• ahaas's avatar
    Reland [heap] Avoid the use of cells to point from code to new-space objects. · 5e058540
    ahaas authored
    The reason for reverting is: This breaks gc-stress bot:
    https://chromegw.corp.google.com/i/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot
    
    Abortion of compaction could cause duplicate entries in the typed-old-to-new remembered set. These duplicates could cause a DCHECK to trigger which checks that slots recorded in the remembered set never point to to-space. This reland-CL allows duplicates in the remembered set by removing the DCHECK, and additionally clears entries in the remembered set if objects are moved.
    
    Original issue's description:
    
    Cells were needed originally because there was no typed remembered set to
    record direct pointers from code space to new space. A previous
    CL (https://codereview.chromium.org/2003553002/) already introduced
    the remembered set, this CL uses it.
    
    This CL
    * stores direct pointers in code objects, even if the target is in new space,
    * records the slot of the pointer in typed-old-to-new remembered set,
    * adds a list which stores weak code-to-new-space references,
    * adds a test to test-heap.cc for weak code-to-new-space references,
    * removes prints in tail-call-megatest.js
    
    Review-Url: https://codereview.chromium.org/2097023002
    Cr-Commit-Position: refs/heads/master@{#37325}
    5e058540
macro-assembler-x64.cc 169 KB