michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "jit/BaselineInspector.h"
michael@0: 
michael@0: #include "mozilla/DebugOnly.h"
michael@0: 
michael@0: #include "jit/BaselineIC.h"
michael@0: 
michael@0: using namespace js;
michael@0: using namespace js::jit;
michael@0: 
michael@0: using mozilla::DebugOnly;
michael@0: 
michael@0: bool
michael@0: SetElemICInspector::sawOOBDenseWrite() const
michael@0: {
michael@0:     if (!icEntry_)
michael@0:         return false;
michael@0: 
michael@0:     // Check for a SetElem_DenseAdd stub.
michael@0:     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
michael@0:         if (stub->isSetElem_DenseAdd())
michael@0:             return true;
michael@0:     }
michael@0: 
michael@0:     // Check for a write hole bit on the SetElem_Fallback stub.
michael@0:     ICStub *stub = icEntry_->fallbackStub();
michael@0:     if (stub->isSetElem_Fallback())
michael@0:         return stub->toSetElem_Fallback()->hasArrayWriteHole();
michael@0: 
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: SetElemICInspector::sawOOBTypedArrayWrite() const
michael@0: {
michael@0:     if (!icEntry_)
michael@0:         return false;
michael@0: 
michael@0:     // Check for SetElem_TypedArray stubs with expectOutOfBounds set.
michael@0:     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
michael@0:         if (!stub->isSetElem_TypedArray())
michael@0:             continue;
michael@0:         if (stub->toSetElem_TypedArray()->expectOutOfBounds())
michael@0:             return true;
michael@0:     }
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: SetElemICInspector::sawDenseWrite() const
michael@0: {
michael@0:     if (!icEntry_)
michael@0:         return false;
michael@0: 
michael@0:     // Check for a SetElem_DenseAdd or SetElem_Dense stub.
michael@0:     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
michael@0:         if (stub->isSetElem_DenseAdd() || stub->isSetElem_Dense())
michael@0:             return true;
michael@0:     }
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: SetElemICInspector::sawTypedArrayWrite() const
michael@0: {
michael@0:     if (!icEntry_)
michael@0:         return false;
michael@0: 
michael@0:     // Check for a SetElem_TypedArray stub.
michael@0:     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
michael@0:         if (stub->isSetElem_TypedArray())
michael@0:             return true;
michael@0:     }
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::maybeShapesForPropertyOp(jsbytecode *pc, ShapeVector &shapes)
michael@0: {
michael@0:     // Return a list of shapes seen by the baseline IC for the current op.
michael@0:     // An empty list indicates no shapes are known, or there was an uncacheable
michael@0:     // access.
michael@0:     JS_ASSERT(shapes.empty());
michael@0: 
michael@0:     if (!hasBaselineScript())
michael@0:         return true;
michael@0: 
michael@0:     JS_ASSERT(isValidPC(pc));
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0: 
michael@0:     ICStub *stub = entry.firstStub();
michael@0:     while (stub->next()) {
michael@0:         Shape *shape;
michael@0:         if (stub->isGetProp_Native()) {
michael@0:             shape = stub->toGetProp_Native()->shape();
michael@0:         } else if (stub->isSetProp_Native()) {
michael@0:             shape = stub->toSetProp_Native()->shape();
michael@0:         } else {
michael@0:             shapes.clear();
michael@0:             return true;
michael@0:         }
michael@0: 
michael@0:         // Don't add the same shape twice (this can happen if there are multiple
michael@0:         // SetProp_Native stubs with different TypeObject's).
michael@0:         bool found = false;
michael@0:         for (size_t i = 0; i < shapes.length(); i++) {
michael@0:             if (shapes[i] == shape) {
michael@0:                 found = true;
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         if (!found && !shapes.append(shape))
michael@0:             return false;
michael@0: 
michael@0:         stub = stub->next();
michael@0:     }
michael@0: 
michael@0:     if (stub->isGetProp_Fallback()) {
michael@0:         if (stub->toGetProp_Fallback()->hadUnoptimizableAccess())
michael@0:             shapes.clear();
michael@0:     } else {
michael@0:         if (stub->toSetProp_Fallback()->hadUnoptimizableAccess())
michael@0:             shapes.clear();
michael@0:     }
michael@0: 
michael@0:     // Don't inline if there are more than 5 shapes.
michael@0:     if (shapes.length() > 5)
michael@0:         shapes.clear();
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: ICStub *
michael@0: BaselineInspector::monomorphicStub(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0: 
michael@0:     ICStub *stub = entry.firstStub();
michael@0:     ICStub *next = stub->next();
michael@0: 
michael@0:     if (!next || !next->isFallback())
michael@0:         return nullptr;
michael@0: 
michael@0:     return stub;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::dimorphicStub(jsbytecode *pc, ICStub **pfirst, ICStub **psecond)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return false;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0: 
michael@0:     ICStub *stub = entry.firstStub();
michael@0:     ICStub *next = stub->next();
michael@0:     ICStub *after = next ? next->next() : nullptr;
michael@0: 
michael@0:     if (!after || !after->isFallback())
michael@0:         return false;
michael@0: 
michael@0:     *pfirst = stub;
michael@0:     *psecond = next;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: MIRType
michael@0: BaselineInspector::expectedResultType(jsbytecode *pc)
michael@0: {
michael@0:     // Look at the IC entries for this op to guess what type it will produce,
michael@0:     // returning MIRType_None otherwise.
michael@0: 
michael@0:     ICStub *stub = monomorphicStub(pc);
michael@0:     if (!stub)
michael@0:         return MIRType_None;
michael@0: 
michael@0:     switch (stub->kind()) {
michael@0:       case ICStub::BinaryArith_Int32:
michael@0:         if (stub->toBinaryArith_Int32()->allowDouble())
michael@0:             return MIRType_Double;
michael@0:         return MIRType_Int32;
michael@0:       case ICStub::BinaryArith_BooleanWithInt32:
michael@0:       case ICStub::UnaryArith_Int32:
michael@0:       case ICStub::BinaryArith_DoubleWithInt32:
michael@0:         return MIRType_Int32;
michael@0:       case ICStub::BinaryArith_Double:
michael@0:       case ICStub::UnaryArith_Double:
michael@0:         return MIRType_Double;
michael@0:       case ICStub::BinaryArith_StringConcat:
michael@0:       case ICStub::BinaryArith_StringObjectConcat:
michael@0:         return MIRType_String;
michael@0:       default:
michael@0:         return MIRType_None;
michael@0:     }
michael@0: }
michael@0: 
michael@0: // Whether a baseline stub kind is suitable for a double comparison that
michael@0: // converts its operands to doubles.
michael@0: static bool
michael@0: CanUseDoubleCompare(ICStub::Kind kind)
michael@0: {
michael@0:     return kind == ICStub::Compare_Double || kind == ICStub::Compare_NumberWithUndefined;
michael@0: }
michael@0: 
michael@0: // Whether a baseline stub kind is suitable for an int32 comparison that
michael@0: // converts its operands to int32.
michael@0: static bool
michael@0: CanUseInt32Compare(ICStub::Kind kind)
michael@0: {
michael@0:     return kind == ICStub::Compare_Int32 || kind == ICStub::Compare_Int32WithBoolean;
michael@0: }
michael@0: 
michael@0: MCompare::CompareType
michael@0: BaselineInspector::expectedCompareType(jsbytecode *pc)
michael@0: {
michael@0:     ICStub *first = monomorphicStub(pc), *second = nullptr;
michael@0:     if (!first && !dimorphicStub(pc, &first, &second))
michael@0:         return MCompare::Compare_Unknown;
michael@0: 
michael@0:     if (CanUseInt32Compare(first->kind()) && (!second || CanUseInt32Compare(second->kind()))) {
michael@0:         ICCompare_Int32WithBoolean *coerce =
michael@0:             first->isCompare_Int32WithBoolean()
michael@0:             ? first->toCompare_Int32WithBoolean()
michael@0:             : ((second && second->isCompare_Int32WithBoolean())
michael@0:                ? second->toCompare_Int32WithBoolean()
michael@0:                : nullptr);
michael@0:         if (coerce) {
michael@0:             return coerce->lhsIsInt32()
michael@0:                    ? MCompare::Compare_Int32MaybeCoerceRHS
michael@0:                    : MCompare::Compare_Int32MaybeCoerceLHS;
michael@0:         }
michael@0:         return MCompare::Compare_Int32;
michael@0:     }
michael@0: 
michael@0:     if (CanUseDoubleCompare(first->kind()) && (!second || CanUseDoubleCompare(second->kind()))) {
michael@0:         ICCompare_NumberWithUndefined *coerce =
michael@0:             first->isCompare_NumberWithUndefined()
michael@0:             ? first->toCompare_NumberWithUndefined()
michael@0:             : (second && second->isCompare_NumberWithUndefined())
michael@0:               ? second->toCompare_NumberWithUndefined()
michael@0:               : nullptr;
michael@0:         if (coerce) {
michael@0:             return coerce->lhsIsUndefined()
michael@0:                    ? MCompare::Compare_DoubleMaybeCoerceLHS
michael@0:                    : MCompare::Compare_DoubleMaybeCoerceRHS;
michael@0:         }
michael@0:         return MCompare::Compare_Double;
michael@0:     }
michael@0: 
michael@0:     return MCompare::Compare_Unknown;
michael@0: }
michael@0: 
michael@0: static bool
michael@0: TryToSpecializeBinaryArithOp(ICStub **stubs,
michael@0:                              uint32_t nstubs,
michael@0:                              MIRType *result)
michael@0: {
michael@0:     DebugOnly<bool> sawInt32 = false;
michael@0:     bool sawDouble = false;
michael@0:     bool sawOther = false;
michael@0: 
michael@0:     for (uint32_t i = 0; i < nstubs; i++) {
michael@0:         switch (stubs[i]->kind()) {
michael@0:           case ICStub::BinaryArith_Int32:
michael@0:             sawInt32 = true;
michael@0:             break;
michael@0:           case ICStub::BinaryArith_BooleanWithInt32:
michael@0:             sawInt32 = true;
michael@0:             break;
michael@0:           case ICStub::BinaryArith_Double:
michael@0:             sawDouble = true;
michael@0:             break;
michael@0:           case ICStub::BinaryArith_DoubleWithInt32:
michael@0:             sawDouble = true;
michael@0:             break;
michael@0:           default:
michael@0:             sawOther = true;
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (sawOther)
michael@0:         return false;
michael@0: 
michael@0:     if (sawDouble) {
michael@0:         *result = MIRType_Double;
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0:     JS_ASSERT(sawInt32);
michael@0:     *result = MIRType_Int32;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: MIRType
michael@0: BaselineInspector::expectedBinaryArithSpecialization(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return MIRType_None;
michael@0: 
michael@0:     MIRType result;
michael@0:     ICStub *stubs[2];
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     ICStub *stub = entry.fallbackStub();
michael@0:     if (stub->isBinaryArith_Fallback() &&
michael@0:         stub->toBinaryArith_Fallback()->hadUnoptimizableOperands())
michael@0:     {
michael@0:         return MIRType_None;
michael@0:     }
michael@0: 
michael@0:     stubs[0] = monomorphicStub(pc);
michael@0:     if (stubs[0]) {
michael@0:         if (TryToSpecializeBinaryArithOp(stubs, 1, &result))
michael@0:             return result;
michael@0:     }
michael@0: 
michael@0:     if (dimorphicStub(pc, &stubs[0], &stubs[1])) {
michael@0:         if (TryToSpecializeBinaryArithOp(stubs, 2, &result))
michael@0:             return result;
michael@0:     }
michael@0: 
michael@0:     return MIRType_None;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::hasSeenNonNativeGetElement(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return false;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     ICStub *stub = entry.fallbackStub();
michael@0: 
michael@0:     if (stub->isGetElem_Fallback())
michael@0:         return stub->toGetElem_Fallback()->hasNonNativeAccess();
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::hasSeenNegativeIndexGetElement(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return false;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     ICStub *stub = entry.fallbackStub();
michael@0: 
michael@0:     if (stub->isGetElem_Fallback())
michael@0:         return stub->toGetElem_Fallback()->hasNegativeIndex();
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::hasSeenAccessedGetter(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return false;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     ICStub *stub = entry.fallbackStub();
michael@0: 
michael@0:     if (stub->isGetProp_Fallback())
michael@0:         return stub->toGetProp_Fallback()->hasAccessedGetter();
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::hasSeenNonStringIterNext(jsbytecode *pc)
michael@0: {
michael@0:     JS_ASSERT(JSOp(*pc) == JSOP_ITERNEXT);
michael@0: 
michael@0:     if (!hasBaselineScript())
michael@0:         return false;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     ICStub *stub = entry.fallbackStub();
michael@0: 
michael@0:     return stub->toIteratorNext_Fallback()->hasNonStringResult();
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineInspector::hasSeenDoubleResult(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return false;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     ICStub *stub = entry.fallbackStub();
michael@0: 
michael@0:     JS_ASSERT(stub->isUnaryArith_Fallback() || stub->isBinaryArith_Fallback());
michael@0: 
michael@0:     if (stub->isUnaryArith_Fallback())
michael@0:         return stub->toUnaryArith_Fallback()->sawDoubleResult();
michael@0:     else
michael@0:         return stub->toBinaryArith_Fallback()->sawDoubleResult();
michael@0: 
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: JSObject *
michael@0: BaselineInspector::getTemplateObject(jsbytecode *pc)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
michael@0:         switch (stub->kind()) {
michael@0:           case ICStub::NewArray_Fallback:
michael@0:             return stub->toNewArray_Fallback()->templateObject();
michael@0:           case ICStub::NewObject_Fallback:
michael@0:             return stub->toNewObject_Fallback()->templateObject();
michael@0:           case ICStub::Rest_Fallback:
michael@0:             return stub->toRest_Fallback()->templateObject();
michael@0:           case ICStub::Call_Scripted:
michael@0:             if (JSObject *obj = stub->toCall_Scripted()->templateObject())
michael@0:                 return obj;
michael@0:             break;
michael@0:           default:
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     return nullptr;
michael@0: }
michael@0: 
michael@0: JSObject *
michael@0: BaselineInspector::getTemplateObjectForNative(jsbytecode *pc, Native native)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
michael@0:         if (stub->isCall_Native() && stub->toCall_Native()->callee()->native() == native)
michael@0:             return stub->toCall_Native()->templateObject();
michael@0:     }
michael@0: 
michael@0:     return nullptr;
michael@0: }
michael@0: 
michael@0: DeclEnvObject *
michael@0: BaselineInspector::templateDeclEnvObject()
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     JSObject *res = &templateCallObject()->as<ScopeObject>().enclosingScope();
michael@0:     JS_ASSERT(res);
michael@0: 
michael@0:     return &res->as<DeclEnvObject>();
michael@0: }
michael@0: 
michael@0: CallObject *
michael@0: BaselineInspector::templateCallObject()
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     JSObject *res = baselineScript()->templateScope();
michael@0:     JS_ASSERT(res);
michael@0: 
michael@0:     return &res->as<CallObject>();
michael@0: }
michael@0: 
michael@0: JSObject *
michael@0: BaselineInspector::commonGetPropFunction(jsbytecode *pc, Shape **lastProperty, JSFunction **commonGetter)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
michael@0:         if (stub->isGetProp_CallScripted()  ||
michael@0:             stub->isGetProp_CallNative()    ||
michael@0:             stub->isGetProp_CallNativePrototype())
michael@0:         {
michael@0:             ICGetPropCallGetter *nstub = static_cast<ICGetPropCallGetter *>(stub);
michael@0:             *lastProperty = nstub->holderShape();
michael@0:             *commonGetter = nstub->getter();
michael@0:             return nstub->holder();
michael@0:         }
michael@0:     }
michael@0:     return nullptr;
michael@0: }
michael@0: 
michael@0: JSObject *
michael@0: BaselineInspector::commonSetPropFunction(jsbytecode *pc, Shape **lastProperty, JSFunction **commonSetter)
michael@0: {
michael@0:     if (!hasBaselineScript())
michael@0:         return nullptr;
michael@0: 
michael@0:     const ICEntry &entry = icEntryFromPC(pc);
michael@0:     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
michael@0:         if (stub->isSetProp_CallScripted() || stub->isSetProp_CallNative()) {
michael@0:             ICSetPropCallSetter *nstub = static_cast<ICSetPropCallSetter *>(stub);
michael@0:             *lastProperty = nstub->holderShape();
michael@0:             *commonSetter = nstub->setter();
michael@0:             return nstub->holder();
michael@0:         }
michael@0:     }
michael@0:     return nullptr;
michael@0: }