llvm/test/Transforms/LoopUnroll/disable-after-count.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt < %s -passes=loop-unroll -S | FileCheck %s

; Verify that llvm.loop.unroll.disable is added after partial unrolling
; with a pragma unroll count, even when the last latch's exit branch is
; folded into an unconditional branch by UnrollLoop.
;
; The loop has trip count 5 and unroll count 2. After unrolling, the
; second copy's exit is folded (since iteration 2,4,... cannot be the
; last), and the conditional branch is replaced with an unconditional
; one that does not carry !llvm.loop metadata. setLoopAlreadyUnrolled
; must still mark the loop to prevent further unrolling.

define void @count(ptr %p) {
; CHECK-LABEL: define void @count(
; CHECK-SAME: ptr [[P:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT_1:%.*]], %[[LOOP_1:.*]] ]
; CHECK-NEXT:    [[PTR:%.*]] = getelementptr i32, ptr [[P]], i64 [[IV]]
; CHECK-NEXT:    store i32 0, ptr [[PTR]], align 4
; CHECK-NEXT:    [[IV_NEXT:%.*]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i64 [[IV_NEXT]], 5
; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP_1]], label %[[EXIT:.*]]
; CHECK:       [[LOOP_1]]:
; CHECK-NEXT:    [[PTR_1:%.*]] = getelementptr i32, ptr [[P]], i64 [[IV_NEXT]]
; CHECK-NEXT:    store i32 0, ptr [[PTR_1]], align 4
; CHECK-NEXT:    [[IV_NEXT_1]] = add nuw nsw i64 [[IV]], 2
; CHECK-NEXT:    br label %[[LOOP]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %ptr = getelementptr i32, ptr %p, i64 %iv
  store i32 0, ptr %ptr
  %iv.next = add nuw nsw i64 %iv, 1
  %cmp = icmp ne i64 %iv.next, 5
  br i1 %cmp, label %loop, label %exit, !llvm.loop !0

exit:
  ret void
}

!0 = distinct !{!0, !1}
!1 = !{!"llvm.loop.unroll.count", i32 2}
;.
; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]]}
; CHECK: [[META1]] = !{!"llvm.loop.unroll.disable"}
;.