mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-01-23 17:32:49 +00:00
Chandler Carruth
b8087451ca
The hash function for MI expressions, used by MachineCSE, is really
broken. This patch fixes the superficial problems which lead to the intractably slow compile times reported in PR13225. The specific issue is that we were failing to include the *offset* of a global variable in the hash code. Oops. This would in turn cause all MIs which were only distinguishable due to operating on different offsets of a global variable to produce identical hash functions. In some of the test cases attached to the PR I saw hash table activity where there were O(1000) probes-per-lookup *on average*. A very few entries were responsible for most of these probes. There is still quite a bit more to do here. The ad-hoc layering of data in MachineOperands makes them *extremely* brittle to hash correctly. We're missing quite a few other cases, the only ones I've fixed here are the specific MO types which were allowed through the assert() in getOffset(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159741 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 HTML documentation provided in docs/index.html for further assistance with LLVM. If you're writing a package for LLVM, see docs/Packaging.html for our suggestions.
Description
Languages
C++
48.7%
LLVM
38.5%
Assembly
10.2%
C
0.9%
Python
0.4%
Other
1.2%