; LLVM IR from BrunoLevy/learn-fpga :: FemtoRV/FIRMWARE/LIBFEMTORV32 (spi_sd)

; 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
declare dso_local i32 @_sd_init() #1

declare void @milliwait(i32 noundef) #2

; Function Attrs: nounwind uwtable
define dso_local i32 @sd_init() #1 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #3
  store i32 0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %16, %0
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = icmp slt i32 %6, 10
  br i1 %7, label %9, label %8

8:                                                ; preds = %5
  store i32 2, ptr %4, align 4
  br label %19

9:                                                ; preds = %5
  %10 = call i32 @_sd_init()
  store i32 %10, ptr %2, align 4, !tbaa !5
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = icmp eq i32 %11, 0
  br i1 %12, label %13, label %15

13:                                               ; preds = %9
  %14 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %14, ptr %1, align 4
  store i32 1, ptr %4, align 4
  br label %19

15:                                               ; preds = %9
  call void @milliwait(i32 noundef 100)
  br label %16

16:                                               ; preds = %15
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = add nsw i32 %17, 1
  store i32 %18, ptr %3, align 4, !tbaa !5
  br label %5, !llvm.loop !9

19:                                               ; preds = %13, %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  %20 = load i32, ptr %4, align 4
  switch i32 %20, label %23 [
    i32 2, label %21
  ]

21:                                               ; preds = %19
  %22 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %22, ptr %1, align 4
  store i32 1, ptr %4, align 4
  br label %23

23:                                               ; preds = %21, %19
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #3
  %24 = load i32, ptr %1, align 4
  ret i32 %24
}

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 = { "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 #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 = !{!"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: nounwind uwtable
declare dso_local i32 @_sd_init() local_unnamed_addr #0

declare void @milliwait(i32 noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local i32 @sd_init() local_unnamed_addr #0 {
  %1 = tail call i32 @_sd_init()
  %2 = icmp eq i32 %1, 0
  br i1 %2, label %31, label %3

3:                                                ; preds = %0
  tail call void @milliwait(i32 noundef 100) #2
  %4 = tail call i32 @_sd_init()
  %5 = icmp eq i32 %4, 0
  br i1 %5, label %31, label %6

6:                                                ; preds = %3
  tail call void @milliwait(i32 noundef 100) #2
  %7 = tail call i32 @_sd_init()
  %8 = icmp eq i32 %7, 0
  br i1 %8, label %31, label %9

9:                                                ; preds = %6
  tail call void @milliwait(i32 noundef 100) #2
  %10 = tail call i32 @_sd_init()
  %11 = icmp eq i32 %10, 0
  br i1 %11, label %31, label %12

12:                                               ; preds = %9
  tail call void @milliwait(i32 noundef 100) #2
  %13 = tail call i32 @_sd_init()
  %14 = icmp eq i32 %13, 0
  br i1 %14, label %31, label %15

15:                                               ; preds = %12
  tail call void @milliwait(i32 noundef 100) #2
  %16 = tail call i32 @_sd_init()
  %17 = icmp eq i32 %16, 0
  br i1 %17, label %31, label %18

18:                                               ; preds = %15
  tail call void @milliwait(i32 noundef 100) #2
  %19 = tail call i32 @_sd_init()
  %20 = icmp eq i32 %19, 0
  br i1 %20, label %31, label %21

21:                                               ; preds = %18
  tail call void @milliwait(i32 noundef 100) #2
  %22 = tail call i32 @_sd_init()
  %23 = icmp eq i32 %22, 0
  br i1 %23, label %31, label %24

24:                                               ; preds = %21
  tail call void @milliwait(i32 noundef 100) #2
  %25 = tail call i32 @_sd_init()
  %26 = icmp eq i32 %25, 0
  br i1 %26, label %31, label %27

27:                                               ; preds = %24
  tail call void @milliwait(i32 noundef 100) #2
  %28 = tail call i32 @_sd_init()
  %29 = icmp eq i32 %28, 0
  br i1 %29, label %31, label %30

30:                                               ; preds = %27
  tail call void @milliwait(i32 noundef 100) #2
  br label %31

31:                                               ; preds = %30, %27, %24, %21, %18, %15, %12, %9, %6, %3, %0
  %spec.select = phi i32 [ 0, %0 ], [ 0, %3 ], [ 0, %6 ], [ 0, %9 ], [ 0, %12 ], [ 0, %15 ], [ 0, %18 ], [ 0, %21 ], [ 0, %24 ], [ 0, %27 ], [ %28, %30 ]
  ret i32 %spec.select
}

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 = { "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)"}


; Effective O3 passes: GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,SROAPass,SimplifyCFGPass,TailCallElimPass