mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-15 20:29:48 +00:00
LLVM backend for 6502
dacc4cf146
Background: When handling underlying objects for a store, the vector
of previous mem uses, mapped to the same Value, is afterwards cleared
(regardless of ThisMayAlias). This means that during handling of the
next store using the same Value, adjustChainDeps() must be called,
otherwise a dependency might be missed.
For example, three spill/reload (NonAliasing) memory accesses using
the same Value 'a', with different offsets:
SU(2): store @a
SU(1): store @a, Offset:1
SU(0): load @a
In this case we have:
* SU(1) does not need a dep against SU(0). Therefore,SU(0) ends up in
RejectMemNodes and is removed from the mem-uses list (AliasMemUses
or NonAliasMemUses), as this list is cleared.
* SU(2) needs a dep against SU(0). Therefore, SU(2) must check
RejectMemNodes by calling adjustChainDeps().
Previously, for store SUs, adjustChainDeps() was only called if
MayAlias was true, missing the S(2) to S(0) dependency in the case
above. The fix is to always call adjustChainDeps(), regardless of
MayAlias, since this applies both for AliasMemUses and
NonAliasMemUses.
No testcase found for any in-tree target.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228686 91177308-0d34-0410-b5e6-96231b3b80d8
|
||
|---|---|---|
| autoconf | ||
| bindings | ||
| cmake | ||
| docs | ||
| examples | ||
| include | ||
| lib | ||
| projects | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| .arcconfig | ||
| .clang-format | ||
| .clang-tidy | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| configure | ||
| CREDITS.TXT | ||
| LICENSE.TXT | ||
| llvm.spec.in | ||
| LLVMBuild.txt | ||
| Makefile | ||
| Makefile.common | ||
| Makefile.config.in | ||
| Makefile.rules | ||
| README.txt | ||
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're writing a package for LLVM, see docs/Packaging.rst for our suggestions.