentInRegister(Reference temp, RegisterID dest, int argumentNumber)
     {
         Q_ASSERT(temp.value);
-        Pointer addr = loadTempAddress(dest, temp.value);
+        Pointer addr = loadAddress(dest, temp.value);
         loadArgumentInRegister(addr, dest, argumentNumber);
     }
 
@@ -603,12 +606,25 @@ public:
     {
         Q_UNUSED(argumentNumber);
 
-        if (!temp) {
+        if (temp) {
+            Pointer addr = loadTempAddress(temp);
+            load64(addr, dest);
+        } else {
             QV4::Value undefined = QV4::Primitive::undefinedValue();
             move(TrustedImm64(undefined.val), dest);
-        } else {
-            Pointer addr = loadTempAddress(dest, temp);
+        }
+    }
+
+    void loadArgumentInRegister(IR::ArgLocal* al, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(argumentNumber);
+
+        if (al) {
+            Pointer addr = loadArgLocalAddress(dest, al);
             load64(addr, dest);
+        } else {
+            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            move(TrustedImm64(undefined.val), dest);
         }
     }
 
@@ -627,10 +643,12 @@ public:
         if (!expr) {
             QV4::Value undefined = QV4::Primitive::undefinedValue();
             move(TrustedImm64(undefined.val), dest);
-        } else if (expr->asTemp()){
-            loadArgumentInRegister(expr->asTemp(), dest, argumentNumber);
-        } else if (expr->asConst()) {
-            loadArgumentInRegister(expr->asConst(), dest, argumentNumber);
+        } else if (IR::Temp *t = expr->asTemp()){
+            loadArgumentInRegister(t, dest, argumentNumber);
+        } else if (IR::ArgLocal *al = expr->asArgLocal()) {
+            loadArgumentInRegister(al, dest, argumentNumber);
+        } else if (IR::Const *c = expr->asConst()) {
+            loadArgumentInRegister(c, dest, argumentNumber);
         } else {
             Q_ASSERT(!"unimplemented expression type in loadArgument");
         }
@@ -704,20 +722,26 @@ public:
     }
 #endif
 
-    void storeReturnValue(IR::Temp *temp)
+    void storeReturnValue(IR::Expr *target)
     {
-        if (!temp)
+        if (!target)
             return;
 
-        if (temp->kind == IR::Temp::PhysicalRegister) {
-            if (temp->type == IR::DoubleType)
-                storeReturnValue((FPRegisterID) temp->index);
-            else if (temp->type == IR::UInt32Type)
-                storeUInt32ReturnValue((RegisterID) temp->index);
-            else
-                storeReturnValue((RegisterID) temp->index);
-        } else {
-            Pointer addr = loadTempAddress(ScratchRegister, temp);
+        if (IR::Temp *temp = target->asTemp()) {
+            if (temp->kind == IR::Temp::PhysicalRegister) {
+                if (temp->type == IR::DoubleType)
+                    storeReturnValue((FPRegisterID) temp->index);
+                else if (temp->type == IR::UInt32Type)
+                    storeUInt32ReturnValue((RegisterID) temp->index);
+                else
+                    storeReturnValue((RegisterID) temp->index);
+                return;
+            } else {
+                Pointer addr = loadTempAddress(temp);
+                storeReturnValue(addr);
+            }
+        } else if (IR::ArgLocal *al = target->asArgLocal()) {
+            Pointer addr = loadArgLocalAddress(ScratchRegister, al);
             storeReturnValue(addr);
         }
     }
@@ -775,7 +799,7 @@ public:
     {
         Q_ASSERT (temp.value);
 
-        Pointer ptr = loadTempAddress(ScratchRegister, temp.value);
+        Pointer ptr = loadAddress(ScratchRegister, temp.value);
         loadArgumentOnStack<StackSlot>(ptr, argumentNumber);
     }
 
@@ -807,30 +831,32 @@ public:
         poke(TrustedImmPtr(name), StackSlot);
     }
 
-    void loadDouble(IR::Temp* temp, FPRegisterID dest)
+    void loadDouble(IR::Expr *source, FPRegisterID dest)
     {
-        if (temp->kind == IR::Temp::PhysicalRegister) {
-            moveDouble((FPRegisterID) temp->index, dest);
+        IR::Temp *sourceTemp = source->asTemp();
+        if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
+            moveDouble((FPRegisterID) sourceTemp->index, dest);
             return;
         }
-        Pointer ptr = loadTempAddress(ScratchRegister, temp);
+        Pointer ptr = loadAddress(ScratchRegister, source);
         loadDouble(ptr, dest);
     }
 
-    void storeDouble(FPRegisterID source, IR::Temp* temp)
+    void storeDouble(FPRegisterID source, IR::Expr* target)
     {
-        if (temp->kind == IR::Temp::PhysicalRegister) {
-            moveDouble(source, (FPRegisterID) temp->index);
+        IR::Temp *targetTemp = target->asTemp();
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
+            moveDouble(source, (FPRegisterID) targetTemp->index);
             return;
         }
 #if QT_POINTER_SIZE == 8
         moveDoubleTo64(source, ReturnValueRegister);
         move(TrustedImm64(QV4::Value::NaNEncodeMask), ScratchRegister);
         xor64(ScratchRegister, ReturnValueRegister);
-        Pointer ptr = loadTempAddress(ScratchRegister, temp);
+        Pointer ptr = loadAddress(ScratchRegister, target);
         store64(ReturnValueRegister, ptr);
 #else
-        Pointer ptr = loadTempAddress(ScratchRegister, temp);
+        Pointer ptr = loadAddress(ScratchRegister, target);
         storeDouble(source, ptr);
 #endif
     }
@@ -862,11 +888,11 @@ public:
     void copyValue(Result result, IR::Expr* source);
 
     // The scratch register is used to calculate the temp address for the source.
-    void memcopyValue(Pointer target, IR::Temp *sourceTemp, RegisterID scratchRegister)
+    void memcopyValue(Pointer target, IR::Expr *source, RegisterID scratchRegister)
     {
-        Q_ASSERT(sourceTemp->kind != IR::Temp::PhysicalRegister);
+        Q_ASSERT(!source->asTemp() || source->asTemp()->kind != IR::Temp::PhysicalRegister);
         Q_ASSERT(target.base != scratchRegister);
-        JSC::MacroAssembler::loadDouble(loadTempAddress(scratchRegister, sourceTemp), FPGpr0);
+        JSC::MacroAssembler::loadDouble(loadAddress(scratchRegister, source), FPGpr0);
         JSC::MacroAssembler::storeDouble(FPGpr0, target);
     }
 
@@ -888,7 +914,7 @@ public:
 #endif
     }
 
-    void storeValue(QV4::Primitive value, IR::Temp* temp);
+    void storeValue(QV4::Primitive value, IR::Expr* temp);
 
     void enterStandardStackFrame();
     void leaveStandardStackFrame();
@@ -1050,13 +1076,11 @@ public:
             return Pointer(addr);
         }
 
-        IR::Temp *t = e->asTemp();
-        Q_ASSERT(t);
-        if (t->kind != IR::Temp::PhysicalRegister)
-            return loadTempAddress(tmpReg, t);
+        if (IR::Temp *t = e->asTemp())
+            if (t->kind == IR::Temp::PhysicalRegister)
+                return Pointer(_stackLayout.savedRegPointer(offset));
 
-
-        return Pointer(_stackLayout.savedRegPointer(offset));
+        return loadAddress(tmpReg, e);
     }
 
     void storeBool(RegisterID reg, Pointer addr)
@@ -1071,24 +1095,31 @@ public:
         move(src, dest);
     }
 
-    void storeBool(RegisterID reg, IR::Temp *target)
+    void storeBool(RegisterID reg, IR::Expr *target)
     {
-        if (target->kind == IR::Temp::PhysicalRegister) {
-            move(reg, (RegisterID) target->index);
-        } else {
-            Pointer addr = loadTempAddress(ScratchRegister, target);
-            storeBool(reg, addr);
+        if (IR::Temp *targetTemp = target->asTemp()) {
+            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+                move(reg, (RegisterID) targetTemp->index);
+                return;
+            }
         }
+
+        Pointer addr = loadAddress(ScratchRegister, target);
+        storeBool(reg, addr);
     }
 
-    void storeBool(bool value, IR::Temp *target) {
+    void storeBool(bool value, IR::Expr *target) {
         TrustedImm32 trustedValue(value ? 1 : 0);
-        if (target->kind == IR::Temp::PhysicalRegister) {
-            move(trustedValue, (RegisterID) target->index);
-        } else {
-            move(trustedValue, ScratchRegister);
-            storeBool(ScratchRegister, target);
+
+        if (IR::Temp *targetTemp = target->asTemp()) {
+            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+                move(trustedValue, (RegisterID) targetTemp->index);
+                return;
+            }
         }
+
+        move(trustedValue, ScratchRegister);
+        storeBool(ScratchRegister, target);
     }
 
     void storeInt32(RegisterID src, RegisterID dest)
@@ -1103,12 +1134,17 @@ public:
         store32(TrustedImm32(QV4::Primitive::fromInt32(0).tag), addr);
     }
 
-    void storeInt32(RegisterID reg, IR::Temp *target)
+    void storeInt32(RegisterID reg, IR::Expr *target)
     {
-        if (target->kind == IR::Temp::PhysicalRegister) {
-            move(reg, (RegisterID) target->index);
-        } else {
-            Pointer addr = loadTempAddress(ScratchRegister, target);
+        if (IR::Temp *targetTemp = target->asTemp()) {
+            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+                move(reg, (RegisterID) targetTemp->index);
+            } else {
+                Pointer addr = loadTempAddress(targetTemp);
+                storeInt32(reg, addr);
+            }
+        } else if (IR::ArgLocal *al = target->asArgLocal()) {
+            Pointer addr = loadArgLocalAddress(ScratchRegister, al);
             storeInt32(reg, addr);
         }
     }
@@ -1130,12 +1166,13 @@ public:
         done.link(this);
     }
 
-    void storeUInt32(RegisterID reg, IR::Temp *target)
+    void storeUInt32(RegisterID reg, IR::Expr *target)
     {
-        if (target->kind == IR::Temp::PhysicalRegister) {
-            move(reg, (RegisterID) target->index);
+        IR::Temp *targetTemp = target->asTemp();
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
+            move(reg, (RegisterID) targetTemp->index);
         } else {
-            Pointer addr = loadTempAddress(ScratchRegister, target);
+            Pointer addr = loadAddress(ScratchRegister, target);
             storeUInt32(reg, addr);
         }
     }
@@ -1157,12 +1194,11 @@ public:
             return target;
         }
 
-        IR::Temp *t = e->asTemp();
-        Q_ASSERT(t);
-        if (t->kind == IR::Temp::PhysicalRegister)
-            return (FPRegisterID) t->index;
+        if (IR::Temp *t = e->asTemp())
+            if (t->kind == IR::Temp::PhysicalRegister)
+                return (FPRegisterID) t->index;
 
-        loadDouble(t, target);
+        loadDouble(e, target);
         return target;
     }
 
@@ -1178,12 +1214,11 @@ public:
             return scratchReg;
         }
 
-        IR::Temp *t = e->asTemp();
-        Q_ASSERT(t);
-        if (t->kind == IR::Temp::PhysicalRegister)
-            return (RegisterID) t->index;
+        if (IR::Temp *t = e->asTemp())
+            if (t->kind == IR::Temp::PhysicalRegister)
+                return (RegisterID) t->index;
 
-        return toInt32Register(loadTempAddress(scratchReg, t), scratchReg);
+        return toInt32Register(loadAddress(scratchReg, e), scratchReg);
     }
 
     RegisterID toInt32Register(Pointer addr, RegisterID scratchReg)
@@ -1199,12 +1234,11 @@ public:
             return scratchReg;
         }
 
-        IR::Temp *t = e->asTemp();
-        Q_ASSERT(t);
-        if (t->kind == IR::Temp::PhysicalRegister)
-            return (RegisterID) t->index;
+        if (IR::Temp *t = e->asTemp())
+            if (t->kind == IR::Temp::PhysicalRegister)
+                return (RegisterID) t->index;
 
-        return toUInt32Register(loadTempAddress(scratchReg, t), scratchReg);
+        return toUInt32Register(loadAddress(scratchReg, e), scratchReg);
     }
 
     RegisterID toUInt32Register(Pointer addr, RegisterID scratchReg)
@@ -1291,17 +1325,15 @@ void Assembler::copyValue(Result result, IR::Expr* source)
         storeUInt32(reg, result);
     } else if (source->type == IR::DoubleType) {
         storeDouble(toDoubleRegister(source), result);
-    } else if (IR::Temp *temp = source->asTemp()) {
+    } else if (source->asTemp() || source->asArgLocal()) {
 #ifdef VALUE_FITS_IN_REGISTER
-        Q_UNUSED(temp);
-
-        // Use ReturnValueRegister as "scratch" register because loadArgument
-        // and storeArgument are functions that may need a scratch register themselves.
-        loadArgumentInRegister(source, ReturnValueRegister, 0);
-        storeReturnValue(result);
+            // Use ReturnValueRegister as "scratch" register because loadArgument
+            // and storeArgument are functions that may need a scratch register themselves.
+            loadArgumentInRegister(source, ReturnValueRegister, 0);
+            storeReturnValue(result);
 #else
-        loadDouble(temp, FPGpr0);
-        storeDouble(FPGpr0, result);
+            loadDouble(source, FPGpr0);
+            storeDouble(FPGpr0, result);
 #endif
     } else if (IR::Const *c = source->asConst()) {
         QV4::Primitive v = convertToValue(c);
diff --git a/src/qml/jit/qv4binop.cpp b/src/qml/jit/qv4binop.cpp
index 344bbf56e0..a19072f52e 100644
--- a/src/qml/jit/qv4binop.cpp
+++ b/src/qml/jit/qv4binop.cpp
@@ -112,7 +112,7 @@ const Binop::OpInfo Binop::operations[IR::LastAluOp + 1] = {
 
 
 
-void Binop::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Temp *target)
+void Binop::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 {
     if (op != IR::OpMod
             && lhs->type == IR::DoubleType && rhs->type == IR::DoubleType
@@ -156,14 +156,15 @@ void Binop::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Temp *target)
 
 }
 
-void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Temp *target)
+void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 {
     Q_ASSERT(lhs->asConst() == 0 || rhs->asConst() == 0);
     Q_ASSERT(isPregOrConst(lhs));
     Q_ASSERT(isPregOrConst(rhs));
+    IR::Temp *targetTemp = target->asTemp();
     Assembler::FPRegisterID targetReg;
-    if (target->kind == IR::Temp::PhysicalRegister)
-        targetReg = (Assembler::FPRegisterID) target->index;
+    if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
+        targetReg = (Assembler::FPRegisterID) targetTemp->index;
     else
         targetReg = Assembler::FPGpr0;
 
@@ -232,31 +233,33 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Temp *target)
     } return;
     }
 
-    if (target->kind != IR::Temp::PhysicalRegister)
+    if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
         as->storeDouble(Assembler::FPGpr0, target);
 }
 
 
-bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *target)
+bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
 {
     Q_ASSERT(leftSource->type == IR::SInt32Type);
+    IR::Temp *targetTemp = target->asTemp();
     Assembler::RegisterID targetReg = Assembler::ReturnValueRegister;
-    if (target->kind == IR::Temp::PhysicalRegister) {
+    if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
         // We try to load leftSource into the target's register, but we can't do that if
         // the target register is the same as rightSource.
         IR::Temp *rhs = rightSource->asTemp();
-        if (!rhs || rhs->kind != IR::Temp::PhysicalRegister || rhs->index != target->index)
-            targetReg = (Assembler::RegisterID) target->index;
+        if (!rhs || rhs->kind != IR::Temp::PhysicalRegister || rhs->index != targetTemp->index)
+            targetReg = (Assembler::RegisterID) targetTemp->index;
     }
 
     switch (op) {
     case IR::OpBitAnd: {
         Q_ASSERT(rightSource->type == IR::SInt32Type);
         if (rightSource->asTemp() && rightSource->asTemp()->kind == IR::Temp::PhysicalRegister
-                && target->kind == IR::Temp::PhysicalRegister
-                && target->index == rightSource->asTemp()->index) {
+                && targetTemp
+                && targetTemp->kind == IR::Temp::PhysicalRegister
+                && targetTemp->index == rightSource->asTemp()->index) {
             as->and32(as->toInt32Register(leftSource, Assembler::ScratchRegister),
-                       (Assembler::RegisterID) target->index);
+                       (Assembler::RegisterID) targetTemp->index);
             return true;
         }
 
@@ -268,10 +271,11 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *ta
     case IR::OpBitOr: {
         Q_ASSERT(rightSource->type == IR::SInt32Type);
         if (rightSource->asTemp() && rightSource->asTemp()->kind == IR::Temp::PhysicalRegister
-                && target->kind == IR::Temp::PhysicalRegister
-                && target->index == rightSource->asTemp()->index) {
+                && targetTemp
+                && targetTemp->kind == IR::Temp::PhysicalRegister
+                && targetTemp->index == rightSource->asTemp()->index) {
             as->or32(as->toInt32Register(leftSource, Assembler::ScratchRegister),
-                       (Assembler::RegisterID) target->index);
+                       (Assembler::RegisterID) targetTemp->index);
             return true;
         }
 
@@ -283,10 +287,11 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *ta
     case IR::OpBitXor: {
         Q_ASSERT(rightSource->type == IR::SInt32Type);
         if (rightSource->asTemp() && rightSource->asTemp()->kind == IR::Temp::PhysicalRegister
-                && target->kind == IR::Temp::PhysicalRegister
-                && target->index == rightSource->asTemp()->index) {
+                && targetTemp
+                && targetTemp->kind == IR::Temp::PhysicalRegister
+                && targetTemp->index == rightSource->asTemp()->index) {
             as->xor32(as->toInt32Register(leftSource, Assembler::ScratchRegister),
-                       (Assembler::RegisterID) target->index);
+                       (Assembler::RegisterID) targetTemp->index);
             return true;
         }
 
@@ -370,9 +375,10 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *ta
         Q_ASSERT(rightSource->type == IR::SInt32Type);
 
         if (rightSource->asTemp() && rightSource->asTemp()->kind == IR::Temp::PhysicalRegister
-                && target->kind == IR::Temp::PhysicalRegister
-                && target->index == rightSource->asTemp()->index) {
-            Assembler::RegisterID targetReg = (Assembler::RegisterID) target->index;
+                && targetTemp
+                && targetTemp->kind == IR::Temp::PhysicalRegister
+                && targetTemp->index == rightSource->asTemp()->index) {
+            Assembler::RegisterID targetReg = (Assembler::RegisterID) targetTemp->index;
             as->move(targetReg, Assembler::ScratchRegister);
             as->move(as->toInt32Register(leftSource, targetReg), targetReg);
             as->sub32(Assembler::ScratchRegister, targetReg);
@@ -407,7 +413,7 @@ static inline Assembler::FPRegisterID getFreeFPReg(IR::Expr *shouldNotOverlap, u
     return Assembler::FPRegisterID(hint);
 }
 
-Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *target)
+Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
 {
     Assembler::Jump done;
 
diff --git a/src/qml/jit/qv4binop_p.h b/src/qml/jit/qv4binop_p.h
index a6292e6fb5..8c7fa4337a 100644
--- a/src/qml/jit/qv4binop_p.h
+++ b/src/qml/jit/qv4binop_p.h
@@ -58,10 +58,10 @@ struct Binop {
         , op(operation)
     {}
 
-    void generate(IR::Expr *lhs, IR::Expr *rhs, IR::Temp *target);
-    void doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Temp *target);
-    bool int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *target);
-    Assembler::Jump genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *target);
+    void generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target);
+    void doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target);
+    bool int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target);
+    Assembler::Jump genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target);
 
     typedef Assembler::Jump (Binop::*MemRegOp)(Assembler::Address, Assembler::RegisterID);
     typedef Assembler::Jump (Binop::*ImmRegOp)(Assembler::TrustedImm32, Assembler::RegisterID);
diff --git a/src/qml/jit/qv4isel_masm.cpp b/src/qml/jit/qv4isel_masm.cpp
index 3307fcc0d1..d82fa990f4 100644
--- a/src/qml/jit/qv4isel_masm.cpp
+++ b/src/qml/jit/qv4isel_masm.cpp
@@ -389,7 +389,7 @@ QV4::CompiledData::CompilationUnit *InstructionSelection::backendCompileStep()
     return compilationUnit;
 }
 
-void InstructionSelection::callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Temp *result)
+void InstructionSelection::callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result)
 {
     prepareCallData(args, 0);
 
@@ -408,52 +408,52 @@ void InstructionSelection::callBuiltinInvalid(IR::Name *func, IR::ExprList *args
 }
 
 void InstructionSelection::callBuiltinTypeofMember(IR::Expr *base, const QString &name,
-                                                   IR::Temp *result)
+                                                   IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::typeofMember, Assembler::ContextRegister,
                          Assembler::PointerToValue(base), Assembler::PointerToString(name));
 }
 
 void InstructionSelection::callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index,
-                                                      IR::Temp *result)
+                                                      IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::typeofElement,
                          Assembler::ContextRegister,
                          Assembler::PointerToValue(base), Assembler::PointerToValue(index));
 }
 
-void InstructionSelection::callBuiltinTypeofName(const QString &name, IR::Temp *result)
+void InstructionSelection::callBuiltinTypeofName(const QString &name, IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::typeofName, Assembler::ContextRegister,
                          Assembler::PointerToString(name));
 }
 
-void InstructionSelection::callBuiltinTypeofValue(IR::Expr *value, IR::Temp *result)
+void InstructionSelection::callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::typeofValue, Assembler::ContextRegister,
                          Assembler::PointerToValue(value));
 }
 
-void InstructionSelection::callBuiltinDeleteMember(IR::Temp *base, const QString &name, IR::Temp *result)
+void InstructionSelection::callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::deleteMember, Assembler::ContextRegister,
                          Assembler::Reference(base), Assembler::PointerToString(name));
 }
 
-void InstructionSelection::callBuiltinDeleteSubscript(IR::Temp *base, IR::Expr *index,
-                                                      IR::Temp *result)
+void InstructionSelection::callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index,
+                                                      IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::deleteElement, Assembler::ContextRegister,
                          Assembler::Reference(base), Assembler::PointerToValue(index));
 }
 
-void InstructionSelection::callBuiltinDeleteName(const QString &name, IR::Temp *result)
+void InstructionSelection::callBuiltinDeleteName(const QString &name, IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::deleteName, Assembler::ContextRegister,
                          Assembler::PointerToString(name));
 }
 
-void InstructionSelection::callBuiltinDeleteValue(IR::Temp *result)
+void InstructionSelection::callBuiltinDeleteValue(IR::Expr *result)
 {
     _as->storeValue(Primitive::fromBoolean(false), result);
 }
@@ -469,7 +469,7 @@ void InstructionSelection::callBuiltinReThrow()
     _as->jumpToExceptionHandler();
 }
 
-void InstructionSelection::callBuiltinUnwindException(IR::Temp *result)
+void InstructionSelection::callBuiltinUnwindException(IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::unwindException, Assembler::ContextRegister);
 
@@ -481,7 +481,7 @@ void InstructionSelection::callBuiltinPushCatchScope(const QString &exceptionNam
     generateFunctionCall(Assembler::ContextRegister, Runtime::pushCatchScope, Assembler::ContextRegister, s);
 }
 
-void InstructionSelection::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Temp *result)
+void InstructionSelection::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result)
 {
     Q_ASSERT(arg);
     Q_ASSERT(result);
@@ -489,7 +489,7 @@ void InstructionSelection::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::T
     generateFunctionCall(result, Runtime::foreachIterator, Assembler::ContextRegister, Assembler::PointerToValue(arg));
 }
 
-void InstructionSelection::callBuiltinForeachNextPropertyname(IR::Temp *arg, IR::Temp *result)
+void InstructionSelection::callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result)
 {
     Q_ASSERT(arg);
     Q_ASSERT(result);
@@ -497,7 +497,7 @@ void InstructionSelection::callBuiltinForeachNextPropertyname(IR::Temp *arg, IR:
     generateFunctionCall(result, Runtime::foreachNextPropertyName, Assembler::Reference(arg));
 }
 
-void InstructionSelection::callBuiltinPushWithScope(IR::Temp *arg)
+void InstructionSelection::callBuiltinPushWithScope(IR::Expr *arg)
 {
     Q_ASSERT(arg);
 
@@ -515,7 +515,7 @@ void InstructionSelection::callBuiltinDeclareVar(bool deletable, const QString &
                          Assembler::TrustedImm32(deletable), Assembler::PointerToString(name));
 }
 
-void InstructionSelection::callBuiltinDefineArray(IR::Temp *result, IR::ExprList *args)
+void InstructionSelection::callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args)
 {
     Q_ASSERT(result);
 
@@ -524,7 +524,7 @@ void InstructionSelection::callBuiltinDefineArray(IR::Temp *result, IR::ExprList
                          baseAddressForCallArguments(), Assembler::TrustedImm32(length));
 }
 
-void InstructionSelection::callBuiltinDefineObjectLiteral(IR::Temp *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray)
+void InstructionSelection::callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray)
 {
     Q_ASSERT(result);
 
@@ -605,7 +605,7 @@ void InstructionSelection::callBuiltinDefineObjectLiteral(IR::Temp *result, int
                          Assembler::TrustedImm32(arrayValueCount), Assembler::TrustedImm32(arrayGetterSetterCount | (needSparseArray << 30)));
 }
 
-void InstructionSelection::callBuiltinSetupArgumentObject(IR::Temp *result)
+void InstructionSelection::callBuiltinSetupArgumentObject(IR::Expr *result)
 {
     generateFunctionCall(result, Runtime::setupArgumentsObject, Assembler::ContextRegister);
 }
@@ -615,7 +615,7 @@ void InstructionSelection::callBuiltinConvertThisToObject()
     generateFunctionCall(Assembler::Void, Runtime::convertThisToObject, Assembler::ContextRegister);
 }
 
-void InstructionSelection::callValue(IR::Temp *value, IR::ExprList *args, IR::Temp *result)
+void InstructionSelection::callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
 {
     Q_ASSERT(value);
 
@@ -625,7 +625,7 @@ void InstructionSelection::callValue(IR::Temp *value, IR::ExprList *args, IR::Te
                          baseAddressForCallData());
 }
 
-void InstructionSelection::loadThisObject(IR::Temp *temp)
+void InstructionSelection::loadThisObject(IR::Expr *temp)
 {
     _as->loadPtr(Address(Assembler::ContextRegister, qOffsetOf(ExecutionContext, callData)), Assembler::ScratchRegister);
 #if defined(VALUE_FITS_IN_REGISTER)
@@ -637,60 +637,63 @@ void InstructionSelection::loadThisObject(IR::Temp *temp)
 #endif
 }
 
-void InstructionSelection::loadQmlIdArray(IR::Temp *temp)
+void InstructionSelection::loadQmlIdArray(IR::Expr *temp)
 {
     generateFunctionCall(temp, Runtime::getQmlIdArray, Assembler::ContextRegister);
 }
 
-void InstructionSelection::loadQmlImportedScripts(IR::Temp *temp)
+void InstructionSelection::loadQmlImportedScripts(IR::Expr *temp)
 {
     generateFunctionCall(temp, Runtime::getQmlImportedScripts, Assembler::ContextRegister);
 }
 
-void InstructionSelection::loadQmlContextObject(IR::Temp *temp)
+void InstructionSelection::loadQmlContextObject(IR::Expr *temp)
 {
     generateFunctionCall(temp, Runtime::getQmlContextObject, Assembler::ContextRegister);
 }
 
-void InstructionSelection::loadQmlScopeObject(IR::Temp *temp)
+void InstructionSelection::loadQmlScopeObject(IR::Expr *temp)
 {
     generateFunctionCall(temp, Runtime::getQmlScopeObject, Assembler::ContextRegister);
 }
 
-void InstructionSelection::loadQmlSingleton(const QString &name, IR::Temp *temp)
+void InstructionSelection::loadQmlSingleton(const QString &name, IR::Expr *temp)
 {
     generateFunctionCall(temp, Runtime::getQmlSingleton, Assembler::ContextRegister, Assembler::PointerToString(name));
 }
 
-void InstructionSelection::loadConst(IR::Const *sourceConst, IR::Temp *targetTemp)
-{
-    if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-        if (targetTemp->type == IR::DoubleType) {
-            Q_ASSERT(sourceConst->type == IR::DoubleType);
-            _as->toDoubleRegister(sourceConst, (Assembler::FPRegisterID) targetTemp->index);
-        } else if (targetTemp->type == IR::SInt32Type) {
-            Q_ASSERT(sourceConst->type == IR::SInt32Type);
-            _as->toInt32Register(sourceConst, (Assembler::RegisterID) targetTemp->index);
-        } else if (targetTemp->type == IR::UInt32Type) {
-            Q_ASSERT(sourceConst->type == IR::UInt32Type);
-            _as->toUInt32Register(sourceConst, (Assembler::RegisterID) targetTemp->index);
-        } else if (targetTemp->type == IR::BoolType) {
-            Q_ASSERT(sourceConst->type == IR::BoolType);
-            _as->move(Assembler::TrustedImm32(convertToValue(sourceConst).int_32),
-                      (Assembler::RegisterID) targetTemp->index);
-        } else {
-            Q_UNREACHABLE();
+void InstructionSelection::loadConst(IR::Const *sourceConst, IR::Expr *target)
+{
+    if (IR::Temp *targetTemp = target->asTemp()) {
+        if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+            if (targetTemp->type == IR::DoubleType) {
+                Q_ASSERT(sourceConst->type == IR::DoubleType);
+                _as->toDoubleRegister(sourceConst, (Assembler::FPRegisterID) targetTemp->index);
+            } else if (targetTemp->type == IR::SInt32Type) {
+                Q_ASSERT(sourceConst->type == IR::SInt32Type);
+                _as->toInt32Register(sourceConst, (Assembler::RegisterID) targetTemp->index);
+            } else if (targetTemp->type == IR::UInt32Type) {
+                Q_ASSERT(sourceConst->type == IR::UInt32Type);
+                _as->toUInt32Register(sourceConst, (Assembler::RegisterID) targetTemp->index);
+            } else if (targetTemp->type == IR::BoolType) {
+                Q_ASSERT(sourceConst->type == IR::BoolType);
+                _as->move(Assembler::TrustedImm32(convertToValue(sourceConst).int_32),
+                          (Assembler::RegisterID) targetTemp->index);
+            } else {
+                Q_UNREACHABLE();
+            }
+            return;
         }
-    } else {
-        _as->storeValue(convertToValue(sourceConst), targetTemp);
     }
+
+    _as->storeValue(convertToValue(sourceConst), target);
 }
 
-void InstructionSelection::loadString(const QString &str, IR::Temp *targetTemp)
+void InstructionSelection::loadString(const QString &str, IR::Expr *target)
 {
     Pointer srcAddr = _as->loadStringAddress(Assembler::ReturnValueRegister, str);
     _as->loadPtr(srcAddr, Assembler::ReturnValueRegister);
-    Pointer destAddr = _as->loadTempAddress(Assembler::ScratchRegister, targetTemp);
+    Pointer destAddr = _as->loadAddress(Assembler::ScratchRegister, target);
 #if QT_POINTER_SIZE == 8
     _as->store64(Assembler::ReturnValueRegister, destAddr);
 #else
@@ -700,20 +703,20 @@ void InstructionSelection::loadString(const QString &str, IR::Temp *targetTemp)
 #endif
 }
 
-void InstructionSelection::loadRegexp(IR::RegExp *sourceRegexp, IR::Temp *targetTemp)
+void InstructionSelection::loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target)
 {
     int id = registerRegExp(sourceRegexp);
-    generateFunctionCall(targetTemp, Runtime::regexpLiteral, Assembler::ContextRegister, Assembler::TrustedImm32(id));
+    generateFunctionCall(target, Runtime::regexpLiteral, Assembler::ContextRegister, Assembler::TrustedImm32(id));
 }
 
-void InstructionSelection::getActivationProperty(const IR::Name *name, IR::Temp *temp)
+void InstructionSelection::getActivationProperty(const IR::Name *name, IR::Expr *target)
 {
     if (useFastLookups && name->global) {
         uint index = registerGlobalGetterLookup(*name->id);
-        generateLookupCall(temp, index, qOffsetOf(QV4::Lookup, globalGetter), Assembler::ContextRegister, Assembler::Void);
+        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, globalGetter), Assembler::ContextRegister, Assembler::Void);
         return;
     }
-    generateFunctionCall(temp, Runtime::getActivationProperty, Assembler::ContextRegister, Assembler::PointerToString(*name->id));
+    generateFunctionCall(target, Runtime::getActivationProperty, Assembler::ContextRegister, Assembler::PointerToString(*name->id));
 }
 
 void InstructionSelection::setActivationProperty(IR::Expr *source, const QString &targetName)
@@ -723,13 +726,13 @@ void InstructionSelection::setActivationProperty(IR::Expr *source, const QString
                          Assembler::ContextRegister, Assembler::PointerToString(targetName), Assembler::PointerToValue(source));
 }
 
-void InstructionSelection::initClosure(IR::Closure *closure, IR::Temp *target)
+void InstructionSelection::initClosure(IR::Closure *closure, IR::Expr *target)
 {
     int id = closure->value;
     generateFunctionCall(target, Runtime::closure, Assembler::ContextRegister, Assembler::TrustedImm32(id));
 }
 
-void InstructionSelection::getProperty(IR::Expr *base, const QString &name, IR::Temp *target)
+void InstructionSelection::getProperty(IR::Expr *base, const QString &name, IR::Expr *target)
 {
     if (useFastLookups) {
         uint index = registerGetterLookup(name);
@@ -740,7 +743,7 @@ void InstructionSelection::getProperty(IR::Expr *base, const QString &name, IR::
     }
 }
 
-void InstructionSelection::getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, int attachedPropertiesId, IR::Temp *target)
+void InstructionSelection::getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, int attachedPropertiesId, IR::Expr *target)
 {
     if (attachedPropertiesId != 0)
         generateFunctionCall(target, Runtime::getQmlAttachedProperty, Assembler::ContextRegister, Assembler::TrustedImm32(attachedPropertiesId), Assembler::TrustedImm32(propertyIndex));
@@ -770,7 +773,7 @@ void InstructionSelection::setQObjectProperty(IR::Expr *source, IR::Expr *target
                          Assembler::TrustedImm32(propertyIndex), Assembler::PointerToValue(source));
 }
 
-void InstructionSelection::getElement(IR::Expr *base, IR::Expr *index, IR::Temp *target)
+void InstructionSelection::getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target)
 {
     if (useFastLookups) {
         uint lookup = registerIndexedGetterLookup();
@@ -798,13 +801,20 @@ void InstructionSelection::setElement(IR::Expr *source, IR::Expr *targetBase, IR
                          Assembler::PointerToValue(source));
 }
 
-void InstructionSelection::copyValue(IR::Temp *sourceTemp, IR::Temp *targetTemp)
+void InstructionSelection::copyValue(IR::Expr *source, IR::Expr *target)
 {
-    if (*sourceTemp == *targetTemp)
+    IR::Temp *sourceTemp = source->asTemp();
+    IR::Temp *targetTemp = target->asTemp();
+
+    if (sourceTemp && targetTemp && *sourceTemp == *targetTemp)
         return;
+    if (IR::ArgLocal *sal = source->asArgLocal())
+        if (IR::ArgLocal *tal = target->asArgLocal())
+            if (*sal == *tal)
+                return;
 
-    if (sourceTemp->kind == IR::Temp::PhysicalRegister) {
-        if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+    if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
             if (sourceTemp->type == IR::DoubleType)
                 _as->moveDouble((Assembler::FPRegisterID) sourceTemp->index,
                                 (Assembler::FPRegisterID) targetTemp->index);
@@ -815,16 +825,16 @@ void InstructionSelection::copyValue(IR::Temp *sourceTemp, IR::Temp *targetTemp)
         } else {
             switch (sourceTemp->type) {
             case IR::DoubleType:
-                _as->storeDouble((Assembler::FPRegisterID) sourceTemp->index, targetTemp);
+                _as->storeDouble((Assembler::FPRegisterID) sourceTemp->index, target);
                 break;
             case IR::SInt32Type:
-                _as->storeInt32((Assembler::RegisterID) sourceTemp->index, targetTemp);
+                _as->storeInt32((Assembler::RegisterID) sourceTemp->index, target);
                 break;
             case IR::UInt32Type:
-                _as->storeUInt32((Assembler::RegisterID) sourceTemp->index, targetTemp);
+                _as->storeUInt32((Assembler::RegisterID) sourceTemp->index, target);
                 break;
             case IR::BoolType:
-                _as->storeBool((Assembler::RegisterID) sourceTemp->index, targetTemp);
+                _as->storeBool((Assembler::RegisterID) sourceTemp->index, target);
                 break;
             default:
                 Q_ASSERT(!"Unreachable");
@@ -832,23 +842,23 @@ void InstructionSelection::copyValue(IR::Temp *sourceTemp, IR::Temp *targetTemp)
             }
             return;
         }
-    } else if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+    } else if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
         switch (targetTemp->type) {
         case IR::DoubleType:
-            Q_ASSERT(sourceTemp->type == IR::DoubleType);
-            _as->toDoubleRegister(sourceTemp, (Assembler::FPRegisterID) targetTemp->index);
+            Q_ASSERT(source->type == IR::DoubleType);
+            _as->toDoubleRegister(source, (Assembler::FPRegisterID) targetTemp->index);
             return;
         case IR::BoolType:
-            Q_ASSERT(sourceTemp->type == IR::BoolType);
-            _as->toInt32Register(sourceTemp, (Assembler::RegisterID) targetTemp->index);
+            Q_ASSERT(source->type == IR::BoolType);
+            _as->toInt32Register(source, (Assembler::RegisterID) targetTemp->index);
             return;
         case IR::SInt32Type:
-            Q_ASSERT(sourceTemp->type == IR::SInt32Type);
-            _as->toInt32Register(sourceTemp, (Assembler::RegisterID) targetTemp->index);
+            Q_ASSERT(source->type == IR::SInt32Type);
+            _as->toInt32Register(source, (Assembler::RegisterID) targetTemp->index);
             return;
         case IR::UInt32Type:
-            Q_ASSERT(sourceTemp->type == IR::UInt32Type);
-            _as->toUInt32Register(sourceTemp, (Assembler::RegisterID) targetTemp->index);
+            Q_ASSERT(source->type == IR::UInt32Type);
+            _as->toUInt32Register(source, (Assembler::RegisterID) targetTemp->index);
             return;
         default:
             Q_ASSERT(!"Unreachable");
@@ -857,14 +867,16 @@ void InstructionSelection::copyValue(IR::Temp *sourceTemp, IR::Temp *targetTemp)
     }
 
     // The target is not a physical register, nor is the source. So we can do a memory-to-memory copy:
-    _as->memcopyValue(_as->loadTempAddress(Assembler::ReturnValueRegister, targetTemp), sourceTemp,
-                      Assembler::ScratchRegister);
+    _as->memcopyValue(_as->loadAddress(Assembler::ReturnValueRegister, target), source, Assembler::ScratchRegister);
 }
 
-void InstructionSelection::swapValues(IR::Temp *sourceTemp, IR::Temp *targetTemp)
+void InstructionSelection::swapValues(IR::Expr *source, IR::Expr *target)
 {
-    if (sourceTemp->kind == IR::Temp::PhysicalRegister) {
-        if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+    IR::Temp *sourceTemp = source->asTemp();
+    IR::Temp *targetTemp = target->asTemp();
+
+    if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
             Q_ASSERT(sourceTemp->type == targetTemp->type);
 
             if (sourceTemp->type == IR::DoubleType) {
@@ -878,11 +890,11 @@ void InstructionSelection::swapValues(IR::Temp *sourceTemp, IR::Temp *targetTemp
             }
             return;
         }
-    } else if (sourceTemp->kind == IR::Temp::StackSlot) {
-        if (targetTemp->kind == IR::Temp::StackSlot) {
+    } else if (!sourceTemp || sourceTemp->kind == IR::Temp::StackSlot) {
+        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
             // Note: a swap for two stack-slots can involve different types.
-            Assembler::Pointer sAddr = _as->stackSlotPointer(sourceTemp);
-            Assembler::Pointer tAddr = _as->stackSlotPointer(targetTemp);
+            Assembler::Pointer sAddr = _as->loadAddress(Assembler::ScratchRegister, source);
+            Assembler::Pointer tAddr = _as->loadAddress(Assembler::ReturnValueRegister, target);
             // use the implementation in JSC::MacroAssembler, as it doesn't do bit swizzling
             _as->JSC::MacroAssembler::loadDouble(sAddr, Assembler::FPGpr0);
             _as->JSC::MacroAssembler::loadDouble(tAddr, Assembler::FPGpr1);
@@ -892,25 +904,28 @@ void InstructionSelection::swapValues(IR::Temp *sourceTemp, IR::Temp *targetTemp
         }
     }
 
-    IR::Temp *stackTemp = sourceTemp->kind == IR::Temp::StackSlot ? sourceTemp : targetTemp;
-    IR::Temp *registerTemp = sourceTemp->kind == IR::Temp::PhysicalRegister ? sourceTemp
-                                                                                : targetTemp;
-    Assembler::Pointer addr = _as->stackSlotPointer(stackTemp);
-    if (registerTemp->type == IR::DoubleType) {
+    IR::Expr *memExpr = !sourceTemp || sourceTemp->kind == IR::Temp::StackSlot ? source : target;
+    IR::Temp *regTemp = sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister ? sourceTemp
+                                                                                     : targetTemp;
+    Q_ASSERT(memExpr);
+    Q_ASSERT(regTemp);
+
+    Assembler::Pointer addr = _as->loadAddress(Assembler::ReturnValueRegister, memExpr);
+    if (regTemp->type == IR::DoubleType) {
         _as->loadDouble(addr, Assembler::FPGpr0);
-        _as->storeDouble((Assembler::FPRegisterID) registerTemp->index, addr);
-        _as->moveDouble(Assembler::FPGpr0, (Assembler::FPRegisterID) registerTemp->index);
-    } else if (registerTemp->type == IR::UInt32Type) {
+        _as->storeDouble((Assembler::FPRegisterID) regTemp->index, addr);
+        _as->moveDouble(Assembler::FPGpr0, (Assembler::FPRegisterID) regTemp->index);
+    } else if (regTemp->type == IR::UInt32Type) {
         _as->toUInt32Register(addr, Assembler::ScratchRegister);
-        _as->storeUInt32((Assembler::RegisterID) registerTemp->index, addr);
-        _as->move(Assembler::ScratchRegister, (Assembler::RegisterID) registerTemp->index);
+        _as->storeUInt32((Assembler::RegisterID) regTemp->index, addr);
+        _as->move(Assembler::ScratchRegister, (Assembler::RegisterID) regTemp->index);
     } else {
         _as->load32(addr, Assembler::ScratchRegister);
-        _as->store32((Assembler::RegisterID) registerTemp->index, addr);
-        if (registerTemp->type != stackTemp->type) {
+        _as->store32((Assembler::RegisterID) regTemp->index, addr);
+        if (regTemp->type != memExpr->type) {
             addr.offset += 4;
             quint32 tag;
-            switch (registerTemp->type) {
+            switch (regTemp->type) {
             case IR::BoolType:
                 tag = QV4::Value::_Boolean_Type;
                 break;
@@ -923,7 +938,7 @@ void InstructionSelection::swapValues(IR::Temp *sourceTemp, IR::Temp *targetTemp
             }
             _as->store32(Assembler::TrustedImm32(tag), addr);
         }
-        _as->move(Assembler::ScratchRegister, (Assembler::RegisterID) registerTemp->index);
+        _as->move(Assembler::ScratchRegister, (Assembler::RegisterID) regTemp->index);
     }
 }
 
@@ -932,21 +947,21 @@ void InstructionSelection::swapValues(IR::Temp *sourceTemp, IR::Temp *targetTemp
 #define setOpContext(op, opName, operation) \
     do { opContext = operation; opName = isel_stringIfy(operation); } while (0)
 
-void InstructionSelection::unop(IR::AluOp oper, IR::Temp *sourceTemp, IR::Temp *targetTemp)
+void InstructionSelection::unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target)
 {
     QV4::JIT::Unop unop(_as, oper);
-    unop.generate(sourceTemp, targetTemp);
+    unop.generate(source, target);
 }
 
 
-void InstructionSelection::binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *target)
+void InstructionSelection::binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
 {
     QV4::JIT::Binop binop(_as, oper);
     binop.generate(leftSource, rightSource, target);
 }
 
 void InstructionSelection::callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
-                                        IR::Temp *result)
+                                        IR::Expr *result)
 {
     Q_ASSERT(base != 0);
 
@@ -966,7 +981,7 @@ void InstructionSelection::callProperty(IR::Expr *base, const QString &name, IR:
 }
 
 void InstructionSelection::callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
-                                         IR::Temp *result)
+                                         IR::Expr *result)
 {
     Q_ASSERT(base != 0);
 
@@ -976,7 +991,7 @@ void InstructionSelection::callSubscript(IR::Expr *base, IR::Expr *index, IR::Ex
                          baseAddressForCallData());
 }
 
-void InstructionSelection::convertType(IR::Temp *source, IR::Temp *target)
+void InstructionSelection::convertType(IR::Expr *source, IR::Expr *target)
 {
     switch (target->type) {
     case IR::DoubleType:
@@ -997,7 +1012,7 @@ void InstructionSelection::convertType(IR::Temp *source, IR::Temp *target)
     }
 }
 
-void InstructionSelection::convertTypeSlowPath(IR::Temp *source, IR::Temp *target)
+void InstructionSelection::convertTypeSlowPath(IR::Expr *source, IR::Expr *target)
 {
     Q_ASSERT(target->type != IR::BoolType);
 
@@ -1007,7 +1022,7 @@ void InstructionSelection::convertTypeSlowPath(IR::Temp *source, IR::Temp *targe
         copyValue(source, target);
 }
 
-void InstructionSelection::convertTypeToDouble(IR::Temp *source, IR::Temp *target)
+void InstructionSelection::convertTypeToDouble(IR::Expr *source, IR::Expr *target)
 {
     switch (source->type) {
     case IR::SInt32Type:
@@ -1019,13 +1034,13 @@ void InstructionSelection::convertTypeToDouble(IR::Temp *source, IR::Temp *targe
         convertUIntToDouble(source, target);
         break;
     case IR::UndefinedType:
-        _as->loadDouble(_as->loadTempAddress(Assembler::ScratchRegister, source), Assembler::FPGpr0);
+        _as->loadDouble(_as->loadAddress(Assembler::ScratchRegister, source), Assembler::FPGpr0);
         _as->storeDouble(Assembler::FPGpr0, target);
         break;
     case IR::StringType:
     case IR::VarType: {
         // load the tag:
-        Assembler::Pointer tagAddr = _as->loadTempAddress(Assembler::ScratchRegister, source);
+        Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, source);
         tagAddr.offset += 4;
         _as->load32(tagAddr, Assembler::ScratchRegister);
 
@@ -1052,17 +1067,18 @@ void InstructionSelection::convertTypeToDouble(IR::Temp *source, IR::Temp *targe
 
         // it is a double:
         isDbl.link(_as);
-        Assembler::Pointer addr2 = _as->loadTempAddress(Assembler::ScratchRegister, source);
-        if (target->kind == IR::Temp::StackSlot) {
+        Assembler::Pointer addr2 = _as->loadAddress(Assembler::ScratchRegister, source);
+        IR::Temp *targetTemp = target->asTemp();
+        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
 #if QT_POINTER_SIZE == 8
             _as->load64(addr2, Assembler::ScratchRegister);
-            _as->store64(Assembler::ScratchRegister, _as->stackSlotPointer(target));
+            _as->store64(Assembler::ScratchRegister, _as->loadAddress(Assembler::ReturnValueRegister, target));
 #else
             _as->loadDouble(addr2, Assembler::FPGpr0);
-            _as->storeDouble(Assembler::FPGpr0, _as->stackSlotPointer(target));
+            _as->storeDouble(Assembler::FPGpr0, _as->loadAddress(Assembler::ReturnValueRegister, target));
 #endif
         } else {
-            _as->loadDouble(addr2, (Assembler::FPRegisterID) target->index);
+            _as->loadDouble(addr2, (Assembler::FPRegisterID) targetTemp->index);
         }
 
         noDoubleDone.link(_as);
@@ -1074,8 +1090,9 @@ void InstructionSelection::convertTypeToDouble(IR::Temp *source, IR::Temp *targe
     }
 }
 
-void InstructionSelection::convertTypeToBool(IR::Temp *source, IR::Temp *target)
+void InstructionSelection::convertTypeToBool(IR::Expr *source, IR::Expr *target)
 {
+    IR::Temp *sourceTemp = source->asTemp();
     switch (source->type) {
     case IR::SInt32Type:
     case IR::UInt32Type:
@@ -1086,8 +1103,8 @@ void InstructionSelection::convertTypeToBool(IR::Temp *source, IR::Temp *target)
         // allocator was not used, then that means that we can use any register for to
         // load the double into.
         Assembler::FPRegisterID reg;
-        if (source->kind == IR::Temp::PhysicalRegister)
-            reg = (Assembler::FPRegisterID) source->index;
+        if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister)
+            reg = (Assembler::FPRegisterID) sourceTemp->index;
         else
             reg = _as->toDoubleRegister(source, (Assembler::FPRegisterID) 1);
         Assembler::Jump nonZero = _as->branchDoubleNonZero(reg, Assembler::FPGpr0);
@@ -1117,13 +1134,13 @@ void InstructionSelection::convertTypeToBool(IR::Temp *source, IR::Temp *target)
     }
 }
 
-void InstructionSelection::convertTypeToSInt32(IR::Temp *source, IR::Temp *target)
+void InstructionSelection::convertTypeToSInt32(IR::Expr *source, IR::Expr *target)
 {
     switch (source->type) {
     case IR::VarType: {
 
 #if QT_POINTER_SIZE == 8
-        Assembler::Pointer addr = _as->loadTempAddress(Assembler::ScratchRegister, source);
+        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
         _as->load64(addr, Assembler::ScratchRegister);
         _as->move(Assembler::ScratchRegister, Assembler::ReturnValueRegister);
 
@@ -1143,12 +1160,13 @@ void InstructionSelection::convertTypeToSInt32(IR::Temp *source, IR::Temp *targe
         // not an int:
         fallback.link(_as);
         generateFunctionCall(Assembler::ReturnValueRegister, Runtime::toInt,
-                             _as->loadTempAddress(Assembler::ScratchRegister, source));
+                             _as->loadAddress(Assembler::ScratchRegister, source));
 
         isInt.link(_as);
         success.link(_as);
-        if (target->kind == IR::Temp::StackSlot) {
-            Assembler::Pointer targetAddr = _as->stackSlotPointer(target);
+        IR::Temp *targetTemp = target->asTemp();
+        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
+            Assembler::Pointer targetAddr = _as->loadAddress(Assembler::ScratchRegister, target);
             _as->store32(Assembler::ReturnValueRegister, targetAddr);
             targetAddr.offset += 4;
             _as->store32(Assembler::TrustedImm32(Value::_Integer_Type), targetAddr);
@@ -1157,7 +1175,7 @@ void InstructionSelection::convertTypeToSInt32(IR::Temp *source, IR::Temp *targe
         }
 #else
         // load the tag:
-        Assembler::Pointer addr = _as->loadTempAddress(Assembler::ScratchRegister, source);
+        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
         Assembler::Pointer tagAddr = addr;
         tagAddr.offset += 4;
         _as->load32(tagAddr, Assembler::ReturnValueRegister);
@@ -1165,21 +1183,22 @@ void InstructionSelection::convertTypeToSInt32(IR::Temp *source, IR::Temp *targe
         // check if it's an int32:
         Assembler::Jump fallback = _as->branch32(Assembler::NotEqual, Assembler::ReturnValueRegister,
                                                 Assembler::TrustedImm32(Value::_Integer_Type));
-        if (target->kind == IR::Temp::StackSlot) {
-            _as->load32(addr, Assembler::ScratchRegister);
-            Assembler::Pointer targetAddr = _as->stackSlotPointer(target);
-            _as->store32(Assembler::ScratchRegister, targetAddr);
+        IR::Temp *targetTemp = target->asTemp();
+        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
+            _as->load32(addr, Assembler::ReturnValueRegister);
+            Assembler::Pointer targetAddr = _as->loadAddress(Assembler::ScratchRegister, target);
+            _as->store32(Assembler::ReturnValueRegister, targetAddr);
             targetAddr.offset += 4;
             _as->store32(Assembler::TrustedImm32(Value::_Integer_Type), targetAddr);
         } else {
-            _as->load32(addr, (Assembler::RegisterID) target->index);
+            _as->load32(addr, (Assembler::RegisterID) targetTemp->index);
         }
         Assembler::Jump intDone = _as->jump();
 
         // not an int:
         fallback.link(_as);
         generateFunctionCall(Assembler::ReturnValueRegister, Runtime::toInt,
-                             _as->loadTempAddress(Assembler::ScratchRegister, source));
+                             _as->loadAddress(Assembler::ScratchRegister, source));
         _as->storeInt32(Assembler::ReturnValueRegister, target);
 
         intDone.link(_as);
@@ -1210,32 +1229,32 @@ void InstructionSelection::convertTypeToSInt32(IR::Temp *source, IR::Temp *targe
     case IR::StringType:
     default:
         generateFunctionCall(Assembler::ReturnValueRegister, Runtime::toInt,
-                             _as->loadTempAddress(Assembler::ScratchRegister, source));
+                             _as->loadAddress(Assembler::ScratchRegister, source));
         _as->storeInt32(Assembler::ReturnValueRegister, target);
         break;
     } // switch (source->type)
 }
 
-void InstructionSelection::convertTypeToUInt32(IR::Temp *source, IR::Temp *target)
+void InstructionSelection::convertTypeToUInt32(IR::Expr *source, IR::Expr *target)
 {
     switch (source->type) {
     case IR::VarType: {
         // load the tag:
-        Assembler::Pointer tagAddr = _as->loadTempAddress(Assembler::ScratchRegister, source);
+        Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, source);
         tagAddr.offset += 4;
         _as->load32(tagAddr, Assembler::ScratchRegister);
 
         // check if it's an int32:
         Assembler::Jump isNoInt = _as->branch32(Assembler::NotEqual, Assembler::ScratchRegister,
                                                 Assembler::TrustedImm32(Value::_Integer_Type));
-        Assembler::Pointer addr = _as->loadTempAddress(Assembler::ScratchRegister, source);
+        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
         _as->storeUInt32(_as->toInt32Register(addr, Assembler::ScratchRegister), target);
         Assembler::Jump intDone = _as->jump();
 
         // not an int:
         isNoInt.link(_as);
         generateFunctionCall(Assembler::ReturnValueRegister, Runtime::toUInt,
-                             _as->loadTempAddress(Assembler::ScratchRegister, source));
+                             _as->loadAddress(Assembler::ScratchRegister, source));
         _as->storeInt32(Assembler::ReturnValueRegister, target);
 
         intDone.link(_as);
@@ -1269,7 +1288,7 @@ void InstructionSelection::convertTypeToUInt32(IR::Temp *source, IR::Temp *targe
     } // switch (source->type)
 }
 
-void InstructionSelection::constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Temp *result)
+void InstructionSelection::constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result)
 {
     Q_ASSERT(func != 0);
     prepareCallData(args, 0);
@@ -1289,7 +1308,7 @@ void InstructionSelection::constructActivationProperty(IR::Name *func, IR::ExprL
 }
 
 
-void InstructionSelection::constructProperty(IR::Temp *base, const QString &name, IR::ExprList *args, IR::Temp *result)
+void InstructionSelection::constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result)
 {
     prepareCallData(args, base);
     if (useFastLookups) {
@@ -1306,7 +1325,7 @@ void InstructionSelection::constructProperty(IR::Temp *base, const QString &name
                          baseAddressForCallData());
 }
 
-void InstructionSelection::constructValue(IR::Temp *value, IR::ExprList *args, IR::Temp *result)
+void InstructionSelection::constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
 {
     Q_ASSERT(value != 0);
 
@@ -1325,16 +1344,17 @@ void InstructionSelection::visitJump(IR::Jump *s)
 
 void InstructionSelection::visitCJump(IR::CJump *s)
 {
-    if (IR::Temp *t = s->cond->asTemp()) {
+    IR::Temp *t = s->cond->asTemp();
+    if (t || s->cond->asArgLocal()) {
         Assembler::RegisterID reg;
-        if (t->kind == IR::Temp::PhysicalRegister) {
+        if (t && t->kind == IR::Temp::PhysicalRegister) {
             Q_ASSERT(t->type == IR::BoolType);
             reg = (Assembler::RegisterID) t->index;
-        } else if (t->kind == IR::Temp::StackSlot && t->type == IR::BoolType) {
+        } else if (t && t->kind == IR::Temp::StackSlot && t->type == IR::BoolType) {
             reg = Assembler::ReturnValueRegister;
             _as->toInt32Register(t, reg);
         } else {
-            Address temp = _as->loadTempAddress(Assembler::ScratchRegister, t);
+            Address temp = _as->loadAddress(Assembler::ScratchRegister, s->cond);
             Address tag = temp;
             tag.offset += qOffsetOf(QV4::Value, tag);
             Assembler::Jump booleanConversion = _as->branch32(Assembler::NotEqual, tag, Assembler::TrustedImm32(QV4::Value::Boolean_Type));
@@ -1346,7 +1366,7 @@ void InstructionSelection::visitCJump(IR::CJump *s)
 
             booleanConversion.link(_as);
             reg = Assembler::ReturnValueRegister;
-            generateFunctionCall(reg, Runtime::toBoolean, Assembler::Reference(t));
+            generateFunctionCall(reg, Runtime::toBoolean, Assembler::Reference(s->cond));
 
             testBoolean.link(_as);
         }
@@ -1456,7 +1476,7 @@ void InstructionSelection::visitRet(IR::Ret *s)
                 Q_UNREACHABLE();
             }
         } else {
-            Pointer addr = _as->loadTempAddress(Assembler::ScratchRegister, t);
+            Pointer addr = _as->loadAddress(Assembler::ScratchRegister, t);
             _as->load32(addr, lowReg);
             addr.offset += 4;
             _as->load32(addr, highReg);
@@ -1693,10 +1713,7 @@ bool InstructionSelection::visitCJumpStrictNullUndefined(IR::Type nullOrUndef, I
         return true;
     }
 
-    IR::Temp *t = varSrc->asTemp();
-    Q_ASSERT(t);
-
-    Assembler::Pointer tagAddr = _as->loadTempAddress(Assembler::ScratchRegister, t);
+    Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, varSrc);
     tagAddr.offset += 4;
     const Assembler::RegisterID tagReg = Assembler::ScratchRegister;
     _as->load32(tagAddr, tagReg);
@@ -1739,11 +1756,7 @@ bool InstructionSelection::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock
         return true;
     }
 
-    IR::Temp *otherTemp = otherSrc->asTemp();
-    Q_ASSERT(otherTemp); // constants cannot have "var" type
-    Q_ASSERT(otherTemp->kind != IR::Temp::PhysicalRegister);
-
-    Assembler::Pointer otherAddr = _as->loadTempAddress(Assembler::ReturnValueRegister, otherTemp);
+    Assembler::Pointer otherAddr = _as->loadAddress(Assembler::ReturnValueRegister, otherSrc);
     otherAddr.offset += 4; // tag address
 
     // check if the tag of the var operand is indicates 'boolean'
@@ -1791,10 +1804,7 @@ bool InstructionSelection::visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Bin
         return true;
     }
 
-    IR::Temp *t = varSrc->asTemp();
-    Q_ASSERT(t);
-
-    Assembler::Pointer tagAddr = _as->loadTempAddress(Assembler::ScratchRegister, t);
+    Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, varSrc);
     tagAddr.offset += 4;
     const Assembler::RegisterID tagReg = Assembler::ScratchRegister;
     _as->load32(tagAddr, tagReg);
diff --git a/src/qml/jit/qv4isel_masm_p.h b/src/qml/jit/qv4isel_masm_p.h
index d589223d7e..83d2464ef3 100644
--- a/src/qml/jit/qv4isel_masm_p.h
+++ b/src/qml/jit/qv4isel_masm_p.h
@@ -76,54 +76,54 @@ public:
 protected:
     virtual QV4::CompiledData::CompilationUnit *backendCompileStep();
 
-    virtual void callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Temp *result);
-    virtual void callBuiltinTypeofMember(IR::Expr *base, const QString &name, IR::Temp *result);
-    virtual void callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index, IR::Temp *result);
-    virtual void callBuiltinTypeofName(const QString &name, IR::Temp *result);
-    virtual void callBuiltinTypeofValue(IR::Expr *value, IR::Temp *result);
-    virtual void callBuiltinDeleteMember(IR::Temp *base, const QString &name, IR::Temp *result);
-    virtual void callBuiltinDeleteSubscript(IR::Temp *base, IR::Expr *index, IR::Temp *result);
-    virtual void callBuiltinDeleteName(const QString &name, IR::Temp *result);
-    virtual void callBuiltinDeleteValue(IR::Temp *result);
+    virtual void callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result);
+    virtual void callBuiltinTypeofMember(IR::Expr *base, const QString &name, IR::Expr *result);
+    virtual void callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result);
+    virtual void callBuiltinTypeofName(const QString &name, IR::Expr *result);
+    virtual void callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result);
+    virtual void callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result);
+    virtual void callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result);
+    virtual void callBuiltinDeleteName(const QString &name, IR::Expr *result);
+    virtual void callBuiltinDeleteValue(IR::Expr *result);
     virtual void callBuiltinThrow(IR::Expr *arg);
     virtual void callBuiltinReThrow();
-    virtual void callBuiltinUnwindException(IR::Temp *);
+    virtual void callBuiltinUnwindException(IR::Expr *);
     virtual void callBuiltinPushCatchScope(const QString &exceptionName);
-    virtual void callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Temp *result);
-    virtual void callBuiltinForeachNextPropertyname(IR::Temp *arg, IR::Temp *result);
-    virtual void callBuiltinPushWithScope(IR::Temp *arg);
+    virtual void callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result);
+    virtual void callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result);
+    virtual void callBuiltinPushWithScope(IR::Expr *arg);
     virtual void callBuiltinPopScope();
     virtual void callBuiltinDeclareVar(bool deletable, const QString &name);
-    virtual void callBuiltinDefineArray(IR::Temp *result, IR::ExprList *args);
-    virtual void callBuiltinDefineObjectLiteral(IR::Temp *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray);
-    virtual void callBuiltinSetupArgumentObject(IR::Temp *result);
+    virtual void callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args);
+    virtual void callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray);
+    virtual void callBuiltinSetupArgumentObject(IR::Expr *result);
     virtual void callBuiltinConvertThisToObject();
-    virtual void callValue(IR::Temp *value, IR::ExprList *args, IR::Temp *result);
-    virtual void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Temp *result);
-    virtual void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args, IR::Temp *result);
-    virtual void convertType(IR::Temp *source, IR::Temp *target);
-    virtual void loadThisObject(IR::Temp *temp);
-    virtual void loadQmlIdArray(IR::Temp *temp);
-    virtual void loadQmlImportedScripts(IR::Temp *temp);
-    virtual void loadQmlContextObject(IR::Temp *temp);
-    virtual void loadQmlScopeObject(IR::Temp *temp);
-    virtual void loadQmlSingleton(const QString &name, IR::Temp *temp);
-    virtual void loadConst(IR::Const *sourceConst, IR::Temp *targetTemp);
-    virtual void loadString(const QString &str, IR::Temp *targetTemp);
-    virtual void loadRegexp(IR::RegExp *sourceRegexp, IR::Temp *targetTemp);
-    virtual void getActivationProperty(const IR::Name *name, IR::Temp *temp);
+    virtual void callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result);
+    virtual void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result);
+    virtual void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args, IR::Expr *result);
+    virtual void convertType(IR::Expr *source, IR::Expr *target);
+    virtual void loadThisObject(IR::Expr *temp);
+    virtual void loadQmlIdArray(IR::Expr *target);
+    virtual void loadQmlImportedScripts(IR::Expr *target);
+    virtual void loadQmlContextObject(IR::Expr *target);
+    virtual void loadQmlScopeObject(IR::Expr *target);
+    virtual void loadQmlSingleton(const QString &name, IR::Expr *target);
+    virtual void loadConst(IR::Const *sourceConst, IR::Expr *target);
+    virtual void loadString(const QString &str, IR::Expr *target);
+    virtual void loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target);
+    virtual void getActivationProperty(const IR::Name *name, IR::Expr *target);
     virtual void setActivationProperty(IR::Expr *source, const QString &targetName);
-    virtual void initClosure(IR::Closure *closure, IR::Temp *target);
-    virtual void getProperty(IR::Expr *base, const QString &name, IR::Temp *target);
+    virtual void initClosure(IR::Closure *closure, IR::Expr *target);
+    virtual void getProperty(IR::Expr *base, const QString &name, IR::Expr *target);
+    virtual void getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, int attachedPropertiesId, IR::Expr *target);
     virtual void setProperty(IR::Expr *source, IR::Expr *targetBase, const QString &targetName);
     virtual void setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex);
-    virtual void getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, int attachedPropertiesId, IR::Temp *target);
-    virtual void getElement(IR::Expr *base, IR::Expr *index, IR::Temp *target);
+    virtual void getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target);
     virtual void setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex);
-    virtual void copyValue(IR::Temp *sourceTemp, IR::Temp *targetTemp);
-    virtual void swapValues(IR::Temp *sourceTemp, IR::Temp *targetTemp);
-    virtual void unop(IR::AluOp oper, IR::Temp *sourceTemp, IR::Temp *targetTemp);
-    virtual void binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Temp *target);
+    virtual void copyValue(IR::Expr *source, IR::Expr *target);
+    virtual void swapValues(IR::Expr *source, IR::Expr *target);
+    virtual void unop(IR::AluOp oper, IR::Expr *sourceTemp, IR::Expr *target);
+    virtual void binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target);
 
     typedef Assembler::Address Address;
     typedef Assembler::Pointer Pointer;
@@ -148,9 +148,9 @@ protected:
         return _as->stackLayout().callDataAddress();
     }
 
-    virtual void constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Temp *result);
-    virtual void constructProperty(IR::Temp *base, const QString &name, IR::ExprList *args, IR::Temp *result);
-    virtual void constructValue(IR::Temp *value, IR::ExprList *args, IR::Temp *result);
+    virtual void constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result);
+    virtual void constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr*result);
+    virtual void constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result);
 
     virtual void visitJump(IR::Jump *);
     virtual void visitCJump(IR::CJump *);
@@ -167,44 +167,51 @@ protected:
     void visitCJumpEqual(IR::Binop *binop, IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
 
 private:
-    void convertTypeSlowPath(IR::Temp *source, IR::Temp *target);
-    void convertTypeToDouble(IR::Temp *source, IR::Temp *target);
-    void convertTypeToBool(IR::Temp *source, IR::Temp *target);
-    void convertTypeToSInt32(IR::Temp *source, IR::Temp *target);
-    void convertTypeToUInt32(IR::Temp *source, IR::Temp *target);
+    void convertTypeSlowPath(IR::Expr *source, IR::Expr *target);
+    void convertTypeToDouble(IR::Expr *source, IR::Expr *target);
+    void convertTypeToBool(IR::Expr *source, IR::Expr *target);
+    void convertTypeToSInt32(IR::Expr *source, IR::Expr *target);
+    void convertTypeToUInt32(IR::Expr *source, IR::Expr *target);
 
-    void convertIntToDouble(IR::Temp *source, IR::Temp *target)
+    void convertIntToDouble(IR::Expr *source, IR::Expr *target)
     {
-        if (target->kind == IR::Temp::PhysicalRegister) {
-            _as->convertInt32ToDouble(_as->toInt32Register(source, Assembler::ScratchRegister),
-                                      (Assembler::FPRegisterID) target->index);
-        } else {
-            _as->convertInt32ToDouble(_as->toInt32Register(source, Assembler::ScratchRegister),
-                                      Assembler::FPGpr0);
-            _as->storeDouble(Assembler::FPGpr0, _as->stackSlotPointer(target));
+        if (IR::Temp *targetTemp = target->asTemp()) {
+            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+                _as->convertInt32ToDouble(_as->toInt32Register(source, Assembler::ScratchRegister),
+                                          (Assembler::FPRegisterID) targetTemp->index);
+                return;
+            }
         }
+
+        _as->convertInt32ToDouble(_as->toInt32Register(source, Assembler::ScratchRegister),
+                                  Assembler::FPGpr0);
+        _as->storeDouble(Assembler::FPGpr0, _as->loadAddress(Assembler::ScratchRegister, target));
     }
 
-    void convertUIntToDouble(IR::Temp *source, IR::Temp *target)
+    void convertUIntToDouble(IR::Expr *source, IR::Expr *target)
     {
         Assembler::RegisterID tmpReg = Assembler::ScratchRegister;
         Assembler::RegisterID reg = _as->toInt32Register(source, tmpReg);
 
-        if (target->kind == IR::Temp::PhysicalRegister) {
-            _as->convertUInt32ToDouble(reg, (Assembler::FPRegisterID) target->index, tmpReg);
-        } else {
-            _as->convertUInt32ToDouble(_as->toUInt32Register(source, tmpReg),
-                                      Assembler::FPGpr0, tmpReg);
-            _as->storeDouble(Assembler::FPGpr0, _as->stackSlotPointer(target));
+        if (IR::Temp *targetTemp = target->asTemp()) {
+            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
+                _as->convertUInt32ToDouble(reg, (Assembler::FPRegisterID) targetTemp->index, tmpReg);
+                return;
+            }
         }
+
+        _as->convertUInt32ToDouble(_as->toUInt32Register(source, tmpReg),
+                                   Assembler::FPGpr0, tmpReg);
+        _as->storeDouble(Assembler::FPGpr0, _as->loadAddress(tmpReg, target));
     }
 
-    void convertIntToBool(IR::Temp *source, IR::Temp *target)
+    void convertIntToBool(IR::Expr *source, IR::Expr *target)
     {
-        Assembler::RegisterID reg = target->kind == IR::Temp::PhysicalRegister
-                ? (Assembler::RegisterID) target->index
-                : Assembler::ScratchRegister;
+        Assembler::RegisterID reg = Assembler::ScratchRegister;
 
+        if (IR::Temp *targetTemp = target->asTemp())
+            if (targetTemp->kind == IR::Temp::PhysicalRegister)
+                reg = (Assembler::RegisterID) targetTemp->index;
         _as->move(_as->toInt32Register(source, reg), reg);
         _as->compare32(Assembler::NotEqual, reg, Assembler::TrustedImm32(0), reg);
         _as->storeBool(reg, target);
diff --git a/src/qml/jit/qv4regalloc.cpp b/src/qml/jit/qv4regalloc.cpp
index a66eab005f..331af3d635 100644
--- a/src/qml/jit/qv4regalloc.cpp
+++ b/src/qml/jit/qv4regalloc.cpp
@@ -139,7 +139,7 @@ public:
     void addHint(const Temp &t, int physicalRegister)
     {
         Temp hint;
-        hint.init(Temp::PhysicalRegister, physicalRegister, 0);
+        hint.init(Temp::PhysicalRegister, physicalRegister);
         _hints[t].append(hint);
     }
 
@@ -196,40 +196,41 @@ public:
     }
 
 protected: // IRDecoder
-    virtual void callBuiltinInvalid(IR::Name *, IR::ExprList *, IR::Temp *) {}
-    virtual void callBuiltinTypeofMember(IR::Expr *, const QString &, IR::Temp *) {}
-    virtual void callBuiltinTypeofSubscript(IR::Expr *, IR::Expr *, IR::Temp *) {}
-    virtual void callBuiltinTypeofName(const QString &, IR::Temp *) {}
-    virtual void callBuiltinTypeofValue(IR::Expr *, IR::Temp *) {}
-    virtual void callBuiltinDeleteMember(IR::Temp *, const QString &, IR::Temp *) {}
-    virtual void callBuiltinDeleteSubscript(IR::Temp *, IR::Expr *, IR::Temp *) {}
-    virtual void callBuiltinDeleteName(const QString &, IR::Temp *) {}
-    virtual void callBuiltinDeleteValue(IR::Temp *) {}
+    virtual void callBuiltinInvalid(IR::Name *, IR::ExprList *, IR::Expr *) {}
+    virtual void callBuiltinTypeofMember(IR::Expr *, const QString &, IR::Expr *) {}
+    virtual void callBuiltinTypeofSubscript(IR::Expr *, IR::Expr *, IR::Expr *) {}
+    virtual void callBuiltinTypeofName(const QString &, IR::Expr *) {}
+    virtual void callBuiltinTypeofValue(IR::Expr *, IR::Expr *) {}
+    virtual void callBuiltinDeleteMember(IR::Expr *, const QString &, IR::Expr *) {}
+    virtual void callBuiltinDeleteSubscript(IR::Expr *, IR::Expr *, IR::Expr *) {}
+    virtual void callBuiltinDeleteName(const QString &, IR::Expr *) {}
+    virtual void callBuiltinDeleteValue(IR::Expr *) {}
     virtual void callBuiltinThrow(IR::Expr *) {}
     virtual void callBuiltinReThrow() {}
-    virtual void callBuiltinUnwindException(IR::Temp *) {}
+    virtual void callBuiltinUnwindException(IR::Expr *) {}
     virtual void callBuiltinPushCatchScope(const QString &) {};
-    virtual void callBuiltinForeachIteratorObject(IR::Expr *, IR::Temp *) {}
+    virtual void callBuiltinForeachIteratorObject(IR::Expr *, IR::Expr *) {}
     virtual void callBuiltinForeachNextProperty(IR::Temp *, IR::Temp *) {}
-    virtual void callBuiltinForeachNextPropertyname(IR::Temp *, IR::Temp *) {}
-    virtual void callBuiltinPushWithScope(IR::Temp *) {}
+    virtual void callBuiltinForeachNextPropertyname(IR::Expr *, IR::Expr *) {}
+    virtual void callBuiltinPushWithScope(IR::Expr *) {}
     virtual void callBuiltinPopScope() {}
     virtual void callBuiltinDeclareVar(bool , const QString &) {}
-    virtual void callBuiltinDefineArray(IR::Temp *, IR::ExprList *) {}
-    virtual void callBuiltinDefineObjectLiteral(IR::Temp *, int, IR::ExprList *, IR::ExprList *, bool) {}
-    virtual void callBuiltinSetupArgumentObject(IR::Temp *) {}
+    virtual void callBuiltinDefineArray(IR::Expr *, IR::ExprList *) {}
+    virtual void callBuiltinDefineObjectLiteral(IR::Expr *, int, IR::ExprList *, IR::ExprList *, bool) {}
+    virtual void callBuiltinSetupArgumentObject(IR::Expr *) {}
     virtual void callBuiltinConvertThisToObject() {}
 
-    virtual void callValue(IR::Temp *value, IR::ExprList *args, IR::Temp *result)
+    virtual void callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
     {
         addDef(result);
-        addUses(value, Use::CouldHaveRegister);
+        if (IR::Temp *tempValue = value->asTemp())
+            addUses(tempValue, Use::CouldHaveRegister);
         addUses(args, Use::CouldHaveRegister);
         addCall();
     }
 
     virtual void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
-                              IR::Temp *result)
+                              IR::Expr *result)
     {
         Q_UNUSED(name)
 
@@ -240,7 +241,7 @@ protected: // IRDecoder
     }
 
     virtual void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
-                               IR::Temp *result)
+                               IR::Expr *result)
     {
         addDef(result);
         addUses(base->asTemp(), Use::CouldHaveRegister);
@@ -249,7 +250,7 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void convertType(IR::Temp *source, IR::Temp *target)
+    virtual void convertType(IR::Expr *source, IR::Expr *target)
     {
         addDef(target);
 
@@ -312,22 +313,24 @@ protected: // IRDecoder
             break;
         }
 
-        addUses(source, sourceReg);
+        Temp *sourceTemp = source->asTemp();
+        if (sourceTemp)
+            addUses(sourceTemp, sourceReg);
 
         if (needsCall)
             addCall();
-        else
-            addHint(target, source);
+        else if (target->asTemp())
+            addHint(target->asTemp(), sourceTemp);
     }
 
-    virtual void constructActivationProperty(IR::Name *, IR::ExprList *args, IR::Temp *result)
+    virtual void constructActivationProperty(IR::Name *, IR::ExprList *args, IR::Expr *result)
     {
         addDef(result);
         addUses(args, Use::CouldHaveRegister);
         addCall();
     }
 
-    virtual void constructProperty(IR::Temp *base, const QString &, IR::ExprList *args, IR::Temp *result)
+    virtual void constructProperty(IR::Expr *base, const QString &, IR::ExprList *args, IR::Expr *result)
     {
         addDef(result);
         addUses(base, Use::CouldHaveRegister);
@@ -335,7 +338,7 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void constructValue(IR::Temp *value, IR::ExprList *args, IR::Temp *result)
+    virtual void constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
     {
         addDef(result);
         addUses(value, Use::CouldHaveRegister);
@@ -343,30 +346,30 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void loadThisObject(IR::Temp *temp)
+    virtual void loadThisObject(IR::Expr *temp)
     {
         addDef(temp);
     }
 
-    virtual void loadQmlIdArray(IR::Temp *temp)
+    virtual void loadQmlIdArray(IR::Expr *temp)
     {
         addDef(temp);
         addCall();
     }
 
-    virtual void loadQmlImportedScripts(IR::Temp *temp)
+    virtual void loadQmlImportedScripts(IR::Expr *temp)
     {
         addDef(temp);
         addCall();
     }
 
-    virtual void loadQmlContextObject(Temp *temp)
+    virtual void loadQmlContextObject(Expr *temp)
     {
         addDef(temp);
         addCall();
     }
 
-    virtual void loadQmlScopeObject(Temp *temp)
+    virtual void loadQmlScopeObject(Expr *temp)
     {
         Q_UNUSED(temp);
 
@@ -374,7 +377,7 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void loadQmlSingleton(const QString &/*name*/, Temp *temp)
+    virtual void loadQmlSingleton(const QString &/*name*/, Expr *temp)
     {
         Q_UNUSED(temp);
 
@@ -382,21 +385,21 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void loadConst(IR::Const *sourceConst, IR::Temp *targetTemp)
+    virtual void loadConst(IR::Const *sourceConst, Expr *targetTemp)
     {
         Q_UNUSED(sourceConst);
 
         addDef(targetTemp);
     }
 
-    virtual void loadString(const QString &str, IR::Temp *targetTemp)
+    virtual void loadString(const QString &str, Expr *targetTemp)
     {
         Q_UNUSED(str);
 
         addDef(targetTemp);
     }
 
-    virtual void loadRegexp(IR::RegExp *sourceRegexp, IR::Temp *targetTemp)
+    virtual void loadRegexp(IR::RegExp *sourceRegexp, Expr *targetTemp)
     {
         Q_UNUSED(sourceRegexp);
 
@@ -404,7 +407,7 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void getActivationProperty(const IR::Name *, IR::Temp *temp)
+    virtual void getActivationProperty(const IR::Name *, Expr *temp)
     {
         addDef(temp);
         addCall();
@@ -416,7 +419,7 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void initClosure(IR::Closure *closure, IR::Temp *target)
+    virtual void initClosure(IR::Closure *closure, Expr *target)
     {
         Q_UNUSED(closure);
 
@@ -424,7 +427,7 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void getProperty(IR::Expr *base, const QString &, IR::Temp *target)
+    virtual void getProperty(IR::Expr *base, const QString &, Expr *target)
     {
         addDef(target);
         addUses(base->asTemp(), Use::CouldHaveRegister);
@@ -445,14 +448,14 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void getQObjectProperty(IR::Expr *base, int /*propertyIndex*/, bool /*captureRequired*/, int /*attachedPropertiesId*/, IR::Temp *target)
+    virtual void getQObjectProperty(IR::Expr *base, int /*propertyIndex*/, bool /*captureRequired*/, int /*attachedPropertiesId*/, IR::Expr *target)
     {
         addDef(target);
         addUses(base->asTemp(), Use::CouldHaveRegister);
         addCall();
     }
 
-    virtual void getElement(IR::Expr *base, IR::Expr *index, IR::Temp *target)
+    virtual void getElement(IR::Expr *base, IR::Expr *index, Expr *target)
     {
         addDef(target);
         addUses(base->asTemp(), Use::CouldHaveRegister);
@@ -468,25 +471,30 @@ protected: // IRDecoder
         addCall();
     }
 
-    virtual void copyValue(IR::Temp *sourceTemp, IR::Temp *targetTemp)
+    virtual void copyValue(Expr *source, Expr *target)
     {
-        addDef(targetTemp);
+        addDef(target);
+        Temp *sourceTemp = source->asTemp();
+        if (!sourceTemp)
+            return;
         addUses(sourceTemp, Use::CouldHaveRegister);
-        addHint(targetTemp, sourceTemp);
+        Temp *targetTemp = target->asTemp();
+        if (targetTemp)
+            addHint(targetTemp, sourceTemp);
     }
 
-    virtual void swapValues(IR::Temp *, IR::Temp *)
+    virtual void swapValues(Expr *, Expr *)
     {
         // Inserted by the register allocator, so it cannot occur here.
         Q_UNREACHABLE();
     }
 
-    virtual void unop(AluOp oper, Temp *sourceTemp, Temp *targetTemp)
+    virtual void unop(AluOp oper, Expr *source, Expr *target)
     {
-        addDef(targetTemp);
+        addDef(target);
 
         bool needsCall = true;
-        if (oper == OpNot && sourceTemp->type == IR::BoolType && targetTemp->type == IR::BoolType)
+        if (oper == OpNot && source->type == IR::BoolType && target->type == IR::BoolType)
             needsCall = false;
 
 #if 0 // TODO: change masm to generate code
@@ -506,15 +514,18 @@ protected: // IRDecoder
         }
 #endif
 
+        IR::Temp *sourceTemp = source->asTemp();
         if (needsCall) {
-            addUses(sourceTemp, Use::CouldHaveRegister);
+            if (sourceTemp)
+                addUses(sourceTemp, Use::CouldHaveRegister);
             addCall();
         } else {
-            addUses(sourceTemp, Use::MustHaveRegister);
+            if (sourceTemp)
+                addUses(sourceTemp, Use::MustHaveRegister);
         }
     }
 
-    virtual void binop(AluOp oper, Expr *leftSource, Expr *rightSource, Temp *target)
+    virtual void binop(AluOp oper, Expr *leftSource, Expr *rightSource, Expr *target)
     {
         bool needsCall = true;
 
@@ -597,17 +608,22 @@ protected: // IRDecoder
     }
 
 protected:
-    virtual void callBuiltin(IR::Call *c, IR::Temp *result)
+    virtual void callBuiltin(IR::Call *c, IR::Expr *result)
     {
         addDef(result);
-        addUses(c->base->asTemp(), Use::CouldHaveRegister);
+        addUses(c->base, Use::CouldHaveRegister);
         addUses(c->args, Use::CouldHaveRegister);
         addCall();
     }
 
 private:
-    void addDef(Temp *t, bool isPhiTarget = false)
+    void addDef(Expr *e, bool isPhiTarget = false)
     {
+        if (!e)
+            return;
+        Temp *t = e->asTemp();
+        if (!t)
+            return;
         if (!t || t->kind != Temp::VirtualRegister)
             return;
         Q_ASSERT(!_defs.contains(*t));
@@ -627,9 +643,14 @@ private:
         _defs[*t] = Def(_currentStmt->id, canHaveReg, isPhiTarget);
     }
 
-    void addUses(Temp *t, Use::RegisterFlag flag)
+    void addUses(Expr *e, Use::RegisterFlag flag)
     {
         Q_ASSERT(_currentStmt->id > 0);
+        if (!e)
+            return;
+        Temp *t = e->asTemp();
+        if (!t)
+            return;
         if (t && t->kind == Temp::VirtualRegister)
             _uses[*t].append(Use(_currentStmt->id, flag));
     }
@@ -637,7 +658,7 @@ private:
     void addUses(ExprList *l, Use::RegisterFlag flag)
     {
         for (ExprList *it = l; it; it = it->next)
-            addUses(it->expr->asTemp(), flag);
+            addUses(it->expr, flag);
     }
 
     void addCall()
@@ -645,6 +666,13 @@ private:
         _calls.append(_currentStmt->id);
     }
 
+    void addHint(Expr *hinted, Temp *hint1, Temp *hint2 = 0)
+    {
+        if (hinted)
+            if (Temp *hintedTemp = hinted->asTemp())
+                addHint(hintedTemp, hint1, hint2);
+    }
+
     void addHint(Temp *hinted, Temp *hint1, Temp *hint2 = 0)
     {
         if (!hinted || hinted->kind != Temp::VirtualRegister)
@@ -986,7 +1014,7 @@ private:
     {
         Q_ASSERT(index >= 0);
         Temp *t = _function->New<Temp>();
-        t->init(kind, index, 0);
+        t->init(kind, index);
         t->type = type;
         return t;
     }
@@ -1040,6 +1068,7 @@ protected:
         }
     }
 
+    virtual void visitArgLocal(ArgLocal *) {}
     virtual void visitConst(Const *) {}
     virtual void visitString(IR::String *) {}
     virtual void visitRegExp(IR::RegExp *) {}
@@ -1140,7 +1169,7 @@ static inline LifeTimeInterval createFixedInterval(int rangeCount)
     i.setReg(0);
 
     Temp t;
-    t.init(Temp::PhysicalRegister, 0, 0);
+    t.init(Temp::PhysicalRegister, 0);
     t.type = IR::SInt32Type;
     i.setTemp(t);
 
@@ -1153,7 +1182,7 @@ static inline LifeTimeInterval cloneFixedInterval(int reg, bool isFP, LifeTimeIn
     lti.setFixedInterval(true);
 
     Temp t;
-    t.init(Temp::PhysicalRegister, reg, 0);
+    t.init(Temp::PhysicalRegister, reg);
     t.type = isFP ? IR::DoubleType : IR::SInt32Type;
     lti.setTemp(t);
 
diff --git a/src/qml/jit/qv4unop.cpp b/src/qml/jit/qv4unop.cpp
index 40f86f91b5..d92b5797cd 100644
--- a/src/qml/jit/qv4unop.cpp
+++ b/src/qml/jit/qv4unop.cpp
@@ -51,7 +51,7 @@ using namespace JIT;
 #define setOp(operation) \
     do { call = operation; name = stringIfy(operation); } while (0)
 
-void Unop::generate(IR::Temp *source, IR::Temp *target)
+void Unop::generate(IR::Expr *source, IR::Expr *target)
 {
     Runtime::UnaryOperation call = 0;
     const char *name = 0;
@@ -77,16 +77,17 @@ void Unop::generate(IR::Temp *source, IR::Temp *target)
     }
 }
 
-void Unop::generateUMinus(IR::Temp *source, IR::Temp *target)
+void Unop::generateUMinus(IR::Expr *source, IR::Expr *target)
 {
+    IR::Temp *targetTemp = target->asTemp();
     if (source->type == IR::SInt32Type) {
         Assembler::RegisterID tReg = Assembler::ScratchRegister;
-        if (target->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) target->index;
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
+            tReg = (Assembler::RegisterID) targetTemp->index;
         Assembler::RegisterID sReg = as->toInt32Register(source, tReg);
         as->move(sReg, tReg);
         as->neg32(tReg);
-        if (target->kind != IR::Temp::PhysicalRegister)
+        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             as->storeInt32(tReg, target);
         return;
     }
@@ -94,24 +95,25 @@ void Unop::generateUMinus(IR::Temp *source, IR::Temp *target)
     as->generateFunctionCallImp(target, "Runtime::uMinus", Runtime::uMinus, Assembler::PointerToValue(source));
 }
 
-void Unop::generateNot(IR::Temp *source, IR::Temp *target)
+void Unop::generateNot(IR::Expr *source, IR::Expr *target)
 {
+    IR::Temp *targetTemp = target->asTemp();
     if (source->type == IR::BoolType) {
         Assembler::RegisterID tReg = Assembler::ScratchRegister;
-        if (target->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) target->index;
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
+            tReg = (Assembler::RegisterID) targetTemp->index;
         as->xor32(Assembler::TrustedImm32(0x1), as->toInt32Register(source, tReg), tReg);
-        if (target->kind != IR::Temp::PhysicalRegister)
+        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             as->storeBool(tReg, target);
         return;
     } else if (source->type == IR::SInt32Type) {
         Assembler::RegisterID tReg = Assembler::ScratchRegister;
-        if (target->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) target->index;
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
+            tReg = (Assembler::RegisterID) targetTemp->index;
         as->compare32(Assembler::Equal,
                       as->toInt32Register(source, Assembler::ScratchRegister), Assembler::TrustedImm32(0),
                       tReg);
-        if (target->kind != IR::Temp::PhysicalRegister)
+        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             as->storeBool(tReg, target);
         return;
     } else if (source->type == IR::DoubleType) {
@@ -122,14 +124,15 @@ void Unop::generateNot(IR::Temp *source, IR::Temp *target)
     as->generateFunctionCallImp(target, "Runtime::uNot", Runtime::uNot, Assembler::PointerToValue(source));
 }
 
-void Unop::generateCompl(IR::Temp *source, IR::Temp *target)
+void Unop::generateCompl(IR::Expr *source, IR::Expr *target)
 {
+    IR::Temp *targetTemp = target->asTemp();
     if (source->type == IR::SInt32Type) {
         Assembler::RegisterID tReg = Assembler::ScratchRegister;
-        if (target->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) target->index;
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
+            tReg = (Assembler::RegisterID) targetTemp->index;
         as->xor32(Assembler::TrustedImm32(0xffffffff), as->toInt32Register(source, tReg), tReg);
-        if (target->kind != IR::Temp::PhysicalRegister)
+        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             as->storeInt32(tReg, target);
         return;
     }
diff --git a/src/qml/jit/qv4unop_p.h b/src/qml/jit/qv4unop_p.h
index a8c62182ad..07fb6e5ad6 100644
--- a/src/qml/jit/qv4unop_p.h
+++ b/src/qml/jit/qv4unop_p.h
@@ -59,11 +59,11 @@ struct Unop {
         , op(operation)
     {}
 
-    void generate(IR::Temp *source, IR::Temp *target);
+    void generate(IR::Expr *source, IR::Expr *target);
 
-    void generateUMinus(IR::Temp *source, IR::Temp *target);
-    void generateNot(IR::Temp *source, IR::Temp *target);
-    void generateCompl(IR::Temp *source, IR::Temp *target);
+    void generateUMinus(IR::Expr *source, IR::Expr *target);
+    void generateNot(IR::Expr *source, IR::Expr *target);
+    void generateCompl(IR::Expr *source, IR::Expr *target);
 
     Assembler *as;
     IR::AluOp op;