; LLVM IR from LeoVen/C-Macro-Collections :: examples (dfs)

; 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.Stack = type { ptr, i64, i64, i32, ptr, ptr }

; Function Attrs: nounwind uwtable
declare dso_local zeroext i1 @stk_empty(ptr noundef) #0

; Function Attrs: nounwind uwtable
define dso_local ptr @stk_top(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %5 = load ptr, ptr %3, align 8, !tbaa !5
  %6 = call zeroext i1 @stk_empty(ptr noundef %5)
  br i1 %6, label %7, label %11

7:                                                ; preds = %1
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.Stack, ptr %8, i32 0, i32 3
  store i32 2, ptr %9, align 8, !tbaa !9
  store ptr null, ptr %4, align 8, !tbaa !5
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %10, ptr %2, align 8
  br label %23

11:                                               ; preds = %1
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.Stack, ptr %12, i32 0, i32 3
  store i32 0, ptr %13, align 8, !tbaa !9
  %14 = load ptr, ptr %3, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.Stack, ptr %14, i32 0, i32 0
  %16 = load ptr, ptr %15, align 8, !tbaa !13
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.Stack, ptr %17, i32 0, i32 2
  %19 = load i64, ptr %18, align 8, !tbaa !14
  %20 = sub i64 %19, 1
  %21 = getelementptr inbounds ptr, ptr %16, i64 %20
  %22 = load ptr, ptr %21, align 8, !tbaa !5
  store ptr %22, ptr %2, align 8
  br label %23

23:                                               ; preds = %11, %7
  %24 = load ptr, ptr %2, align 8
  ret ptr %24
}

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" }

!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, !12, i64 24}
!10 = !{!"Stack", !6, i64 0, !11, i64 8, !11, i64 16, !12, i64 24, !6, i64 32, !6, i64 40}
!11 = !{!"long", !7, i64 0}
!12 = !{!"int", !7, i64 0}
!13 = !{!10, !6, i64 0}
!14 = !{!10, !11, i64 16}


; 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: nounwind uwtable
declare dso_local zeroext i1 @stk_empty(ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local ptr @stk_top(ptr noundef %0) local_unnamed_addr #0 {
  %2 = tail call zeroext i1 @stk_empty(ptr noundef %0)
  br i1 %2, label %10, label %3

3:                                                ; preds = %1
  %4 = load ptr, ptr %0, align 8, !tbaa !5
  %5 = getelementptr inbounds i8, ptr %0, i64 16
  %6 = load i64, ptr %5, align 8, !tbaa !12
  %7 = getelementptr ptr, ptr %4, i64 %6
  %8 = getelementptr i8, ptr %7, i64 -8
  %9 = load ptr, ptr %8, align 8, !tbaa !13
  br label %10

10:                                               ; preds = %1, %3
  %.sink = phi i32 [ 0, %3 ], [ 2, %1 ]
  %.0 = phi ptr [ %9, %3 ], [ null, %1 ]
  %11 = getelementptr inbounds i8, ptr %0, i64 24
  store i32 %.sink, ptr %11, align 8
  ret ptr %.0
}

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" }

!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, !7, i64 0}
!6 = !{!"Stack", !7, i64 0, !10, i64 8, !10, i64 16, !11, i64 24, !7, i64 32, !7, i64 40}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"long", !8, i64 0}
!11 = !{!"int", !8, i64 0}
!12 = !{!6, !10, i64 16}
!13 = !{!7, !7, i64 0}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InstCombinePass,JumpThreadingPass,MergedLoadStoreMotionPass,SROAPass,TailCallElimPass