C++ SimdConstant类代码示例

void
MacroAssemblerX86::loadConstantFloat32x4(const SimdConstant &v, FloatRegister dest)
{
    MOZ_ASSERT(v.type() == SimdConstant::Float32x4);
    if (maybeInlineFloat32x4(v, dest))
        return;
    SimdData *f4 = getSimdData(v);
    if (!f4)
        return;
    MOZ_ASSERT(f4->type() == SimdConstant::Float32x4);
    masm.movaps_mr(reinterpret_cast<const void *>(f4->uses.prev()), dest.code());
    f4->uses.setPrev(masm.size());
}

void
MacroAssemblerX86::loadConstantInt32x4(const SimdConstant& v, FloatRegister dest)
{
    MOZ_ASSERT(v.type() == SimdConstant::Int32x4);
    if (maybeInlineInt32x4(v, dest))
        return;
    SimdData* i4 = getSimdData(v);
    if (!i4)
        return;
    MOZ_ASSERT(i4->type() == SimdConstant::Int32x4);
    masm.vmovdqa_mr(reinterpret_cast<const void*>(i4->uses.prev()), dest.code());
    i4->uses.setPrev(masm.size());
}

void
MacroAssemblerX64::loadConstantFloat32x4(const SimdConstant&v, FloatRegister dest)
{
    MOZ_ASSERT(v.type() == SimdConstant::Float32x4);
    if (maybeInlineFloat32x4(v, dest))
        return;
    SimdData* val = getSimdData(v);
    if (!val)
        return;
    MOZ_ASSERT(val->type() == SimdConstant::Float32x4);
    JmpSrc j = masm.vmovaps_ripr(dest.encoding());
    propagateOOM(val->uses.append(CodeOffset(j.offset())));
}

void
MacroAssemblerX86::loadConstantFloat32x4(const SimdConstant& v, FloatRegister dest)
{
    MOZ_ASSERT(v.type() == SimdConstant::Float32x4);
    if (maybeInlineFloat32x4(v, dest))
        return;
    SimdData* f4 = getSimdData(v);
    if (!f4)
        return;
    MOZ_ASSERT(f4->type() == SimdConstant::Float32x4);
    masm.vmovaps_mr(nullptr, dest.encoding());
    propagateOOM(f4->uses.append(CodeOffset(masm.size())));
}

void
MacroAssemblerX64::loadConstantFloat32x4(const SimdConstant&v, FloatRegister dest)
{
    MOZ_ASSERT(v.type() == SimdConstant::Float32x4);
    if (maybeInlineFloat32x4(v, dest))
        return;
    SimdData* val = getSimdData(v);
    if (!val)
        return;
    MOZ_ASSERT(val->type() == SimdConstant::Float32x4);
    JmpSrc j = masm.vmovaps_ripr(dest.encoding());
    JmpSrc prev = JmpSrc(val->uses.use(j.offset()));
    masm.setNextJump(j, prev);
}

// This is the js::Native for functions exported by an asm.js module.
static bool
CallAsmJS(JSContext *cx, unsigned argc, Value *vp)
{
    CallArgs callArgs = CallArgsFromVp(argc, vp);
    RootedFunction callee(cx, &callArgs.callee().as<JSFunction>());
    AsmJSModule &module = FunctionToEnclosingModule(callee);
    const AsmJSModule::ExportedFunction &func = FunctionToExportedFunction(callee, module);

    // The heap-changing function is a special-case and is implemented by C++.
    if (func.isChangeHeap())
        return ChangeHeap(cx, module, callArgs);

    // Enable/disable profiling in the asm.js module to match the current global
    // profiling state. Don't do this if the module is already active on the
    // stack since this would leave the module in a state where profiling is
    // enabled but the stack isn't unwindable.
    if (module.profilingEnabled() != cx->runtime()->spsProfiler.enabled() && !module.active())
        module.setProfilingEnabled(cx->runtime()->spsProfiler.enabled(), cx);

    // The calling convention for an external call into asm.js is to pass an
    // array of 16-byte values where each value contains either a coerced int32
    // (in the low word), a double value (in the low dword) or a SIMD vector
    // value, with the coercions specified by the asm.js signature. The
    // external entry point unpacks this array into the system-ABI-specified
    // registers and stack memory and then calls into the internal entry point.
    // The return value is stored in the first element of the array (which,
    // therefore, must have length >= 1).
    js::Vector<AsmJSModule::EntryArg, 8> coercedArgs(cx);
    if (!coercedArgs.resize(Max<size_t>(1, func.numArgs())))
        return false;

    RootedValue v(cx);
    for (unsigned i = 0; i < func.numArgs(); ++i) {
        v = i < callArgs.length() ? callArgs[i] : UndefinedValue();
        switch (func.argCoercion(i)) {
        case AsmJS_ToInt32:
            if (!ToInt32(cx, v, (int32_t*)&coercedArgs[i]))
                return false;
            break;
        case AsmJS_ToNumber:
            if (!ToNumber(cx, v, (double*)&coercedArgs[i]))
                return false;
            break;
        case AsmJS_FRound:
            if (!RoundFloat32(cx, v, (float *)&coercedArgs[i]))
                return false;
            break;
        case AsmJS_ToInt32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Int32x4>(cx, v, &simd))
                return false;
            memcpy(&coercedArgs[i], simd.asInt32x4(), Simd128DataSize);
            break;
        }
        case AsmJS_ToFloat32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Float32x4>(cx, v, &simd))
                return false;
            memcpy(&coercedArgs[i], simd.asFloat32x4(), Simd128DataSize);
            break;
        }
        }
    }

    // The correct way to handle this situation would be to allocate a new range
    // of PROT_NONE memory and module.changeHeap to this memory. That would
    // cause every access to take the out-of-bounds signal-handler path which
    // does the right thing. For now, just throw an out-of-memory exception
    // since these can technically pop out anywhere and the full fix may
    // actually OOM when trying to allocate the PROT_NONE memory.
    if (module.hasDetachedHeap()) {
        JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_OUT_OF_MEMORY);
        return false;
    }

    {
        // Push an AsmJSActivation to describe the asm.js frames we're about to
        // push when running this module. Additionally, push a JitActivation so
        // that the optimized asm.js-to-Ion FFI call path (which we want to be
        // very fast) can avoid doing so. The JitActivation is marked as
        // inactive so stack iteration will skip over it.
        AsmJSActivation activation(cx, module);
        JitActivation jitActivation(cx, /* active */ false);

        // Call the per-exported-function trampoline created by GenerateEntry.
        AsmJSModule::CodePtr enter = module.entryTrampoline(func);
        if (!CALL_GENERATED_2(enter, coercedArgs.begin(), module.globalData()))
            return false;
    }

    if (callArgs.isConstructing()) {
        // By spec, when a function is called as a constructor and this function
        // returns a primary type, which is the case for all asm.js exported
        // functions, the returned value is discarded and an empty object is
        // returned instead.
        PlainObject *obj = NewBuiltinClassInstance<PlainObject>(cx);
        callArgs.rval().set(ObjectValue(*obj));
        return true;
    }
//.........这里部分代码省略.........

static bool
ValidateGlobalVariable(JSContext *cx, const AsmJSModule &module, AsmJSModule::Global &global,
                       HandleValue importVal)
{
    MOZ_ASSERT(global.which() == AsmJSModule::Global::Variable);

    void *datum = module.globalVarToGlobalDatum(global);

    switch (global.varInitKind()) {
    case AsmJSModule::Global::InitConstant: {
        const AsmJSNumLit &lit = global.varInitNumLit();
        switch (lit.which()) {
        case AsmJSNumLit::Fixnum:
        case AsmJSNumLit::NegativeInt:
        case AsmJSNumLit::BigUnsigned:
            *(int32_t *)datum = lit.scalarValue().toInt32();
            break;
        case AsmJSNumLit::Double:
            *(double *)datum = lit.scalarValue().toDouble();
            break;
        case AsmJSNumLit::Float:
            *(float *)datum = static_cast<float>(lit.scalarValue().toDouble());
            break;
        case AsmJSNumLit::Int32x4:
            memcpy(datum, lit.simdValue().asInt32x4(), Simd128DataSize);
            break;
        case AsmJSNumLit::Float32x4:
            memcpy(datum, lit.simdValue().asFloat32x4(), Simd128DataSize);
            break;
        case AsmJSNumLit::OutOfRangeInt:
            MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("OutOfRangeInt isn't valid in the first place");
        }
        break;
    }

    case AsmJSModule::Global::InitImport: {
        RootedPropertyName field(cx, global.varImportField());
        RootedValue v(cx);
        if (!GetDataProperty(cx, importVal, field, &v))
            return false;

        if (!v.isPrimitive() && !HasPureCoercion(cx, v))
            return LinkFail(cx, "Imported values must be primitives");

        SimdConstant simdConstant;
        switch (global.varInitCoercion()) {
        case AsmJS_ToInt32:
            if (!ToInt32(cx, v, (int32_t *)datum))
                return false;
            break;
        case AsmJS_ToNumber:
            if (!ToNumber(cx, v, (double *)datum))
                return false;
            break;
        case AsmJS_FRound:
            if (!RoundFloat32(cx, v, (float *)datum))
                return false;
            break;
        case AsmJS_ToInt32x4:
            if (!ToSimdConstant<Int32x4>(cx, v, &simdConstant))
                return false;
            memcpy(datum, simdConstant.asInt32x4(), Simd128DataSize);
            break;
        case AsmJS_ToFloat32x4:
            if (!ToSimdConstant<Float32x4>(cx, v, &simdConstant))
                return false;
            memcpy(datum, simdConstant.asFloat32x4(), Simd128DataSize);
            break;
        }
        break;
    }
    }

    return true;
}

bool
Module::callExport(JSContext* cx, uint32_t exportIndex, CallArgs args)
{
    MOZ_ASSERT(dynamicallyLinked_);

    const Export& exp = exports()[exportIndex];

    // Enable/disable profiling in the Module to match the current global
    // profiling state. Don't do this if the Module is already active on the
    // stack since this would leave the Module in a state where profiling is
    // enabled but the stack isn't unwindable.
    if (profilingEnabled() != cx->runtime()->spsProfiler.enabled() && !activation()) {
        if (!setProfilingEnabled(cx, cx->runtime()->spsProfiler.enabled()))
            return false;
    }

    // The calling convention for an external call into wasm is to pass an
    // array of 16-byte values where each value contains either a coerced int32
    // (in the low word), a double value (in the low dword) or a SIMD vector
    // value, with the coercions specified by the wasm signature. The external
    // entry point unpacks this array into the system-ABI-specified registers
    // and stack memory and then calls into the internal entry point. The return
    // value is stored in the first element of the array (which, therefore, must
    // have length >= 1).
    Vector<Module::EntryArg, 8> coercedArgs(cx);
    if (!coercedArgs.resize(Max<size_t>(1, exp.sig().args().length())))
        return false;

    RootedValue v(cx);
    for (unsigned i = 0; i < exp.sig().args().length(); ++i) {
        v = i < args.length() ? args[i] : UndefinedValue();
        switch (exp.sig().arg(i)) {
          case ValType::I32:
            if (!ToInt32(cx, v, (int32_t*)&coercedArgs[i]))
                return false;
            break;
          case ValType::I64:
            MOZ_CRASH("int64");
          case ValType::F32:
            if (!RoundFloat32(cx, v, (float*)&coercedArgs[i]))
                return false;
            break;
          case ValType::F64:
            if (!ToNumber(cx, v, (double*)&coercedArgs[i]))
                return false;
            break;
          case ValType::I32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Int32x4>(cx, v, &simd))
                return false;
            memcpy(&coercedArgs[i], simd.asInt32x4(), Simd128DataSize);
            break;
          }
          case ValType::F32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Float32x4>(cx, v, &simd))
                return false;
            memcpy(&coercedArgs[i], simd.asFloat32x4(), Simd128DataSize);
            break;
          }
          case ValType::B32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Bool32x4>(cx, v, &simd))
                return false;
            // Bool32x4 uses the same representation as Int32x4.
            memcpy(&coercedArgs[i], simd.asInt32x4(), Simd128DataSize);
            break;
          }
          case ValType::Limit:
            MOZ_CRASH("Limit");
        }
    }

    {
        // Push a WasmActivation to describe the wasm frames we're about to push
        // when running this module. Additionally, push a JitActivation so that
        // the optimized wasm-to-Ion FFI call path (which we want to be very
        // fast) can avoid doing so. The JitActivation is marked as inactive so
        // stack iteration will skip over it.
        WasmActivation activation(cx, *this);
        JitActivation jitActivation(cx, /* active */ false);

        // Call the per-exported-function trampoline created by GenerateEntry.
        auto entry = JS_DATA_TO_FUNC_PTR(EntryFuncPtr, code() + exp.stubOffset());
        if (!CALL_GENERATED_2(entry, coercedArgs.begin(), globalData()))
            return false;
    }

    if (args.isConstructing()) {
        // By spec, when a function is called as a constructor and this function
        // returns a primary type, which is the case for all wasm exported
        // functions, the returned value is discarded and an empty object is
        // returned instead.
        PlainObject* obj = NewBuiltinClassInstance<PlainObject>(cx);
        if (!obj)
            return false;
        args.rval().set(ObjectValue(*obj));
        return true;
    }

//.........这里部分代码省略.........

bool
Instance::callExport(JSContext* cx, uint32_t funcIndex, CallArgs args)
{
    if (!cx->compartment()->wasm.ensureProfilingState(cx))
        return false;

    const FuncExport& func = metadata().lookupFuncExport(funcIndex);

    // The calling convention for an external call into wasm is to pass an
    // array of 16-byte values where each value contains either a coerced int32
    // (in the low word), a double value (in the low dword) or a SIMD vector
    // value, with the coercions specified by the wasm signature. The external
    // entry point unpacks this array into the system-ABI-specified registers
    // and stack memory and then calls into the internal entry point. The return
    // value is stored in the first element of the array (which, therefore, must
    // have length >= 1).
    Vector<ExportArg, 8> exportArgs(cx);
    if (!exportArgs.resize(Max<size_t>(1, func.sig().args().length())))
        return false;

    RootedValue v(cx);
    for (unsigned i = 0; i < func.sig().args().length(); ++i) {
        v = i < args.length() ? args[i] : UndefinedValue();
        switch (func.sig().arg(i)) {
          case ValType::I32:
            if (!ToInt32(cx, v, (int32_t*)&exportArgs[i]))
                return false;
            break;
          case ValType::I64:
            if (!JitOptions.wasmTestMode) {
                JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_WASM_BAD_I64);
                return false;
            }
            if (!ReadI64Object(cx, v, (int64_t*)&exportArgs[i]))
                return false;
            break;
          case ValType::F32:
            if (JitOptions.wasmTestMode && v.isObject()) {
                if (!ReadCustomFloat32NaNObject(cx, v, (float*)&exportArgs[i]))
                    return false;
                break;
            }
            if (!RoundFloat32(cx, v, (float*)&exportArgs[i]))
                return false;
            break;
          case ValType::F64:
            if (JitOptions.wasmTestMode && v.isObject()) {
                if (!ReadCustomDoubleNaNObject(cx, v, (double*)&exportArgs[i]))
                    return false;
                break;
            }
            if (!ToNumber(cx, v, (double*)&exportArgs[i]))
                return false;
            break;
          case ValType::I8x16: {
            SimdConstant simd;
            if (!ToSimdConstant<Int8x16>(cx, v, &simd))
                return false;
            memcpy(&exportArgs[i], simd.asInt8x16(), Simd128DataSize);
            break;
          }
          case ValType::I16x8: {
            SimdConstant simd;
            if (!ToSimdConstant<Int16x8>(cx, v, &simd))
                return false;
            memcpy(&exportArgs[i], simd.asInt16x8(), Simd128DataSize);
            break;
          }
          case ValType::I32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Int32x4>(cx, v, &simd))
                return false;
            memcpy(&exportArgs[i], simd.asInt32x4(), Simd128DataSize);
            break;
          }
          case ValType::F32x4: {
            SimdConstant simd;
            if (!ToSimdConstant<Float32x4>(cx, v, &simd))
                return false;
            memcpy(&exportArgs[i], simd.asFloat32x4(), Simd128DataSize);
            break;
          }
          case ValType::B8x16: {
            SimdConstant simd;
            if (!ToSimdConstant<Bool8x16>(cx, v, &simd))
                return false;
            // Bool8x16 uses the same representation as Int8x16.
            memcpy(&exportArgs[i], simd.asInt8x16(), Simd128DataSize);
            break;
          }
          case ValType::B16x8: {
            SimdConstant simd;
            if (!ToSimdConstant<Bool16x8>(cx, v, &simd))
                return false;
            // Bool16x8 uses the same representation as Int16x8.
            memcpy(&exportArgs[i], simd.asInt16x8(), Simd128DataSize);
            break;
          }
          case ValType::B32x4: {
            SimdConstant simd;
//.........这里部分代码省略.........

static bool
ValidateGlobalVariable(JSContext* cx, const AsmJSModule& module, AsmJSModule::Global& global,
                       HandleValue importVal)
{
    void* datum = module.globalData() + global.varGlobalDataOffset();

    switch (global.varInitKind()) {
      case AsmJSModule::Global::InitConstant: {
        Val v = global.varInitVal();
        switch (v.type()) {
          case ValType::I32:
            *(int32_t*)datum = v.i32();
            break;
          case ValType::I64:
            MOZ_CRASH("int64");
          case ValType::F32:
            *(float*)datum = v.f32();
            break;
          case ValType::F64:
            *(double*)datum = v.f64();
            break;
          case ValType::I32x4:
            memcpy(datum, v.i32x4(), Simd128DataSize);
            break;
          case ValType::F32x4:
            memcpy(datum, v.f32x4(), Simd128DataSize);
            break;
        }
        break;
      }

      case AsmJSModule::Global::InitImport: {
        RootedPropertyName field(cx, global.varImportField());
        RootedValue v(cx);
        if (!GetDataProperty(cx, importVal, field, &v))
            return false;

        if (!v.isPrimitive() && !HasPureCoercion(cx, v))
            return LinkFail(cx, "Imported values must be primitives");

        switch (global.varInitImportType()) {
          case ValType::I32:
            if (!ToInt32(cx, v, (int32_t*)datum))
                return false;
            break;
          case ValType::I64:
            MOZ_CRASH("int64");
          case ValType::F32:
            if (!RoundFloat32(cx, v, (float*)datum))
                return false;
            break;
          case ValType::F64:
            if (!ToNumber(cx, v, (double*)datum))
                return false;
            break;
          case ValType::I32x4: {
            SimdConstant simdConstant;
            if (!ToSimdConstant<Int32x4>(cx, v, &simdConstant))
                return false;
            memcpy(datum, simdConstant.asInt32x4(), Simd128DataSize);
            break;
          }
          case ValType::F32x4: {
            SimdConstant simdConstant;
            if (!ToSimdConstant<Float32x4>(cx, v, &simdConstant))
                return false;
            memcpy(datum, simdConstant.asFloat32x4(), Simd128DataSize);
            break;
          }
        }
        break;
      }
    }

    return true;
}