; LLVM IR from BrunoLevy/learn-fpga :: FemtoRV/TUTORIALS/FROM_BLINKER_TO_RISCV/FIRMWARE (pi)

; 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: nounwind uwtable
define dso_local i32 @is_prime(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = srem i32 %7, 2
  %9 = icmp eq i32 %8, 0
  br i1 %9, label %10, label %11

10:                                               ; preds = %1
  store i32 0, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %29

11:                                               ; preds = %1
  store i32 3, ptr %5, align 4, !tbaa !5
  br label %12

12:                                               ; preds = %25, %11
  %13 = load i32, ptr %5, align 4, !tbaa !5
  %14 = load i32, ptr %5, align 4, !tbaa !5
  %15 = mul nsw i32 %13, %14
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = icmp sle i32 %15, %16
  br i1 %17, label %18, label %28

18:                                               ; preds = %12
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = srem i32 %19, %20
  %22 = icmp eq i32 %21, 0
  br i1 %22, label %23, label %24

23:                                               ; preds = %18
  store i32 0, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %29

24:                                               ; preds = %18
  br label %25

25:                                               ; preds = %24
  %26 = load i32, ptr %5, align 4, !tbaa !5
  %27 = add nsw i32 %26, 2
  store i32 %27, ptr %5, align 4, !tbaa !5
  br label %12, !llvm.loop !9

28:                                               ; preds = %12
  store i32 1, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %29

29:                                               ; preds = %28, %23, %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %30 = load i32, ptr %2, align 4
  ret i32 %30
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/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: nofree norecurse nosync nounwind memory(none) uwtable
define dso_local range(i32 0, 2) i32 @is_prime(i32 noundef %0) local_unnamed_addr #0 {
  %2 = and i32 %0, 1
  %3 = icmp eq i32 %2, 0
  br i1 %3, label %.loopexit, label %.preheader

.preheader:                                       ; preds = %1
  %.not10 = icmp slt i32 %0, 9
  br i1 %.not10, label %.loopexit, label %.lr.ph

4:                                                ; preds = %.lr.ph
  %5 = add nuw nsw i32 %.011, 2
  %6 = mul nuw nsw i32 %5, %5
  %.not = icmp sgt i32 %6, %0
  br i1 %.not, label %.loopexit, label %.lr.ph, !llvm.loop !5

.lr.ph:                                           ; preds = %.preheader, %4
  %.011 = phi i32 [ %5, %4 ], [ 3, %.preheader ]
  %7 = urem i32 %0, %.011
  %8 = icmp eq i32 %7, 0
  br i1 %8, label %.loopexit, label %4

.loopexit:                                        ; preds = %.lr.ph, %4, %.preheader, %1
  %.08 = phi i32 [ 0, %1 ], [ 1, %.preheader ], [ 0, %.lr.ph ], [ 1, %4 ]
  ret i32 %.08
}

attributes #0 = { nofree norecurse nosync nounwind 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: GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass