Tim Northover 8f2a85e099 IR: add "cmpxchg weak" variant to support permitted failure. ... This commit adds a weak variant of the cmpxchg operation, as described in C++11. A cmpxchg instruction with this modifier is permitted to fail to store, even if the comparison indicated it should. As a result, cmpxchg instructions must return a flag indicating success in addition to their original iN value loaded. Thus, for uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The second flag is 1 when the store succeeded. At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been added as the natural representation for the new cmpxchg instructions. It is a strong cmpxchg. By default this gets Expanded to the existing ATOMIC_CMP_SWAP during Legalization, so existing backends should see no change in behaviour. If they wish to deal with the enhanced node instead, they can call setOperationAction on it. Beware: as a node with 2 results, it cannot be selected from TableGen. Currently, no use is made of the extra information provided in this patch. Test updates are almost entirely adapting the input IR to the new scheme. Summary for out of tree users: ------------------------------ + Legacy Bitcode files are upgraded during read. + Legacy assembly IR files will be invalid. + Front-ends must adapt to different type for "cmpxchg". + Backends should be unaffected by default. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8		2014-06-13 14:24:07 +00:00
..
AsmWriter.cpp	IR: add "cmpxchg weak" variant to support permitted failure.	2014-06-13 14:24:07 +00:00
AsmWriter.h
AttributeImpl.h
Attributes.cpp
AutoUpgrade.cpp
BasicBlock.cpp
CMakeLists.txt
ConstantFold.cpp
ConstantFold.h
ConstantRange.cpp
Constants.cpp
ConstantsContext.h
Core.cpp
DataLayout.cpp
DebugInfo.cpp
DebugLoc.cpp
DiagnosticInfo.cpp
DiagnosticPrinter.cpp
DIBuilder.cpp
Dominators.cpp
Function.cpp
GCOV.cpp
Globals.cpp
GVMaterializer.cpp
InlineAsm.cpp
Instruction.cpp	IR: add "cmpxchg weak" variant to support permitted failure.	2014-06-13 14:24:07 +00:00
Instructions.cpp	IR: add "cmpxchg weak" variant to support permitted failure.	2014-06-13 14:24:07 +00:00
IntrinsicInst.cpp
IRBuilder.cpp
IRPrintingPasses.cpp
LeakDetector.cpp
LeaksContext.h
LegacyPassManager.cpp
LLVMBuild.txt
LLVMContext.cpp
LLVMContextImpl.cpp
LLVMContextImpl.h
Makefile
Mangler.cpp
MDBuilder.cpp
Metadata.cpp
Module.cpp
module.modulemap
Pass.cpp
PassManager.cpp
PassRegistry.cpp
SymbolTableListTraitsImpl.h
Type.cpp
TypeFinder.cpp
Use.cpp
User.cpp
Value.cpp
ValueSymbolTable.cpp
ValueTypes.cpp
Verifier.cpp