; LLVM IR from UtkarshPathrabe/Competitive-Coding :: SPOJ Solutions/LOOPEXP.ll (Z3prev)

; 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"

@res = external dso_local global [100009 x double], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z3prev() #0 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #2
  store double 1.000000e+00, ptr getelementptr inbounds ([100009 x double], ptr @res, i64 0, i64 1), align 8, !tbaa !5
  store i32 2, ptr %1, align 4, !tbaa !9
  br label %2

2:                                                ; preds = %18, %0
  %3 = load i32, ptr %1, align 4, !tbaa !9
  %4 = icmp sle i32 %3, 100000
  br i1 %4, label %5, label %21

5:                                                ; preds = %2
  %6 = load i32, ptr %1, align 4, !tbaa !9
  %7 = sub nsw i32 %6, 1
  %8 = sext i32 %7 to i64
  %9 = getelementptr inbounds [100009 x double], ptr @res, i64 0, i64 %8
  %10 = load double, ptr %9, align 8, !tbaa !5
  %11 = load i32, ptr %1, align 4, !tbaa !9
  %12 = sitofp i32 %11 to double
  %13 = fdiv double 1.000000e+00, %12
  %14 = fadd double %10, %13
  %15 = load i32, ptr %1, align 4, !tbaa !9
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds [100009 x double], ptr @res, i64 0, i64 %16
  store double %14, ptr %17, align 8, !tbaa !5
  br label %18

18:                                               ; preds = %5
  %19 = load i32, ptr %1, align 4, !tbaa !9
  %20 = add nsw i32 %19, 1
  store i32 %20, ptr %1, align 4, !tbaa !9
  br label %2, !llvm.loop !11

21:                                               ; preds = %2
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #2
  ret void
}

; 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 = !{!"double", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

@res = external dso_local local_unnamed_addr global [100009 x double], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(write, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z3prev() local_unnamed_addr #0 {
  store double 1.000000e+00, ptr getelementptr inbounds (i8, ptr @res, i64 8), align 8, !tbaa !5
  br label %1

1:                                                ; preds = %1, %0
  %2 = phi double [ 1.000000e+00, %0 ], [ %16, %1 ]
  %indvars.iv = phi i64 [ 2, %0 ], [ %indvars.iv.next.2, %1 ]
  %3 = trunc nuw nsw i64 %indvars.iv to i32
  %4 = uitofp nneg i32 %3 to double
  %5 = fdiv double 1.000000e+00, %4
  %6 = fadd double %5, %2
  %7 = getelementptr inbounds [100009 x double], ptr @res, i64 0, i64 %indvars.iv
  store double %6, ptr %7, align 8, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %8 = trunc nuw nsw i64 %indvars.iv.next to i32
  %9 = uitofp nneg i32 %8 to double
  %10 = fdiv double 1.000000e+00, %9
  %11 = fadd double %10, %6
  %12 = getelementptr inbounds [100009 x double], ptr @res, i64 0, i64 %indvars.iv.next
  store double %11, ptr %12, align 8, !tbaa !5
  %indvars.iv.next.1 = add nuw nsw i64 %indvars.iv, 2
  %13 = trunc nuw nsw i64 %indvars.iv.next.1 to i32
  %14 = uitofp nneg i32 %13 to double
  %15 = fdiv double 1.000000e+00, %14
  %16 = fadd double %15, %11
  %17 = getelementptr inbounds [100009 x double], ptr @res, i64 0, i64 %indvars.iv.next.1
  store double %16, ptr %17, align 8, !tbaa !5
  %indvars.iv.next.2 = add nuw nsw i64 %indvars.iv, 3
  %exitcond.not.2 = icmp eq i64 %indvars.iv.next.2, 100001
  br i1 %exitcond.not.2, label %18, label %1, !llvm.loop !9

18:                                               ; preds = %1
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(write, 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 = !{!"double", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: BDCEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass