; LLVM IR from smwikipedia/EmbeddedAndRTOSSamples :: C2.5 (full)

; 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"

%struct.uart = type { ptr, i32 }

@uart = external dso_local global [4 x %struct.uart], align 16

; Function Attrs: nounwind uwtable
define dso_local i32 @uart_init() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  store i32 0, ptr %2, align 4, !tbaa !5
  br label %4

4:                                                ; preds = %21, %0
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = icmp slt i32 %5, 4
  br i1 %6, label %7, label %24

7:                                                ; preds = %4
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [4 x %struct.uart], ptr @uart, i64 0, i64 %9
  store ptr %10, ptr %3, align 8, !tbaa !9
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = mul nsw i32 %11, 4096
  %13 = add nsw i32 270471168, %12
  %14 = sext i32 %13 to i64
  %15 = inttoptr i64 %14 to ptr
  %16 = load ptr, ptr %3, align 8, !tbaa !9
  %17 = getelementptr inbounds %struct.uart, ptr %16, i32 0, i32 0
  store volatile ptr %15, ptr %17, align 8, !tbaa !11
  %18 = load i32, ptr %2, align 4, !tbaa !5
  %19 = load ptr, ptr %3, align 8, !tbaa !9
  %20 = getelementptr inbounds %struct.uart, ptr %19, i32 0, i32 1
  store volatile i32 %18, ptr %20, align 8, !tbaa !13
  br label %21

21:                                               ; preds = %7
  %22 = load i32, ptr %2, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr %2, align 4, !tbaa !5
  br label %4, !llvm.loop !14

24:                                               ; preds = %4
  store volatile ptr inttoptr (i64 268472320 to ptr), ptr getelementptr inbounds ([4 x %struct.uart], ptr @uart, i64 0, i64 3), align 16, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #2
  %25 = load i32, ptr %1, align 4
  ret i32 %25
}

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

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

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 = { 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 = !{!12, !10, i64 0}
!12 = !{!"uart", !10, i64 0, !6, i64 8}
!13 = !{!12, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

%struct.uart = type { ptr, i32 }

@uart = external dso_local global [4 x %struct.uart], align 16

; Function Attrs: nofree norecurse nounwind memory(readwrite, argmem: none) uwtable
define dso_local i32 @uart_init() local_unnamed_addr #0 {
  store volatile ptr inttoptr (i64 270471168 to ptr), ptr @uart, align 16, !tbaa !5
  store volatile i32 0, ptr getelementptr inbounds (i8, ptr @uart, i64 8), align 8, !tbaa !11
  store volatile ptr inttoptr (i64 270475264 to ptr), ptr getelementptr inbounds (i8, ptr @uart, i64 16), align 16, !tbaa !5
  store volatile i32 1, ptr getelementptr inbounds (i8, ptr @uart, i64 24), align 8, !tbaa !11
  store volatile ptr inttoptr (i64 270479360 to ptr), ptr getelementptr inbounds (i8, ptr @uart, i64 32), align 16, !tbaa !5
  store volatile i32 2, ptr getelementptr inbounds (i8, ptr @uart, i64 40), align 8, !tbaa !11
  store volatile ptr inttoptr (i64 270483456 to ptr), ptr getelementptr inbounds (i8, ptr @uart, i64 48), align 16, !tbaa !5
  store volatile i32 3, ptr getelementptr inbounds (i8, ptr @uart, i64 56), align 8, !tbaa !11
  store volatile ptr inttoptr (i64 268472320 to ptr), ptr getelementptr inbounds (i8, ptr @uart, i64 48), align 16, !tbaa !5
  ret i32 undef
}

attributes #0 = { nofree norecurse nounwind memory(readwrite, argmem: none) 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, !7, i64 0}
!6 = !{!"uart", !7, i64 0, !10, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"int", !8, i64 0}
!11 = !{!6, !10, i64 8}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass