; LLVM IR from bartobri/data-structures-c :: symbol-table/linked-list-ordered (st)

; 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.STnode = type { ptr, ptr }

@z = external hidden global ptr, align 8
@head = external hidden 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 @STsort(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %4 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %4, ptr %3, align 8, !tbaa !5
  br label %5

5:                                                ; preds = %14, %1
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = load ptr, ptr @z, align 8, !tbaa !5
  %8 = icmp ne ptr %6, %7
  br i1 %8, label %9, label %18

9:                                                ; preds = %5
  %10 = load ptr, ptr %2, align 8, !tbaa !5
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.STnode, ptr %11, i32 0, i32 0
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  call void %10(ptr noundef %13)
  br label %14

14:                                               ; preds = %9
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.STnode, ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !11
  store ptr %17, ptr %3, align 8, !tbaa !5
  br label %5, !llvm.loop !12

18:                                               ; preds = %5
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #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, !6, i64 0}
!10 = !{!"STnode", !6, i64 0, !6, i64 8}
!11 = !{!10, !6, i64 8}
!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"

@z = external hidden local_unnamed_addr global ptr, align 8
@head = external hidden local_unnamed_addr global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local void @STsort(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %.04 = load ptr, ptr @head, align 8, !tbaa !5
  %2 = load ptr, ptr @z, align 8, !tbaa !5
  %.not5 = icmp eq ptr %.04, %2
  br i1 %.not5, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.06 = phi ptr [ %.0, %.lr.ph ], [ %.04, %1 ]
  %3 = load ptr, ptr %.06, align 8, !tbaa !9
  tail call void %0(ptr noundef %3) #1
  %4 = getelementptr inbounds i8, ptr %.06, i64 8
  %.0 = load ptr, ptr %4, align 8, !tbaa !5
  %5 = load ptr, ptr @z, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, %5
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph, %1
  ret void
}

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 = { 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, !6, i64 0}
!10 = !{!"STnode", !6, i64 0, !6, i64 8}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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