llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-04 06:09:05 +00:00

LLVM backend for 6502

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Andrew Trick a6a9ac5aa1 Fix the ExecutionDepsFix pass to handle AVX instructions. This pass is needed to break false dependencies. Without it, unlucky register assignment can result in wild (5x) swings in performance. This pass was trying to handle AVX but not getting it right. AVX doesn't have partial register defs, it has unused register reads in which the high bits of a source operand are copied into the unused bits of the dest. Fixing this requires conservative liveness analysis. This is awkard because the pass already has its own pseudo-liveness. However, proper liveness is expensive, and we would like to use a generic utility to compute it. The fix only invokes liveness on-demand. It is rare to detect a case that needs undef-read dependence breaking, but when it happens, it can be needed many times within a very large block. I think the existing heuristic which uses a register window of 16 is too conservative for loop-carried false dependencies. If the loop is a reduction. The out-of-order engine may be able to execute several loop iterations in parallel. However, I'll leave this tuning exercise for next time. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192635 91177308-0d34-0410-b5e6-96231b3b80d8		2013-10-14 22:19:03 +00:00
autoconf	Update so that it uses the `-V' command line option and supports Python 3.x.	2013-10-12 08:42:59 +00:00
bindings	[python-bindings] Added support for getting/setting operands of values and getting the number of operands of a value.	2013-09-11 01:38:12 +00:00
cmake	cmake: don't set LLVM_COMPILER_IS_GCC_COMPATIBLE when using clang-cl	2013-10-07 22:03:23 +00:00
docs	Add warning about CHECK-DAG with variable definition	2013-10-11 18:50:22 +00:00
examples	Add missing #include's to cctype when using isdigit/alpha/etc.	2013-10-12 00:55:57 +00:00
include	Fix the ExecutionDepsFix pass to handle AVX instructions.	2013-10-14 22:19:03 +00:00
lib	Fix the ExecutionDepsFix pass to handle AVX instructions.	2013-10-14 22:19:03 +00:00
projects	Revert "Revert "Windows: Add support for unicode command lines""	2013-10-07 01:00:07 +00:00
test	Fix a typo, in a comment, in a test.	2013-10-14 22:02:53 +00:00
tools	vs2013 msbuild integration: add missing .target files, fix typo in CMakeLists	2013-10-14 18:16:37 +00:00
unittests	Silencing an MSVC warning.	2013-10-05 19:41:41 +00:00
utils	Remove utils/profile.pl.	2013-10-14 16:48:32 +00:00
.arcconfig
.clang-format
.gitignore
CMakeLists.txt	Restore LLVM_BUILD_RUNTIME option that was deleted in r191835, but is still used to control building of compiler-rt and libcxx	2013-10-04 10:41:38 +00:00
CODE_OWNERS.TXT
configure	Update so that it uses the `-V' command line option and supports Python 3.x.	2013-10-12 08:42:59 +00:00
CREDITS.TXT	Update.	2013-09-27 20:40:40 +00:00
LICENSE.TXT
llvm.spec.in
LLVMBuild.txt	Remove the very substantial, largely unmaintained legacy PGO	2013-10-02 15:42:23 +00:00
Makefile	Remove the very substantial, largely unmaintained legacy PGO	2013-10-02 15:42:23 +00:00
Makefile.common
Makefile.config.in
Makefile.rules
README.txt	Revert "Test commit to check e-mail address. Please discard this."	2013-10-04 10:59:13 +00:00

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