[llvm] ae7bffd - [InstCombine] Don't create unnecessary zero-index GEP (NFCI)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-12-11T13:09:09+01:00
New Revision: ae7bffd71c44c8fa21b91e62da22e4d9272b0193

URL: https://github.com/llvm/llvm-project/commit/ae7bffd71c44c8fa21b91e62da22e4d9272b0193
DIFF: https://github.com/llvm/llvm-project/commit/ae7bffd71c44c8fa21b91e62da22e4d9272b0193.diff

LOG: [InstCombine] Don't create unnecessary zero-index GEP (NFCI)

Note needed with opaque pointers.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index b72b68c68d985..f8fae773e476d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -215,27 +215,7 @@ static Instruction *simplifyAllocaArraySize(InstCombinerImpl &IC,
       New->setAlignment(AI.getAlign());
 
       replaceAllDbgUsesWith(AI, *New, *New, DT);
-
-      // Scan to the end of the allocation instructions, to skip over a block of
-      // allocas if possible...also skip interleaved debug info
-      //
-      BasicBlock::iterator It(New);
-      while (isa<AllocaInst>(*It) || isa<DbgInfoIntrinsic>(*It))
-        ++It;
-
-      // Now that I is pointing to the first non-allocation-inst in the block,
-      // insert our getelementptr instruction...
-      //
-      Type *IdxTy = IC.getDataLayout().getIndexType(AI.getType());
-      Value *NullIdx = Constant::getNullValue(IdxTy);
-      Value *Idx[2] = {NullIdx, NullIdx};
-      Instruction *GEP = GetElementPtrInst::CreateInBounds(
-          NewTy, New, Idx, New->getName() + ".sub");
-      IC.InsertNewInstBefore(GEP, It);
-
-      // Now make everything use the getelementptr instead of the original
-      // allocation.
-      return IC.replaceInstUsesWith(AI, GEP);
+      return IC.replaceInstUsesWith(AI, New);
     }
   }