diff --git a/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll b/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll index 6c4c16a94a5f..8abfcbf4444c 100644 --- a/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll +++ b/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll @@ -3,6 +3,10 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +@a = external global [32 x i8], align 16 + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64, i1 immarg) + ; Test case for PR16520. The store in %if.then is dead, because the same value ; has been stored earlier to the same location. define void @test1_pr16520(i1 %b, i8* nocapture %r) { @@ -296,3 +300,16 @@ define void @pr49927(i32* %q, i32* %p) { store i32 %v, i32* %p, align 4 ret void } + + +define void @pr50339(i8* nocapture readonly %0) { +; CHECK-LABEL: @pr50339( +; CHECK-NEXT: tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 16 dereferenceable(16) getelementptr inbounds ([32 x i8], [32 x i8]* @a, i64 0, i64 0), i8* noundef nonnull align 1 dereferenceable(16) [[TMP0:%.*]], i64 16, i1 false) +; CHECK-NEXT: tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 16 dereferenceable(16) getelementptr inbounds ([32 x i8], [32 x i8]* @a, i64 0, i64 0), i8* noundef nonnull align 1 dereferenceable(16) [[TMP0]], i64 16, i1 false) +; CHECK-NEXT: ret void +; + tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 16 dereferenceable(16) getelementptr inbounds ([32 x i8], [32 x i8]* @a, i64 0, i64 0), i8* noundef nonnull align 1 dereferenceable(16) %0, i64 16, i1 false) + ; FIXME: Eliminate the second memcpy as a "store of existing value" for this particular case, where both memcpy's are identical (same source, not just same dest). + tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 16 dereferenceable(16) getelementptr inbounds ([32 x i8], [32 x i8]* @a, i64 0, i64 0), i8* noundef nonnull align 1 dereferenceable(16) %0, i64 16, i1 false) + ret void +}