Bug 108938
| Summary: | Assertion failed with DFG JIT on ARM traditional. | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | Zoltan Herczeg <zherczeg> |
| Component: | JavaScriptCore | Assignee: | Nobody <webkit-unassigned> |
| Status: | NEW | ||
| Severity: | Normal | CC: | barraclough, fpizlo, laszlo.gombos, ossy, rgabor |
| Priority: | P2 | ||
| Version: | 528+ (Nightly build) | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Bug Depends on: | |||
| Bug Blocks: | 108645 | ||
Zoltan Herczeg
There is an assertion fail: "ASSERTION FAILED: !m_used[i] || m_used[i] == max() in DFGScoreBoard.h(70) : void JSC::DFG::ScoreBoard::assertClear()" because of a speculated integer division on traditional ARMv7. Reason: a virtual register is referenced 4 times, but only two are found by the ScoreBoard.
Test.js:
function test() {
return Math.floor( 16 / Math.pow(16,1) );
}
for(var i=0; i<100; i++) {
test();
}
I suspect the following code is the reason:
DFGFixupPhase.cpp
case ArithDiv: {
if (Node::shouldSpeculateIntegerForArithmetic(node->child1().node(), node->child2().node())
&& node->canSpeculateInteger()) {
}
I saw there is a new optimization using the division supported by CortexA15, but what about old ARMs, which does not have this instruction? Any idea?
| Attachments | ||
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