; LLVM IR from Ayon-SSP/The-SDE-Prep :: 1]_Data Structures/2]_Linked List (7_improvingsearching)

; 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"

%struct.Node = type { i32, ptr }

@first = external dso_local global ptr, align 8

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

; 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
define dso_local void @search(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  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 8, ptr %5) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %7, ptr %6, align 8, !tbaa !5
  br label %8

8:                                                ; preds = %27, %2
  %9 = load ptr, ptr %6, align 8, !tbaa !5
  %10 = icmp ne ptr %9, null
  br i1 %10, label %11, label %32

11:                                               ; preds = %8
  %12 = load ptr, ptr %6, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.Node, ptr %12, i32 0, i32 0
  %14 = load i32, ptr %13, align 8, !tbaa !11
  %15 = load i32, ptr %4, align 4, !tbaa !9
  %16 = icmp eq i32 %14, %15
  br i1 %16, label %17, label %27

17:                                               ; preds = %11
  %18 = load ptr, ptr %6, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.Node, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !13
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.Node, ptr %21, i32 0, i32 1
  store ptr %20, ptr %22, align 8, !tbaa !13
  %23 = load ptr, ptr @first, align 8, !tbaa !5
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.Node, ptr %24, i32 0, i32 1
  store ptr %23, ptr %25, align 8, !tbaa !13
  %26 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %26, ptr @first, align 8, !tbaa !5
  br label %27

27:                                               ; preds = %17, %11
  %28 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %28, ptr %5, align 8, !tbaa !5
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.Node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !13
  store ptr %31, ptr %6, align 8, !tbaa !5
  br label %8, !llvm.loop !14

32:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!12, !10, i64 0}
!12 = !{!"Node", !10, i64 0, !6, i64 8}
!13 = !{!12, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

@first = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @search(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not12 = icmp eq ptr %0, null
  br i1 %.not12, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %first.promoted = load ptr, ptr @first, align 8, !tbaa !5
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph._crit_edge
  %.015 = phi ptr [ %9, %.lr.ph._crit_edge ], [ %0, %.lr.ph.preheader ]
  %.0914 = phi ptr [ %.015, %.lr.ph._crit_edge ], [ undef, %.lr.ph.preheader ]
  %.01113 = phi ptr [ %.010, %.lr.ph._crit_edge ], [ %first.promoted, %.lr.ph.preheader ]
  %3 = load i32, ptr %.015, align 8, !tbaa !9
  %4 = icmp eq i32 %3, %1
  %5 = getelementptr inbounds i8, ptr %.015, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !12
  br i1 %4, label %7, label %.lr.ph._crit_edge

7:                                                ; preds = %.lr.ph
  %8 = getelementptr inbounds i8, ptr %.0914, i64 8
  store ptr %6, ptr %8, align 8, !tbaa !12
  store ptr %.01113, ptr %5, align 8, !tbaa !12
  store ptr %.015, ptr @first, align 8, !tbaa !5
  br label %.lr.ph._crit_edge

.lr.ph._crit_edge:                                ; preds = %.lr.ph, %7
  %9 = phi ptr [ %.01113, %7 ], [ %6, %.lr.ph ]
  %.010 = phi ptr [ %.015, %7 ], [ %.01113, %.lr.ph ]
  %.not = icmp eq ptr %9, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph._crit_edge, %2
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !11, i64 0}
!10 = !{!"Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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