; LLVM IR from viveakrt/Competitive-programing :: Codeforces/1370A_Maximum_GCD.ll (Z7max_gcdi)

; 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 @_Z7max_gcdi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %8 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %8, ptr %3, align 4, !tbaa !5
  store i32 0, ptr %4, align 4, !tbaa !5
  %9 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %9, ptr %5, align 4, !tbaa !5
  br label %10

10:                                               ; preds = %30, %1
  %11 = load i32, ptr %5, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 0
  br i1 %12, label %13, label %33

13:                                               ; preds = %10
  %14 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %14, ptr %6, align 4, !tbaa !5
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %15

15:                                               ; preds = %19, %13
  %16 = load i32, ptr %6, align 4, !tbaa !5
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = icmp sle i32 %16, %17
  br i1 %18, label %19, label %25

19:                                               ; preds = %15
  %20 = load i32, ptr %7, align 4, !tbaa !5
  %21 = add nsw i32 %20, 1
  store i32 %21, ptr %7, align 4, !tbaa !5
  %22 = load i32, ptr %5, align 4, !tbaa !5
  %23 = load i32, ptr %6, align 4, !tbaa !5
  %24 = add nsw i32 %23, %22
  store i32 %24, ptr %6, align 4, !tbaa !5
  br label %15, !llvm.loop !9

25:                                               ; preds = %15
  %26 = load i32, ptr %7, align 4, !tbaa !5
  %27 = icmp sge i32 %26, 2
  br i1 %27, label %28, label %30

28:                                               ; preds = %25
  %29 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %29, ptr %4, align 4, !tbaa !5
  br label %33

30:                                               ; preds = %25
  %31 = load i32, ptr %5, align 4, !tbaa !5
  %32 = sub nsw i32 %31, 1
  store i32 %32, ptr %5, align 4, !tbaa !5
  br label %10, !llvm.loop !11

33:                                               ; preds = %28, %10
  %34 = load i32, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %34
}

; 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


; 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 range(i32 0, -2147483648) i32 @_Z7max_gcdi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i32 %0, 0
  br i1 %2, label %.preheader.preheader, label %._crit_edge20

.preheader.preheader:                             ; preds = %1
  %3 = shl nuw i32 %0, 1
  %4 = add nuw i32 %0, 1
  %5 = mul i32 %0, -2
  br label %.preheader

.preheader:                                       ; preds = %.preheader.preheader, %._crit_edge.thread
  %indvars.iv24 = phi i32 [ %5, %.preheader.preheader ], [ %indvars.iv.next25, %._crit_edge.thread ]
  %indvars.iv = phi i32 [ %3, %.preheader.preheader ], [ %indvars.iv.next, %._crit_edge.thread ]
  %.01419 = phi i32 [ %0, %.preheader.preheader ], [ %13, %._crit_edge.thread ]
  %.not16 = icmp sgt i32 %.01419, %0
  br i1 %.not16, label %._crit_edge.thread, label %._crit_edge

._crit_edge:                                      ; preds = %.preheader
  %smax = tail call i32 @llvm.smax.i32(i32 %indvars.iv, i32 %4)
  %6 = add i32 %smax, %indvars.iv24
  %7 = icmp ne i32 %6, 0
  %umin.neg = sext i1 %7 to i32
  %8 = add i32 %6, %umin.neg
  %9 = udiv i32 %8, %.01419
  %10 = select i1 %7, i32 2, i32 1
  %11 = add i32 %10, %9
  %12 = icmp ugt i32 %11, 1
  br i1 %12, label %._crit_edge20, label %._crit_edge.thread

._crit_edge.thread:                               ; preds = %.preheader, %._crit_edge
  %13 = add nsw i32 %.01419, -1
  %14 = icmp sgt i32 %.01419, 1
  %indvars.iv.next = add i32 %indvars.iv, -2
  %indvars.iv.next25 = add i32 %indvars.iv24, 2
  br i1 %14, label %.preheader, label %._crit_edge20, !llvm.loop !5

._crit_edge20:                                    ; preds = %._crit_edge.thread, %._crit_edge, %1
  %.015 = phi i32 [ 0, %1 ], [ %.01419, %._crit_edge ], [ 0, %._crit_edge.thread ]
  ret i32 %.015
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #1

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" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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: CorrelatedValuePropagationPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SCCPPass,SROAPass,SimplifyCFGPass,TailCallElimPass