; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x18-总结与练习/150. 括号画家.ll (Z7isClosec)

; 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"

@b = external dso_local global [2 x [4 x i8]], align 1

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z7isClosec(i8 noundef signext %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i8, align 1
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i8 %0, ptr %3, align 1, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !8
  br label %6

6:                                                ; preds = %22, %1
  %7 = load i32, ptr %4, align 4, !tbaa !8
  %8 = icmp slt i32 %7, 3
  br i1 %8, label %10, label %9

9:                                                ; preds = %6
  store i32 2, ptr %5, align 4
  br label %25

10:                                               ; preds = %6
  %11 = load i8, ptr %3, align 1, !tbaa !5
  %12 = sext i8 %11 to i32
  %13 = load i32, ptr %4, align 4, !tbaa !8
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [4 x i8], ptr getelementptr inbounds ([2 x [4 x i8]], ptr @b, i64 0, i64 1), i64 0, i64 %14
  %16 = load i8, ptr %15, align 1, !tbaa !5
  %17 = sext i8 %16 to i32
  %18 = icmp eq i32 %12, %17
  br i1 %18, label %19, label %21

19:                                               ; preds = %10
  %20 = load i32, ptr %4, align 4, !tbaa !8
  store i32 %20, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %25

21:                                               ; preds = %10
  br label %22

22:                                               ; preds = %21
  %23 = load i32, ptr %4, align 4, !tbaa !8
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %4, align 4, !tbaa !8
  br label %6, !llvm.loop !10

25:                                               ; preds = %19, %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %26 = load i32, ptr %5, align 4
  switch i32 %26, label %30 [
    i32 2, label %27
    i32 1, label %28
  ]

27:                                               ; preds = %25
  store i32 -1, ptr %2, align 4
  br label %28

28:                                               ; preds = %27, %25
  %29 = load i32, ptr %2, align 4
  ret i32 %29

30:                                               ; preds = %25
  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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !6, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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"

@b = external dso_local local_unnamed_addr global [2 x [4 x i8]], align 1

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z7isClosec(i8 noundef signext %0) local_unnamed_addr #0 {
  %2 = load i8, ptr getelementptr inbounds (i8, ptr @b, i64 4), align 1, !tbaa !5
  %3 = icmp eq i8 %2, %0
  br i1 %3, label %10, label %4

4:                                                ; preds = %1
  %5 = load i8, ptr getelementptr inbounds (i8, ptr @b, i64 5), align 1, !tbaa !5
  %6 = icmp eq i8 %5, %0
  br i1 %6, label %10, label %7

7:                                                ; preds = %4
  %8 = load i8, ptr getelementptr inbounds (i8, ptr @b, i64 6), align 1, !tbaa !5
  %9 = icmp eq i8 %8, %0
  %spec.select11 = select i1 %9, i32 2, i32 -1
  br label %10

10:                                               ; preds = %7, %4, %1
  %spec.select = phi i32 [ 0, %1 ], [ 1, %4 ], [ %spec.select11, %7 ]
  ret i32 %spec.select
}

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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}


; Effective O3 passes: CorrelatedValuePropagationPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass