Debug Info: Simplify Frame Index handling in DBG_VALUE Machine Instructions

Rather than using the full power of target-specific addressing modes in
DBG_VALUEs with Frame Indicies, simply use Frame Index + Offset. This
reduces the complexity of debug info handling down to two
representations of values (reg+offset and frame index+offset) rather
than three or four.

Ideally we could ensure that frame indicies had been eliminated by the
time we reached an assembly or dwarf generation, but I haven't spent the
time to figure out where the FIs are leaking through into that & whether
there's a good place to convert them. Some FI+offset=>reg+offset
conversion is done (see PrologEpilogInserter, for example) which is
necessary for some SelectionDAG assumptions about registers, I believe,
but it might be possible to make this a more thorough conversion &
ensure there are no remaining FIs no matter how instruction selection
is performed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184066 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 3b1abd7c83..0639238b1e 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -639,8 +639,8 @@ InstrEmitter::EmitDbgValue(SDDbgValue *SD,
   if (SD->getKind() == SDDbgValue::FRAMEIX) {
     // Stack address; this needs to be lowered in target-dependent fashion.
     // EmitTargetCodeForFrameDebugValue is responsible for allocation.
-    unsigned FrameIx = SD->getFrameIx();
-    return TII->emitFrameIndexDebugValue(*MF, FrameIx, Offset, MDPtr, DL);
+    return BuildMI(*MF, DL, TII->get(TargetOpcode::DBG_VALUE))
+        .addFrameIndex(SD->getFrameIx()).addImm(Offset).addMetadata(MDPtr);
   }
   // Otherwise, we're going to create an instruction here.
   const MCInstrDesc &II = TII->get(TargetOpcode::DBG_VALUE);