REOPENED Bug 125425
Fold storage pointer for GC-allocated typed arrays
https://bugs.webkit.org/show_bug.cgi?id=125425
Summary Fold storage pointer for GC-allocated typed arrays
Filip Pizlo
Reported 2013-12-08 12:04:26 PST
This probably won't be *too* profitable but I suspect that eventually it'll be needed.
Attachments
Filip Pizlo
Comment 1 2016-08-23 13:43:12 PDT
*** This bug has been marked as a duplicate of bug 161100 ***
Filip Pizlo
Comment 2 2016-08-23 15:15:22 PDT
Nope, this is still a bug. Even if the GC-allocated typed array doesn't move, we still can't constant-fold pointers to it because of neutering: - To constant-fold, we need to install a watchpoint on the typed array's underlying buffer to make sure that we get notified if it gets neutered. - To install a watchpoint, we need to request the buffer. - To request the buffer, we need to move the backing store out of GC space. - To move it out of GC space, we need to malloc a new backing store and copy the data over and repoint m_vector. - Therefore, constant folding will fold to the *old* buffer. Ouch!
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