diff options
Diffstat (limited to 'llvm/test/Transforms/LoopIdiom/basic.ll')
-rw-r--r-- | llvm/test/Transforms/LoopIdiom/basic.ll | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopIdiom/basic.ll b/llvm/test/Transforms/LoopIdiom/basic.ll index 0bf4ad4f6495..e30d20a22299 100644 --- a/llvm/test/Transforms/LoopIdiom/basic.ll +++ b/llvm/test/Transforms/LoopIdiom/basic.ll @@ -1530,6 +1530,49 @@ for.body: ; preds = %entry, %for.body br i1 %cmp, label %for.body, label %for.cond.cleanup } +; Do not form memmove when there's an aliasing operation, even +; if the memcpy source and destination are in the same object. +define void @do_not_form_memmove8(i64* %p) { +; CHECK-LABEL: @do_not_form_memmove8( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[P2:%.*]] = getelementptr inbounds i64, i64* [[P:%.*]], i64 1000 +; CHECK-NEXT: br label [[LOOP:%.*]] +; CHECK: exit: +; CHECK-NEXT: ret void +; CHECK: loop: +; CHECK-NEXT: [[X4:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[X13:%.*]], [[LOOP]] ] +; CHECK-NEXT: [[X5:%.*]] = zext i32 [[X4]] to i64 +; CHECK-NEXT: [[X7:%.*]] = getelementptr inbounds i64, i64* [[P2]], i64 [[X5]] +; CHECK-NEXT: [[X8:%.*]] = bitcast i64* [[X7]] to i8* +; CHECK-NEXT: store i64 1, i64* [[X7]], align 4 +; CHECK-NEXT: [[X11:%.*]] = getelementptr inbounds i64, i64* [[P]], i64 [[X5]] +; CHECK-NEXT: [[X12:%.*]] = bitcast i64* [[X11]] to i8* +; CHECK-NEXT: tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[X12]], i8* [[X8]], i64 8, i1 false) +; CHECK-NEXT: [[X13]] = add i32 [[X4]], 1 +; CHECK-NEXT: [[X14:%.*]] = icmp eq i32 [[X13]], 44 +; CHECK-NEXT: br i1 [[X14]], label [[EXIT:%.*]], label [[LOOP]] +; +entry: + %p2 = getelementptr inbounds i64, i64* %p, i64 1000 + br label %loop + +exit: + ret void + +loop: + %x4 = phi i32 [ 0, %entry ], [ %x13, %loop ] + %x5 = zext i32 %x4 to i64 + %x7 = getelementptr inbounds i64, i64* %p2, i64 %x5 + %x8 = bitcast i64* %x7 to i8* + store i64 1, i64* %x7, align 4 + %x11 = getelementptr inbounds i64, i64* %p, i64 %x5 + %x12 = bitcast i64* %x11 to i8* + tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %x12, i8* %x8, i64 8, i1 false) + %x13 = add i32 %x4, 1 + %x14 = icmp eq i32 %x13, 44 + br i1 %x14, label %exit, label %loop +} + ;; Memcpy formation is still preferred over memmove. define void @prefer_memcpy_over_memmove(i8* noalias %Src, i8* noalias %Dest, i64 %Size) { ; CHECK-LABEL: @prefer_memcpy_over_memmove( |