[llvm] [LAA] Fix recordAnalysis receiving null Instruction pointer (PR #183512)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Igor Kirillov (igogo-x86)

<details>
<summary>Changes</summary>

When a memory-reading or memory-writing instruction is not a LoadInst/StoreInst, the dyn_cast to Ld/St returns nullptr, which is then passed to recordAnalysis. This causes the optimization remark to fall back to the loop header location instead of pointing at the actual problematic instruction.

Pass &I (the actual Instruction) instead.

---
Full diff: https://github.com/llvm/llvm-project/pull/183512.diff


1 Files Affected:

- (modified) llvm/lib/Analysis/LoopAccessAnalysis.cpp (+2-2) 


``````````diff
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index ca6b8461970b5..524caab0367cc 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -2581,7 +2581,7 @@ bool LoopAccessInfo::analyzeLoop(AAResults *AA, const LoopInfo *LI,
 
         auto *Ld = dyn_cast<LoadInst>(&I);
         if (!Ld) {
-          recordAnalysis("CantVectorizeInstruction", Ld)
+          recordAnalysis("CantVectorizeInstruction", &I)
             << "instruction cannot be vectorized";
           HasComplexMemInst = true;
           continue;
@@ -2605,7 +2605,7 @@ bool LoopAccessInfo::analyzeLoop(AAResults *AA, const LoopInfo *LI,
       if (I.mayWriteToMemory()) {
         auto *St = dyn_cast<StoreInst>(&I);
         if (!St) {
-          recordAnalysis("CantVectorizeInstruction", St)
+          recordAnalysis("CantVectorizeInstruction", &I)
               << "instruction cannot be vectorized";
           HasComplexMemInst = true;
           continue;

``````````

</details>


https://github.com/llvm/llvm-project/pull/183512