x86_64/memory: simplify region allocator

1 files changed, 8 insertions, 5 deletions

diff --git a/arch/x86_64/src/memory/region_allocator.cpp b/arch/x86_64/src/memory/region_allocator.cpp
index 11ffce2..d94e810 100644
--- a/arch/x86_64/src/memory/region_allocator.cpp
+++ b/arch/x86_64/src/memory/region_allocator.cpp
@@ -16,6 +16,11 @@ namespace teachos::memory::x86_64
     {
       return frame::containing(physical_address{region.base + region.size_in_B - 1});
     }
+
+    auto constexpr falls_within(frame const & candidate, frame const & start, frame const & end)
+    {
+      return candidate >= start && candidate <= end;
+    }
   }  // namespace
 
   region_allocator::region_allocator(memory_information const & mem_info)
@@ -65,19 +70,17 @@ namespace teachos::memory::x86_64
     {
       choose_next_area();
     }
-    else if (m_next_frame >= m_kernel_start && m_next_frame <= m_kernel_end)
+    else if (falls_within(m_next_frame, m_kernel_start, m_kernel_end))
     {
       m_next_frame = m_kernel_end + 1;
     }
-    else if (m_next_frame >= m_multiboot_start && m_next_frame <= m_multiboot_end)
+    else if (falls_within(m_next_frame, m_multiboot_start, m_multiboot_end))
     {
       m_next_frame = m_multiboot_end + 1;
     }
     else
     {
-      auto allocated = m_next_frame;
-      ++m_next_frame;
-      return allocated;
+      return m_next_frame++;
     }
 
     return allocate();