; LLVM IR from Shah-Shishir/Codeforces-Solutions :: 1027A. Palindromic Twist (main)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [5 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca [105 x i8], align 16
  %8 = alloca i8, align 1
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  call void @llvm.lifetime.start.p0(i64 105, ptr %7) #4
  call void @llvm.lifetime.start.p0(i64 1, ptr %8) #4
  %9 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %2)
  br label %10

10:                                               ; preds = %55, %0
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = add nsw i32 %11, -1
  store i32 %12, ptr %2, align 4, !tbaa !5
  %13 = icmp ne i32 %11, 0
  br i1 %13, label %14, label %56

14:                                               ; preds = %10
  %15 = getelementptr inbounds [105 x i8], ptr %7, i64 0, i64 0
  %16 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %3, ptr noundef %15)
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = sdiv i32 %17, 2
  store i32 %18, ptr %5, align 4, !tbaa !5
  store i8 1, ptr %8, align 1, !tbaa !9
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %19

19:                                               ; preds = %47, %14
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = icmp slt i32 %20, %21
  br i1 %22, label %23, label %50

23:                                               ; preds = %19
  %24 = load i32, ptr %4, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [105 x i8], ptr %7, i64 0, i64 %25
  %27 = load i8, ptr %26, align 1, !tbaa !11
  %28 = sext i8 %27 to i32
  %29 = load i32, ptr %3, align 4, !tbaa !5
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = sub nsw i32 %29, %30
  %32 = sub nsw i32 %31, 1
  %33 = sext i32 %32 to i64
  %34 = getelementptr inbounds [105 x i8], ptr %7, i64 0, i64 %33
  %35 = load i8, ptr %34, align 1, !tbaa !11
  %36 = sext i8 %35 to i32
  %37 = sub nsw i32 %28, %36
  %38 = call i32 @llvm.abs.i32(i32 %37, i1 true)
  store i32 %38, ptr %6, align 4, !tbaa !5
  %39 = load i32, ptr %6, align 4, !tbaa !5
  %40 = icmp eq i32 %39, 0
  br i1 %40, label %46, label %41

41:                                               ; preds = %23
  %42 = load i32, ptr %6, align 4, !tbaa !5
  %43 = icmp eq i32 %42, 2
  br i1 %43, label %46, label %44

44:                                               ; preds = %41
  store i8 0, ptr %8, align 1, !tbaa !9
  %45 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  br label %50

46:                                               ; preds = %41, %23
  br label %47

47:                                               ; preds = %46
  %48 = load i32, ptr %4, align 4, !tbaa !5
  %49 = add nsw i32 %48, 1
  store i32 %49, ptr %4, align 4, !tbaa !5
  br label %19, !llvm.loop !12

50:                                               ; preds = %44, %19
  %51 = load i8, ptr %8, align 1, !tbaa !9, !range !14, !noundef !15
  %52 = trunc i8 %51 to i1
  br i1 %52, label %53, label %55

53:                                               ; preds = %50
  %54 = call i32 (ptr, ...) @printf(ptr noundef @.str.3)
  br label %55

55:                                               ; preds = %53, %50
  br label %10, !llvm.loop !16

56:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 1, ptr %8) #4
  call void @llvm.lifetime.end.p0(i64 105, ptr %7) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  ret i32 0
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

declare i32 @__isoc99_scanf(ptr noundef, ...) #2

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #3

declare i32 @printf(ptr noundef, ...) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { mustprogress norecurse uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #4 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{i8 0, i8 2}
!15 = !{}
!16 = distinct !{!16, !13}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [5 x i8], align 1

; Function Attrs: mustprogress nofree norecurse nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca [105 x i8], align 16
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #4
  call void @llvm.lifetime.start.p0(i64 105, ptr nonnull %3) #4
  %4 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %1)
  %5 = load i32, ptr %1, align 4, !tbaa !5
  %6 = add nsw i32 %5, -1
  store i32 %6, ptr %1, align 4, !tbaa !5
  %.not13 = icmp eq i32 %5, 0
  br i1 %.not13, label %._crit_edge, label %.lr.ph14

.lr.ph14:                                         ; preds = %0, %.critedge
  %7 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %2, ptr noundef nonnull %3)
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %.not1011 = icmp sgt i32 %8, 1
  br i1 %.not1011, label %.lr.ph.preheader, label %.critedge

.lr.ph.preheader:                                 ; preds = %.lr.ph14
  %9 = lshr i32 %8, 1
  %10 = zext nneg i32 %8 to i64
  %wide.trip.count = zext nneg i32 %9 to i64
  br label %.lr.ph

11:                                               ; preds = %.lr.ph
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %.critedge, label %.lr.ph, !llvm.loop !9

.lr.ph:                                           ; preds = %.lr.ph.preheader, %11
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %11 ]
  %12 = getelementptr inbounds [105 x i8], ptr %3, i64 0, i64 %indvars.iv
  %13 = load i8, ptr %12, align 1, !tbaa !11
  %14 = sext i8 %13 to i32
  %15 = xor i64 %indvars.iv, -1
  %16 = add nsw i64 %10, %15
  %17 = getelementptr inbounds [105 x i8], ptr %3, i64 0, i64 %16
  %18 = load i8, ptr %17, align 1, !tbaa !11
  %19 = sext i8 %18 to i32
  %20 = sub nsw i32 %14, %19
  %21 = call i32 @llvm.abs.i32(i32 %20, i1 true)
  %22 = icmp eq i8 %13, %18
  %23 = icmp eq i32 %21, 2
  %or.cond = select i1 %22, i1 true, i1 %23
  br i1 %or.cond, label %11, label %.critedge

.critedge:                                        ; preds = %11, %.lr.ph, %.lr.ph14
  %.str.2.sink = phi ptr [ @.str.3, %.lr.ph14 ], [ @.str.2, %.lr.ph ], [ @.str.3, %11 ]
  %24 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) %.str.2.sink)
  %25 = load i32, ptr %1, align 4, !tbaa !5
  %26 = add nsw i32 %25, -1
  store i32 %26, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %25, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph14, !llvm.loop !12

._crit_edge:                                      ; preds = %.critedge, %0
  call void @llvm.lifetime.end.p0(i64 105, ptr nonnull %3) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  ret i32 0
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #3

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { mustprogress nofree norecurse nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nofree nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #4 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !10}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopInstSimplifyPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass