; LLVM IR from ksw2000/Data-Structure-in-C :: Queue (01-陣列實作佇列-基礎)

; 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"

@rear = external dso_local global i32, align 4
@front = external dso_local global i32, align 4
@queue = external dso_local global [100 x i32], align 16

; Function Attrs: nounwind uwtable
declare dso_local void @queueEmpty() #0

; Function Attrs: nounwind uwtable
define dso_local i32 @dequeue() #0 {
  %1 = load i32, ptr @front, align 4, !tbaa !5
  %2 = load i32, ptr @rear, align 4, !tbaa !5
  %3 = icmp eq i32 %1, %2
  br i1 %3, label %4, label %5

4:                                                ; preds = %0
  call void @queueEmpty()
  br label %5

5:                                                ; preds = %4, %0
  %6 = load i32, ptr @front, align 4, !tbaa !5
  %7 = add nsw i32 %6, 1
  store i32 %7, ptr @front, align 4, !tbaa !5
  %8 = sext i32 %7 to i64
  %9 = getelementptr inbounds [100 x i32], ptr @queue, i64 0, i64 %8
  %10 = load i32, ptr %9, align 4, !tbaa !5
  ret i32 %10
}

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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}


; 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"

@rear = external dso_local local_unnamed_addr global i32, align 4
@front = external dso_local local_unnamed_addr global i32, align 4
@queue = external dso_local local_unnamed_addr global [100 x i32], align 16

; Function Attrs: nounwind uwtable
declare dso_local void @queueEmpty() local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local i32 @dequeue() local_unnamed_addr #0 {
  %1 = load i32, ptr @front, align 4, !tbaa !5
  %2 = load i32, ptr @rear, align 4, !tbaa !5
  %3 = icmp eq i32 %1, %2
  br i1 %3, label %4, label %5

4:                                                ; preds = %0
  tail call void @queueEmpty()
  %.pre = load i32, ptr @front, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %4, %0
  %6 = phi i32 [ %.pre, %4 ], [ %1, %0 ]
  %7 = add nsw i32 %6, 1
  store i32 %7, ptr @front, align 4, !tbaa !5
  %8 = sext i32 %7 to i64
  %9 = getelementptr inbounds [100 x i32], ptr @queue, i64 0, i64 %8
  %10 = load i32, ptr %9, align 4, !tbaa !5
  ret i32 %10
}

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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}


; Effective O3 passes: GVNPass,GlobalOptPass,TailCallElimPass