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Jakob Gruber authored
This is another step towards considering the unoptimized frame size in stack checks within optimized code. With the changes in this CL, we now keep track of the maximal unoptimized frame size of the function that is currently being compiled. An optimized function may inline multiple unoptimized functions, so a single optimized frame can deopt to multiple frames. The real frame size thus differs in different parts of the optimized function. We only care about the maximal frame size, which we calculate conservatively as an over-approximation, and track in InstructionSelector::max_unoptimized_frame_height_ for now. In future work, this value will be passed on to codegen, where it will be applied as an offset to the stack pointer during the stack check. (The motivation behind this is to avoid stack overflows through deopts, caused by size differences between optimized and unoptimized frames.) Note that this offset only ensure that the topmost optimized frame can deopt without overflowing the stack limit. That's fine, because we only deopt optimized frames one at a time. Other (non-topmost) frames are only deoptimized once they are returned to. Drive-by: Print variable and total frame height in --trace-deopt. Bug: v8:9534 Change-Id: I821684a9da93bff59c20c8ab226105e7e12d93eb Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1762024 Commit-Queue: Jakob Gruber <jgruber@chromium.org> Auto-Submit: Jakob Gruber <jgruber@chromium.org> Reviewed-by: Sigurd Schneider <sigurds@chromium.org> Reviewed-by: Georg Neis <neis@chromium.org> Cr-Commit-Position: refs/heads/master@{#63330}
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