third_party/llvm-7.0/llvm/test/Transforms/LoopUnroll/unroll-heuristics-pgo.ll

; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-threshold=40 -unroll-max-percent-threshold-boost=100 | FileCheck %s

@known_constant = internal unnamed_addr constant [9 x i32] [i32 0, i32 -1, i32 0, i32 -1, i32 5, i32 -1, i32 0, i32 -1, i32 0], align 16

; CHECK-LABEL: @bar_prof
; CHECK: loop:
; CHECK: %mul = mul
; CHECK: %mul.1 = mul
; CHECK: %mul.2 = mul
; CHECK: %mul.3 = mul
; CHECK: loop.epil:
define i32 @bar_prof(i32* noalias nocapture readonly %src, i64 %c) !prof !1 {
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]
  %r  = phi i32 [ 0, %entry ], [ %add, %loop ]
  %arrayidx = getelementptr inbounds i32, i32* %src, i64 %iv
  %src_element = load i32, i32* %arrayidx, align 4
  %array_const_idx = getelementptr inbounds [9 x i32], [9 x i32]* @known_constant, i64 0, i64 %iv
  %const_array_element = load i32, i32* %array_const_idx, align 4
  %mul = mul nsw i32 %src_element, %const_array_element
  %add = add nsw i32 %mul, %r
  %inc = add nuw nsw i64 %iv, 1
  %exitcond86.i = icmp eq i64 %inc, %c
  br i1 %exitcond86.i, label %loop.end, label %loop, !prof !2

loop.end:
  %r.lcssa = phi i32 [ %r, %loop ]
  ret i32 %r.lcssa
}

; CHECK-LABEL: @bar_prof_flat
; CHECK-NOT: loop.epil
define i32 @bar_prof_flat(i32* noalias nocapture readonly %src, i64 %c) !prof !1 {
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]
  %r  = phi i32 [ 0, %entry ], [ %add, %loop ]
  %arrayidx = getelementptr inbounds i32, i32* %src, i64 %iv
  %src_element = load i32, i32* %arrayidx, align 4
  %array_const_idx = getelementptr inbounds [9 x i32], [9 x i32]* @known_constant, i64 0, i64 %iv
  %const_array_element = load i32, i32* %array_const_idx, align 4
  %mul = mul nsw i32 %src_element, %const_array_element
  %add = add nsw i32 %mul, %r
  %inc = add nuw nsw i64 %iv, 1
  %exitcond86.i = icmp eq i64 %inc, %c
  br i1 %exitcond86.i, label %loop, label %loop.end, !prof !2

loop.end:
  %r.lcssa = phi i32 [ %r, %loop ]
  ret i32 %r.lcssa
}

!1 = !{!"function_entry_count", i64 1}
!2 = !{!"branch_weights", i32 1, i32 1000}