; LLVM IR from LeetCode-in-C/LeetCode-in-C :: src/main/c/g0001_0100/s0041_first_missing_positive (Solution)

; 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 @dfs(ptr noundef %0, i32 noundef %1, i32 noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = 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
  %8 = load i32, ptr %6, align 4, !tbaa !9
  %9 = icmp sle i32 %8, 0
  br i1 %9, label %23, label %10

10:                                               ; preds = %3
  %11 = load i32, ptr %6, align 4, !tbaa !9
  %12 = load i32, ptr %5, align 4, !tbaa !9
  %13 = icmp sgt i32 %11, %12
  br i1 %13, label %23, label %14

14:                                               ; preds = %10
  %15 = load i32, ptr %6, align 4, !tbaa !9
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = sub nsw i32 %17, 1
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds i32, ptr %16, i64 %19
  %21 = load i32, ptr %20, align 4, !tbaa !9
  %22 = icmp eq i32 %15, %21
  br i1 %22, label %23, label %24

23:                                               ; preds = %14, %10, %3
  br label %40

24:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  %26 = load i32, ptr %6, align 4, !tbaa !9
  %27 = sub nsw i32 %26, 1
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds i32, ptr %25, i64 %28
  %30 = load i32, ptr %29, align 4, !tbaa !9
  store i32 %30, ptr %7, align 4, !tbaa !9
  %31 = load i32, ptr %6, align 4, !tbaa !9
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = load i32, ptr %6, align 4, !tbaa !9
  %34 = sub nsw i32 %33, 1
  %35 = sext i32 %34 to i64
  %36 = getelementptr inbounds i32, ptr %32, i64 %35
  store i32 %31, ptr %36, align 4, !tbaa !9
  %37 = load ptr, ptr %4, align 8, !tbaa !5
  %38 = load i32, ptr %5, align 4, !tbaa !9
  %39 = load i32, ptr %7, align 4, !tbaa !9
  call void @dfs(ptr noundef %37, i32 noundef %38, i32 noundef %39)
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %40

40:                                               ; preds = %24, %23
  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}


; 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 @dfs(ptr nocapture noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %invariant.gep = getelementptr i8, ptr %0, i64 -4
  %4 = icmp slt i32 %2, 1
  %5 = icmp sgt i32 %2, %1
  %or.cond17 = or i1 %4, %5
  br i1 %or.cond17, label %tailrecurse._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %3, %tailrecurse
  %.tr1618 = phi i32 [ %7, %tailrecurse ], [ %2, %3 ]
  %6 = zext nneg i32 %.tr1618 to i64
  %gep = getelementptr i32, ptr %invariant.gep, i64 %6
  %7 = load i32, ptr %gep, align 4, !tbaa !5
  %8 = icmp eq i32 %7, %.tr1618
  br i1 %8, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse:                                      ; preds = %.lr.ph
  store i32 %.tr1618, ptr %gep, align 4, !tbaa !5
  %9 = icmp slt i32 %7, 1
  %10 = icmp sgt i32 %7, %1
  %or.cond = or i1 %9, %10
  br i1 %or.cond, label %tailrecurse._crit_edge, label %.lr.ph

tailrecurse._crit_edge:                           ; preds = %.lr.ph, %tailrecurse, %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"}


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