mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-01-31 10:34:17 +00:00
f84407be32
make much more sense and in theory be more correct. If you trace the code alllll the way back to when it was first introduced, the comments make it slightly more clear what was going on here. At that time, the only way Base != V was if DL (then TD) was non-null. As a consequence, if DL *was* null, that meant we were loading directly from the alloca or global found above the test. After refactoring, this has become at least terribly subtle and potentially incorrect. There are many forms of pointer manipulation that can be traversed without DataLayout, and some of them would in fact change the size of object being loaded vs. allocated. Rather than this subtlety, I've hoisted the actual 'return true' bits into the code which actually found an alloca or global and based them on the loaded pointer being that alloca or global. This is both more clear and safer. I've also added comments about exactly why this set of predicates is used. I've also corrected a misleading comment about globals -- if overridden they may not just have a different size, they may be null and completely unsafe to load from! Hopefully this confuses the next reader a bit less. I don't have any test cases or anything, the patch is motivated strictly to improve the readability of the code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220156 91177308-0d34-0410-b5e6-96231b3b80d8
Low Level Virtual Machine (LLVM) ================================ This directory and its subdirectories contain source code for the Low Level Virtual Machine, 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're writing a package for LLVM, see docs/Packaging.rst for our suggestions.