; LLVM IR from ahampriyanshu/algo-ds-101 :: Algorithms/String/LPS (longest_palindromic_substring)

; 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.2 = external hidden unnamed_addr constant [29 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.4 = external hidden unnamed_addr constant [27 x i8], align 1

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

declare i32 @printf(ptr noundef, ...) #1

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

; Function Attrs: nounwind uwtable
declare dso_local void @longestSubstr(ptr noundef) #2

; Function Attrs: nounwind uwtable
define dso_local i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca [1000 x i8], align 16
  %3 = alloca i8, align 1
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 1000, ptr %2) #3
  call void @llvm.lifetime.start.p0(i64 1, ptr %3) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %5 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.3, ptr noundef %4)
  %7 = call i32 (ptr, ...) @printf(ptr noundef @.str.4)
  store i8 0, ptr %3, align 1, !tbaa !5
  br label %8

8:                                                ; preds = %18, %0
  %9 = load i8, ptr %3, align 1, !tbaa !5
  %10 = sext i8 %9 to i32
  %11 = load i32, ptr %4, align 4, !tbaa !8
  %12 = icmp slt i32 %10, %11
  br i1 %12, label %13, label %21

13:                                               ; preds = %8
  %14 = load i8, ptr %3, align 1, !tbaa !5
  %15 = sext i8 %14 to i64
  %16 = getelementptr inbounds [1000 x i8], ptr %2, i64 0, i64 %15
  %17 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %16)
  br label %18

18:                                               ; preds = %13
  %19 = load i8, ptr %3, align 1, !tbaa !5
  %20 = add i8 %19, 1
  store i8 %20, ptr %3, align 1, !tbaa !5
  br label %8, !llvm.loop !10

21:                                               ; preds = %8
  %22 = getelementptr inbounds [1000 x i8], ptr %2, i64 0, i64 0
  call void @longestSubstr(ptr noundef %22)
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr %3) #3
  call void @llvm.lifetime.end.p0(i64 1000, ptr %2) #3
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #1

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { "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 = { 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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !6, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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"

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [29 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.4 = external hidden unnamed_addr constant [27 x i8], align 1

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

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

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

; Function Attrs: nounwind uwtable
declare dso_local void @longestSubstr(ptr noundef) local_unnamed_addr #2

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca [1000 x i8], align 16
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 1000, ptr nonnull %1) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #3
  %3 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2)
  %4 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.3, ptr noundef nonnull %2)
  %5 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.4)
  %6 = load i32, ptr %2, align 4, !tbaa !5
  %7 = icmp sgt i32 %6, 0
  br i1 %7, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.03 = phi i8 [ %11, %.lr.ph ], [ 0, %0 ]
  %8 = sext i8 %.03 to i64
  %9 = getelementptr inbounds [1000 x i8], ptr %1, i64 0, i64 %8
  %10 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %9)
  %11 = add i8 %.03, 1
  %12 = sext i8 %11 to i32
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = icmp sgt i32 %13, %12
  br i1 %14, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @longestSubstr(ptr noundef nonnull %1)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #3
  call void @llvm.lifetime.end.p0(i64 1000, ptr nonnull %1) #3
  ret i32 0
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

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


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass