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Milad Farazmand authored
Port 0aa204fe Original Commit Message: This CL unifies how stack checks are handled in the Turbofan pipeline across architectures, in preparation for properly handling stack overflows caused by deoptimization in follow-up work. It will also open up possibilities to simplify related logic. How this used to work: JSStackCheck was lowered to a UintLessThan with the stack pointer (sp) and stack limit as inputs. On x64 and ia32, this node pattern was later recognized during instruction selection and rewritten to dedicated operators. On other platforms, including arm and arm64, special logic exists to avoid useless register-to-register moves when accessing the sp. This CL introduces a new StackPointerGreaterThan operator, which takes the stack limit as its sole input. This is what JSStackCheck now lowers to. This is threaded through to code generation, where we emit the appropriate code (in the future, we will apply an additional offset to the sp here). In follow-up CLs, we can remove or replace remaining uses of LoadStackPointer in CSA, Wasm, and the interpreter; and then remove the LoadStackPointer operator, related node matchers, related register constraints, and the pseudo-smi stack limit roots. R=jgruber@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com BUG= LOG=N Change-Id: I175c110d30190bb543001b6fa77cd65cf22e5874 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1748002Reviewed-by: Junliang Yan <jyan@ca.ibm.com> Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com> Cr-Commit-Position: refs/heads/master@{#63167}
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