The JSCallWithArraylike can be replaced with a JSCall if its probable arguments list is empty literal array. This replacement will introduce a deoptimization check to make sure the length of arguments list is 0 at runtime.
This CL change this optimization to a diamond speculation which may help avoid deoptimization once and keep the fast path. This change may benefit a following usecase,
function calcMax(testArray) {
Array.max = function(array) {
return Math.max.apply(Math, array);
};
var result = [];
for (var i = 0; i < testArray.length - 3; i++) {
var positiveNumbers = [];
for (var j = 0; j < 3; j++) {
if (testArray[i + j] > 0) {
positiveNumbers.push(testArray[i + j]);
}
}
result.push(Array.max(positiveNumbers));
}
return result;
}
testArray = [-1, 2, 3, -4, -5, -6, -7, -8, -9, 10];
for (var i = 0; i < 1000000; i++) {
calcMax(testArray);
}
Bug: v8:9974
Change-Id: I595627e2fd937527350c8f8652d701c791b41dd3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2967757
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75636}
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