; LLVM IR from priyankchheda/algorithms :: _other_languages/cpp/Maths/modular_exponential.ll (Z19mod_power_iterativexxx)

; 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: 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 i64 @_Z19mod_power_iterativexxx(i64 noundef %0, i64 noundef %1, i64 noundef %2) #1 {
  %4 = alloca i64, align 8
  %5 = alloca i64, align 8
  %6 = alloca i64, align 8
  %7 = alloca i64, align 8
  store i64 %0, ptr %4, align 8, !tbaa !5
  store i64 %1, ptr %5, align 8, !tbaa !5
  store i64 %2, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  store i64 1, ptr %7, align 8, !tbaa !5
  br label %8

8:                                                ; preds = %25, %3
  %9 = load i64, ptr %5, align 8, !tbaa !5
  %10 = icmp ne i64 %9, 0
  br i1 %10, label %11, label %37

11:                                               ; preds = %8
  %12 = load i64, ptr %5, align 8, !tbaa !5
  %13 = srem i64 %12, 2
  %14 = icmp ne i64 %13, 0
  br i1 %14, label %15, label %25

15:                                               ; preds = %11
  %16 = load i64, ptr %7, align 8, !tbaa !5
  %17 = load i64, ptr %6, align 8, !tbaa !5
  %18 = srem i64 %16, %17
  %19 = load i64, ptr %4, align 8, !tbaa !5
  %20 = load i64, ptr %6, align 8, !tbaa !5
  %21 = srem i64 %19, %20
  %22 = mul nsw i64 %18, %21
  %23 = load i64, ptr %6, align 8, !tbaa !5
  %24 = srem i64 %22, %23
  store i64 %24, ptr %7, align 8, !tbaa !5
  br label %25

25:                                               ; preds = %15, %11
  %26 = load i64, ptr %4, align 8, !tbaa !5
  %27 = load i64, ptr %6, align 8, !tbaa !5
  %28 = srem i64 %26, %27
  %29 = load i64, ptr %4, align 8, !tbaa !5
  %30 = load i64, ptr %6, align 8, !tbaa !5
  %31 = srem i64 %29, %30
  %32 = mul nsw i64 %28, %31
  %33 = load i64, ptr %6, align 8, !tbaa !5
  %34 = srem i64 %32, %33
  store i64 %34, ptr %4, align 8, !tbaa !5
  %35 = load i64, ptr %5, align 8, !tbaa !5
  %36 = sdiv i64 %35, 2
  store i64 %36, ptr %5, align 8, !tbaa !5
  br label %8, !llvm.loop !9

37:                                               ; preds = %8
  %38 = load i64, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  ret i64 %38
}

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 = !{!"long 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 i64 @_Z19mod_power_iterativexxx(i64 noundef %0, i64 noundef %1, i64 noundef %2) local_unnamed_addr #0 {
  %.not17 = icmp eq i64 %1, 0
  br i1 %.not17, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %3, %10
  %.020 = phi i64 [ %.1, %10 ], [ 1, %3 ]
  %.01419 = phi i64 [ %12, %10 ], [ %0, %3 ]
  %.01518 = phi i64 [ %13, %10 ], [ %1, %3 ]
  %4 = and i64 %.01518, 1
  %.not16 = icmp eq i64 %4, 0
  br i1 %.not16, label %.lr.ph._crit_edge, label %5

.lr.ph._crit_edge:                                ; preds = %.lr.ph
  %.pre = srem i64 %.01419, %2
  br label %10

5:                                                ; preds = %.lr.ph
  %6 = srem i64 %.020, %2
  %7 = srem i64 %.01419, %2
  %8 = mul nsw i64 %7, %6
  %9 = srem i64 %8, %2
  br label %10

10:                                               ; preds = %.lr.ph._crit_edge, %5
  %.pre-phi = phi i64 [ %.pre, %.lr.ph._crit_edge ], [ %7, %5 ]
  %.1 = phi i64 [ %.020, %.lr.ph._crit_edge ], [ %9, %5 ]
  %11 = mul nsw i64 %.pre-phi, %.pre-phi
  %12 = srem i64 %11, %2
  %13 = sdiv i64 %.01518, 2
  %.01518.off = add i64 %.01518, 1
  %.not = icmp ult i64 %.01518.off, 3
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !5

._crit_edge:                                      ; preds = %10, %3
  %.0.lcssa = phi i64 [ 1, %3 ], [ %.1, %10 ]
  ret i64 %.0.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: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass