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// Some optimization tests for the Atomics primitives.
//
// These do not test atomicity, just code generation on a single
// thread.
//
// It's useful to look at the code generated for this test with -D to
// the JS shell.
//
// all platforms
function test(SharedOrUnsharedArrayBuffer) {
var sum = 0;
function f(ia, k) {
// For effect, variable value. The generated code on x86/x64
// should be one LOCK ADDB. (On ARM, there should be no
// sign-extend of the current value in the cell, otherwise this is
// still a LDREX/STREX loop.)
Atomics.add(ia, 0, k);
// Ditto constant value. Here the LOCK ADDB should have an
// immediate operand.
Atomics.add(ia, 0, 1);
}
function f2(ia, k) {
// For effect, variable value and constant value. The generated
// code on x86/x64 should be one LOCK SUBB.
Atomics.sub(ia, 2, k);
// Ditto constant value. Here the LOCK SUBB should have an
// immediate operand.
Atomics.sub(ia, 2, 1);
}
function f4(ia, k) {
// For effect, variable value. The generated code on x86/x64
// should be one LOCK ORB. (On ARM, there should be no
// sign-extend of the current value in the cell, otherwise this is
// still a LDREX/STREX loop.)
Atomics.or(ia, 6, k);
// Ditto constant value. Here the LOCK ORB should have an
// immediate operand.
Atomics.or(ia, 6, 1);
}
function g(ia, k) {
// For its value, variable value. The generated code on x86/x64
// should be one LOCK XADDB.
sum += Atomics.add(ia, 1, k);
// Ditto constant value. XADD does not admit an immediate
// operand, so in the second case there should be a preliminary
// MOV of the immediate to the output register.
sum += Atomics.add(ia, 1, 1);
}
function g2(ia, k) {
// For its value, variable value. The generated code on x86/x64
// should be one LOCK XADDB, preceded by a NEG into the output
// register instead of a MOV.
sum += Atomics.sub(ia, 3, k);
// Ditto constant value. XADD does not admit an immediate
// operand, so in the second case there should be a preliminary
// MOV of the negated immediate to the output register.
sum += Atomics.sub(ia, 3, 1);
}
function g4(ia, k) {
// For its value, variable value. The generated code on x86/x64
// should be a loop around ORB ; CMPXCHGB
sum += Atomics.or(ia, 7, k);
// Ditto constant value. Here the ORB in the loop should have
// an immediate operand.
sum += Atomics.or(ia, 7, 1);
}
var i8a = new Int8Array(new SharedOrUnsharedArrayBuffer(65536));
for ( var i=0 ; i < 10000 ; i++ ) {
f(i8a, i % 10);
g(i8a, i % 10);
f2(i8a, i % 10);
g2(i8a, i % 10);
f4(i8a, i % 10);
g4(i8a, i % 10);
}
assertEq(i8a[0], ((10000 + 10000*4.5) << 24) >> 24);
assertEq(i8a[1], ((10000 + 10000*4.5) << 24) >> 24);
assertEq(i8a[2], ((-10000 + -10000*4.5) << 24) >> 24);
assertEq(i8a[3], ((-10000 + -10000*4.5) << 24) >> 24);
assertEq(i8a[6], 15);
assertEq(i8a[7], 15);
}
test(SharedArrayBuffer);
test(ArrayBuffer);