llvm-6502/include/llvm
Hal Finkel afe2f43e4e Fix bug in PEI's virtual-register scavenging
This change fixes a bug that I introduced in r178058. After a register is
scavenged using one of the available spills slots the instruction defining the
virtual register needs to be moved to after the spill code. The scavenger has
already processed the defining instruction so that registers killed by that
instruction are available for definition in that same instruction. Unfortunately,
after this, the scavenger needs to iterate through the spill code and then
visit, again, the instruction that defines the now-scavenged register. In order
to avoid confusion, the register scavenger needs the ability to 'back up'
through the spill code so that it can again process the instructions in the
appropriate order. Prior to this fix, once the scavenger reached the
just-moved instruction, it would assert if it killed any registers because,
having already processed the instruction, it believed they were undefined.

Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
for diagnosing the problem and testing this fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178845 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 05:01:13 +00:00
..
ADT
Analysis
Assembly
Bitcode
CodeGen Fix bug in PEI's virtual-register scavenging 2013-04-05 05:01:13 +00:00
Config
DebugInfo
ExecutionEngine
IR
IRReader
MC
Object
Option
Support
TableGen
Target
Transforms
AutoUpgrade.h
CMakeLists.txt
DebugInfo.h
DIBuilder.h
GVMaterializer.h
InitializePasses.h
InstVisitor.h
LinkAllIR.h
LinkAllPasses.h
Linker.h
Pass.h
PassAnalysisSupport.h
PassManager.h
PassManagers.h
PassRegistry.h
PassSupport.h