From 0a4900c5291a8b04710abb63bf3f46bca0fa76fe Mon Sep 17 00:00:00 2001
From: Douglas Katzman <dougk@google.com>
Date: Sun, 19 Mar 2017 14:18:12 -0400
Subject: [PATCH] Rearrange/comment/remove some stuff

* PAGE_BYTES is totally superfluous.
* ALLOC_BOXED and ALLOC_UNBOXED are never used.
---
 src/runtime/gc-internal.h | 14 +++++++-------
 src/runtime/gc.h          | 10 +++-------
 src/runtime/runtime.c     |  2 +-
 3 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/runtime/gc-internal.h b/src/runtime/gc-internal.h
index 23525e1fa..ae4b4e629 100644
--- a/src/runtime/gc-internal.h
+++ b/src/runtime/gc-internal.h
@@ -122,20 +122,17 @@ code_n_funs(struct code* code) { return fixnum_value((code)->n_entries) & 0x3FFF
 #define SIMPLE_FUN_SCAV_START(fun_ptr) &fun_ptr->name
 #define SIMPLE_FUN_SCAV_NWORDS(fun_ptr) ((lispobj*)fun_ptr->code - &fun_ptr->name)
 
-#define WEAK_POINTER_NWORDS \
-        CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
-
 /* values for the *_alloc_* parameters, also see the commentary for
- * struct page in gencgc-internal.h.  FIXME: Perhaps these constants
- * should be there, or at least defined on gencgc only? */
+ * struct page in gencgc-internal.h. These constants are used in gc-common,
+ * so they can't easily be made gencgc-only */
 #define FREE_PAGE_FLAG 0
 #define BOXED_PAGE_FLAG 1
 #define UNBOXED_PAGE_FLAG 2
 #define OPEN_REGION_PAGE_FLAG 4
 #define CODE_PAGE_FLAG        (BOXED_PAGE_FLAG|UNBOXED_PAGE_FLAG)
 
-#define ALLOC_BOXED 0
-#define ALLOC_UNBOXED 1
+// Gencgc distinguishes between "quick" and "ordinary" requests.
+// Even on cheneygc we need this flag, but it's actually just ignored.
 #define ALLOC_QUICK 1
 
 #ifdef LISP_FEATURE_GENCGC
@@ -330,6 +327,9 @@ static inline boolean immobile_filler_p(lispobj* obj) {
 
 #endif /* immobile space */
 
+#define WEAK_POINTER_NWORDS \
+        CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
+
 static inline boolean weak_pointer_breakable_p(struct weak_pointer *wp)
 {
     lispobj pointee;
diff --git a/src/runtime/gc.h b/src/runtime/gc.h
index 0057bb8b1..35a783210 100644
--- a/src/runtime/gc.h
+++ b/src/runtime/gc.h
@@ -17,10 +17,9 @@
 #define _GC_H_
 
 #include "sbcl.h"
+#include "os.h"
 #include <stdint.h>
 
-#define PAGE_BYTES BACKEND_PAGE_BYTES
-
 typedef intptr_t page_index_t;
 #ifdef LISP_FEATURE_WIN32
 #define PAGE_INDEX_FMT "Id"
@@ -30,20 +29,17 @@ typedef intptr_t page_index_t;
 #define PAGE_INDEX_FMT "d"
 #endif
 
+// This decl should probably be be in gencgc-internal,
+// except it can't be: collect_garbage() receives a generation number.
 typedef signed char generation_index_t;
 
 extern void gc_init(void);
 extern void gc_initialize_pointers(void);
 extern void collect_garbage(generation_index_t last_gen);
 
-
-#include "os.h"
-
 extern void set_auto_gc_trigger(os_vm_size_t usage);
 extern void clear_auto_gc_trigger(void);
 
-#include "fixnump.h"
-
 extern boolean maybe_gc(os_context_t *context);
 
 extern os_vm_size_t bytes_consed_between_gcs;
diff --git a/src/runtime/runtime.c b/src/runtime/runtime.c
index 385723f20..26b08dc69 100644
--- a/src/runtime/runtime.c
+++ b/src/runtime/runtime.c
@@ -615,7 +615,7 @@ main(int argc, char *argv[], char *envp[])
 
     /* Align down to multiple of page_table page size, and to the appropriate
      * stack alignment. */
-    dynamic_space_size &= ~(sword_t)(PAGE_BYTES-1);
+    dynamic_space_size &= ~(sword_t)(BACKEND_PAGE_BYTES-1);
 #ifdef LISP_FEATURE_GENCGC
     dynamic_space_size &= ~(sword_t)(GENCGC_CARD_BYTES-1);
 #endif
-- 
2.11.4.GIT