1// Copyright 2018 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5namespace array {
6transitioning javascript builtin
7ArrayReducePreLoopEagerDeoptContinuation(
8    js-implicit context: NativeContext, receiver: JSAny)(
9    callback: JSAny, length: JSAny): JSAny {
10  // All continuation points in the optimized every implementation are
11  // after the ToObject(O) call that ensures we are dealing with a
12  // JSReceiver.
13  //
14  // Also, this great mass of casts is necessary because the signature
15  // of Torque javascript builtins requires JSAny type for all parameters
16  // other than {context}.
17  const jsreceiver = Cast<JSReceiver>(receiver) otherwise unreachable;
18  const callbackfn = Cast<Callable>(callback) otherwise unreachable;
19  const numberLength = Cast<Number>(length) otherwise unreachable;
20
21  // Simulate starting the loop at 0, but ensuring that the accumulator is
22  // the hole. The continuation stub will search for the initial non-hole
23  // element, rightly throwing an exception if not found.
24  return ArrayReduceLoopContinuation(
25      jsreceiver, callbackfn, TheHole, jsreceiver, 0, numberLength);
26}
27
28transitioning javascript builtin
29ArrayReduceLoopEagerDeoptContinuation(
30    js-implicit context: NativeContext, receiver: JSAny)(
31    callback: JSAny, initialK: JSAny, length: JSAny,
32    accumulator: JSAny): JSAny {
33  // All continuation points in the optimized every implementation are
34  // after the ToObject(O) call that ensures we are dealing with a
35  // JSReceiver.
36  //
37  // Also, this great mass of casts is necessary because the signature
38  // of Torque javascript builtins requires JSAny type for all parameters
39  // other than {context}.
40  const jsreceiver = Cast<JSReceiver>(receiver) otherwise unreachable;
41  const callbackfn = Cast<Callable>(callback) otherwise unreachable;
42  const numberK = Cast<Number>(initialK) otherwise unreachable;
43  const numberLength = Cast<Number>(length) otherwise unreachable;
44
45  return ArrayReduceLoopContinuation(
46      jsreceiver, callbackfn, accumulator, jsreceiver, numberK, numberLength);
47}
48
49transitioning javascript builtin
50ArrayReduceLoopLazyDeoptContinuation(
51    js-implicit context: NativeContext, receiver: JSAny)(
52    callback: JSAny, initialK: JSAny, length: JSAny, result: JSAny): JSAny {
53  // All continuation points in the optimized every implementation are
54  // after the ToObject(O) call that ensures we are dealing with a
55  // JSReceiver.
56  const jsreceiver = Cast<JSReceiver>(receiver) otherwise unreachable;
57  const callbackfn = Cast<Callable>(callback) otherwise unreachable;
58  const numberK = Cast<Number>(initialK) otherwise unreachable;
59  const numberLength = Cast<Number>(length) otherwise unreachable;
60
61  // The accumulator is the result from the callback call which just occured.
62  const r = ArrayReduceLoopContinuation(
63      jsreceiver, callbackfn, result, jsreceiver, numberK, numberLength);
64  return r;
65}
66
67transitioning builtin ArrayReduceLoopContinuation(implicit context: Context)(
68    _receiver: JSReceiver, callbackfn: Callable,
69    initialAccumulator: JSAny|TheHole, o: JSReceiver, initialK: Number,
70    length: Number): JSAny {
71  let accumulator = initialAccumulator;
72
73  // 8b and 9. Repeat, while k < len
74  for (let k: Number = initialK; k < length; k++) {
75    // 8b i and 9a. Let Pk be ! ToString(k).
76    // k is guaranteed to be a positive integer, hence ToString is
77    // side-effect free and HasProperty/GetProperty do the conversion inline.
78
79    // 8b ii and 9b. Set kPresent to ? HasProperty(O, Pk).
80    const present: Boolean = HasProperty_Inline(o, k);
81
82    // 6c. If kPresent is true, then
83    if (present == True) {
84      // 6c. i. Let kValue be ? Get(O, Pk).
85      const value: JSAny = GetProperty(o, k);
86
87      typeswitch (accumulator) {
88        case (TheHole): {
89          // 8b.
90          accumulator = value;
91        }
92        case (accumulatorNotHole: JSAny): {
93          // 9c. ii. Set accumulator to ? Call(callbackfn, undefined,
94          //         <accumulator, kValue, k, O>).
95          accumulator = Call(
96              context, callbackfn, Undefined, accumulatorNotHole, value, k, o);
97        }
98      }
99    }
100
101    // 8b iv and 9d. Increase k by 1. (done by the loop).
102  }
103
104  // 8c. if kPresent is false, throw a TypeError exception.
105  // If the accumulator is discovered with the sentinel hole value,
106  // this means kPresent is false.
107  typeswitch (accumulator) {
108    case (TheHole): {
109      ThrowTypeError(
110          MessageTemplate::kReduceNoInitial, 'Array.prototype.reduce');
111    }
112    case (accumulator: JSAny): {
113      return accumulator;
114    }
115  }
116}
117
118transitioning macro FastArrayReduce(implicit context: Context)(
119    o: JSReceiver, len: Number, callbackfn: Callable,
120    initialAccumulator: JSAny|TheHole): JSAny
121    labels Bailout(Number, JSAny | TheHole) {
122  const k = 0;
123  let accumulator = initialAccumulator;
124  Cast<Smi>(len) otherwise goto Bailout(k, accumulator);
125  const fastO =
126      Cast<FastJSArrayForRead>(o) otherwise goto Bailout(k, accumulator);
127  let fastOW = NewFastJSArrayForReadWitness(fastO);
128
129  // Build a fast loop over the array.
130  for (let k: Smi = 0; k < len; k++) {
131    fastOW.Recheck() otherwise goto Bailout(k, accumulator);
132
133    // Ensure that we haven't walked beyond a possibly updated length.
134    if (k >= fastOW.Get().length) goto Bailout(k, accumulator);
135
136    const value: JSAny = fastOW.LoadElementNoHole(k) otherwise continue;
137    typeswitch (accumulator) {
138      case (TheHole): {
139        accumulator = value;
140      }
141      case (accumulatorNotHole: JSAny): {
142        accumulator = Call(
143            context, callbackfn, Undefined, accumulatorNotHole, value, k,
144            fastOW.Get());
145      }
146    }
147  }
148  typeswitch (accumulator) {
149    case (TheHole): {
150      ThrowTypeError(
151          MessageTemplate::kReduceNoInitial, 'Array.prototype.reduce');
152    }
153    case (accumulator: JSAny): {
154      return accumulator;
155    }
156  }
157}
158
159// https://tc39.github.io/ecma262/#sec-array.prototype.reduce
160transitioning javascript builtin
161ArrayReduce(
162    js-implicit context: NativeContext, receiver: JSAny)(...arguments): JSAny {
163  try {
164    RequireObjectCoercible(receiver, 'Array.prototype.reduce');
165
166    // 1. Let O be ? ToObject(this value).
167    const o: JSReceiver = ToObject_Inline(context, receiver);
168
169    // 2. Let len be ? ToLength(? Get(O, "length")).
170    const len: Number = GetLengthProperty(o);
171
172    // 3. If IsCallable(callbackfn) is false, throw a TypeError exception.
173    if (arguments.length == 0) {
174      goto NoCallableError;
175    }
176    const callbackfn = Cast<Callable>(arguments[0]) otherwise NoCallableError;
177
178    // 4. If len is 0 and initialValue is not present, throw a TypeError
179    // exception. (This case is handled at the end of
180    // ArrayReduceLoopContinuation).
181
182    const initialValue: JSAny|TheHole =
183        arguments.length > 1 ? arguments[1] : TheHole;
184
185    try {
186      return FastArrayReduce(o, len, callbackfn, initialValue)
187          otherwise Bailout;
188    } label Bailout(value: Number, accumulator: JSAny|TheHole) {
189      return ArrayReduceLoopContinuation(
190          o, callbackfn, accumulator, o, value, len);
191    }
192  } label NoCallableError deferred {
193    ThrowTypeError(MessageTemplate::kCalledNonCallable, arguments[0]);
194  }
195}
196}
197