Index: lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp =================================================================== --- lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -870,6 +870,15 @@ } } + if (auto *AT = dyn_cast(T)) { + // If the array only have one element, we unpack. + if (AT->getNumElements() == 1) { + V = IC.Builder->CreateExtractValue(V, 0); + combineStoreToNewValue(IC, SI, V); + return true; + } + } + return false; } Index: test/Transforms/InstCombine/unpack-fca.ll =================================================================== --- test/Transforms/InstCombine/unpack-fca.ll +++ test/Transforms/InstCombine/unpack-fca.ll @@ -32,6 +32,26 @@ ret void } +define void @storeArrayOfA() { +body: + %0 = tail call i8* @allocmemory(i64 32) + %1 = bitcast i8* %0 to [1 x %A]* +; CHECK-LABEL: storeStructOfA +; CHECK: store %A__vtbl* @A__vtblZ + store [1 x %A] [%A { %A__vtbl* @A__vtblZ }], [1 x %A]* %1, align 8 + ret void +} + +define void @storeStructOfArrayOfA() { +body: + %0 = tail call i8* @allocmemory(i64 32) + %1 = bitcast i8* %0 to { [1 x %A] }* +; CHECK-LABEL: storeStructOfArrayOfA +; CHECK: store %A__vtbl* @A__vtblZ + store { [1 x %A] } { [1 x %A] [%A { %A__vtbl* @A__vtblZ }] }, { [1 x %A] }* %1, align 8 + ret void +} + define %A @loadA() { body: %0 = tail call i8* @allocmemory(i64 32)