From 50f846d63443781a5c00ec7022c381c4f09f543d Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov@redhat.com>
Date: Thu, 12 May 2022 12:22:51 +0200
Subject: [PATCH] [FastISel] Add some debug output (NFC)

Print a debug message when aborting isel (next to the ORE report)
and when folding a load.
---
 llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index dab5d3fe68a8..cd1d63086edc 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -706,6 +706,7 @@ static void reportFastISelFailure(MachineFunction &MF,
     report_fatal_error(Twine(R.getMsg()));
 
   ORE.emit(R);
+  LLVM_DEBUG(dbgs() << R.getMsg() << "\n");
 }
 
 void SelectionDAGISel::SelectBasicBlock(BasicBlock::const_iterator Begin,
@@ -1524,6 +1525,8 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
               BeforeInst->hasOneUse() &&
               FastIS->tryToFoldLoad(cast<LoadInst>(BeforeInst), Inst)) {
             // If we succeeded, don't re-select the load.
+            LLVM_DEBUG(dbgs()
+                       << "FastISel folded load: " << *BeforeInst << "\n");
             BI = std::next(BasicBlock::const_iterator(BeforeInst));
             --NumFastIselRemaining;
             ++NumFastIselSuccess;