| // Copyright (C) 2016 the V8 project authors. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| /*--- |
| esid: sec-integer-indexed-exotic-objects-defineownproperty-p-desc |
| description: Consistent canonicalization of NaN values |
| info: | |
| This test does not compare the actual byte values, instead it simply checks that |
| the value is some valid NaN encoding. |
| |
| --- |
| |
| [[DefineOwnProperty]] ( P, Desc) |
| |
| ... |
| 3. If Type(P) is String, then |
| ... |
| b. If numericIndex is not undefined, then |
| ... |
| xi. If Desc has a [[Value]] field, then |
| 1. Let value be Desc.[[Value]]. |
| 2. Return ? IntegerIndexedElementSet(O, intIndex, value). |
| ... |
| |
| #sec-integerindexedelementset |
| IntegerIndexedElementSet ( O, index, value ) |
| |
| ... |
| 15. Perform SetValueInBuffer(buffer, indexedPosition, elementType, numValue). |
| ... |
| |
| #sec-setvalueinbuffer |
| SetValueInBuffer ( arrayBuffer, byteIndex, type, value [ , |
| isLittleEndian ] ) |
| |
| 8. Let rawBytes be NumberToRawBytes(type, value, isLittleEndian). |
| |
| #sec-numbertorawbytes |
| NumberToRawBytes( type, value, isLittleEndian ) |
| |
| 1. If type is "Float32", then |
| a. Set rawBytes to a List containing the 4 bytes that are the result |
| of converting value to IEEE 754-2008 binary32 format using “Round to |
| nearest, ties to even” rounding mode. If isLittleEndian is false, the |
| bytes are arranged in big endian order. Otherwise, the bytes are |
| arranged in little endian order. If value is NaN, rawValue may be set |
| to any implementation chosen IEEE 754-2008 binary64 format Not-a-Number |
| encoding. An implementation must always choose either the same encoding |
| for each implementation distinguishable *NaN* value, or an |
| implementation-defined canonical value. |
| 2. Else, if type is "Float64", then |
| a. Set _rawBytes_ to a List containing the 8 bytes that are the IEEE |
| 754-2008 binary64 format encoding of _value_. If _isLittleEndian_ is |
| *false*, the bytes are arranged in big endian order. Otherwise, |
| the bytes are arranged in little endian order. If _value_ is *NaN*, |
| _rawValue_ may be set to any implementation chosen IEEE 754-2008 |
| binary64 format Not-a-Number encoding. An implementation must |
| always choose either the same encoding for each implementation |
| distinguishable *NaN* value, or an implementation-defined |
| canonical value. |
| ... |
| |
| #sec-isnan-number |
| |
| NOTE: A reliable way for ECMAScript code to test if a value X is a NaN is |
| an expression of the form X !== X. The result will be true if and only |
| if X is a NaN. |
| includes: [nans.js, testTypedArray.js] |
| features: [TypedArray] |
| ---*/ |
| |
| testWithTypedArrayConstructors(function(FA) { |
| var precision = FA === Float32Array ? "single" : "double"; |
| var samples = new FA(1); |
| var controls, idx, aNaN; |
| |
| for (idx = 0; idx < NaNs.length; ++idx) { |
| aNaN = NaNs[idx]; |
| controls = new FA([aNaN, aNaN, aNaN]); |
| |
| Object.defineProperty(samples, "0", { value: aNaN }); |
| |
| for (var i = 0; i < samples.length; i++) { |
| var sample = samples[i]; |
| var control = controls[i]; |
| |
| assert( |
| samples[i] !== samples[i], |
| `samples (index=${idx}) produces a valid NaN (${precision} precision)` |
| ); |
| |
| assert( |
| controls[i] !== controls[i], |
| `controls (index=${idx}) produces a valid NaN (${precision} precision)` |
| ); |
| } |
| } |
| }, [Float32Array, Float64Array]); |
| |