1 files changed, 11 insertions, 11 deletions

diff --git a/include/mimalloc-internal.h b/include/mimalloc-internal.h
index e8fa1ba..3aee4ae 100644
--- a/include/mimalloc-internal.h
+++ b/include/mimalloc-internal.h
@@ -254,20 +254,21 @@ static inline mi_slice_t* mi_page_to_slice(mi_page_t* p) {
   return (mi_slice_t*)(p);
 }
 
-static size_t mi_slice_index(const mi_slice_t* slice) {
-  mi_segment_t* segment = _mi_ptr_segment(slice);
-  ptrdiff_t index = slice - segment->slices;
-  mi_assert_internal(index >= 0 && index < (ptrdiff_t)segment->slice_count);
-  return index;
-}
-
 // Segment belonging to a page
 static inline mi_segment_t* _mi_page_segment(const mi_page_t* page) {
-  mi_segment_t* segment = _mi_ptr_segment(page);
-  mi_assert_internal(segment == NULL || page == mi_slice_to_page(&segment->slices[mi_slice_index(mi_page_to_slice((mi_page_t*)page))]));
+  mi_segment_t* segment = _mi_ptr_segment(page); 
+  mi_assert_internal(segment == NULL || (mi_slice_t*)page >= segment->slices && (mi_slice_t*)page < segment->slices + segment->slice_count);
   return segment;
 }
 
+static inline mi_slice_t* mi_slice_first(const mi_slice_t* slice) {
+  mi_slice_t* start = (mi_slice_t*)((uint8_t*)slice - slice->slice_offset);  
+  mi_assert_internal(start >= _mi_ptr_segment(slice)->slices);
+  mi_assert_internal(start->slice_offset == 0);
+  mi_assert_internal(start + start->slice_count > slice);
+  return start;
+}
+
 // Get the page containing the pointer
 static inline mi_page_t* _mi_segment_page_of(const mi_segment_t* segment, const void* p) {
   ptrdiff_t diff = (uint8_t*)p - (uint8_t*)segment;
@@ -275,8 +276,7 @@ static inline mi_page_t* _mi_segment_page_of(const mi_segment_t* segment, const
   uintptr_t idx = (uintptr_t)diff >> MI_SEGMENT_SLICE_SHIFT;
   mi_assert_internal(idx < segment->slice_count);
   mi_slice_t* slice0 = (mi_slice_t*)&segment->slices[idx]; 
-  mi_slice_t* slice = slice0 - slice0->slice_offset;  // adjust to the block that holds the page data
-  mi_assert_internal(slice->slice_count > slice0->slice_offset);
+  mi_slice_t* slice = mi_slice_first(slice0);  // adjust to the block that holds the page data  
   mi_assert_internal(slice->slice_offset == 0);
   mi_assert_internal(slice >= segment->slices && slice < segment->slices + segment->slice_count);
   return mi_slice_to_page(slice);