mirror of
https://github.com/RPCSX/llvm.git
synced 2025-05-13 10:56:01 +00:00
4f2d8229c1
Summary: When InstCombine is optimizing certain select-cmp-br patterns it replaces the result of the select in uses outside of the basic block containing the select. This is only legal if the path from the select to the outside use is disjoint from all other paths out from the originating basic block. The problem found was that InstCombiner::replacedSelectWithOperand did not consider the case when both edges out from the br pointed to the same label. In that case the paths aren't disjoint and the transformation is illegal. This patch avoids the faulty rewrites by verifying that there is a single flow to the successor where we want to replace uses. Reviewers: llvm-commits, spatel, majnemer Differential Revision: https://reviews.llvm.org/D30455 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296752 91177308-0d34-0410-b5e6-96231b3b80d8
Low Level Virtual Machine (LLVM) ================================ 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.