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Mini Shell
Mini Shell
// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
namespace array {
// Continuation for lazy deopt triggered by allocation of the result array.
transitioning javascript builtin ArrayMapPreLoopLazyDeoptContinuation(
js-implicit context: NativeContext, receiver: JSAny)(callback: JSAny,
thisArg: JSAny, length: JSAny, result: JSAny): JSAny {
const jsreceiver = Cast<JSReceiver>(receiver) otherwise unreachable;
const outputArray = Cast<JSReceiver>(result) otherwise unreachable;
const numberLength = Cast<Number>(length) otherwise unreachable;
const callbackfn = Cast<Callable>(callback)
otherwise ThrowCalledNonCallable(callback);
return ArrayMapLoopContinuation(
jsreceiver, callbackfn, thisArg, outputArray, jsreceiver, kZero,
numberLength);
}
transitioning javascript builtin ArrayMapLoopEagerDeoptContinuation(
js-implicit context: NativeContext, receiver: JSAny)(callback: JSAny,
thisArg: JSAny, array: JSAny, initialK: JSAny, length: JSAny): JSAny {
const jsreceiver = Cast<JSReceiver>(receiver) otherwise unreachable;
const callbackfn = Cast<Callable>(callback) otherwise unreachable;
const outputArray = Cast<JSReceiver>(array) otherwise unreachable;
const numberK = Cast<Number>(initialK) otherwise unreachable;
const numberLength = Cast<Number>(length) otherwise unreachable;
return ArrayMapLoopContinuation(
jsreceiver, callbackfn, thisArg, outputArray, jsreceiver, numberK,
numberLength);
}
transitioning javascript builtin ArrayMapLoopLazyDeoptContinuation(
js-implicit context: NativeContext, receiver: JSAny)(callback: JSAny,
thisArg: JSAny, array: JSAny, initialK: JSAny, length: JSAny,
result: JSAny): JSAny {
const jsreceiver = Cast<JSReceiver>(receiver) otherwise unreachable;
const callbackfn = Cast<Callable>(callback) otherwise unreachable;
const outputArray = Cast<JSReceiver>(array) otherwise unreachable;
let numberK = Cast<Number>(initialK) otherwise unreachable;
const numberLength = Cast<Number>(length) otherwise unreachable;
// This custom lazy deopt point is right after the callback. The continuation
// needs to pick up at the next step, which is setting the callback result in
// the output array. After incrementing k, we can glide into the loop
// continuation builtin.
// iii. Perform ? CreateDataPropertyOrThrow(A, Pk, mappedValue).
FastCreateDataProperty(outputArray, numberK, result);
// 7d. Increase k by 1.
numberK = numberK + 1;
return ArrayMapLoopContinuation(
jsreceiver, callbackfn, thisArg, outputArray, jsreceiver, numberK,
numberLength);
}
transitioning builtin ArrayMapLoopContinuation(
implicit context: Context)(_receiver: JSReceiver, callbackfn: Callable,
thisArg: JSAny, array: JSReceiver, o: JSReceiver, initialK: Number,
length: Number): JSAny {
// 6. Let k be 0.
// 7. Repeat, while k < len
for (let k: Number = initialK; k < length; k++) {
// 7a. Let Pk be ! ToString(k).
// k is guaranteed to be a positive integer, hence ToString is
// side-effect free and HasProperty/GetProperty do the conversion inline.
// 7b. Let kPresent be ? HasProperty(O, Pk).
const kPresent: Boolean = HasProperty_Inline(o, k);
// 7c. If kPresent is true, then:
if (kPresent == True) {
// i. Let kValue be ? Get(O, Pk).
const kValue: JSAny = GetProperty(o, k);
// ii. Let mapped_value be ? Call(callbackfn, T, kValue, k, O).
const mappedValue: JSAny =
Call(context, callbackfn, thisArg, kValue, k, o);
// iii. Perform ? CreateDataPropertyOrThrow(A, Pk, mapped_value).
FastCreateDataProperty(array, k, mappedValue);
}
// 7d. Increase k by 1. (done by the loop).
}
// 8. Return A.
return array;
}
struct Vector {
macro ReportSkippedElement(): void {
this.skippedElements = true;
}
macro CreateJSArray(implicit context: Context)(validLength: Smi):
JSArray {
const length: Smi = this.fixedArray.length;
dcheck(validLength <= length);
let kind: ElementsKind = ElementsKind::PACKED_SMI_ELEMENTS;
if (!this.onlySmis) {
if (this.onlyNumbers) {
kind = ElementsKind::PACKED_DOUBLE_ELEMENTS;
} else {
kind = ElementsKind::PACKED_ELEMENTS;
}
}
if (this.skippedElements || validLength < length) {
// We also need to create a holey output array if we are
// bailing out of the fast path partway through the array.
// This is indicated by {validLength} < {length}.
// Who knows if the bailout condition will continue to fill in
// every element?
kind = FastHoleyElementsKind(kind);
}
const map: Map = LoadJSArrayElementsMap(kind, LoadNativeContext(context));
let a: JSArray;
if (IsDoubleElementsKind(kind)) {
// We need to allocate and copy.
// First, initialize the elements field before allocation to prevent
// heap corruption.
const elements: FixedDoubleArray =
AllocateFixedDoubleArrayWithHoles(SmiUntag(length));
a = NewJSArray(map, this.fixedArray);
for (let i: Smi = 0; i < validLength; i++) {
typeswitch (
UnsafeCast<(Number | TheHole)>(this.fixedArray.objects[i])) {
case (n: Number): {
elements.floats[i] = Convert<float64_or_hole>(n);
}
case (TheHole): {
}
}
}
a.elements = elements;
} else {
// Simply install the given fixedArray in {vector}.
a = NewJSArray(map, this.fixedArray);
}
// Paranoia. the FixedArray now "belongs" to JSArray {a}.
this.fixedArray = kEmptyFixedArray;
return a;
}
macro StoreResult(implicit context: Context)(index: Smi, result: JSAny):
void {
typeswitch (result) {
case (s: Smi): {
this.fixedArray.objects[index] = s;
}
case (s: HeapNumber): {
this.onlySmis = false;
this.fixedArray.objects[index] = s;
}
case (s: JSAnyNotNumber): {
this.onlySmis = false;
this.onlyNumbers = false;
this.fixedArray.objects[index] = s;
}
}
}
fixedArray: FixedArray;
onlySmis: bool; // initially true.
onlyNumbers: bool; // initially true.
skippedElements: bool; // initially false.
}
macro NewVector(implicit context: Context)(length: Smi): Vector {
const fixedArray = length > 0 ?
AllocateFixedArrayWithHoles(SmiUntag(length)) :
kEmptyFixedArray;
return Vector{
fixedArray,
onlySmis: true,
onlyNumbers: true,
skippedElements: false
};
}
transitioning macro FastArrayMap(
implicit context: Context)(fastO: FastJSArrayForRead, len: Smi,
callbackfn: Callable, thisArg: JSAny): JSArray
labels Bailout(JSArray, Smi) {
let k: Smi = 0;
let fastOW = NewFastJSArrayForReadWitness(fastO);
let vector = NewVector(len);
// Build a fast loop over the smi array.
// 7. Repeat, while k < len.
try {
for (; k < len; k++) {
fastOW.Recheck() otherwise goto PrepareBailout(k);
// Ensure that we haven't walked beyond a possibly updated length.
if (k >= fastOW.Get().length) goto PrepareBailout(k);
try {
const value: JSAny = fastOW.LoadElementNoHole(k)
otherwise FoundHole;
const result: JSAny =
Call(context, callbackfn, thisArg, value, k, fastOW.Get());
vector.StoreResult(k, result);
} label FoundHole {
// Our output array must necessarily be holey because of holes in
// the input array.
vector.ReportSkippedElement();
}
}
} label PrepareBailout(k: Smi) deferred {
// Transform {vector} into a JSArray and bail out.
goto Bailout(vector.CreateJSArray(k), k);
}
return vector.CreateJSArray(len);
}
// https://tc39.github.io/ecma262/#sec-array.prototype.map
transitioning javascript builtin ArrayMap(
js-implicit context: NativeContext, receiver: JSAny)(...arguments): JSAny {
try {
RequireObjectCoercible(receiver, 'Array.prototype.map');
// 1. Let O be ? ToObject(this value).
const o: JSReceiver = ToObject_Inline(context, receiver);
// 2. Let len be ? ToLength(? Get(O, "length")).
const len: Number = GetLengthProperty(o);
// 3. If IsCallable(callbackfn) is false, throw a TypeError exception.
if (arguments.length == 0) goto TypeError;
const callbackfn = Cast<Callable>(arguments[0]) otherwise TypeError;
// 4. If thisArg is present, let T be thisArg; else let T be undefined.
const thisArg: JSAny = arguments[1];
let array: JSReceiver;
let k: Number = 0;
try {
// 5. Let A be ? ArraySpeciesCreate(O, len).
if (IsArraySpeciesProtectorCellInvalid()) goto SlowSpeciesCreate;
const o: FastJSArrayForRead = Cast<FastJSArrayForRead>(receiver)
otherwise SlowSpeciesCreate;
const smiLength: Smi = Cast<Smi>(len)
otherwise SlowSpeciesCreate;
return FastArrayMap(o, smiLength, callbackfn, thisArg)
otherwise Bailout;
} label SlowSpeciesCreate {
array = ArraySpeciesCreate(context, receiver, len);
} label Bailout(output: JSArray, kValue: Smi) deferred {
array = output;
k = kValue;
}
return ArrayMapLoopContinuation(o, callbackfn, thisArg, array, o, k, len);
} label TypeError deferred {
ThrowCalledNonCallable(arguments[0]);
}
}
}
Zerion Mini Shell 1.0