Remove hipe constants pool

Hipe constants used to be allocated within a single, fixed-size pool for
interaction with the garbage collector. However, the garbage collector
no longer depends on constants being allocated within a single pool, and
the fixed size of the pool both meant unnecessary allocations on most
deployments and crashes on deployments requiring more constants.

The code was simplified to directly invoke erts_alloc.
Debugging and undocumented function hipe_bifs:show_literals/0 was
removed (it returned true and output text to the console), and
debugging and undocumented function hipe_bifs:constants_size/0 was
rewritten with a global to count the size of allocated constants.

1 files changed, 7 insertions, 43 deletions

diff --git a/erts/emulator/hipe/hipe_bif0.c b/erts/emulator/hipe/hipe_bif0.c
index 2a877d8ace..4205b05831 100644
--- a/erts/emulator/hipe/hipe_bif0.c
+++ b/erts/emulator/hipe/hipe_bif0.c
@@ -450,52 +450,13 @@ BIF_RETTYPE hipe_bifs_alloc_data_2(BIF_ALIST_2)
 }
 
 /*
- * Memory area for constant Erlang terms.
- *
- * These constants must not be forwarded by the gc.
- * Therefore, the gc needs to be able to distinguish between
- * collectible objects and constants. Unfortunately, an Erlang
- * process' collectible objects are scattered around in two
- * heaps and a list of message buffers, so testing "is X a
- * collectible object?" can be expensive.
- *
- * Instead, constants are placed in a single contiguous area,
- * which allows for an inexpensive "is X a constant?" test.
- *
- * XXX: Allow this area to be grown.
+ * Statistics on hipe constants: size of HiPE constants, in words.
  */
-
-/* not static, needed by garbage collector */
-Eterm *hipe_constants_start = NULL;
-Eterm *hipe_constants_next = NULL;
-static unsigned constants_avail_words = 0;
-#define CONSTANTS_BYTES	(1536*1024*sizeof(Eterm))  /* 1.5 M words */
-
-static Eterm *constants_alloc(unsigned nwords)
-{
-    Eterm *next;
-
-    /* initialise at the first call */
-    if ((next = hipe_constants_next) == NULL) {
-	next = (Eterm*)erts_alloc(ERTS_ALC_T_HIPE, CONSTANTS_BYTES);
-	hipe_constants_start = next;
-	hipe_constants_next = next;
-	constants_avail_words = CONSTANTS_BYTES / sizeof(Eterm);
-    }
-    if (nwords > constants_avail_words) {
-	fprintf(stderr, "Native code constants pool depleted!\r\n");
-	/* Must terminate immediately. erl_exit() seems to
-	   continue running some code which then SIGSEGVs. */
-	exit(1);
-    }
-    constants_avail_words -= nwords;
-    hipe_constants_next = next + nwords;
-    return next;
-}
+unsigned int hipe_constants_size = 0;
 
 BIF_RETTYPE hipe_bifs_constants_size_0(BIF_ALIST_0)
 {
-    BIF_RET(make_small(hipe_constants_next - hipe_constants_start));
+    BIF_RET(make_small(hipe_constants_size));
 }
 
 /*
@@ -526,14 +487,17 @@ static void *const_term_alloc(void *tmpl)
 {
     Eterm obj;
     Uint size;
+    Uint alloc_size;
     Eterm *hp;
     struct const_term *p;
 
     obj = (Eterm)tmpl;
     ASSERT(is_not_immed(obj));
     size = size_object(obj);
+    alloc_size = size + (offsetof(struct const_term, mem)/sizeof(Eterm));
+    hipe_constants_size += alloc_size;
 
-    p = (struct const_term*)constants_alloc(size + (offsetof(struct const_term, mem)/sizeof(Eterm)));
+    p = (struct const_term*)erts_alloc(ERTS_ALC_T_HIPE, alloc_size * sizeof(Eterm));
 
     /* I have absolutely no idea if having a private 'off_heap'
        works or not. _Some_ off_heap object is required for