; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C/Algorithms/Pattern-Searching (kmp_algorithm)

; 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 void @computeLPSArray(ptr noundef %0, i32 noundef %1, ptr noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %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 ptr %2, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 1, ptr %8, align 4, !tbaa !9
  %9 = load ptr, ptr %6, align 8, !tbaa !5
  %10 = getelementptr inbounds i32, ptr %9, i64 0
  store i32 0, ptr %10, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %57, %3
  %12 = load i32, ptr %8, align 4, !tbaa !9
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %15, label %58

15:                                               ; preds = %11
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = load i32, ptr %8, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds i8, ptr %16, i64 %18
  %20 = load i8, ptr %19, align 1, !tbaa !11
  %21 = sext i8 %20 to i32
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds i8, ptr %22, i64 %24
  %26 = load i8, ptr %25, align 1, !tbaa !11
  %27 = sext i8 %26 to i32
  %28 = icmp eq i32 %21, %27
  br i1 %28, label %29, label %39

29:                                               ; preds = %15
  %30 = load i32, ptr %7, align 4, !tbaa !9
  %31 = add nsw i32 %30, 1
  store i32 %31, ptr %7, align 4, !tbaa !9
  %32 = load i32, ptr %7, align 4, !tbaa !9
  %33 = load ptr, ptr %6, align 8, !tbaa !5
  %34 = load i32, ptr %8, align 4, !tbaa !9
  %35 = sext i32 %34 to i64
  %36 = getelementptr inbounds i32, ptr %33, i64 %35
  store i32 %32, ptr %36, align 4, !tbaa !9
  %37 = load i32, ptr %8, align 4, !tbaa !9
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %8, align 4, !tbaa !9
  br label %57

39:                                               ; preds = %15
  %40 = load i32, ptr %7, align 4, !tbaa !9
  %41 = icmp ne i32 %40, 0
  br i1 %41, label %42, label %49

42:                                               ; preds = %39
  %43 = load ptr, ptr %6, align 8, !tbaa !5
  %44 = load i32, ptr %7, align 4, !tbaa !9
  %45 = sub nsw i32 %44, 1
  %46 = sext i32 %45 to i64
  %47 = getelementptr inbounds i32, ptr %43, i64 %46
  %48 = load i32, ptr %47, align 4, !tbaa !9
  store i32 %48, ptr %7, align 4, !tbaa !9
  br label %56

49:                                               ; preds = %39
  %50 = load ptr, ptr %6, align 8, !tbaa !5
  %51 = load i32, ptr %8, align 4, !tbaa !9
  %52 = sext i32 %51 to i64
  %53 = getelementptr inbounds i32, ptr %50, i64 %52
  store i32 0, ptr %53, align 4, !tbaa !9
  %54 = load i32, ptr %8, align 4, !tbaa !9
  %55 = add nsw i32 %54, 1
  store i32 %55, ptr %8, align 4, !tbaa !9
  br label %56

56:                                               ; preds = %49, %42
  br label %57

57:                                               ; preds = %56, %29
  br label %11, !llvm.loop !12

58:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  ret void
}

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

; 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 = { 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 norecurse nosync nounwind memory(argmem: readwrite) uwtable
define dso_local void @computeLPSArray(ptr nocapture noundef readonly %0, i32 noundef %1, ptr nocapture noundef %2) local_unnamed_addr #0 {
  store i32 0, ptr %2, align 4, !tbaa !5
  %invariant.gep = getelementptr i8, ptr %2, i64 -4
  %4 = icmp sgt i32 %1, 1
  br i1 %4, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %3, %22
  %.020 = phi i32 [ %.1, %22 ], [ 1, %3 ]
  %.01719 = phi i32 [ %.118, %22 ], [ 0, %3 ]
  %5 = sext i32 %.020 to i64
  %6 = getelementptr inbounds i8, ptr %0, i64 %5
  %7 = load i8, ptr %6, align 1, !tbaa !9
  %8 = sext i32 %.01719 to i64
  %9 = getelementptr inbounds i8, ptr %0, i64 %8
  %10 = load i8, ptr %9, align 1, !tbaa !9
  %11 = icmp eq i8 %7, %10
  br i1 %11, label %12, label %16

12:                                               ; preds = %.lr.ph
  %13 = add nsw i32 %.01719, 1
  %14 = getelementptr inbounds i32, ptr %2, i64 %5
  store i32 %13, ptr %14, align 4, !tbaa !5
  %15 = add nsw i32 %.020, 1
  br label %22

16:                                               ; preds = %.lr.ph
  %.not = icmp eq i32 %.01719, 0
  br i1 %.not, label %19, label %17

17:                                               ; preds = %16
  %gep = getelementptr i32, ptr %invariant.gep, i64 %8
  %18 = load i32, ptr %gep, align 4, !tbaa !5
  br label %22

19:                                               ; preds = %16
  %20 = getelementptr inbounds i32, ptr %2, i64 %5
  store i32 0, ptr %20, align 4, !tbaa !5
  %21 = add nsw i32 %.020, 1
  br label %22

22:                                               ; preds = %17, %19, %12
  %.118 = phi i32 [ %13, %12 ], [ %18, %17 ], [ 0, %19 ]
  %.1 = phi i32 [ %15, %12 ], [ %.020, %17 ], [ %21, %19 ]
  %23 = icmp slt i32 %.1, %1
  br i1 %23, label %.lr.ph, label %._crit_edge, !llvm.loop !10

._crit_edge:                                      ; preds = %22, %3
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: readwrite) 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}


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