test/Transforms/LoopSimplify/unique-backedge-loop-metadata.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes=loop-simplify < %s | FileCheck %s --implicit-check-not="!llvm.loop"

; When the backedges of a loop are merged into a unique backedge block, the
; llvm.loop metadata is only kept if all backedges carry the same loop ID.
; Backedges with different metadata may come from different source loops.
; The convergent call keeps LoopSimplify from separating the loops.
; The case where all backedges share the same loop ID is covered by
; preserve-llvm-loop-metadata.ll.

declare void @convergent() convergent

define void @different_md(i1 %c1, i1 %c2) {
; CHECK-LABEL: define void @different_md(
; CHECK-SAME: i1 [[C1:%.*]], i1 [[C2:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    br label %[[HEADER:.*]]
; CHECK:       [[HEADER]]:
; CHECK-NEXT:    call void @convergent()
; CHECK-NEXT:    br i1 [[C1]], label %[[INNER_LATCH:.*]], label %[[OUTER_LATCH:.*]]
; CHECK:       [[INNER_LATCH]]:
; CHECK-NEXT:    br i1 [[C2]], label %[[HEADER_BACKEDGE:.*]], label %[[EXIT:.*]]
; CHECK:       [[HEADER_BACKEDGE]]:
; CHECK-NEXT:    br label %[[HEADER]]
; CHECK:       [[OUTER_LATCH]]:
; CHECK-NEXT:    br i1 [[C2]], label %[[HEADER_BACKEDGE]], label %[[EXIT]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %header

header:
  call void @convergent()
  br i1 %c1, label %inner.latch, label %outer.latch

inner.latch:
  br i1 %c2, label %header, label %exit, !llvm.loop !0

outer.latch:
  br i1 %c2, label %header, label %exit, !llvm.loop !2

exit:
  ret void
}

define void @partial_md(i1 %c1, i1 %c2) {
; CHECK-LABEL: define void @partial_md(
; CHECK-SAME: i1 [[C1:%.*]], i1 [[C2:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    br label %[[HEADER:.*]]
; CHECK:       [[HEADER]]:
; CHECK-NEXT:    call void @convergent()
; CHECK-NEXT:    br i1 [[C1]], label %[[INNER_LATCH:.*]], label %[[OUTER_LATCH:.*]]
; CHECK:       [[INNER_LATCH]]:
; CHECK-NEXT:    br i1 [[C2]], label %[[HEADER_BACKEDGE:.*]], label %[[EXIT:.*]]
; CHECK:       [[HEADER_BACKEDGE]]:
; CHECK-NEXT:    br label %[[HEADER]]
; CHECK:       [[OUTER_LATCH]]:
; CHECK-NEXT:    br i1 [[C2]], label %[[HEADER_BACKEDGE]], label %[[EXIT]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %header

header:
  call void @convergent()
  br i1 %c1, label %inner.latch, label %outer.latch

inner.latch:
  br i1 %c2, label %header, label %exit, !llvm.loop !4

outer.latch:
  br i1 %c2, label %header, label %exit

exit:
  ret void
}

!0 = distinct !{!0, !1}
!1 = !{!"llvm.loop.mustprogress"}
!2 = distinct !{!2, !3}
!3 = !{!"llvm.loop.unroll.disable"}
!4 = distinct !{!4, !1}