llvm/test/Transforms/LoopUnroll/runtime-unroll-assume-no-remainder.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -S -loop-unroll -unroll-runtime=true -unroll-runtime-epilog=true -unroll-count=2 | FileCheck %s

; Make sure the loop is unrolled without a remainder loop based on an assumption
; that the least significant bit is known to be zero.

define dso_local void @assumeDivisibleTC(i8* noalias nocapture %a, i8* noalias nocapture readonly %b, i32 %p, i32 %q) local_unnamed_addr {
; CHECK-LABEL: @assumeDivisibleTC(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[AND:%.*]] = and i32 [[P:%.*]], 1
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[AND]], 0
; CHECK-NEXT:    br i1 [[CMP]], label [[GUARDED:%.*]], label [[EXIT:%.*]]
; CHECK:       guarded:
; CHECK-NEXT:    [[REM:%.*]] = urem i32 [[Q:%.*]], 2
; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i32 [[REM]], 0
; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP2]])
; CHECK-NEXT:    [[GT:%.*]] = icmp sgt i32 [[P]], [[Q]]
; CHECK-NEXT:    [[N:%.*]] = select i1 [[GT]], i32 [[P]], i32 [[Q]]
; CHECK-NEXT:    [[CMP110:%.*]] = icmp sgt i32 [[N]], 0
; CHECK-NEXT:    br i1 [[CMP110]], label [[FOR_BODY_PREHEADER:%.*]], label [[EXIT]]
; CHECK:       for.body.preheader:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[I_011:%.*]] = phi i32 [ 0, [[FOR_BODY_PREHEADER]] ], [ [[INC_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, i8* [[B:%.*]], i32 [[I_011]]
; CHECK-NEXT:    [[TMP0:%.*]] = load i8, i8* [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[TMP0]], 3
; CHECK-NEXT:    [[ARRAYIDX4:%.*]] = getelementptr inbounds i8, i8* [[A:%.*]], i32 [[I_011]]
; CHECK-NEXT:    store i8 [[ADD]], i8* [[ARRAYIDX4]], align 1
; CHECK-NEXT:    [[INC:%.*]] = add nuw nsw i32 [[I_011]], 1
; CHECK-NEXT:    [[ARRAYIDX_1:%.*]] = getelementptr inbounds i8, i8* [[B]], i32 [[INC]]
; CHECK-NEXT:    [[TMP1:%.*]] = load i8, i8* [[ARRAYIDX_1]], align 1
; CHECK-NEXT:    [[ADD_1:%.*]] = add i8 [[TMP1]], 3
; CHECK-NEXT:    [[ARRAYIDX4_1:%.*]] = getelementptr inbounds i8, i8* [[A]], i32 [[INC]]
; CHECK-NEXT:    store i8 [[ADD_1]], i8* [[ARRAYIDX4_1]], align 1
; CHECK-NEXT:    [[INC_1]] = add nuw nsw i32 [[INC]], 1
; CHECK-NEXT:    [[CMP1_1:%.*]] = icmp slt i32 [[INC_1]], [[N]]
; CHECK-NEXT:    br i1 [[CMP1_1]], label [[FOR_BODY]], label [[EXIT_LOOPEXIT:%.*]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK:       exit.loopexit:
; CHECK-NEXT:    br label [[EXIT]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;
entry:
  %and = and i32 %p, 1
  %cmp = icmp eq i32 %and, 0
  br i1 %cmp, label %guarded, label %exit

guarded:
  %rem = urem i32 %q, 2
  %cmp2 = icmp eq i32 %rem, 0
  tail call void @llvm.assume(i1 %cmp2)
  %gt = icmp sgt i32 %p, %q
  %n = select i1 %gt, i32 %p, i32 %q
  %cmp110 = icmp sgt i32 %n, 0
  br i1 %cmp110, label %for.body, label %exit

for.body:
  %i.011 = phi i32 [ %inc, %for.body ], [ 0, %guarded ]
  %arrayidx = getelementptr inbounds i8, i8* %b, i32 %i.011
  %0 = load i8, i8* %arrayidx, align 1
  %add = add i8 %0, 3
  %arrayidx4 = getelementptr inbounds i8, i8* %a, i32 %i.011
  store i8 %add, i8* %arrayidx4, align 1
  %inc = add nuw nsw i32 %i.011, 1
  %cmp1 = icmp slt i32 %inc, %n
  br i1 %cmp1, label %for.body, label %exit

exit:
  ret void
}

; Make sure the loop is unrolled with a remainder loop when the trip-count
; is not provably divisible by the unroll factor.

define dso_local void @cannotProveDivisibleTC(i8* noalias nocapture %a, i8* noalias nocapture readonly %b, i32 %p, i32 %q) local_unnamed_addr {
; CHECK-LABEL: @cannotProveDivisibleTC(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[AND:%.*]] = and i32 [[P:%.*]], 6
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[AND]], 0
; CHECK-NEXT:    br i1 [[CMP]], label [[GUARDED:%.*]], label [[EXIT:%.*]]
; CHECK:       guarded:
; CHECK-NEXT:    [[REM:%.*]] = urem i32 [[Q:%.*]], 2
; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i32 [[REM]], 0
; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP2]])
; CHECK-NEXT:    [[GT:%.*]] = icmp sgt i32 [[P]], [[Q]]
; CHECK-NEXT:    [[N:%.*]] = select i1 [[GT]], i32 [[P]], i32 [[Q]]
; CHECK-NEXT:    [[CMP110:%.*]] = icmp sgt i32 [[N]], 0
; CHECK-NEXT:    br i1 [[CMP110]], label [[FOR_BODY_PREHEADER:%.*]], label [[EXIT]]
; CHECK:       for.body.preheader:
; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[N]], -1
; CHECK-NEXT:    [[XTRAITER:%.*]] = and i32 [[N]], 1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[TMP0]], 1
; CHECK-NEXT:    br i1 [[TMP1]], label [[EXIT_LOOPEXIT_UNR_LCSSA:%.*]], label [[FOR_BODY_PREHEADER_NEW:%.*]]
; CHECK:       for.body.preheader.new:
; CHECK-NEXT:    [[UNROLL_ITER:%.*]] = sub i32 [[N]], [[XTRAITER]]
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[I_011:%.*]] = phi i32 [ 0, [[FOR_BODY_PREHEADER_NEW]] ], [ [[INC_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[NITER:%.*]] = phi i32 [ 0, [[FOR_BODY_PREHEADER_NEW]] ], [ [[NITER_NEXT_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, i8* [[B:%.*]], i32 [[I_011]]
; CHECK-NEXT:    [[TMP2:%.*]] = load i8, i8* [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[TMP2]], 3
; CHECK-NEXT:    [[ARRAYIDX4:%.*]] = getelementptr inbounds i8, i8* [[A:%.*]], i32 [[I_011]]
; CHECK-NEXT:    store i8 [[ADD]], i8* [[ARRAYIDX4]], align 1
; CHECK-NEXT:    [[INC:%.*]] = add nuw nsw i32 [[I_011]], 1
; CHECK-NEXT:    [[NITER_NEXT:%.*]] = add nuw nsw i32 [[NITER]], 1
; CHECK-NEXT:    [[ARRAYIDX_1:%.*]] = getelementptr inbounds i8, i8* [[B]], i32 [[INC]]
; CHECK-NEXT:    [[TMP3:%.*]] = load i8, i8* [[ARRAYIDX_1]], align 1
; CHECK-NEXT:    [[ADD_1:%.*]] = add i8 [[TMP3]], 3
; CHECK-NEXT:    [[ARRAYIDX4_1:%.*]] = getelementptr inbounds i8, i8* [[A]], i32 [[INC]]
; CHECK-NEXT:    store i8 [[ADD_1]], i8* [[ARRAYIDX4_1]], align 1
; CHECK-NEXT:    [[INC_1]] = add nuw nsw i32 [[INC]], 1
; CHECK-NEXT:    [[NITER_NEXT_1]] = add i32 [[NITER_NEXT]], 1
; CHECK-NEXT:    [[NITER_NCMP_1:%.*]] = icmp ne i32 [[NITER_NEXT_1]], [[UNROLL_ITER]]
; CHECK-NEXT:    br i1 [[NITER_NCMP_1]], label [[FOR_BODY]], label [[EXIT_LOOPEXIT_UNR_LCSSA_LOOPEXIT:%.*]], !llvm.loop [[LOOP2:![0-9]+]]
; CHECK:       exit.loopexit.unr-lcssa.loopexit:
; CHECK-NEXT:    [[I_011_UNR_PH:%.*]] = phi i32 [ [[INC_1]], [[FOR_BODY]] ]
; CHECK-NEXT:    br label [[EXIT_LOOPEXIT_UNR_LCSSA]]
; CHECK:       exit.loopexit.unr-lcssa:
; CHECK-NEXT:    [[I_011_UNR:%.*]] = phi i32 [ 0, [[FOR_BODY_PREHEADER]] ], [ [[I_011_UNR_PH]], [[EXIT_LOOPEXIT_UNR_LCSSA_LOOPEXIT]] ]
; CHECK-NEXT:    [[LCMP_MOD:%.*]] = icmp ne i32 [[XTRAITER]], 0
; CHECK-NEXT:    br i1 [[LCMP_MOD]], label [[FOR_BODY_EPIL_PREHEADER:%.*]], label [[EXIT_LOOPEXIT:%.*]]
; CHECK:       for.body.epil.preheader:
; CHECK-NEXT:    br label [[FOR_BODY_EPIL:%.*]]
; CHECK:       for.body.epil:
; CHECK-NEXT:    [[ARRAYIDX_EPIL:%.*]] = getelementptr inbounds i8, i8* [[B]], i32 [[I_011_UNR]]
; CHECK-NEXT:    [[TMP4:%.*]] = load i8, i8* [[ARRAYIDX_EPIL]], align 1
; CHECK-NEXT:    [[ADD_EPIL:%.*]] = add i8 [[TMP4]], 3
; CHECK-NEXT:    [[ARRAYIDX4_EPIL:%.*]] = getelementptr inbounds i8, i8* [[A]], i32 [[I_011_UNR]]
; CHECK-NEXT:    store i8 [[ADD_EPIL]], i8* [[ARRAYIDX4_EPIL]], align 1
; CHECK-NEXT:    br label [[EXIT_LOOPEXIT]]
; CHECK:       exit.loopexit:
; CHECK-NEXT:    br label [[EXIT]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;
entry:
  %and = and i32 %p, 6
  %cmp = icmp eq i32 %and, 0
  br i1 %cmp, label %guarded, label %exit

guarded:
  %rem = urem i32 %q, 2
  %cmp2 = icmp eq i32 %rem, 0
  tail call void @llvm.assume(i1 %cmp2)
  %gt = icmp sgt i32 %p, %q
  %n = select i1 %gt, i32 %p, i32 %q
  %cmp110 = icmp sgt i32 %n, 0
  br i1 %cmp110, label %for.body, label %exit

for.body:
  %i.011 = phi i32 [ %inc, %for.body ], [ 0, %guarded ]
  %arrayidx = getelementptr inbounds i8, i8* %b, i32 %i.011
  %0 = load i8, i8* %arrayidx, align 1
  %add = add i8 %0, 3
  %arrayidx4 = getelementptr inbounds i8, i8* %a, i32 %i.011
  store i8 %add, i8* %arrayidx4, align 1
  %inc = add nuw nsw i32 %i.011, 1
  %cmp1 = icmp slt i32 %inc, %n
  br i1 %cmp1, label %for.body, label %exit

exit:
  ret void
}

declare void @llvm.assume(i1 noundef) nofree nosync nounwind willreturn