diff --git a/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll b/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll --- a/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll +++ b/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll @@ -575,5 +575,37 @@ ret void } +; TODO: Even though %num is known to divide by 4, and the loop's IV advances by 4, SCEV can't compute the trip count. +define void @test_trip_multiple_4_vectorized_iv(i32 %num) { +; CHECK-LABEL: 'test_trip_multiple_4_vectorized_iv' +; CHECK-NEXT: Classifying expressions for: @test_trip_multiple_4_vectorized_iv +; CHECK-NEXT: %u = urem i32 %num, 4 +; CHECK-NEXT: --> (zext i2 (trunc i32 %num to i2) to i32) U: [0,4) S: [0,4) +; CHECK-NEXT: %i.010 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +; CHECK-NEXT: --> {0,+,4}<%for.body> U: [0,-3) S: [-2147483648,2147483645) Exits: <> LoopDispositions: { %for.body: Computable } +; CHECK-NEXT: %inc = add i32 %i.010, 4 +; CHECK-NEXT: --> {4,+,4}<%for.body> U: [0,-3) S: [-2147483648,2147483645) Exits: <> LoopDispositions: { %for.body: Computable } +; CHECK-NEXT: Determining loop execution counts for: @test_trip_multiple_4_vectorized_iv +; CHECK-NEXT: Loop %for.body: Unpredictable backedge-taken count. +; CHECK-NEXT: Loop %for.body: Unpredictable constant max backedge-taken count. +; CHECK-NEXT: Loop %for.body: Unpredictable symbolic max backedge-taken count. +; CHECK-NEXT: Loop %for.body: Unpredictable predicated backedge-taken count. +; +entry: + %u = urem i32 %num, 4 + %cmp = icmp eq i32 %u, 0 + tail call void @llvm.assume(i1 %cmp) + br label %for.body + +for.body: + %i.010 = phi i32 [ 0, %entry ], [ %inc, %for.body ] + %inc = add i32 %i.010, 4 + %cmp2 = icmp ult i32 %inc, %num + br i1 %cmp2, label %for.body, label %exit + +exit: + ret void +} + declare void @llvm.assume(i1) declare void @llvm.experimental.guard(i1, ...)