; LLVM IR from codemistic/Data-Structures-and-Algorithms :: CPP/recursion/Fast Exponentiation.ll (Z12fastExponentii)

; 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 i32 @_Z12fastExponentii(i32 noundef %0, i32 noundef %1) #0 {
  %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 %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  %8 = load i32, ptr %5, align 4, !tbaa !5
  %9 = icmp eq i32 %8, 1
  br i1 %9, label %10, label %12

10:                                               ; preds = %2
  %11 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %11, ptr %3, align 4
  br label %31

12:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  %13 = load i32, ptr %4, align 4, !tbaa !5
  %14 = load i32, ptr %5, align 4, !tbaa !5
  %15 = sdiv i32 %14, 2
  %16 = call noundef i32 @_Z12fastExponentii(i32 noundef %13, i32 noundef %15)
  store i32 %16, ptr %6, align 4, !tbaa !5
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = and i32 %17, 1
  %19 = icmp eq i32 %18, 0
  br i1 %19, label %20, label %24

20:                                               ; preds = %12
  %21 = load i32, ptr %6, align 4, !tbaa !5
  %22 = load i32, ptr %6, align 4, !tbaa !5
  %23 = mul nsw i32 %21, %22
  store i32 %23, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %30

24:                                               ; preds = %12
  %25 = load i32, ptr %4, align 4, !tbaa !5
  %26 = load i32, ptr %6, align 4, !tbaa !5
  %27 = load i32, ptr %6, align 4, !tbaa !5
  %28 = mul nsw i32 %26, %27
  %29 = mul nsw i32 %25, %28
  store i32 %29, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %30

30:                                               ; preds = %24, %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %31

31:                                               ; preds = %30, %10
  %32 = load i32, ptr %3, align 4
  ret i32 %32
}

; 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 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"}


; 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 nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z12fastExponentii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %1, 1
  br i1 %3, label %common.ret12, label %4

common.ret12:                                     ; preds = %2, %4
  %common.ret12.op = phi i32 [ %.0, %4 ], [ %0, %2 ]
  ret i32 %common.ret12.op

4:                                                ; preds = %2
  %5 = sdiv i32 %1, 2
  %6 = tail call noundef i32 @_Z12fastExponentii(i32 noundef %0, i32 noundef %5)
  %7 = and i32 %1, 1
  %8 = icmp eq i32 %7, 0
  %9 = select i1 %8, i32 1, i32 %0
  %10 = mul i32 %6, %9
  %.0 = mul i32 %10, %6
  br label %common.ret12
}

attributes #0 = { mustprogress nofree 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: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass