Here is a theoretical example that illustrates why the placement is important.
tmp1 =
store tmp1 -> x
...
tmp2 = add ...
...
call
...
store tmp2 -> x
Now mem2reg comes along:
tmp1 =
dbg_value (tmp1 -> x)
...
tmp2 = add ...
...
call
...
dbg_value (tmp2 -> x)
When the debugger examine the value of x after the add instruction but before the call, it should have the value of tmp1.
Furthermore, for dbg_value's that reference constants, they should not be emitted at the beginning of the block (since they do not have "producers").
This patch also cleans up how SDISel manages DbgValue nodes. It allow a SDNode to be referenced by multiple SDDbgValue nodes. When a SDNode is deleted, it uses the information to find the SDDbgValues and invalidate them. They are not deleted until the corresponding SelectionDAG is destroyed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99469 91177308-0d34-0410-b5e6-96231b3b80d8
2006-07-19-stwbrx-crash.ll for me, but it's the only likely
patch in the blame list of several bots. Lets see if this
fixes it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99453 91177308-0d34-0410-b5e6-96231b3b80d8
an MCSymbol. Make the EH_LABEL MachineInstr hold its label
with an MCSymbol instead of ID. Fix a bug in MMI.cpp which
would return labels named "Label4" instead of "label4".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98463 91177308-0d34-0410-b5e6-96231b3b80d8
into TargetOpcodes.h. #include the new TargetOpcodes.h
into MachineInstr. Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the
codebase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95687 91177308-0d34-0410-b5e6-96231b3b80d8
results. This works around a problem affecting targets which rely on
MVT::Flag to handle physical register defs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85638 91177308-0d34-0410-b5e6-96231b3b80d8
bunch of associated comments, because it doesn't have anything to do
with DAGs or scheduling. This is another step in decoupling MachineInstr
emitting from scheduling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85517 91177308-0d34-0410-b5e6-96231b3b80d8
into MachineInstrs. This is mostly just moving the code from
ScheduleDAGSDNodesEmit.cpp into a new class. This decouples MachineInstr
emitting from scheduling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83699 91177308-0d34-0410-b5e6-96231b3b80d8
