[llvm] d1d7d22 - [AggressiveInstCombine] Fix cases where non-opaque pointers are used

[David Stuttard via llvm-commits]

Author: David Stuttard
Date: 2022-10-05T13:42:46+01:00
New Revision: d1d7d2235ced0a959bf0d2513f8adc50c0e5efd8

URL: https://github.com/llvm/llvm-project/commit/d1d7d2235ced0a959bf0d2513f8adc50c0e5efd8
DIFF: https://github.com/llvm/llvm-project/commit/d1d7d2235ced0a959bf0d2513f8adc50c0e5efd8.diff

LOG: [AggressiveInstCombine] Fix cases where non-opaque pointers are used

In the case of non-opaque pointers, when combining consecutive loads,
need to bitcast the pointer source to the combined type size, otherwise
asserts are triggered.

Differential Revision: https://reviews.llvm.org/D135249

Added: 
    

Modified: 
    llvm/lib/Transforms/AggressiveInstCombine/AggressiveInstCombine.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/AggressiveInstCombine/AggressiveInstCombine.cpp b/llvm/lib/Transforms/AggressiveInstCombine/AggressiveInstCombine.cpp
index 359aa286572c2..0ac9881a5a710 100644
--- a/llvm/lib/Transforms/AggressiveInstCombine/AggressiveInstCombine.cpp
+++ b/llvm/lib/Transforms/AggressiveInstCombine/AggressiveInstCombine.cpp
@@ -795,9 +795,9 @@ static bool foldConsecutiveLoads(Instruction &I, const DataLayout &DL,
   IRBuilder<> Builder(&I);
   LoadInst *NewLoad = nullptr, *LI1 = LOps.Root;
 
+  IntegerType *WiderType = IntegerType::get(I.getContext(), LOps.LoadSize);
   // TTI based checks if we want to proceed with wider load
-  bool Allowed =
-      TTI.isTypeLegal(IntegerType::get(I.getContext(), LOps.LoadSize));
+  bool Allowed = TTI.isTypeLegal(WiderType);
   if (!Allowed)
     return false;
 
@@ -811,9 +811,9 @@ static bool foldConsecutiveLoads(Instruction &I, const DataLayout &DL,
   // New load can be generated
   Value *Load1Ptr = LI1->getPointerOperand();
   Builder.SetInsertPoint(LI1);
-  NewLoad = Builder.CreateAlignedLoad(
-      IntegerType::get(Load1Ptr->getContext(), LOps.LoadSize), Load1Ptr,
-      LI1->getAlign(), LI1->isVolatile(), "");
+  Value *NewPtr = Builder.CreateBitCast(Load1Ptr, WiderType->getPointerTo(AS));
+  NewLoad = Builder.CreateAlignedLoad(WiderType, NewPtr, LI1->getAlign(),
+                                      LI1->isVolatile(), "");
   NewLoad->takeName(LI1);
   // Set the New Load AATags Metadata.
   if (LOps.AATags)