; LLVM IR from af-jk/rtos :: src (usart)

; 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: nounwind uwtable
declare dso_local void @USART_transmit_byte(ptr noundef, i8 noundef zeroext) #0

; Function Attrs: nounwind uwtable
define dso_local void @USART_transmit(ptr noundef %0, ptr noundef %1, i64 noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i64, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  store i64 %2, ptr %6, align 8, !tbaa !9
  br label %7

7:                                                ; preds = %11, %3
  %8 = load i64, ptr %6, align 8, !tbaa !9
  %9 = add i64 %8, -1
  store i64 %9, ptr %6, align 8, !tbaa !9
  %10 = icmp ugt i64 %8, 0
  br i1 %10, label %11, label %16

11:                                               ; preds = %7
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  %14 = getelementptr inbounds i8, ptr %13, i32 1
  store ptr %14, ptr %5, align 8, !tbaa !5
  %15 = load i8, ptr %13, align 1, !tbaa !11
  call void @USART_transmit_byte(ptr noundef %12, i8 noundef zeroext %15)
  br label %7, !llvm.loop !12

16:                                               ; preds = %7
  ret void
}

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" }

!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 = !{!"long", !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"

; Function Attrs: nounwind uwtable
declare dso_local void @USART_transmit_byte(ptr noundef, i8 noundef zeroext) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @USART_transmit(ptr noundef %0, ptr nocapture noundef readonly %1, i64 noundef %2) local_unnamed_addr #0 {
  %.not3 = icmp eq i64 %2, 0
  br i1 %.not3, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %3, %.lr.ph
  %.05 = phi i64 [ %4, %.lr.ph ], [ %2, %3 ]
  %.024 = phi ptr [ %5, %.lr.ph ], [ %1, %3 ]
  %4 = add i64 %.05, -1
  %5 = getelementptr inbounds i8, ptr %.024, i64 1
  %6 = load i8, ptr %.024, align 1, !tbaa !5
  tail call void @USART_transmit_byte(ptr noundef %0, i8 noundef zeroext %6)
  %.not = icmp eq i64 %4, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %.lr.ph, %3
  ret void
}

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" }

!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,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass