; LLVM IR from Mohammed-Shoaib/Coding-Problems :: Codeforces/Solutions/977A.ll (Z17wrong_subtractionii)

; 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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z17wrong_subtractionii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %19, %2
  %6 = load i32, ptr %4, align 4, !tbaa !5
  %7 = add nsw i32 %6, -1
  store i32 %7, ptr %4, align 4, !tbaa !5
  %8 = icmp ne i32 %6, 0
  br i1 %8, label %9, label %20

9:                                                ; preds = %5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = srem i32 %10, 10
  %12 = icmp eq i32 %11, 0
  br i1 %12, label %13, label %16

13:                                               ; preds = %9
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = sdiv i32 %14, 10
  store i32 %15, ptr %3, align 4, !tbaa !5
  br label %19

16:                                               ; preds = %9
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = add nsw i32 %17, -1
  store i32 %18, ptr %3, align 4, !tbaa !5
  br label %19

19:                                               ; preds = %16, %13
  br label %5, !llvm.loop !9

20:                                               ; preds = %5
  %21 = load i32, ptr %3, align 4, !tbaa !5
  ret i32 %21
}

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" }

!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"}


; 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: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z17wrong_subtractionii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not6 = icmp eq i32 %1, 0
  br i1 %.not6, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %.lr.ph
  %.in = phi i32 [ %3, %.lr.ph ], [ %1, %2 ]
  %.057 = phi i32 [ %.1, %.lr.ph ], [ %0, %2 ]
  %3 = add nsw i32 %.in, -1
  %4 = srem i32 %.057, 10
  %5 = sdiv i32 %.057, 10
  %6 = icmp eq i32 %4, 0
  %7 = add nsw i32 %.057, -1
  %.1 = select i1 %6, i32 %5, i32 %7
  %.not = icmp eq i32 %3, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !5

._crit_edge:                                      ; preds = %.lr.ph, %2
  %.05.lcssa = phi i32 [ %0, %2 ], [ %.1, %.lr.ph ]
  ret i32 %.05.lcssa
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: DivRemPairsPass,GVNPass,GlobalOptPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass