llvm-project/llvm/test/Transforms/IRCE/only-lower-check.ll

; RUN: opt -irce-print-range-checks -irce-print-changed-loops -verify-loop-info -irce < %s 2>&1 | FileCheck %s

; CHECK: irce: loop has 1 inductive range checks:
; CHECK-NEXT: InductiveRangeCheck:
; CHECK-NEXT:   Kind: RANGE_CHECK_LOWER
; CHECK-NEXT:   Offset: (-1 + %n)  Scale: -1  Length: (null)
; CHECK-NEXT:   CheckUse:   br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1 Operand: 0
; CHECK-NEXT: irce: in function only_lower_check: constrained Loop at depth 1 containing: %loop<header><exiting>,%in.bounds<latch><exiting>

define void @only_lower_check(i32 *%arr, i32 *%a_len_ptr, i32 %n) {
 entry:
  %len = load i32, i32* %a_len_ptr, !range !0
  %first.itr.check = icmp sgt i32 %n, 0
  %start = sub i32 %n, 1
  br i1 %first.itr.check, label %loop, label %exit

 loop:
  %idx = phi i32 [ %start, %entry ] , [ %idx.dec, %in.bounds ]
  %idx.dec = sub i32 %idx, 1
  %abc = icmp sge i32 %idx, 0
  br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1

 in.bounds:
  %addr = getelementptr i32, i32* %arr, i32 %idx
  store i32 0, i32* %addr
  %next = icmp sgt i32 %idx.dec, -1
  br i1 %next, label %loop, label %exit

 out.of.bounds:
  ret void

 exit:
  ret void
}

!0 = !{i32 0, i32 2147483647}
!1 = !{!"branch_weights", i32 64, i32 4}