mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-02-15 09:51:00 +00:00
3363715e8e
This is an alternate fix for the bug discussed in D70595. This also includes minimal tests for other in-tree targets to show the problem more generally. We check the number of uses as a predicate for whether some value is free to negate, but that use count can change as we rewrite the expression in getNegatedExpression(). So something that was marked free to negate during the cost evaluation phase becomes not free to negate during the rewrite phase (or the inverse - something that was not free becomes free). This can lead to a crash/assert because we expect that everything in an expression that is negatible to be handled in the corresponding code within getNegatedExpression(). This patch skips the use check during the rewrite phase. So we determine that some expression isNegatibleForFree (identically to without this patch), but during the rewrite, don't rely on use counts to decide how to create the optimal expression. Differential Revision: https://reviews.llvm.org/D70975
The LLVM Compiler Infrastructure ================================ This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt. Please see the documentation provided in docs/ for further assistance with LLVM, and in particular docs/GettingStarted.rst for getting started with LLVM and docs/README.txt for an overview of LLVM's documentation setup. If you are writing a package for LLVM, see docs/Packaging.rst for our suggestions.