• Jakob Gruber's avatar
    Reland "[compiler] Optionally apply an offset to stack checks" · b875f466
    Jakob Gruber authored
    This is a reland of 4a16305b
    
    The original CL adjust only one part of the stack check, namely the
    comparison of the stack pointer against the stack limit in generated code.
    There is a second part: Runtime::kStackGuard repeats this check to
    distinguish between a stack overflow and an interrupt request.
    
    This second part in runtime must apply the offset just like in generated
    code. It is implemented in this reland by the StackCheckOffset operator
    and a new StackGuardWithGap runtime function.
    
    Original change's description:
    > [compiler] Optionally apply an offset to stack checks
    >
    > The motivation behind this change is that the frame size of an optimized
    > function and its unoptimized version may differ, and deoptimization
    > may thus trigger a stack overflow. The solution implemented in this CL
    > is to optionally apply an offset to the stack check s.t. the check
    > becomes 'sp - offset > limit'. The offset is applied to stack checks at
    > function-entry, and is set to the difference between the optimized and
    > unoptimized frame size.
    >
    > A caveat: OSR may not be fully handled by this fix since we've already
    > passed the function-entry stack check. A possible solution would be to
    > *not* skip creation of function-entry stack checks for inlinees.
    >
    > This CL: 1. annotates stack check nodes with the stack check kind, where
    > kind is one of {function-entry,iteration-body,unknown}. 2. potentially
    > allocates a temporary register to store the result of the 'sp - offset'
    > in instruction selection (and switches input registers to 'unique'
    > mode). 3. Applies the offset in code generation.
    >
    > Drive-by: Add src/compiler/globals.h for compiler-specific globals.
    >
    > Bug: v8:9534,chromium:1000887
    > Change-Id: I257191c4a4978ccb60cfa5805ef421f30f0e9826
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1762521
    > Commit-Queue: Jakob Gruber <jgruber@chromium.org>
    > Reviewed-by: Georg Neis <neis@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#63701}
    
    Bug: v8:9534, chromium:1000887
    Change-Id: I71771c281afd7d57c09aa48ea1b182d01e6dee2a
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1822037Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
    Reviewed-by: 's avatarSigurd Schneider <sigurds@chromium.org>
    Commit-Queue: Jakob Gruber <jgruber@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#64634}
    b875f466
machine-operator-unittest.cc 15.3 KB