X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fgencgc-internal.h;h=9ff5a19c14aef971a0ea88541d131fd26ec372f9;hb=8bc4923b67afbaed8914200cbabc948d9b5eaece;hp=e257afb0392dacd139e6a6bd1128f6ff9d80d24b;hpb=2378b4fe567a8fea78b1e4915b9497d8c18ca92f;p=sbcl.git

diff --git a/src/runtime/gencgc-internal.h b/src/runtime/gencgc-internal.h
index e257afb..9ff5a19 100644
--- a/src/runtime/gencgc-internal.h
+++ b/src/runtime/gencgc-internal.h
@@ -22,6 +22,12 @@
 #include "gencgc-alloc-region.h"
 #include "genesis/code.h"
 
+/* Size of a page, in bytes. FIXME: needs to be conditionalized per
+ * architecture, preferably by someone with a clue as to what page
+ * sizes are on archs other than x86 and PPC - Patrik */
+#define PAGE_BYTES 4096
+
+
 void gc_free_heap(void);
 inline int find_page_index(void *);
 inline void *page_address(int);
@@ -66,9 +72,10 @@ struct page {
      * hard to achieve). */
     int  bytes_used;
 
-    /* It is important to know the offset to the first object in the
-     * page. Currently it's only important to know if an object starts
-     * at the beginning of the page in which case the offset would be 0. */
+    /* The name of this field is not well-chosen for its actual use.
+     * This is the offset from the start of the page to the start 
+     * of the alloc_region which contains/contained it.  It's negative or 0
+     */
     int  first_object_offset;
 };
 
@@ -76,7 +83,8 @@ struct page {
 
 
 /* the number of pages needed for the dynamic space - rounding up */
-#define NUM_PAGES ((DYNAMIC_SPACE_SIZE+4095)/4096)
+#define NUM_PAGES ((DYNAMIC_SPACE_SIZE+PAGE_BYTES-1)/PAGE_BYTES)
+
 extern struct page page_table[NUM_PAGES];
 
 
@@ -95,7 +103,8 @@ space_matches_p(lispobj obj, int space)
 {
     int page_index=(void*)obj - (void *)DYNAMIC_SPACE_START;
     return ((page_index >= 0)
-	    && ((page_index = ((unsigned int)page_index)/4096) < NUM_PAGES)
+	    && ((page_index =
+		 ((unsigned int)page_index)/PAGE_BYTES) < NUM_PAGES)
 	    && (page_table[page_index].gen == space));
 }