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Diffstat (limited to 'js/src/tests/test262/built-ins/Atomics/compareExchange/expected-return-value.js')
-rw-r--r-- | js/src/tests/test262/built-ins/Atomics/compareExchange/expected-return-value.js | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Atomics/compareExchange/expected-return-value.js b/js/src/tests/test262/built-ins/Atomics/compareExchange/expected-return-value.js new file mode 100644 index 0000000000..dc2a778df2 --- /dev/null +++ b/js/src/tests/test262/built-ins/Atomics/compareExchange/expected-return-value.js @@ -0,0 +1,43 @@ +// |reftest| skip-if(!this.hasOwnProperty('Atomics')||!this.hasOwnProperty('SharedArrayBuffer')||(this.hasOwnProperty('getBuildConfiguration')&&getBuildConfiguration('arm64-simulator'))) -- Atomics,SharedArrayBuffer is not enabled unconditionally, ARM64 Simulator cannot emulate atomics +// Copyright (C) 2018 Rick Waldron. All rights reserved. +// This code is governed by the BSD license found in the LICENSE file. + +/*--- +esid: sec-atomics.compareExchange +description: > + Atomics.compareExchange returns the value that existed at the + index prior to the operation. +info: | + Atomics.compareExchange( typedArray, index, expectedValue, replacementValue ) + + ... + 12. Let compareExchange denote a semantic function of two List of + byte values arguments that returns the second argument if the + first argument is element-wise equal to expectedBytes. + 13. Return GetModifySetValueInBuffer(buffer, indexedPosition, + elementType, replacement, compareExchange). + + + GetModifySetValueInBuffer( arrayBuffer, + byteIndex, type, value, op [ , isLittleEndian ] ) + + ... + 16. Return RawBytesToNumber(type, rawBytesRead, isLittleEndian). + +features: [Atomics, SharedArrayBuffer, TypedArray] +---*/ + +const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4); +const i32a = new Int32Array(buffer); +const update = 0b00000001000000001000000010000001; + +i32a[0] = update; + +assert.sameValue( + Atomics.compareExchange(i32a, 0, update, 0), + update, + 'Atomics.compareExchange(i32a, 0, update, 0) returns the value of `update` (0b00000001000000001000000010000001)' +); +assert.sameValue(i32a[0], 0, 'The value of i32a[0] is 0'); + +reportCompare(0, 0); |