Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp =================================================================== --- llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -552,7 +552,8 @@ ConstantInt::get(IdxType, i), }; auto *Ptr = IC.Builder->CreateInBoundsGEP(ST, Addr, makeArrayRef(Indices), EltName); - auto *L = IC.Builder->CreateLoad(ST->getTypeAtIndex(i), Ptr, LoadName); + auto *L = IC.Builder->CreateAlignedLoad(Ptr, LI.getAlignment(), + LoadName); V = IC.Builder->CreateInsertValue(V, L, i); } Index: llvm/trunk/test/Transforms/InstCombine/unpack-fca.ll =================================================================== --- llvm/trunk/test/Transforms/InstCombine/unpack-fca.ll +++ llvm/trunk/test/Transforms/InstCombine/unpack-fca.ll @@ -136,3 +136,18 @@ %1 = load %B, %B* %b.ptr, align 8 ret %B %1 } + +%struct.S = type <{ i8, %struct.T }> +%struct.T = type { i32, i32 } + +; Make sure that we do not increase alignment of packed struct element +define i32 @packed_alignment(%struct.S* dereferenceable(9) %s) { +; CHECK-LABEL: packed_alignment +; CHECK-NEXT: %tv.elt1 = getelementptr inbounds %struct.S, %struct.S* %s, i64 0, i32 1, i32 1 +; CHECK-NEXT: %tv.unpack2 = load i32, i32* %tv.elt1, align 1 +; CHECK-NEXT: ret i32 %tv.unpack2 + %t = getelementptr inbounds %struct.S, %struct.S* %s, i32 0, i32 1 + %tv = load %struct.T, %struct.T* %t, align 1 + %v = extractvalue %struct.T %tv, 1 + ret i32 %v +}