[llvm] b7c91a9 - [SCEV] SCEVExpander::InsertNoopCastOfTo - reduce scope of pointer type. NFCI.

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-10-30T14:55:09Z
New Revision: b7c91a9b8e4762c9e052b67fcd3329615309f1d0

URL: https://github.com/llvm/llvm-project/commit/b7c91a9b8e4762c9e052b67fcd3329615309f1d0
DIFF: https://github.com/llvm/llvm-project/commit/b7c91a9b8e4762c9e052b67fcd3329615309f1d0.diff

LOG: [SCEV] SCEVExpander::InsertNoopCastOfTo - reduce scope of pointer type. NFCI.

By reducing the scope of the dyn_cast<PointerType> we can make this a cast<PointerType> and avoid clang static analyzer null deference warnings.

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index a45b5cdf0b17..df100d85f32c 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -126,19 +126,21 @@ Value *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) {
   assert(SE.getTypeSizeInBits(V->getType()) == SE.getTypeSizeInBits(Ty) &&
          "InsertNoopCastOfTo cannot change sizes!");
 
-  auto *PtrTy = dyn_cast<PointerType>(Ty);
   // inttoptr only works for integral pointers. For non-integral pointers, we
   // can create a GEP on i8* null  with the integral value as index. Note that
   // it is safe to use GEP of null instead of inttoptr here, because only
   // expressions already based on a GEP of null should be converted to pointers
   // during expansion.
-  if (Op == Instruction::IntToPtr && DL.isNonIntegralPointerType(PtrTy)) {
-    auto *Int8PtrTy = Builder.getInt8PtrTy(PtrTy->getAddressSpace());
-    assert(DL.getTypeAllocSize(Int8PtrTy->getElementType()) == 1 &&
-           "alloc size of i8 must by 1 byte for the GEP to be correct");
-    auto *GEP = Builder.CreateGEP(
-        Builder.getInt8Ty(), Constant::getNullValue(Int8PtrTy), V, "uglygep");
-    return Builder.CreateBitCast(GEP, Ty);
+  if (Op == Instruction::IntToPtr) {
+    auto *PtrTy = cast<PointerType>(Ty);
+    if (DL.isNonIntegralPointerType(PtrTy)) {
+      auto *Int8PtrTy = Builder.getInt8PtrTy(PtrTy->getAddressSpace());
+      assert(DL.getTypeAllocSize(Int8PtrTy->getElementType()) == 1 &&
+             "alloc size of i8 must by 1 byte for the GEP to be correct");
+      auto *GEP = Builder.CreateGEP(
+          Builder.getInt8Ty(), Constant::getNullValue(Int8PtrTy), V, "uglygep");
+      return Builder.CreateBitCast(GEP, Ty);
+    }
   }
   // Short-circuit unnecessary bitcasts.
   if (Op == Instruction::BitCast) {