; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C/Data-Structures/LinkedList (ReverseSinglyLL)

; 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 }

@start = external dso_local global ptr, align 8
@.str.2 = external hidden unnamed_addr constant [3 x i8], align 1
@currptr = external dso_local global ptr, align 8
@.str.3 = external hidden unnamed_addr constant [21 x i8], align 1

declare i32 @printf(ptr noundef, ...) #0

; Function Attrs: nounwind uwtable
define dso_local void @display() #1 {
  %1 = load ptr, ptr @start, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %3, label %5

3:                                                ; preds = %0
  %4 = call i32 (ptr, ...) @printf(ptr noundef @.str.3)
  br label %5

5:                                                ; preds = %3, %0
  %6 = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %6, ptr @currptr, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %15, %5
  %8 = load ptr, ptr @currptr, align 8, !tbaa !5
  %9 = icmp ne ptr %8, null
  br i1 %9, label %10, label %19

10:                                               ; preds = %7
  %11 = load ptr, ptr @currptr, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.node, ptr %11, i32 0, i32 0
  %13 = load i32, ptr %12, align 8, !tbaa !9
  %14 = call i32 (ptr, ...) @printf(ptr noundef @.str.2, i32 noundef %13)
  br label %15

15:                                               ; preds = %10
  %16 = load ptr, ptr @currptr, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !12
  store ptr %18, ptr @currptr, align 8, !tbaa !5
  br label %7, !llvm.loop !13

19:                                               ; preds = %7
  ret void
}

attributes #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 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"}


; 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"

@start = external dso_local local_unnamed_addr global ptr, align 8
@.str.2 = external hidden unnamed_addr constant [3 x i8], align 1
@currptr = external dso_local local_unnamed_addr global ptr, align 8
@.str.3 = external hidden unnamed_addr constant [21 x i8], align 1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #0

; Function Attrs: nofree nounwind uwtable
define dso_local void @display() local_unnamed_addr #1 {
  %1 = load ptr, ptr @start, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %3, label %.thread

.thread:                                          ; preds = %0
  store ptr %1, ptr @currptr, align 8, !tbaa !5
  br label %.lr.ph.preheader

3:                                                ; preds = %0
  %4 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.3)
  %storemerge1.pre = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %storemerge1.pre, ptr @currptr, align 8, !tbaa !5
  %.not2 = icmp eq ptr %storemerge1.pre, null
  br i1 %.not2, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %.thread, %3
  %storemerge3.ph = phi ptr [ %storemerge1.pre, %3 ], [ %1, %.thread ]
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %storemerge3 = phi ptr [ %storemerge, %.lr.ph ], [ %storemerge3.ph, %.lr.ph.preheader ]
  %5 = load i32, ptr %storemerge3, align 8, !tbaa !9
  %6 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %5)
  %7 = load ptr, ptr @currptr, align 8, !tbaa !5
  %8 = getelementptr inbounds i8, ptr %7, i64 8
  %storemerge = load ptr, ptr %8, align 8, !tbaa !5
  store ptr %storemerge, ptr @currptr, align 8, !tbaa !5
  %.not = icmp eq ptr %storemerge, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph, %3
  ret void
}

attributes #0 = { 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" }
attributes #1 = { 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" }

!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 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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