; LLVM IR from ARM-software/ML-examples :: cmsis-pack-examples/device/alif-ensemble/src/retarget.ll (read)

; 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"

@stdin = external global ptr, align 8

; 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 @_read(i32 noundef %0, ptr noundef %1, i32 noundef %2, i32 noundef %3) #1 {
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  %11 = alloca i32, align 4
  store i32 %0, ptr %6, align 4, !tbaa !5
  store ptr %1, ptr %7, align 8, !tbaa !9
  store i32 %2, ptr %8, align 4, !tbaa !5
  store i32 %3, ptr %9, align 4, !tbaa !5
  %12 = load i32, ptr %9, align 4, !tbaa !5
  %13 = load i32, ptr %6, align 4, !tbaa !5
  switch i32 %13, label %32 [
    i32 0, label %14
  ]

14:                                               ; preds = %4
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #2
  br label %15

15:                                               ; preds = %25, %14
  %16 = load i32, ptr %8, align 4, !tbaa !5
  %17 = add i32 %16, -1
  store i32 %17, ptr %8, align 4, !tbaa !5
  %18 = icmp ugt i32 %16, 0
  br i1 %18, label %19, label %30

19:                                               ; preds = %15
  %20 = load ptr, ptr @stdin, align 8, !tbaa !9
  %21 = call i32 @fgetc(ptr noundef %20)
  store i32 %21, ptr %10, align 4, !tbaa !5
  %22 = load i32, ptr %10, align 4, !tbaa !5
  %23 = icmp eq i32 %22, -1
  br i1 %23, label %24, label %25

24:                                               ; preds = %19
  store i32 -1, ptr %5, align 4
  store i32 1, ptr %11, align 4
  br label %31

25:                                               ; preds = %19
  %26 = load i32, ptr %10, align 4, !tbaa !5
  %27 = trunc i32 %26 to i8
  %28 = load ptr, ptr %7, align 8, !tbaa !9
  %29 = getelementptr inbounds i8, ptr %28, i32 1
  store ptr %29, ptr %7, align 8, !tbaa !9
  store i8 %27, ptr %28, align 1, !tbaa !11
  br label %15, !llvm.loop !12

30:                                               ; preds = %15
  store i32 0, ptr %5, align 4
  store i32 1, ptr %11, align 4
  br label %31

31:                                               ; preds = %30, %24
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #2
  br label %33

32:                                               ; preds = %4
  store i32 -1, ptr %5, align 4
  br label %33

33:                                               ; preds = %32, %31
  %34 = load i32, ptr %5, align 4
  ret i32 %34
}

; Function Attrs: nounwind uwtable
declare dso_local i32 @fgetc(ptr noundef) #1

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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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"

@stdin = external local_unnamed_addr global ptr, align 8

; Function Attrs: nofree nounwind uwtable
define dso_local range(i32 -1, 1) i32 @_read(i32 noundef %0, ptr nocapture noundef writeonly %1, i32 noundef %2, i32 noundef %3) local_unnamed_addr #0 {
  %cond = icmp eq i32 %0, 0
  br i1 %cond, label %.preheader, label %.loopexit

.preheader:                                       ; preds = %4
  %.not9 = icmp eq i32 %2, 0
  br i1 %.not9, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %8
  %.in = phi i32 [ %9, %8 ], [ %2, %.preheader ]
  %.0610 = phi ptr [ %11, %8 ], [ %1, %.preheader ]
  %5 = load ptr, ptr @stdin, align 8, !tbaa !5
  %6 = tail call i32 @fgetc(ptr noundef %5)
  %7 = icmp eq i32 %6, -1
  br i1 %7, label %.loopexit, label %8

8:                                                ; preds = %.lr.ph
  %9 = add i32 %.in, -1
  %10 = trunc i32 %6 to i8
  %11 = getelementptr inbounds i8, ptr %.0610, i64 1
  store i8 %10, ptr %.0610, align 1, !tbaa !9
  %.not = icmp eq i32 %9, 0
  br i1 %.not, label %.loopexit, label %.lr.ph, !llvm.loop !10

.loopexit:                                        ; preds = %8, %.lr.ph, %.preheader, %4
  %.1 = phi i32 [ -1, %4 ], [ 0, %.preheader ], [ 0, %8 ], [ -1, %.lr.ph ]
  ret i32 %.1
}

; Function Attrs: nofree nounwind uwtable
declare dso_local noundef i32 @fgetc(ptr nocapture noundef) local_unnamed_addr #0

attributes #0 = { nofree 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 = !{!6, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass