llvm/test/Transforms/LoopVectorize/X86/tail_loop_folding.ll

; RUN: opt < %s -loop-vectorize -S | FileCheck %s

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

define dso_local void @tail_folding_enabled(i32* noalias nocapture %A, i32* noalias nocapture readonly %B, i32* noalias nocapture readonly %C) local_unnamed_addr #0 {
; CHECK-LABEL: tail_folding_enabled(
; CHECK:  vector.body:
; CHECK:  %wide.masked.load = call <8 x i32> @llvm.masked.load.v8i32.p0v8i32(
; CHECK:  %wide.masked.load1 = call <8 x i32> @llvm.masked.load.v8i32.p0v8i32(
; CHECK:  %8 = add nsw <8 x i32> %wide.masked.load1, %wide.masked.load
; CHECK:  call void @llvm.masked.store.v8i32.p0v8i32(
; CHECK:  %index.next = add i64 %index, 8
; CHECK:  %12 = icmp eq i64 %index.next, 432
; CHECK:  br i1 %12, label %middle.block, label %vector.body, !llvm.loop !0

entry:
  br label %for.body

for.cond.cleanup:
  ret void

for.body:
  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
  %arrayidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
  %0 = load i32, i32* %arrayidx, align 4
  %arrayidx2 = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
  %1 = load i32, i32* %arrayidx2, align 4
  %add = add nsw i32 %1, %0
  %arrayidx4 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
  store i32 %add, i32* %arrayidx4, align 4
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond = icmp eq i64 %indvars.iv.next, 430
  br i1 %exitcond, label %for.cond.cleanup, label %for.body, !llvm.loop !6
}

define dso_local void @tail_folding_disabled(i32* noalias nocapture %A, i32* noalias nocapture readonly %B, i32* noalias nocapture readonly %C) local_unnamed_addr #0 {
; CHECK-LABEL: tail_folding_disabled(
; CHECK:      vector.body:
; CHECK-NOT:  @llvm.masked.load.v8i32.p0v8i32(
; CHECK-NOT:  @llvm.masked.store.v8i32.p0v8i32(
; CHECK:      br i1 %44, label {{.*}}, label %vector.body
entry:
  br label %for.body

for.cond.cleanup:
  ret void

for.body:
  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
  %arrayidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
  %0 = load i32, i32* %arrayidx, align 4
  %arrayidx2 = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
  %1 = load i32, i32* %arrayidx2, align 4
  %add = add nsw i32 %1, %0
  %arrayidx4 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
  store i32 %add, i32* %arrayidx4, align 4
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond = icmp eq i64 %indvars.iv.next, 430
  br i1 %exitcond, label %for.cond.cleanup, label %for.body, !llvm.loop !10
}

; CHECK:      !0 = distinct !{!0, !1}
; CHECK-NEXT: !1 = !{!"llvm.loop.isvectorized", i32 1}
; CHECK-NEXT: !2 = distinct !{!2, !3, !1}
; CHECK-NEXT: !3 = !{!"llvm.loop.unroll.runtime.disable"}
; CHECK-NEXT: !4 = distinct !{!4, !1}
; CHECK-NEXT: !5 = distinct !{!5, !3, !1}

attributes #0 = { nounwind optsize uwtable "target-cpu"="core-avx2" "target-features"="+avx,+avx2" }

!6 = distinct !{!6, !7, !8}
!7 = !{!"llvm.loop.vectorize.predicate.enable", i1 true}
!8 = !{!"llvm.loop.vectorize.enable", i1 true}

!10 = distinct !{!10, !11, !12}
!11 = !{!"llvm.loop.vectorize.predicate.enable", i1 false}
!12 = !{!"llvm.loop.vectorize.enable", i1 true}