; LLVM IR from kazunetakahashi/atcoder :: 2018/0415_s8pc-5/D.ll (Z6nokoriv)

; 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"

@H = external dso_local global i32, align 4
@W = external dso_local global i32, align 4

; 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: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z6nokoriv() #1 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #2
  %2 = load i32, ptr @H, align 4, !tbaa !5
  %3 = load i32, ptr @W, align 4, !tbaa !5
  %4 = mul nsw i32 %2, %3
  %5 = sub nsw i32 %4, 2
  store i32 %5, ptr %1, align 4, !tbaa !5
  %6 = load i32, ptr @H, align 4, !tbaa !5
  %7 = icmp eq i32 %6, 1
  br i1 %7, label %8, label %14

8:                                                ; preds = %0
  %9 = load i32, ptr @W, align 4, !tbaa !5
  %10 = icmp sgt i32 %9, 2
  br i1 %10, label %11, label %14

11:                                               ; preds = %8
  %12 = load i32, ptr %1, align 4, !tbaa !5
  %13 = sub nsw i32 %12, 1
  store i32 %13, ptr %1, align 4, !tbaa !5
  br label %21

14:                                               ; preds = %8, %0
  %15 = load i32, ptr @H, align 4, !tbaa !5
  %16 = icmp sgt i32 %15, 1
  br i1 %16, label %17, label %20

17:                                               ; preds = %14
  %18 = load i32, ptr %1, align 4, !tbaa !5
  %19 = sub nsw i32 %18, 2
  store i32 %19, ptr %1, align 4, !tbaa !5
  br label %20

20:                                               ; preds = %17, %14
  br label %21

21:                                               ; preds = %20, %11
  %22 = load i32, ptr %1, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #2
  ret i32 %22
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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"}


; 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"

@H = external dso_local local_unnamed_addr global i32, align 4
@W = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef range(i32 -2147483648, 2147483646) i32 @_Z6nokoriv() local_unnamed_addr #0 {
  %1 = load i32, ptr @H, align 4, !tbaa !5
  %2 = load i32, ptr @W, align 4
  %3 = mul nsw i32 %2, %1
  %4 = icmp eq i32 %1, 1
  %5 = icmp sgt i32 %2, 2
  %or.cond = and i1 %4, %5
  %6 = icmp sgt i32 %1, 1
  %spec.select.v = select i1 %6, i32 -4, i32 -2
  %.0.v = select i1 %or.cond, i32 -3, i32 %spec.select.v
  %.0 = add nsw i32 %3, %.0.v
  ret i32 %.0
}

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"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass