; LLVM IR from overnote/over-algorithm :: code/code-c-like/01-list/02-LinkList.ll (Z10LocateElemP5LNodei)

; 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.LNode = type { i32, ptr }

; 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: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z10LocateElemP5LNodei(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = 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
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.LNode, ptr %6, i32 0, i32 1
  %8 = load ptr, ptr %7, align 8, !tbaa !11
  store ptr %8, ptr %5, align 8, !tbaa !5
  br label %9

9:                                                ; preds = %20, %2
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  %11 = icmp ne ptr %10, null
  br i1 %11, label %12, label %18

12:                                               ; preds = %9
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.LNode, ptr %13, i32 0, i32 0
  %15 = load i32, ptr %14, align 8, !tbaa !13
  %16 = load i32, ptr %4, align 4, !tbaa !9
  %17 = icmp ne i32 %15, %16
  br label %18

18:                                               ; preds = %12, %9
  %19 = phi i1 [ false, %9 ], [ %17, %12 ]
  br i1 %19, label %20, label %24

20:                                               ; preds = %18
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.LNode, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !11
  store ptr %23, ptr %5, align 8, !tbaa !5
  br label %9, !llvm.loop !14

24:                                               ; preds = %18
  %25 = load ptr, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  ret ptr %25
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 8}
!12 = !{!"_ZTS5LNode", !10, i64 0, !6, i64 8}
!13 = !{!12, !10, i64 0}
!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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, inaccessiblemem: none) uwtable
define dso_local noundef ptr @_Z10LocateElemP5LNodei(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  br label %3

3:                                                ; preds = %4, %2
  %.pn = phi ptr [ %0, %2 ], [ %.0, %4 ]
  %.0.in = getelementptr inbounds i8, ptr %.pn, i64 8
  %.0 = load ptr, ptr %.0.in, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %.critedge, label %4

4:                                                ; preds = %3
  %5 = load i32, ptr %.0, align 8, !tbaa !11
  %.not5 = icmp eq i32 %5, %1
  br i1 %.not5, label %.critedge, label %3, !llvm.loop !12

.critedge:                                        ; preds = %3, %4
  ret ptr %.0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, 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, !10, i64 8}
!6 = !{!"_ZTS5LNode", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass