; LLVM IR from Ali-Mirghasemi/Signal :: Src (Signal)

; 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._Signal = type { ptr, ptr, %union.Signal_Callbacks, i8 }
%union.Signal_Callbacks = type { [4 x ptr] }

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

7:                                                ; preds = %18, %1
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = icmp ne ptr null, %8
  br i1 %9, label %10, label %22

10:                                               ; preds = %7
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct._Signal, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %15 = icmp eq ptr %11, %14
  br i1 %15, label %16, label %18

16:                                               ; preds = %10
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %17, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %23

18:                                               ; preds = %10
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct._Signal, ptr %19, i32 0, i32 0
  %21 = load ptr, ptr %20, align 8, !tbaa !11
  store ptr %21, ptr %4, align 8, !tbaa !5
  br label %7, !llvm.loop !12

22:                                               ; preds = %7
  store ptr null, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %23

23:                                               ; preds = %22, %16
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %24 = load ptr, ptr %2, align 8
  ret ptr %24
}

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 8}
!10 = !{!"_Signal", !6, i64 0, !6, i64 8, !7, i64 16, !7, i64 48, !7, i64 48, !7, i64 48, !7, i64 48, !7, i64 48}
!11 = !{!10, !6, i64 0}
!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"

@lastSignal = external hidden local_unnamed_addr global ptr, align 8

; Function Attrs: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local ptr @Signal_find(ptr noundef readnone %0) local_unnamed_addr #0 {
  br label %2

2:                                                ; preds = %3, %1
  %.0.in = phi ptr [ @lastSignal, %1 ], [ %.0, %3 ]
  %.0 = load ptr, ptr %.0.in, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %7, label %3

3:                                                ; preds = %2
  %4 = getelementptr inbounds i8, ptr %.0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %6 = icmp eq ptr %5, %0
  br i1 %6, label %7, label %2, !llvm.loop !11

7:                                                ; preds = %2, %3
  ret ptr %.0
}

attributes #0 = { nofree norecurse nosync nounwind 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, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_Signal", !6, i64 0, !6, i64 8, !7, i64 16, !7, i64 48, !7, i64 48, !7, i64 48, !7, i64 48, !7, i64 48}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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