; LLVM IR from viveakrt/Competitive-programing :: CodeChef (Longest_Palindrome)

; 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"

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z19max_even_palindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef %0, i32 noundef %1, i32 noundef %2) #1 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store i32 %2, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  %9 = load i32, ptr %5, align 4, !tbaa !9
  %10 = sub nsw i32 %9, 1
  store i32 %10, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  %11 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %11, ptr %8, align 4, !tbaa !9
  br label %12

12:                                               ; preds = %33, %3
  %13 = load i32, ptr %7, align 4, !tbaa !9
  %14 = icmp sge i32 %13, 0
  br i1 %14, label %15, label %31

15:                                               ; preds = %12
  %16 = load i32, ptr %8, align 4, !tbaa !9
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = icmp slt i32 %16, %17
  br i1 %18, label %19, label %31

19:                                               ; preds = %15
  %20 = load i32, ptr %7, align 4, !tbaa !9
  %21 = sext i32 %20 to i64
  %22 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %21)
  %23 = load i8, ptr %22, align 1, !tbaa !11
  %24 = sext i8 %23 to i32
  %25 = load i32, ptr %8, align 4, !tbaa !9
  %26 = sext i32 %25 to i64
  %27 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %26)
  %28 = load i8, ptr %27, align 1, !tbaa !11
  %29 = sext i8 %28 to i32
  %30 = icmp eq i32 %24, %29
  br label %31

31:                                               ; preds = %19, %15, %12
  %32 = phi i1 [ false, %15 ], [ false, %12 ], [ %30, %19 ]
  br i1 %32, label %33, label %38

33:                                               ; preds = %31
  %34 = load i32, ptr %7, align 4, !tbaa !9
  %35 = add nsw i32 %34, -1
  store i32 %35, ptr %7, align 4, !tbaa !9
  %36 = load i32, ptr %8, align 4, !tbaa !9
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %8, align 4, !tbaa !9
  br label %12, !llvm.loop !12

38:                                               ; preds = %31
  %39 = load i32, ptr %8, align 4, !tbaa !9
  %40 = load i32, ptr %7, align 4, !tbaa !9
  %41 = sub nsw i32 %39, %40
  %42 = sub nsw i32 %41, 1
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  ret i32 %42
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #2 align 2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 #2 = { mustprogress 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 #3 = { 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


; 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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef range(i32 -2147483648, 2147483647) i32 @_Z19max_even_palindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %4 = icmp sgt i32 %1, 0
  %5 = icmp slt i32 %1, %2
  %or.cond13 = and i1 %4, %5
  br i1 %or.cond13, label %.lr.ph.preheader, label %.critedge

.lr.ph.preheader:                                 ; preds = %3
  %6 = zext nneg i32 %1 to i64
  %7 = sext i32 %2 to i64
  %8 = zext nneg i32 %1 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %14
  %indvars.iv21 = phi i64 [ %8, %.lr.ph.preheader ], [ %indvars.iv.next22, %14 ]
  %indvars.iv = phi i64 [ %6, %.lr.ph.preheader ], [ %indvars.iv.next, %14 ]
  %indvars.iv.next22 = add nsw i64 %indvars.iv21, -1
  %9 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv.next22)
  %10 = load i8, ptr %9, align 1, !tbaa !5
  %11 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  %12 = load i8, ptr %11, align 1, !tbaa !5
  %13 = icmp eq i8 %10, %12
  br i1 %13, label %14, label %.critedge.loopexit

14:                                               ; preds = %.lr.ph
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %15 = icmp ugt i64 %indvars.iv21, 1
  %16 = icmp slt i64 %indvars.iv.next, %7
  %or.cond = select i1 %15, i1 %16, i1 false
  br i1 %or.cond, label %.lr.ph, label %.critedge.loopexit, !llvm.loop !8

.critedge.loopexit:                               ; preds = %14, %.lr.ph
  %.011.in.lcssa.ph.in = phi i64 [ %indvars.iv21, %.lr.ph ], [ %indvars.iv.next22, %14 ]
  %.0.lcssa.ph.in = phi i64 [ %indvars.iv, %.lr.ph ], [ %indvars.iv.next, %14 ]
  %.0.lcssa.ph = trunc i64 %.0.lcssa.ph.in to i32
  %.011.in.lcssa.ph = trunc i64 %.011.in.lcssa.ph.in to i32
  br label %.critedge

.critedge:                                        ; preds = %.critedge.loopexit, %3
  %.011.in.lcssa = phi i32 [ %1, %3 ], [ %.011.in.lcssa.ph, %.critedge.loopexit ]
  %.0.lcssa = phi i32 [ %1, %3 ], [ %.0.lcssa.ph, %.critedge.loopexit ]
  %17 = sub i32 %.0.lcssa, %.011.in.lcssa
  ret i32 %17
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #0 align 2

attributes #0 = { mustprogress 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" }

!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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass