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LLVM backend for 6502
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Evan Cheng 37b7387da9 Optimize some common usage patterns of atomic built-ins __sync_add_and_fetch() and __sync_sub_and_fetch. 
When the return value is not used (i.e. only care about the value in the memory), x86 does not have to use add to implement these. Instead, it can use add, sub, inc, dec instructions with the "lock" prefix.

This is currently implemented using a bit of instruction selection trick. The issue is the target independent pattern produces one output and a chain and we want to map it into one that just output a chain. The current trick is to select it into a merge_values with the first definition being an implicit_def. The proper solution is to add new ISD opcodes for the no-output variant. DAG combiner can then transform the node before it gets to target node selection.

Problem #2 is we are adding a whole bunch of x86 atomic instructions when in fact these instructions are identical to the non-lock versions. We need a way to add target specific information to target nodes and have this information carried over to machine instructions. Asm printer (or JIT) can use this information to add the "lock" prefix.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77582 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-30 08:33:02 +00:00
autoconf Remove the IA-64 backend. 2009-07-24 00:30:09 +00:00
bindings Reorder the "Metadata" entry to match the C bindings. 2009-07-21 21:52:57 +00:00
cmake CMake configuration: find mkdtemp, mkstemp, mktemp. 2009-07-27 18:23:41 +00:00
docs Move types back to the 2.5 API. 2009-07-29 22:17:13 +00:00
examples Move types back to the 2.5 API. 2009-07-29 22:17:13 +00:00
include Twine: Provide [u]int{32,64} conversions via implicit constructors instead of 2009-07-30 03:47:15 +00:00
lib Optimize some common usage patterns of atomic built-ins __sync_add_and_fetch() and __sync_sub_and_fetch. 2009-07-30 08:33:02 +00:00
projects remove dead makefile flags. 2009-06-24 05:29:56 +00:00
runtime Drop toy GC runtime. 2009-03-02 03:46:48 +00:00
test Optimize some common usage patterns of atomic built-ins __sync_add_and_fetch() and __sync_sub_and_fetch. 2009-07-30 08:33:02 +00:00
tools Move types back to the 2.5 API. 2009-07-29 22:17:13 +00:00
unittests Twine: Provide [u]int{32,64} conversions via implicit constructors instead of 2009-07-30 03:47:15 +00:00
utils Minor whitespace tidiness. 2009-07-30 01:33:17 +00:00
website Prepare for "core" website. 2007-08-03 05:43:35 +00:00
win32 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come. 2009-07-24 23:12:02 +00:00
Xcode Remove the IA-64 backend. 2009-07-24 00:30:09 +00:00
build-for-llvm-top.sh Patch to build llvm with srcdir != objdir from 2009-01-23 08:42:38 +00:00
CMakeLists.txt Remove the IA-64 backend. 2009-07-24 00:30:09 +00:00
configure Remove the IA-64 backend. 2009-07-24 00:30:09 +00:00
CREDITS.TXT Added myself to the blame list. 2009-07-15 13:01:49 +00:00
LICENSE.TXT Now that we have atomics support properly detected by configure, 2009-05-19 00:08:29 +00:00
llvm.spec.in
Makefile Introduce new headers whose inclusion forces linking and 2009-06-16 20:12:29 +00:00
Makefile.common Removed trailing whitespace from Makefiles. 2009-01-09 16:44:42 +00:00
Makefile.config.in LLVMC can be now compiled w/o dynamic plugin support. 2009-07-04 03:55:25 +00:00
Makefile.rules Makefile rules for generating assembly matcher. 2009-07-13 18:35:35 +00:00
ModuleInfo.txt Patch to build llvm with srcdir != objdir from 2009-01-23 08:42:38 +00:00
README.txt README.txt: test commit w/blank line appended 2009-03-23 21:00:45 +00:00

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