[llvm] r304585 - [SROA] Fix crash due to bad bitcast

[Keno Fischer via llvm-commits]

Author: kfischer
Date: Fri Jun  2 14:04:17 2017
New Revision: 304585

URL: http://llvm.org/viewvc/llvm-project?rev=304585&view=rev
Log:
[SROA] Fix crash due to bad bitcast

Summary:
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.

Reviewed By: yaxunl
Differential Revision: https://reviews.llvm.org/D32593

Modified:
    llvm/trunk/lib/Transforms/Scalar/SROA.cpp
    llvm/trunk/test/Transforms/SROA/address-spaces.ll

Modified: llvm/trunk/lib/Transforms/Scalar/SROA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SROA.cpp?rev=304585&r1=304584&r2=304585&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SROA.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SROA.cpp Fri Jun  2 14:04:17 2017
@@ -3698,7 +3698,8 @@ bool SROA::presplitLoadsAndStores(Alloca
     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;
@@ -3709,7 +3710,7 @@ bool SROA::presplitLoadsAndStores(Alloca
         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());
       }
@@ -3719,7 +3720,7 @@ bool SROA::presplitLoadsAndStores(Alloca
       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.

Modified: llvm/trunk/test/Transforms/SROA/address-spaces.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SROA/address-spaces.ll?rev=304585&r1=304584&r2=304585&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SROA/address-spaces.ll (original)
+++ llvm/trunk/test/Transforms/SROA/address-spaces.ll Fri Jun  2 14:04:17 2017
@@ -83,3 +83,21 @@ define void @pr27557() {
   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:
+; CHECK-LABEL: @presplit(
+; CHECK: %[[CAST:.*]] = bitcast i64 addrspace(1)* {{.*}} to i32 addrspace(1)*
+; CHECK: load i32, i32 addrspace(1)* %[[CAST]]
+   %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
+}