; LLVM IR from FOSS-UCSC/FOSSALGO :: algorithms/gr-dfsrh/c (depth_first_search)

; 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"

@visited = external dso_local global [1000 x i8], align 16
@.str = external hidden unnamed_addr constant [4 x i8], align 1
@size = external dso_local global [1000 x i32], align 16
@graph = external dso_local global [1000 x [1000 x i32]], align 16

; Function Attrs: nounwind uwtable
define dso_local void @depthfirstsearch(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %4 = load i32, ptr %2, align 4, !tbaa !5
  %5 = sext i32 %4 to i64
  %6 = getelementptr inbounds [1000 x i8], ptr @visited, i64 0, i64 %5
  store i8 1, ptr %6, align 1, !tbaa !9
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = call i32 (ptr, ...) @printf(ptr noundef @.str, i32 noundef %7)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %40, %1
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [1000 x i32], ptr @size, i64 0, i64 %12
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = icmp slt i32 %10, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  br label %43

17:                                               ; preds = %9
  %18 = load i32, ptr %2, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [1000 x [1000 x i32]], ptr @graph, i64 0, i64 %19
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds [1000 x i32], ptr %20, i64 0, i64 %22
  %24 = load i32, ptr %23, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [1000 x i8], ptr @visited, i64 0, i64 %25
  %27 = load i8, ptr %26, align 1, !tbaa !9, !range !11, !noundef !12
  %28 = trunc i8 %27 to i1
  %29 = zext i1 %28 to i32
  %30 = icmp eq i32 %29, 0
  br i1 %30, label %31, label %39

31:                                               ; preds = %17
  %32 = load i32, ptr %2, align 4, !tbaa !5
  %33 = sext i32 %32 to i64
  %34 = getelementptr inbounds [1000 x [1000 x i32]], ptr @graph, i64 0, i64 %33
  %35 = load i32, ptr %3, align 4, !tbaa !5
  %36 = sext i32 %35 to i64
  %37 = getelementptr inbounds [1000 x i32], ptr %34, i64 0, i64 %36
  %38 = load i32, ptr %37, align 4, !tbaa !5
  call void @depthfirstsearch(i32 noundef %38)
  br label %39

39:                                               ; preds = %31, %17
  br label %40

40:                                               ; preds = %39
  %41 = load i32, ptr %3, align 4, !tbaa !5
  %42 = add nsw i32 %41, 1
  store i32 %42, ptr %3, align 4, !tbaa !5
  br label %9, !llvm.loop !13

43:                                               ; preds = %16
  ret void
}

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

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 = { "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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!10, !10, i64 0}
!10 = !{!"_Bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"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"

@visited = external dso_local local_unnamed_addr global [1000 x i8], align 16
@.str = external hidden unnamed_addr constant [4 x i8], align 1
@size = external dso_local local_unnamed_addr global [1000 x i32], align 16
@graph = external dso_local local_unnamed_addr global [1000 x [1000 x i32]], align 16

; Function Attrs: nofree nounwind uwtable
define dso_local void @depthfirstsearch(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  %3 = getelementptr inbounds [1000 x i8], ptr @visited, i64 0, i64 %2
  store i8 1, ptr %3, align 1, !tbaa !5
  %4 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i32 noundef %0)
  %5 = getelementptr inbounds [1000 x i32], ptr @size, i64 0, i64 %2
  %6 = load i32, ptr %5, align 4, !tbaa !9
  %7 = icmp sgt i32 %6, 0
  br i1 %7, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %16, %1
  ret void

.lr.ph:                                           ; preds = %1, %16
  %8 = phi i32 [ %17, %16 ], [ %6, %1 ]
  %indvars.iv = phi i64 [ %indvars.iv.next, %16 ], [ 0, %1 ]
  %9 = getelementptr inbounds [1000 x [1000 x i32]], ptr @graph, i64 0, i64 %2, i64 %indvars.iv
  %10 = load i32, ptr %9, align 4, !tbaa !9
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [1000 x i8], ptr @visited, i64 0, i64 %11
  %13 = load i8, ptr %12, align 1, !tbaa !5, !range !11, !noundef !12
  %14 = icmp eq i8 %13, 0
  br i1 %14, label %15, label %16

15:                                               ; preds = %.lr.ph
  tail call void @depthfirstsearch(i32 noundef %10)
  %.pre = load i32, ptr %5, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %.lr.ph, %15
  %17 = phi i32 [ %8, %.lr.ph ], [ %.pre, %15 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %18 = sext i32 %17 to i64
  %19 = icmp slt i64 %indvars.iv.next, %18
  br i1 %19, label %.lr.ph, label %._crit_edge, !llvm.loop !13
}

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) 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 = { 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" }

!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 = !{!"_Bool", !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 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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