; LLVM IR from omonimus1/competitive-programming :: codechef/flow004.ll (Z15get_first_digitl)

; 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 @_Z15get_first_digitl(i64 noundef %0) #0 {
  %2 = alloca i64, align 8
  store i64 %0, ptr %2, align 8, !tbaa !5
  br label %3

3:                                                ; preds = %6, %1
  %4 = load i64, ptr %2, align 8, !tbaa !5
  %5 = icmp sge i64 %4, 10
  br i1 %5, label %6, label %9

6:                                                ; preds = %3
  %7 = load i64, ptr %2, align 8, !tbaa !5
  %8 = sdiv i64 %7, 10
  store i64 %8, ptr %2, align 8, !tbaa !5
  br label %3, !llvm.loop !9

9:                                                ; preds = %3
  %10 = load i64, ptr %2, align 8, !tbaa !5
  %11 = trunc i64 %10 to i32
  ret i32 %11
}

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 = !{!"long", !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 @_Z15get_first_digitl(i64 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i64 %0, 9
  br i1 %2, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.03 = phi i64 [ %3, %.lr.ph ], [ %0, %1 ]
  %3 = udiv i64 %.03, 10
  %4 = icmp ugt i64 %.03, 99
  br i1 %4, label %.lr.ph, label %._crit_edge, !llvm.loop !5

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.0.lcssa = phi i64 [ %0, %1 ], [ %3, %.lr.ph ]
  %5 = trunc i64 %.0.lcssa to i32
  ret i32 %5
}

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: GVNPass,GlobalOptPass,IPSCCPPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass