[LV] Update make-follow-up-loop-id.ll to actually check metadata.

Update make-follow-up-loop-id.ll to make it independent of loop-unroll
by just checking if the correct metadata gets emitted for the scalar and
vector loops.

Also added a test to check for the case when the scalar loop is not
known to be dead.

Author: fhahn

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

@@ -1,9 +1,9 @@
 ; 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
+; RUN: opt -passes='loop-vectorize' -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.
+; something like below. In this case, the unrolling metadata from the original
+; loop should be applied to the vector loop as well.
 ;
 ; void f(float *a, float x) {
 ;   #pragma clang loop vectorize(enable) unroll_count(8)
@@ -12,8 +12,8 @@
 ;   }
 ; }
 ;
-define void @f(ptr noundef captures(none) %a, float noundef %x) {
-; CHECK-LABEL: define void @f(
+define void @scalar_loop_dead(ptr noundef captures(none) %a, float noundef %x) {
+; CHECK-LABEL: define void @scalar_loop_dead(
 ; CHECK-SAME: ptr noundef captures(none) [[A:%.*]], float noundef [[X:%.*]]) {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
 ; CHECK-NEXT:    br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
@@ -22,126 +22,113 @@ define void @f(ptr noundef captures(none) %a, float noundef %x) {
 ; 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_NEXT_6:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[TMP14:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_6]]
-; CHECK-NEXT:    [[WIDE_LOAD_7:%.*]] = load <4 x float>, ptr [[TMP14]], align 4
-; CHECK-NEXT:    [[TMP15:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_7]]
-; CHECK-NEXT:    store <4 x float> [[TMP15]], ptr [[TMP14]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT1:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 4
-; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT1]]
-; CHECK-NEXT:    [[WIDE_LOAD_1:%.*]] = load <4 x float>, ptr [[TMP2]], align 4
-; CHECK-NEXT:    [[TMP3:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_1]]
-; CHECK-NEXT:    store <4 x float> [[TMP3]], ptr [[TMP2]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT_1:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 8
-; CHECK-NEXT:    [[TMP16:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_1]]
-; CHECK-NEXT:    [[WIDE_LOAD_2:%.*]] = load <4 x float>, ptr [[TMP16]], align 4
-; CHECK-NEXT:    [[TMP5:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_2]]
-; CHECK-NEXT:    store <4 x float> [[TMP5]], ptr [[TMP16]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT_2:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 12
-; CHECK-NEXT:    [[TMP6:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_2]]
-; CHECK-NEXT:    [[WIDE_LOAD_3:%.*]] = load <4 x float>, ptr [[TMP6]], align 4
-; CHECK-NEXT:    [[TMP7:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_3]]
-; CHECK-NEXT:    store <4 x float> [[TMP7]], ptr [[TMP6]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT_3:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 16
-; CHECK-NEXT:    [[TMP8:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_3]]
-; CHECK-NEXT:    [[WIDE_LOAD_4:%.*]] = load <4 x float>, ptr [[TMP8]], align 4
-; CHECK-NEXT:    [[TMP9:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_4]]
-; CHECK-NEXT:    store <4 x float> [[TMP9]], ptr [[TMP8]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT_4:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 20
-; CHECK-NEXT:    [[TMP10:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_4]]
-; CHECK-NEXT:    [[WIDE_LOAD_5:%.*]] = load <4 x float>, ptr [[TMP10]], align 4
-; CHECK-NEXT:    [[TMP11:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_5]]
-; CHECK-NEXT:    store <4 x float> [[TMP11]], ptr [[TMP10]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT_5:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 24
-; CHECK-NEXT:    [[TMP12:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_5]]
-; CHECK-NEXT:    [[WIDE_LOAD_6:%.*]] = load <4 x float>, ptr [[TMP12]], align 4
-; CHECK-NEXT:    [[TMP13:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_6]]
-; CHECK-NEXT:    store <4 x float> [[TMP13]], ptr [[TMP12]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT_7:%.*]] = add nuw nsw i64 [[INDEX_NEXT_6]], 28
-; CHECK-NEXT:    [[TMP17:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX_NEXT_7]]
-; CHECK-NEXT:    [[WIDE_LOAD_8:%.*]] = load <4 x float>, ptr [[TMP17]], align 4
-; CHECK-NEXT:    [[TMP18:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD_8]]
-; CHECK-NEXT:    store <4 x float> [[TMP18]], ptr [[TMP17]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw nsw i64 [[INDEX_NEXT_6]], 32
-; 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-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX]]
+; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x float>, ptr [[TMP0]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD]]
+; CHECK-NEXT:    store <4 x float> [[TMP1]], ptr [[TMP0]], align 4
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[TMP2]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
 ; CHECK:       [[MIDDLE_BLOCK]]:
 ; CHECK-NEXT:    br label %[[EXIT:.*]]
 ; CHECK:       [[SCALAR_PH]]:
-; CHECK-NEXT:    br label %[[FOR_BODY:.*]]
-; CHECK:       [[FOR_BODY]]:
-; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[SCALAR_PH]] ], [ [[IV_NEXT_7:%.*]], %[[FOR_BODY]] ]
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
 ; 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:    [[ARRAYIDX_1:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT]]
-; CHECK-NEXT:    [[LOAD_1:%.*]] = load float, ptr [[ARRAYIDX_1]], align 4
-; CHECK-NEXT:    [[MUL_1:%.*]] = fmul float [[X]], [[LOAD_1]]
-; CHECK-NEXT:    store float [[MUL_1]], ptr [[ARRAYIDX_1]], align 4
-; CHECK-NEXT:    [[IV_NEXT_1:%.*]] = add nuw nsw i64 [[IV]], 2
-; CHECK-NEXT:    [[ARRAYIDX_2:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT_1]]
-; CHECK-NEXT:    [[LOAD_2:%.*]] = load float, ptr [[ARRAYIDX_2]], align 4
-; CHECK-NEXT:    [[MUL_2:%.*]] = fmul float [[X]], [[LOAD_2]]
-; CHECK-NEXT:    store float [[MUL_2]], ptr [[ARRAYIDX_2]], align 4
-; CHECK-NEXT:    [[IV_NEXT_2:%.*]] = add nuw nsw i64 [[IV]], 3
-; CHECK-NEXT:    [[ARRAYIDX_3:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT_2]]
-; CHECK-NEXT:    [[LOAD_3:%.*]] = load float, ptr [[ARRAYIDX_3]], align 4
-; CHECK-NEXT:    [[MUL_3:%.*]] = fmul float [[X]], [[LOAD_3]]
-; CHECK-NEXT:    store float [[MUL_3]], ptr [[ARRAYIDX_3]], align 4
-; CHECK-NEXT:    [[IV_NEXT_3:%.*]] = add nuw nsw i64 [[IV]], 4
-; CHECK-NEXT:    [[ARRAYIDX_4:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT_3]]
-; CHECK-NEXT:    [[LOAD_4:%.*]] = load float, ptr [[ARRAYIDX_4]], align 4
-; CHECK-NEXT:    [[MUL_4:%.*]] = fmul float [[X]], [[LOAD_4]]
-; CHECK-NEXT:    store float [[MUL_4]], ptr [[ARRAYIDX_4]], align 4
-; CHECK-NEXT:    [[IV_NEXT_4:%.*]] = add nuw nsw i64 [[IV]], 5
-; CHECK-NEXT:    [[ARRAYIDX_5:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT_4]]
-; CHECK-NEXT:    [[LOAD_5:%.*]] = load float, ptr [[ARRAYIDX_5]], align 4
-; CHECK-NEXT:    [[MUL_5:%.*]] = fmul float [[X]], [[LOAD_5]]
-; CHECK-NEXT:    store float [[MUL_5]], ptr [[ARRAYIDX_5]], align 4
-; CHECK-NEXT:    [[IV_NEXT_5:%.*]] = add nuw nsw i64 [[IV]], 6
-; CHECK-NEXT:    [[ARRAYIDX_6:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT_5]]
-; CHECK-NEXT:    [[LOAD_6:%.*]] = load float, ptr [[ARRAYIDX_6]], align 4
-; CHECK-NEXT:    [[MUL_6:%.*]] = fmul float [[X]], [[LOAD_6]]
-; CHECK-NEXT:    store float [[MUL_6]], ptr [[ARRAYIDX_6]], align 4
-; CHECK-NEXT:    [[IV_NEXT_6:%.*]] = add nuw nsw i64 [[IV]], 7
-; CHECK-NEXT:    [[ARRAYIDX_7:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[IV_NEXT_6]]
-; CHECK-NEXT:    [[LOAD_7:%.*]] = load float, ptr [[ARRAYIDX_7]], align 4
-; CHECK-NEXT:    [[MUL_7:%.*]] = fmul float [[X]], [[LOAD_7]]
-; CHECK-NEXT:    store float [[MUL_7]], ptr [[ARRAYIDX_7]], align 4
-; CHECK-NEXT:    [[IV_NEXT_7]] = add nuw nsw i64 [[IV]], 8
-; CHECK-NEXT:    br i1 true, label %[[EXIT_LOOPEXIT:.*]], label %[[FOR_BODY]], !llvm.loop [[LOOP3:![0-9]+]]
-; CHECK:       [[EXIT_LOOPEXIT]]:
-; CHECK-NEXT:    br label %[[EXIT]]
+; 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]], label %[[LOOP]], !llvm.loop [[LOOP4:![0-9]+]]
 ; CHECK:       [[EXIT]]:
 ; CHECK-NEXT:    ret void
 ;
 entry:
-  br label %for.body
+  br label %loop
 
-for.body:
-  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ]
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
   %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
+  br i1 %comp, label %exit, label %loop, !llvm.loop !0
 
 exit:
   ret void
 }
 
+define void @scalar_loop_live(ptr noundef captures(none) %a, float noundef %x, i64 %n) {
+; CHECK-LABEL: define void @scalar_loop_live(
+; CHECK-SAME: ptr noundef captures(none) [[A:%.*]], float noundef [[X:%.*]], i64 [[N:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[N]], 4
+; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
+; CHECK:       [[VECTOR_PH]]:
+; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[N]], 4
+; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[N]], [[N_MOD_VF]]
+; 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:    [[TMP0:%.*]] = getelementptr inbounds nuw float, ptr [[A]], i64 [[INDEX]]
+; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x float>, ptr [[TMP0]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = fmul <4 x float> [[BROADCAST_SPLAT]], [[WIDE_LOAD]]
+; CHECK-NEXT:    store <4 x float> [[TMP1]], ptr [[TMP0]], align 4
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
+; CHECK-NEXT:    br i1 [[TMP2]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
+; CHECK:       [[MIDDLE_BLOCK]]:
+; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[N]], [[N_VEC]]
+; CHECK-NEXT:    br i1 [[CMP_N]], label %[[EXIT:.*]], label %[[SCALAR_PH]]
+; CHECK:       [[SCALAR_PH]]:
+; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], %[[MIDDLE_BLOCK]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; 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]], [[N]]
+; CHECK-NEXT:    br i1 [[COMP]], label %[[EXIT]], label %[[LOOP]], !llvm.loop [[LOOP6:![0-9]+]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %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, %n
+  br i1 %comp, label %exit, label %loop, !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, !4}
 !3 = !{!"llvm.loop.isvectorized"}
 !4 = !{!"llvm.loop.unroll.count", i32 8}
 ;.
-; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]]}
+; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]], [[META3:![0-9]+]]}
 ; CHECK: [[META1]] = !{!"llvm.loop.isvectorized"}
-; CHECK: [[META2]] = !{!"llvm.loop.unroll.disable"}
-; CHECK: [[LOOP3]] = distinct !{[[LOOP3]], [[META1]], [[META2]]}
+; CHECK: [[META2]] = !{!"llvm.loop.unroll.count", i32 8}
+; CHECK: [[META3]] = !{!"llvm.loop.unroll.runtime.disable"}
+; CHECK: [[LOOP4]] = distinct !{[[LOOP4]], [[META1]], [[META2]]}
+; CHECK: [[LOOP5]] = distinct !{[[LOOP5]], [[META1]], [[META2]], [[META3]]}
+; CHECK: [[LOOP6]] = distinct !{[[LOOP6]], [[META1]], [[META2]]}
 ;.