; LLVM IR from jishanshaikh4/lib-math :: fast-fourier-transforms (fast-fourier-transform)

; 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: nounwind uwtable
declare dso_local void @_fft(ptr noundef, ptr noundef, i32 noundef, i32 noundef) #0

; 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

; Function Attrs: nounwind uwtable
define dso_local void @fft(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i64, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  %8 = load i32, ptr %4, align 4, !tbaa !9
  %9 = zext i32 %8 to i64
  %10 = call ptr @llvm.stacksave.p0()
  store ptr %10, ptr %5, align 8
  %11 = alloca { double, double }, i64 %9, align 16
  store i64 %9, ptr %6, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %12

12:                                               ; preds = %31, %2
  %13 = load i32, ptr %7, align 4, !tbaa !9
  %14 = load i32, ptr %4, align 4, !tbaa !9
  %15 = icmp slt i32 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  br label %34

17:                                               ; preds = %12
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = load i32, ptr %7, align 4, !tbaa !9
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds { double, double }, ptr %18, i64 %20
  %22 = getelementptr inbounds { double, double }, ptr %21, i32 0, i32 0
  %23 = load double, ptr %22, align 8
  %24 = getelementptr inbounds { double, double }, ptr %21, i32 0, i32 1
  %25 = load double, ptr %24, align 8
  %26 = load i32, ptr %7, align 4, !tbaa !9
  %27 = sext i32 %26 to i64
  %28 = getelementptr inbounds { double, double }, ptr %11, i64 %27
  %29 = getelementptr inbounds { double, double }, ptr %28, i32 0, i32 0
  %30 = getelementptr inbounds { double, double }, ptr %28, i32 0, i32 1
  store double %23, ptr %29, align 16
  store double %25, ptr %30, align 8
  br label %31

31:                                               ; preds = %17
  %32 = load i32, ptr %7, align 4, !tbaa !9
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %7, align 4, !tbaa !9
  br label %12, !llvm.loop !11

34:                                               ; preds = %16
  %35 = load ptr, ptr %3, align 8, !tbaa !5
  %36 = load i32, ptr %4, align 4, !tbaa !9
  call void @_fft(ptr noundef %35, ptr noundef %11, i32 noundef %36, i32 noundef 1)
  %37 = load ptr, ptr %5, align 8
  call void @llvm.stackrestore.p0(ptr %37)
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #2

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #2

attributes #0 = { 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 = { nocallback nofree nosync nounwind willreturn }
attributes #3 = { 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/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"

; Function Attrs: nounwind uwtable
declare dso_local void @_fft(ptr noundef, ptr noundef, i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @fft(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = zext i32 %1 to i64
  %4 = alloca { double, double }, i64 %3, align 16
  %5 = icmp sgt i32 %1, 0
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %xtraiter = and i64 %3, 3
  %6 = icmp ult i32 %1, 4
  br i1 %6, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i64 %3, 2147483644
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %indvars.iv.unr = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next.3, %.lr.ph ]
  %lcmp.mod.not = icmp eq i64 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil
  %indvars.iv.epil = phi i64 [ %indvars.iv.next.epil, %.lr.ph.epil ], [ %indvars.iv.unr, %._crit_edge.loopexit.unr-lcssa ]
  %epil.iter = phi i64 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %._crit_edge.loopexit.unr-lcssa ]
  %7 = getelementptr inbounds { double, double }, ptr %0, i64 %indvars.iv.epil
  %8 = getelementptr inbounds { double, double }, ptr %4, i64 %indvars.iv.epil
  %9 = load <2 x double>, ptr %7, align 8
  store <2 x double> %9, ptr %8, align 16
  %indvars.iv.next.epil = add nuw nsw i64 %indvars.iv.epil, 1
  %epil.iter.next = add i64 %epil.iter, 1
  %epil.iter.cmp.not = icmp eq i64 %epil.iter.next, %xtraiter
  br i1 %epil.iter.cmp.not, label %._crit_edge, label %.lr.ph.epil, !llvm.loop !5

._crit_edge:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil, %2
  call void @_fft(ptr noundef %0, ptr noundef nonnull %4, i32 noundef %1, i32 noundef 1)
  ret void

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader.new ], [ %indvars.iv.next.3, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.3, %.lr.ph ]
  %10 = getelementptr inbounds { double, double }, ptr %0, i64 %indvars.iv
  %11 = getelementptr inbounds { double, double }, ptr %4, i64 %indvars.iv
  %12 = load <2 x double>, ptr %10, align 8
  store <2 x double> %12, ptr %11, align 16
  %indvars.iv.next = or disjoint i64 %indvars.iv, 1
  %13 = getelementptr inbounds { double, double }, ptr %0, i64 %indvars.iv.next
  %14 = getelementptr inbounds { double, double }, ptr %4, i64 %indvars.iv.next
  %15 = load <2 x double>, ptr %13, align 8
  store <2 x double> %15, ptr %14, align 16
  %indvars.iv.next.1 = or disjoint i64 %indvars.iv, 2
  %16 = getelementptr inbounds { double, double }, ptr %0, i64 %indvars.iv.next.1
  %17 = getelementptr inbounds { double, double }, ptr %4, i64 %indvars.iv.next.1
  %18 = load <2 x double>, ptr %16, align 8
  store <2 x double> %18, ptr %17, align 16
  %indvars.iv.next.2 = or disjoint i64 %indvars.iv, 3
  %19 = getelementptr inbounds { double, double }, ptr %0, i64 %indvars.iv.next.2
  %20 = getelementptr inbounds { double, double }, ptr %4, i64 %indvars.iv.next.2
  %21 = load <2 x double>, ptr %19, align 8
  store <2 x double> %21, ptr %20, align 16
  %indvars.iv.next.3 = add nuw nsw i64 %indvars.iv, 4
  %niter.next.3 = add i64 %niter, 4
  %niter.ncmp.3 = icmp eq i64 %niter.next.3, %unroll_iter
  br i1 %niter.ncmp.3, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !7
}

attributes #0 = { 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" }

!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.unroll.disable"}
!7 = distinct !{!7, !8}
!8 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SLPVectorizerPass,SROAPass,SimplifyCFGPass