[PATCH] D32593: [SROA] Fix crash due to bad bitcast

[Keno Fischer via Phabricator via llvm-commits]

loladiro created this revision.

As shown in the test case, SROA was crashing when trying to split
stores (to the alloca) of loads (from anywhere), because it assumed
the pointer operand to the loads and stores had to have the same
address space. This isn't the case. Make sure to use the correct
pointer type for both the load and the store.


https://reviews.llvm.org/D32593

Files:
  lib/Transforms/Scalar/SROA.cpp
  test/Transforms/SROA/address-spaces.ll


Index: test/Transforms/SROA/address-spaces.ll
===================================================================
--- test/Transforms/SROA/address-spaces.ll
+++ test/Transforms/SROA/address-spaces.ll
@@ -83,3 +83,18 @@
   store i32 addrspace(3)* @l, i32 addrspace(3)** %3, align 8
   ret void
 }
+
+; Make sure pre-splitting doesn't try to introduce an illegal bitcast
+define float @presplit(i64 addrspace(1)* %p) {
+entry:
+   %b = alloca i64
+   %b.cast = bitcast i64* %b to [2 x float]*
+   %b.gep1 = getelementptr [2 x float], [2 x float]* %b.cast, i32 0, i32 0
+   %b.gep2 = getelementptr [2 x float], [2 x float]* %b.cast, i32 0, i32 1
+   %l = load i64, i64 addrspace(1)* %p
+   store i64 %l, i64* %b
+   %f1 = load float, float* %b.gep1
+   %f2 = load float, float* %b.gep2
+   %ret = fadd float %f1, %f2
+   ret float %ret
+}
Index: lib/Transforms/Scalar/SROA.cpp
===================================================================
--- lib/Transforms/Scalar/SROA.cpp
+++ lib/Transforms/Scalar/SROA.cpp
@@ -3697,7 +3697,8 @@
     int Idx = 0, Size = Offsets.Splits.size();
     for (;;) {
       auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
-      auto *PartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
+      auto *LoadPartPtrTy = PartTy->getPointerTo(LI->getPointerAddressSpace());
+      auto *StorePartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
 
       // Either lookup a split load or create one.
       LoadInst *PLoad;
@@ -3708,7 +3709,7 @@
         PLoad = IRB.CreateAlignedLoad(
             getAdjustedPtr(IRB, DL, LoadBasePtr,
                            APInt(DL.getPointerSizeInBits(), PartOffset),
-                           PartPtrTy, LoadBasePtr->getName() + "."),
+                           LoadPartPtrTy, LoadBasePtr->getName() + "."),
             getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
             LI->getName());
       }
@@ -3718,7 +3719,7 @@
       StoreInst *PStore = IRB.CreateAlignedStore(
           PLoad, getAdjustedPtr(IRB, DL, StoreBasePtr,
                                 APInt(DL.getPointerSizeInBits(), PartOffset),
-                                PartPtrTy, StoreBasePtr->getName() + "."),
+                                StorePartPtrTy, StoreBasePtr->getName() + "."),
           getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
 
       // Now build a new slice for the alloca.


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