; LLVM IR from cpq/bare-metal-programming-guide :: steps/step-5-cmsis (main)

; 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"

@s_ticks = external hidden global i32, align 4
@main.on = external hidden global i8, align 1
@.str = external hidden unnamed_addr constant [21 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i16, align 2
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 2, ptr %2) #4
  store i16 263, ptr %2, align 2, !tbaa !5
  %5 = load i16, ptr %2, align 2, !tbaa !5
  call void @gpio_set_mode(i16 noundef zeroext %5, i8 noundef zeroext 1)
  call void @uart_init(ptr noundef inttoptr (i64 1073760256 to ptr), i64 noundef 115200)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  store volatile i32 0, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  store volatile i32 500, ptr %4, align 4, !tbaa !9
  br label %6

6:                                                ; preds = %23, %0
  %7 = load volatile i32, ptr %4, align 4, !tbaa !9
  %8 = load volatile i32, ptr @s_ticks, align 4, !tbaa !9
  %9 = call zeroext i1 @timer_expired(ptr noundef %3, i32 noundef %7, i32 noundef %8)
  br i1 %9, label %10, label %23

10:                                               ; preds = %6
  %11 = load i16, ptr %2, align 2, !tbaa !5
  %12 = load i8, ptr @main.on, align 1, !tbaa !11, !range !13, !noundef !14
  %13 = trunc i8 %12 to i1
  call void @gpio_write(i16 noundef zeroext %11, i1 noundef zeroext %13)
  %14 = load i8, ptr @main.on, align 1, !tbaa !11, !range !13, !noundef !14
  %15 = trunc i8 %14 to i1
  %16 = xor i1 %15, true
  %17 = zext i1 %16 to i8
  store i8 %17, ptr @main.on, align 1, !tbaa !11
  %18 = load i8, ptr @main.on, align 1, !tbaa !11, !range !13, !noundef !14
  %19 = trunc i8 %18 to i1
  %20 = zext i1 %19 to i32
  %21 = load volatile i32, ptr @s_ticks, align 4, !tbaa !9
  %22 = call i32 (ptr, ...) @printf(ptr noundef @.str, i32 noundef %20, i32 noundef %21)
  br label %23

23:                                               ; preds = %10, %6
  br label %6
}

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

; Function Attrs: inlinehint nounwind uwtable
declare hidden void @gpio_set_mode(i16 noundef zeroext, i8 noundef zeroext) #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden void @uart_init(ptr noundef, i64 noundef) #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden zeroext i1 @timer_expired(ptr noundef, i32 noundef, i32 noundef) #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden void @gpio_write(i16 noundef zeroext, i1 noundef zeroext) #2

declare i32 @printf(ptr noundef, ...) #3

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 = { inlinehint 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 = { "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 #4 = { 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 = !{!"short", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"_Bool", !7, i64 0}
!13 = !{i8 0, i8 2}
!14 = !{}


; 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"

@s_ticks = external hidden global i32, align 4
@main.on = external hidden local_unnamed_addr global i8, align 1
@.str = external hidden unnamed_addr constant [21 x i8], align 1

; Function Attrs: noreturn nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  tail call void @gpio_set_mode(i16 noundef zeroext 263, i8 noundef zeroext 1)
  tail call void @uart_init(ptr noundef nonnull inttoptr (i64 1073760256 to ptr), i64 noundef 115200)
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  store volatile i32 0, ptr %1, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2)
  store volatile i32 500, ptr %2, align 4, !tbaa !5
  br label %3

3:                                                ; preds = %.backedge, %0
  %.0..0..0..0. = load volatile i32, ptr %2, align 4, !tbaa !5
  %4 = load volatile i32, ptr @s_ticks, align 4, !tbaa !5
  %5 = call zeroext i1 @timer_expired(ptr noundef nonnull %1, i32 noundef %.0..0..0..0., i32 noundef %4)
  br i1 %5, label %6, label %.backedge

6:                                                ; preds = %3
  %7 = load i8, ptr @main.on, align 1, !tbaa !9, !range !11, !noundef !12
  %8 = trunc nuw i8 %7 to i1
  call void @gpio_write(i16 noundef zeroext 263, i1 noundef zeroext %8)
  %9 = load i8, ptr @main.on, align 1, !tbaa !9, !range !11, !noundef !12
  %10 = trunc nuw i8 %9 to i1
  %11 = xor i1 %10, true
  %12 = zext i1 %11 to i8
  store i8 %12, ptr @main.on, align 1, !tbaa !9
  %13 = zext i1 %11 to i32
  %14 = load volatile i32, ptr @s_ticks, align 4, !tbaa !5
  %15 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i32 noundef %13, i32 noundef %14)
  br label %.backedge

.backedge:                                        ; preds = %6, %3
  br label %3
}

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

; Function Attrs: inlinehint nounwind uwtable
declare hidden void @gpio_set_mode(i16 noundef zeroext, i8 noundef zeroext) local_unnamed_addr #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden void @uart_init(ptr noundef, i64 noundef) local_unnamed_addr #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden zeroext i1 @timer_expired(ptr noundef, i32 noundef, i32 noundef) local_unnamed_addr #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden void @gpio_write(i16 noundef zeroext, i1 noundef zeroext) local_unnamed_addr #2

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

attributes #0 = { noreturn 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { inlinehint 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 = { 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 #4 = { 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 = !{!"_Bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}


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