[AMDGPU][DebugInfo] Drop DIExpression we encounter something else tha… (#265)

…n a pointer during FrameLowering

Only happens during optimized builds (the DIExpression is not dropped
with -O0).

This is a workaround, since rocthurst crashes.
Did not have the time to root cause the issue.

Fixes SWDEV-508902

Co-authored-by: Juan Manuel Martinez Caamaño <[email protected]>

Author: kzhuravl

llvm/include/llvm/IR/DebugInfoMetadata.h

@@ -3244,13 +3244,6 @@ class DIExpression : public MDNode {
         ->getElements();
   }
 
-  DIExpression *getPoisoned() const {
-    std::optional<FragmentInfo> Frag = getFragmentInfo();
-    if (!Frag)
-      return DIExpression::get(getContext(), PoisonedExpr);
-    return getPoisonedFragment(Frag->OffsetInBits, Frag->SizeInBits);
-  }
-
   DIExpression(LLVMContext &C, StorageType Storage, ArrayRef<uint64_t> Elements)
       : MDNode(C, DIExpressionKind, Storage, std::nullopt),
         Elements(std::in_place_type<OldElements>, Elements.begin(),
@@ -3278,6 +3271,13 @@ class DIExpression : public MDNode {
   }
 
 public:
+  DIExpression *getPoisoned() const {
+    std::optional<FragmentInfo> Frag = getFragmentInfo();
+    if (!Frag)
+      return DIExpression::get(getContext(), PoisonedExpr);
+    return getPoisonedFragment(Frag->OffsetInBits, Frag->SizeInBits);
+  }
+
   DEFINE_MDNODE_GET(DIExpression, (std::nullopt_t Elements), (Elements))
   DEFINE_MDNODE_GET(DIExpression, (ArrayRef<uint64_t> Elements), (Elements))
   // The bool parameter is ignored, and only present to disambiguate the

llvm/lib/Target/AMDGPU/AMDGPUFrameLowering.cpp

@@ -101,7 +101,13 @@ DIExpression *AMDGPUFrameLowering::lowerFIArgToFPArg(const MachineFunction &MF,
     if (auto *Arg = std::get_if<DIOp::Arg>(&*I)) {
       if (Arg->getIndex() != ArgIndex)
         continue;
+
       Type *ResultType = Arg->getResultType();
+      // Weird case: we expect a pointer but on optimized builds it may not be
+      // the case.
+      if (!ResultType->isPointerTy())
+        return Expr->getPoisoned();
+
       unsigned PointerSizeInBits =
           DL.getPointerSizeInBits(ResultType->getPointerAddressSpace());
       auto *IntTy = IntegerType::get(Context, PointerSizeInBits);