; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 03. Recursion/reverse digits.ll (Z12reversDigitsi)

; 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"

@_ZZ12reversDigitsiE7rev_num = external hidden global i32, align 4
@_ZZ12reversDigitsiE8base_pos = external hidden global i32, align 4

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z12reversDigitsi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %3 = load i32, ptr %2, align 4, !tbaa !5
  %4 = icmp sgt i32 %3, 0
  br i1 %4, label %5, label %17

5:                                                ; preds = %1
  %6 = load i32, ptr %2, align 4, !tbaa !5
  %7 = sdiv i32 %6, 10
  %8 = call noundef i32 @_Z12reversDigitsi(i32 noundef %7)
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = srem i32 %9, 10
  %11 = load i32, ptr @_ZZ12reversDigitsiE8base_pos, align 4, !tbaa !5
  %12 = mul nsw i32 %10, %11
  %13 = load i32, ptr @_ZZ12reversDigitsiE7rev_num, align 4, !tbaa !5
  %14 = add nsw i32 %13, %12
  store i32 %14, ptr @_ZZ12reversDigitsiE7rev_num, align 4, !tbaa !5
  %15 = load i32, ptr @_ZZ12reversDigitsiE8base_pos, align 4, !tbaa !5
  %16 = mul nsw i32 %15, 10
  store i32 %16, ptr @_ZZ12reversDigitsiE8base_pos, align 4, !tbaa !5
  br label %17

17:                                               ; preds = %5, %1
  %18 = load i32, ptr @_ZZ12reversDigitsiE7rev_num, align 4, !tbaa !5
  ret i32 %18
}

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 = !{!"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"

@_ZZ12reversDigitsiE7rev_num = external hidden local_unnamed_addr global i32, align 4
@_ZZ12reversDigitsiE8base_pos = external hidden local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z12reversDigitsi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i32 %0, 0
  br i1 %2, label %3, label %._crit_edge

._crit_edge:                                      ; preds = %1
  %.pre = load i32, ptr @_ZZ12reversDigitsiE7rev_num, align 4, !tbaa !5
  br label %common.ret

common.ret:                                       ; preds = %._crit_edge, %3
  %common.ret.op = phi i32 [ %10, %3 ], [ %.pre, %._crit_edge ]
  ret i32 %common.ret.op

3:                                                ; preds = %1
  %4 = udiv i32 %0, 10
  %5 = tail call noundef i32 @_Z12reversDigitsi(i32 noundef %4)
  %6 = urem i32 %0, 10
  %7 = load i32, ptr @_ZZ12reversDigitsiE8base_pos, align 4, !tbaa !5
  %8 = mul nsw i32 %7, %6
  %9 = load i32, ptr @_ZZ12reversDigitsiE7rev_num, align 4, !tbaa !5
  %10 = add nsw i32 %9, %8
  store i32 %10, ptr @_ZZ12reversDigitsiE7rev_num, align 4, !tbaa !5
  %11 = mul nsw i32 %7, 10
  store i32 %11, ptr @_ZZ12reversDigitsiE8base_pos, align 4, !tbaa !5
  br label %common.ret
}

attributes #0 = { mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: 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 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


; Effective O3 passes: GVNPass,GlobalOptPass,IPSCCPPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass