[llvm] [X86] Don't fold loads from non-fixed stack objects into tail calls (PR #221243)

[Akash Manna via llvm-commits]

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@@ -3682,7 +3683,39 @@ static bool mayUseCarryFlag(X86::CondCode CC) {
   return true;
 }
 
+/// Return true if \p Addr may be matched with a non-fixed frame index as base.
+static bool addrMayUseNonFixedFrameIndex(SDValue Addr,
+                                         const MachineFrameInfo &MFI,
+                                         unsigned Depth = 0) {
+  if (auto *FI = dyn_cast<FrameIndexSDNode>(Addr))
+    return !MFI.isFixedObjectIndex(FI->getIndex());
+  if (Depth >= SelectionDAG::MaxRecursionDepth)
+    return true;
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akash-manna-sky wrote:

Comments added. 

https://github.com/llvm/llvm-project/pull/221243