runtime-loop2.ll   [plain text]

; RUN: opt < %s -S -loop-unroll -unroll-threshold=50 -unroll-runtime -unroll-count=8 | FileCheck %s

; Choose a smaller, power-of-two, unroll count if the loop is too large.
; This test makes sure we're not unrolling 'odd' counts

; CHECK: unr.cmp:
; CHECK: for.body.unr:
; CHECK: for.body:
; CHECK: br i1 %exitcond.3, label %for.end.loopexit{{.*}}, label %for.body
; CHECK-NOT: br i1 %exitcond.4, label %for.end.loopexit{{.*}}, label %for.body

define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly {
entry:
  %cmp1 = icmp eq i32 %n, 0
  br i1 %cmp1, label %for.end, label %for.body

for.body:                                         ; preds = %for.body, %entry
  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
  %sum.02 = phi i32 [ %add, %for.body ], [ 0, %entry ]
  %arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
  %0 = load i32* %arrayidx, align 4
  %add = add nsw i32 %0, %sum.02
  %indvars.iv.next = add i64 %indvars.iv, 1
  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
  %exitcond = icmp eq i32 %lftr.wideiv, %n
  br i1 %exitcond, label %for.end, label %for.body

for.end:                                          ; preds = %for.body, %entry
  %sum.0.lcssa = phi i32 [ 0, %entry ], [ %add, %for.body ]
  ret i32 %sum.0.lcssa
}