; LLVM IR from bartobri/data-structures-c :: symbol-table/array-key-index-first-class (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.symbol_table = type { ptr, i32, i32 }

; 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 @STselect(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %37, %2
  %9 = load i32, ptr %6, align 4, !tbaa !9
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.symbol_table, ptr %10, i32 0, i32 2
  %12 = load i32, ptr %11, align 4, !tbaa !11
  %13 = icmp slt i32 %9, %12
  br i1 %13, label %14, label %40

14:                                               ; preds = %8
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.symbol_table, ptr %15, i32 0, i32 0
  %17 = load ptr, ptr %16, align 8, !tbaa !13
  %18 = load i32, ptr %6, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds ptr, ptr %17, i64 %19
  %21 = load ptr, ptr %20, align 8, !tbaa !5
  %22 = icmp ne ptr %21, null
  br i1 %22, label %23, label %36

23:                                               ; preds = %14
  %24 = load i32, ptr %5, align 4, !tbaa !9
  %25 = add nsw i32 %24, -1
  store i32 %25, ptr %5, align 4, !tbaa !9
  %26 = icmp eq i32 %24, 0
  br i1 %26, label %27, label %35

27:                                               ; preds = %23
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.symbol_table, ptr %28, i32 0, i32 0
  %30 = load ptr, ptr %29, align 8, !tbaa !13
  %31 = load i32, ptr %6, align 4, !tbaa !9
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds ptr, ptr %30, i64 %32
  %34 = load ptr, ptr %33, align 8, !tbaa !5
  store ptr %34, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %41

35:                                               ; preds = %23
  br label %36

36:                                               ; preds = %35, %14
  br label %37

37:                                               ; preds = %36
  %38 = load i32, ptr %6, align 4, !tbaa !9
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %6, align 4, !tbaa !9
  br label %8, !llvm.loop !14

40:                                               ; preds = %8
  store i32 0, ptr %7, align 4
  br label %41

41:                                               ; preds = %40, %27
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  %42 = load i32, ptr %7, align 4
  switch i32 %42, label %45 [
    i32 0, label %43
    i32 1, label %43
  ]

43:                                               ; preds = %41, %41
  %44 = load ptr, ptr %3, align 8
  ret ptr %44

45:                                               ; preds = %41
  unreachable
}

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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 12}
!12 = !{!"symbol_table", !6, i64 0, !10, i64 8, !10, i64 12}
!13 = !{!12, !6, 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: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local ptr @STselect(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = getelementptr inbounds i8, ptr %0, i64 12
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %2
  %6 = load ptr, ptr %0, align 8, !tbaa !11
  %wide.trip.count = zext nneg i32 %4 to i64
  br label %7

7:                                                ; preds = %.lr.ph, %13
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %13 ]
  %.0811 = phi i32 [ %1, %.lr.ph ], [ %.1, %13 ]
  %8 = getelementptr inbounds ptr, ptr %6, i64 %indvars.iv
  %9 = load ptr, ptr %8, align 8, !tbaa !12
  %.not = icmp eq ptr %9, null
  br i1 %.not, label %13, label %10

10:                                               ; preds = %7
  %11 = add nsw i32 %.0811, -1
  %12 = icmp eq i32 %.0811, 0
  br i1 %12, label %._crit_edge, label %13

13:                                               ; preds = %7, %10
  %.1 = phi i32 [ %11, %10 ], [ %.0811, %7 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %7, !llvm.loop !13

._crit_edge:                                      ; preds = %10, %13, %2
  %.09 = phi ptr [ undef, %2 ], [ %9, %13 ], [ %9, %10 ]
  ret ptr %.09
}

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, !10, i64 12}
!6 = !{!"symbol_table", !7, i64 0, !10, i64 8, !10, i64 12}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"int", !8, i64 0}
!11 = !{!6, !7, i64 0}
!12 = !{!7, !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass