v8/test/mjsunit/regress/regress-1146880.js
Thibaud Michaud 0ee6f90a5f [regalloc] Fix slot requirement for live ranges defined by a const
Live ranges defined by a constant operand normally don't require a spill
slot since they can just rematerialize the value from the constant. In
the attached issue however, deoptimization adds an explicit slot
requirement for a range that is defined by a constant operand. This case
is not expected in the register allocator and we eventually hit a
DCHECK.

This fix allocates a new stack slot during the MeetRegisterConstraints
and adds the missing gap move.

Drive-by: remove dead method LiveRange::NextSlotPosition.

R=sigurds@chromium.org
CC=​nicohartmann@chromium.org

Bug: chromium:1146880
Change-Id: I08fbb890f2f3d9574196989cf3e5ef6232433484
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563689
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73510}
2021-03-18 14:25:14 +00:00

27 lines
570 B
JavaScript

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --allow-natives-syntax --assert-types
function f(a,b) {
let t = a >= b;
while (t != 0) {
a = a | (b - a);
let unused = a >= b;
t = a < b;
}
}
function test() {
f(Infinity,1);
f(undefined, undefined);
}
// Trigger TurboFan compilation
%PrepareFunctionForOptimization(test);
%PrepareFunctionForOptimization(f);
test();
test();
%OptimizeFunctionOnNextCall(test);
test();