; LLVM IR from tangjz/acm-icpc :: usaco/Training/Chapter 1 Getting started/transfrom.ll (Z5matchv)

; 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"

@n = external dso_local global i32, align 4
@init = external dso_local global [11 x [11 x i8]], align 16
@goal = external dso_local global [11 x [11 x i8]], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef zeroext i1 @_Z5matchv() #0 {
  %1 = alloca i1, align 1
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #2
  store i32 0, ptr %2, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %42, %0
  %6 = load i32, ptr %2, align 4, !tbaa !5
  %7 = load i32, ptr @n, align 4, !tbaa !5
  %8 = icmp slt i32 %6, %7
  br i1 %8, label %10, label %9

9:                                                ; preds = %5
  store i32 2, ptr %3, align 4
  br label %45

10:                                               ; preds = %5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %11

11:                                               ; preds = %36, %10
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = load i32, ptr @n, align 4, !tbaa !5
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %16, label %15

15:                                               ; preds = %11
  store i32 5, ptr %3, align 4
  br label %39

16:                                               ; preds = %11
  %17 = load i32, ptr %2, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [11 x [11 x i8]], ptr @init, i64 0, i64 %18
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [11 x i8], ptr %19, i64 0, i64 %21
  %23 = load i8, ptr %22, align 1, !tbaa !9
  %24 = sext i8 %23 to i32
  %25 = load i32, ptr %2, align 4, !tbaa !5
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds [11 x [11 x i8]], ptr @goal, i64 0, i64 %26
  %28 = load i32, ptr %4, align 4, !tbaa !5
  %29 = sext i32 %28 to i64
  %30 = getelementptr inbounds [11 x i8], ptr %27, i64 0, i64 %29
  %31 = load i8, ptr %30, align 1, !tbaa !9
  %32 = sext i8 %31 to i32
  %33 = icmp ne i32 %24, %32
  br i1 %33, label %34, label %35

34:                                               ; preds = %16
  store i1 false, ptr %1, align 1
  store i32 1, ptr %3, align 4
  br label %39

35:                                               ; preds = %16
  br label %36

36:                                               ; preds = %35
  %37 = load i32, ptr %4, align 4, !tbaa !5
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %4, align 4, !tbaa !5
  br label %11, !llvm.loop !10

39:                                               ; preds = %34, %15
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %40 = load i32, ptr %3, align 4
  switch i32 %40, label %45 [
    i32 5, label %41
  ]

41:                                               ; preds = %39
  br label %42

42:                                               ; preds = %41
  %43 = load i32, ptr %2, align 4, !tbaa !5
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %2, align 4, !tbaa !5
  br label %5, !llvm.loop !12

45:                                               ; preds = %39, %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #2
  %46 = load i32, ptr %3, align 4
  switch i32 %46, label %50 [
    i32 2, label %47
    i32 1, label %48
  ]

47:                                               ; preds = %45
  store i1 true, ptr %1, align 1
  br label %48

48:                                               ; preds = %47, %45
  %49 = load i1, ptr %1, align 1
  ret i1 %49

50:                                               ; preds = %45
  unreachable
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { mustprogress 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}
!12 = distinct !{!12, !11}


; 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"

@n = external dso_local local_unnamed_addr global i32, align 4
@init = external dso_local local_unnamed_addr global [11 x [11 x i8]], align 16
@goal = external dso_local local_unnamed_addr global [11 x [11 x i8]], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @_Z5matchv() local_unnamed_addr #0 {
  %1 = load i32, ptr @n, align 4, !tbaa !5
  %2 = icmp slt i32 %1, 1
  br i1 %2, label %.thread, label %.preheader.us.preheader

.preheader.us.preheader:                          ; preds = %0
  %3 = zext nneg i32 %1 to i64
  %wide.trip.count28 = zext nneg i32 %1 to i64
  br label %.preheader.us

.preheader.us:                                    ; preds = %.preheader.us.preheader, %._crit_edge.us
  %indvars.iv26 = phi i64 [ 0, %.preheader.us.preheader ], [ %indvars.iv.next27, %._crit_edge.us ]
  %4 = phi i1 [ false, %.preheader.us.preheader ], [ %11, %._crit_edge.us ]
  br label %6

5:                                                ; preds = %6
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count28
  br i1 %exitcond.not, label %._crit_edge.us, label %6, !llvm.loop !9

6:                                                ; preds = %.preheader.us, %5
  %indvars.iv = phi i64 [ 0, %.preheader.us ], [ %indvars.iv.next, %5 ]
  %7 = getelementptr inbounds [11 x [11 x i8]], ptr @init, i64 0, i64 %indvars.iv26, i64 %indvars.iv
  %8 = load i8, ptr %7, align 1, !tbaa !11
  %9 = getelementptr inbounds [11 x [11 x i8]], ptr @goal, i64 0, i64 %indvars.iv26, i64 %indvars.iv
  %10 = load i8, ptr %9, align 1, !tbaa !11
  %.not.us = icmp eq i8 %8, %10
  br i1 %.not.us, label %5, label %.thread

._crit_edge.us:                                   ; preds = %5
  %indvars.iv.next27 = add nuw nsw i64 %indvars.iv26, 1
  %11 = icmp uge i64 %indvars.iv.next27, %3
  %exitcond29 = icmp eq i64 %indvars.iv.next27, %wide.trip.count28
  br i1 %exitcond29, label %.thread, label %.preheader.us, !llvm.loop !12

.thread:                                          ; preds = %._crit_edge.us, %6, %0
  %12 = phi i1 [ true, %0 ], [ %4, %6 ], [ %11, %._crit_edge.us ]
  ret i1 %12
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !10}


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