; LLVM IR from BrunoLevy/learn-fpga :: FemtoRV/FIRMWARE/LIBFEMTOC (print)

; 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"

@.str = external hidden unnamed_addr constant [17 x i8], align 1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

declare i32 @putchar(i32 noundef) #1

; 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 void @print_hex_digits(i32 noundef %0, i32 noundef %1) #2 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %6 = load i32, ptr %4, align 4, !tbaa !5
  %7 = mul nsw i32 4, %6
  %8 = sub nsw i32 %7, 4
  store i32 %8, ptr %5, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %23, %2
  %10 = load i32, ptr %5, align 4, !tbaa !5
  %11 = icmp sge i32 %10, 0
  br i1 %11, label %13, label %12

12:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %26

13:                                               ; preds = %9
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = load i32, ptr %5, align 4, !tbaa !5
  %16 = lshr i32 %14, %15
  %17 = urem i32 %16, 16
  %18 = zext i32 %17 to i64
  %19 = getelementptr inbounds [17 x i8], ptr @.str, i64 0, i64 %18
  %20 = load i8, ptr %19, align 1, !tbaa !9
  %21 = sext i8 %20 to i32
  %22 = call i32 @putchar(i32 noundef %21)
  br label %23

23:                                               ; preds = %13
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = sub nsw i32 %24, 4
  store i32 %25, ptr %5, align 4, !tbaa !5
  br label %9, !llvm.loop !10

26:                                               ; preds = %12
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 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 #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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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"

@.str = external hidden unnamed_addr constant [17 x i8], align 1

; Function Attrs: nofree nounwind
declare noundef i32 @putchar(i32 noundef) local_unnamed_addr #0

; Function Attrs: nofree nounwind uwtable
define dso_local void @print_hex_digits(i32 noundef %0, i32 noundef %1) local_unnamed_addr #1 {
  %3 = icmp sgt i32 %1, 0
  br i1 %3, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %4 = shl nsw i32 %1, 2
  br label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %2
  ret void

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %.0.in5 = phi i32 [ %.0, %.lr.ph ], [ %4, %.lr.ph.preheader ]
  %.0 = add nsw i32 %.0.in5, -4
  %5 = lshr i32 %0, %.0
  %6 = and i32 %5, 15
  %7 = zext nneg i32 %6 to i64
  %8 = getelementptr inbounds [17 x i8], ptr @.str, i64 0, i64 %7
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %10 = sext i8 %9 to i32
  %11 = tail call i32 @putchar(i32 noundef %10)
  %12 = icmp sgt i32 %.0.in5, 7
  br i1 %12, label %.lr.ph, label %._crit_edge, !llvm.loop !8
}

attributes #0 = { nofree nounwind "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 = { 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 = !{!"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,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass