; LLVM IR from kazunetakahashi/atcoder :: 201411_201509/0322_ABC020/D.ll (Z3gcdxx)

; 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 uwtable
define dso_local noundef i64 @_Z3gcdxx(i64 noundef %0, i64 noundef %1) #0 {
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  %5 = alloca i64, align 8
  store i64 %0, ptr %4, align 8, !tbaa !5
  store i64 %1, ptr %5, align 8, !tbaa !5
  %6 = load i64, ptr %4, align 8, !tbaa !5
  %7 = load i64, ptr %5, align 8, !tbaa !5
  %8 = icmp slt i64 %6, %7
  br i1 %8, label %9, label %13

9:                                                ; preds = %2
  %10 = load i64, ptr %5, align 8, !tbaa !5
  %11 = load i64, ptr %4, align 8, !tbaa !5
  %12 = call noundef i64 @_Z3gcdxx(i64 noundef %10, i64 noundef %11)
  store i64 %12, ptr %3, align 8
  br label %24

13:                                               ; preds = %2
  %14 = load i64, ptr %5, align 8, !tbaa !5
  %15 = icmp eq i64 %14, 0
  br i1 %15, label %16, label %18

16:                                               ; preds = %13
  %17 = load i64, ptr %4, align 8, !tbaa !5
  store i64 %17, ptr %3, align 8
  br label %24

18:                                               ; preds = %13
  %19 = load i64, ptr %5, align 8, !tbaa !5
  %20 = load i64, ptr %4, align 8, !tbaa !5
  %21 = load i64, ptr %5, align 8, !tbaa !5
  %22 = srem i64 %20, %21
  %23 = call noundef i64 @_Z3gcdxx(i64 noundef %19, i64 noundef %22)
  store i64 %23, ptr %3, align 8
  br label %24

24:                                               ; preds = %18, %16, %9
  %25 = load i64, ptr %3, align 8
  ret i64 %25
}

attributes #0 = { mustprogress 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 long", !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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i64 @_Z3gcdxx(i64 noundef %0, i64 noundef %1) local_unnamed_addr #0 {
  br label %tailrecurse

tailrecurse:                                      ; preds = %tailrecurse.backedge, %2
  %.tr = phi i64 [ %0, %2 ], [ %.tr13, %tailrecurse.backedge ]
  %.tr13 = phi i64 [ %1, %2 ], [ %.tr13.be, %tailrecurse.backedge ]
  %3 = icmp slt i64 %.tr, %.tr13
  br i1 %3, label %tailrecurse.backedge, label %4

4:                                                ; preds = %tailrecurse
  %5 = icmp eq i64 %.tr13, 0
  br i1 %5, label %8, label %6

6:                                                ; preds = %4
  %7 = srem i64 %.tr, %.tr13
  br label %tailrecurse.backedge

tailrecurse.backedge:                             ; preds = %6, %tailrecurse
  %.tr13.be = phi i64 [ %7, %6 ], [ %.tr, %tailrecurse ]
  br label %tailrecurse

8:                                                ; preds = %4
  ret i64 %.tr
}

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)"}


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