; LLVM IR from mist64/perfect6502 :: cbmbasic (plugin)

; 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"

@A = external global i8, align 1

; Function Attrs: nounwind uwtable
define dso_local i32 @compare(ptr noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i16, align 2
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %7, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 2, ptr %5) #3
  %8 = call zeroext i16 @get_chrptr()
  store i16 %8, ptr %5, align 2, !tbaa !9
  br label %9

9:                                                ; preds = %23, %1
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = load i8, ptr %10, align 1, !tbaa !11
  %12 = icmp ne i8 %11, 0
  br i1 %12, label %13, label %24

13:                                               ; preds = %9
  call void @CHRGET()
  %14 = load i8, ptr @A, align 1, !tbaa !11
  %15 = zext i8 %14 to i32
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = getelementptr inbounds i8, ptr %16, i32 1
  store ptr %17, ptr %4, align 8, !tbaa !5
  %18 = load i8, ptr %16, align 1, !tbaa !11
  %19 = zext i8 %18 to i32
  %20 = icmp ne i32 %15, %19
  br i1 %20, label %21, label %23

21:                                               ; preds = %13
  %22 = load i16, ptr %5, align 2, !tbaa !9
  call void @set_chrptr(i16 noundef zeroext %22)
  store i32 0, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %25

23:                                               ; preds = %13
  br label %9, !llvm.loop !12

24:                                               ; preds = %9
  call void @CHRGET()
  store i32 1, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %25

25:                                               ; preds = %24, %21
  call void @llvm.lifetime.end.p0(i64 2, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  %26 = load i32, ptr %2, align 4
  ret i32 %26
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

declare void @CHRGET() #2

; Function Attrs: nounwind uwtable
declare hidden void @set_chrptr(i16 noundef zeroext) #0

; 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
declare hidden zeroext i16 @get_chrptr() #0

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 = { "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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"short", !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"

@A = external local_unnamed_addr global i8, align 1

; Function Attrs: nounwind uwtable
define dso_local range(i32 0, 2) i32 @compare(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = tail call zeroext i16 @get_chrptr()
  br label %3

3:                                                ; preds = %5, %1
  %.04 = phi ptr [ %0, %1 ], [ %7, %5 ]
  %4 = load i8, ptr %.04, align 1, !tbaa !5
  %.not = icmp eq i8 %4, 0
  tail call void @CHRGET() #2
  br i1 %.not, label %.loopexit, label %5

5:                                                ; preds = %3
  %6 = load i8, ptr @A, align 1, !tbaa !5
  %7 = getelementptr inbounds i8, ptr %.04, i64 1
  %8 = load i8, ptr %.04, align 1, !tbaa !5
  %.not5 = icmp eq i8 %6, %8
  br i1 %.not5, label %3, label %9, !llvm.loop !8

9:                                                ; preds = %5
  tail call void @set_chrptr(i16 noundef zeroext %2)
  br label %.loopexit

.loopexit:                                        ; preds = %3, %9
  %.0 = phi i32 [ 0, %9 ], [ 1, %3 ]
  ret i32 %.0
}

declare void @CHRGET() local_unnamed_addr #1

; Function Attrs: nounwind uwtable
declare hidden void @set_chrptr(i16 noundef zeroext) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
declare hidden zeroext i16 @get_chrptr() local_unnamed_addr #0

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)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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