; LLVM IR from ahampriyanshu/algo-ds-101 :: Algorithms/DP (creating an string input function in C)

; 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: nounwind uwtable
define dso_local i32 @input(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %7

7:                                                ; preds = %22, %2
  %8 = call i32 @getchar()
  store i32 %8, ptr %5, align 4, !tbaa !9
  %9 = icmp ne i32 %8, 10
  br i1 %9, label %10, label %23

10:                                               ; preds = %7
  %11 = load i32, ptr %6, align 4, !tbaa !9
  %12 = load i32, ptr %4, align 4, !tbaa !9
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %14, label %22

14:                                               ; preds = %10
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = trunc i32 %15 to i8
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = load i32, ptr %6, align 4, !tbaa !9
  %19 = add nsw i32 %18, 1
  store i32 %19, ptr %6, align 4, !tbaa !9
  %20 = sext i32 %18 to i64
  %21 = getelementptr inbounds i8, ptr %17, i64 %20
  store i8 %16, ptr %21, align 1, !tbaa !11
  br label %22

22:                                               ; preds = %14, %10
  br label %7, !llvm.loop !12

23:                                               ; preds = %7
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = load i32, ptr %6, align 4, !tbaa !9
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds i8, ptr %24, i64 %26
  store i8 0, ptr %27, align 1, !tbaa !11
  %28 = load i32, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  ret i32 %28
}

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

; Function Attrs: inlinehint nounwind uwtable
declare i32 @getchar() #2

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

attributes #0 = { 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { inlinehint 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/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: nofree nounwind uwtable
define dso_local i32 @input(ptr nocapture noundef writeonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call i32 @getchar()
  %.not8 = icmp eq i32 %3, 10
  br i1 %.not8, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %11
  %4 = phi i32 [ %12, %11 ], [ %3, %2 ]
  %.09 = phi i32 [ %.1, %11 ], [ 0, %2 ]
  %5 = icmp slt i32 %.09, %1
  br i1 %5, label %6, label %11

6:                                                ; preds = %.lr.ph
  %7 = trunc i32 %4 to i8
  %8 = add nsw i32 %.09, 1
  %9 = sext i32 %.09 to i64
  %10 = getelementptr inbounds i8, ptr %0, i64 %9
  store i8 %7, ptr %10, align 1, !tbaa !5
  br label %11

11:                                               ; preds = %6, %.lr.ph
  %.1 = phi i32 [ %8, %6 ], [ %.09, %.lr.ph ]
  %12 = tail call i32 @getchar()
  %.not = icmp eq i32 %12, 10
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %11, %2
  %.0.lcssa = phi i32 [ 0, %2 ], [ %.1, %11 ]
  %13 = sext i32 %.0.lcssa to i64
  %14 = getelementptr inbounds i8, ptr %0, i64 %13
  store i8 0, ptr %14, align 1, !tbaa !5
  ret i32 %.0.lcssa
}

; Function Attrs: inlinehint nofree nounwind uwtable
declare noundef i32 @getchar() local_unnamed_addr #1

attributes #0 = { nofree 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 = { inlinehint nofree 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/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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