[LoopVectorize] Add test for follow-up metadata for loops (NFC)

llvm/test/Transforms/LoopVectorize/make-followup-loop-id.ll

@@ -0,0 +1,87 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes='loop-vectorize,loop-unroll' -force-vector-width=4 -S < %s | FileCheck %s
+
+; Test if the follow-up metadata for loops works fine. The original code is
+; something like below. In this case, unrolling should be applied after
+; vectorization.
+;
+; void f(float *a, float x) {
+;   #pragma clang loop vectorize(enable) unroll_count(8)
+;   for (int i = 0; i < 1024; i++) {
+;     a[i] *= x;
+;   }
+; }
+;
+; FIXME: Currently unrolling is not applied. This is because the new Loop ID
+; created after vectorization does not directly contain unroll metadata.
+; Unexpected nests have been created.
+define void @f(ptr noundef captures(none) %a, float noundef %x) {
+; CHECK-LABEL: define void @f(
+; CHECK-SAME: ptr noundef captures(none) [[A:%.*]], float noundef [[X:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
+; CHECK:       [[VECTOR_PH]]:
+; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x float> poison, float [[X]], i64 0
+; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x float> [[BROADCAST_SPLATINSERT]], <4 x float> poison, <4 x i32> zeroinitializer
+; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
+; CHECK:       [[VECTOR_BODY]]:
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[INDEX_NEXT_6:%.*]] = add i64 [[INDEX]], 0
+; CHECK-NEXT:    [[TMP14:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_6]]
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds nuw float, ptr [[TMP14]], i32 0
+; CHECK-NEXT:    [[WIDE_LOAD_7:%.*]] = load <4 x float>, ptr [[TMP2]], align 4
+; CHECK-NEXT:    [[TMP15:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_7]]
+; CHECK-NEXT:    store <4 x float> [[TMP15]], ptr [[TMP2]], align 4
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[INDEX_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[TMP4]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK:       [[MIDDLE_BLOCK]]:
+; CHECK-NEXT:    br i1 true, label %[[EXIT:.*]], label %[[SCALAR_PH]]
+; CHECK:       [[SCALAR_PH]]:
+; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ 1024, %[[MIDDLE_BLOCK]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    br label %[[FOR_BODY:.*]]
+; CHECK:       [[FOR_BODY]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[FOR_BODY]] ]
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV]]
+; CHECK-NEXT:    [[LOAD:%.*]] = load float, ptr [[ARRAYIDX]], align 4
+; CHECK-NEXT:    [[MUL:%.*]] = fmul float [[X]], [[LOAD]]
+; CHECK-NEXT:    store float [[MUL]], ptr [[ARRAYIDX]], align 4
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
+; CHECK-NEXT:    [[COMP:%.*]] = icmp eq i64 [[IV_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[COMP]], label %[[EXIT_LOOPEXIT:.*]], label %[[FOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
+; CHECK:       [[EXIT_LOOPEXIT]]:
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds nuw float, ptr %a, i64 %iv
+  %load = load float, ptr %arrayidx, align 4
+  %mul = fmul float %x, %load
+  store float %mul, ptr %arrayidx, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %comp = icmp eq i64 %iv.next, 1024
+  br i1 %comp, label %exit, label %for.body, !llvm.loop !0
+
+exit:
+  ret void
+}
+
+!0 = distinct !{!0, !1, !2}
+!1 = !{!"llvm.loop.vectorize.enable", i1 true}
+!2 = !{!"llvm.loop.vectorize.followup_all", !3}
+!3 = distinct !{!3, !4, !5}
+!4 = !{!"llvm.loop.isvectorized"}
+!5 = !{!"llvm.loop.unroll.count", i32 8}
+;.
+; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META4:![0-9]+]]}
+; CHECK: [[META1]] = distinct !{[[META1]], [[META2:![0-9]+]], [[META3:![0-9]+]]}
+; CHECK: [[META2]] = !{!"llvm.loop.isvectorized"}
+; CHECK: [[META3]] = !{!"llvm.loop.unroll.count", i32 8}
+; CHECK: [[META4]] = !{!"llvm.loop.unroll.runtime.disable"}
+; CHECK: [[LOOP5]] = distinct !{[[LOOP5]], [[META1]]}
+;.