5 files changed, 41 insertions, 16 deletions

diff --git a/embed.fnc b/embed.fnc
index 79944b422b..b48af1e8ba 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -87,6 +87,7 @@ Aanop	|Malloc_t|realloc	|Malloc_t where|MEM_SIZE nbytes
 Anop	|Free_t	|mfree		|Malloc_t where
 #if defined(MYMALLOC)
 npR	|MEM_SIZE|malloced_size	|NN void *p
+npR	|MEM_SIZE|malloc_good_size	|size_t nbytes
 #endif
 
 AnpR	|void*	|get_context
diff --git a/embed.h b/embed.h
index 3b6cb78847..f8fce70315 100644
--- a/embed.h
+++ b/embed.h
@@ -38,6 +38,7 @@
 #if defined(MYMALLOC)
 #ifdef PERL_CORE
 #define malloced_size		Perl_malloced_size
+#define malloc_good_size	Perl_malloc_good_size
 #endif
 #endif
 #define get_context		Perl_get_context
@@ -2349,6 +2350,7 @@
 #if defined(MYMALLOC)
 #ifdef PERL_CORE
 #define malloced_size		Perl_malloced_size
+#define malloc_good_size	Perl_malloc_good_size
 #endif
 #endif
 #define get_context		Perl_get_context
diff --git a/makedef.pl b/makedef.pl
index dad466ad42..a559061a5f 100644
--- a/makedef.pl
+++ b/makedef.pl
@@ -667,6 +667,7 @@ else {
 		    Perl_dump_mstats
 		    Perl_get_mstats
 		    Perl_malloced_size
+		    Perl_malloc_good_size
 		    MallocCfg_ptr
 		    MallocCfgP_ptr
 		    )];
diff --git a/malloc.c b/malloc.c
index 46a80a4ecd..682eeb6278 100644
--- a/malloc.c
+++ b/malloc.c
@@ -1404,23 +1404,12 @@ cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
 #  define FILLCHECK_DEADBEEF(s, n)	((void)0)
 #endif
 
-Malloc_t
-Perl_malloc(register size_t nbytes)
+int
+S_ajust_size_and_find_bucket(size_t *nbytes_p)
 {
-        dVAR;
-  	register union overhead *p;
-  	register int bucket;
-  	register MEM_SIZE shiftr;
-
-#if defined(DEBUGGING) || defined(RCHECK)
-	MEM_SIZE size = nbytes;
-#endif
-
-	BARK_64K_LIMIT("Allocation",nbytes,nbytes);
-#ifdef DEBUGGING
-	if ((long)nbytes < 0)
-	    croak("%s", "panic: malloc");
-#endif
+  	MEM_SIZE shiftr;
+	int bucket;
+	size_t nbytes = *nbytes_p;
 
 	/*
 	 * Convert amount of memory requested into
@@ -1455,6 +1444,28 @@ Perl_malloc(register size_t nbytes)
 	    while (shiftr >>= 1)
   		bucket += BUCKETS_PER_POW2;
 	}
+	*nbytes_p = nbytes;
+	return bucket;
+}
+
+Malloc_t
+Perl_malloc(size_t nbytes)
+{
+        dVAR;
+  	register union overhead *p;
+  	register int bucket;
+
+#if defined(DEBUGGING) || defined(RCHECK)
+	MEM_SIZE size = nbytes;
+#endif
+
+	BARK_64K_LIMIT("Allocation",nbytes,nbytes);
+#ifdef DEBUGGING
+	if ((long)nbytes < 0)
+	    croak("%s", "panic: malloc");
+#endif
+
+	bucket = S_ajust_size_and_find_bucket(&nbytes);
 	MALLOC_LOCK;
 	/*
 	 * If nothing in hash bucket right now,
@@ -2376,6 +2387,13 @@ Perl_malloced_size(void *p)
     return BUCKET_SIZE_REAL(bucket);
 }
 
+
+MEM_SIZE
+Perl_malloc_good_size(size_t wanted)
+{
+    return BUCKET_SIZE_REAL(S_ajust_size_and_find_bucket(&wanted));
+}
+
 #  ifdef BUCKETS_ROOT2
 #    define MIN_EVEN_REPORT 6
 #  else
diff --git a/proto.h b/proto.h
index 7ba57ff129..f764d5ccae 100644
--- a/proto.h
+++ b/proto.h
@@ -106,6 +106,9 @@ PERL_CALLCONV MEM_SIZE	Perl_malloced_size(void *p)
 #define PERL_ARGS_ASSERT_MALLOCED_SIZE	\
 	assert(p)
 
+PERL_CALLCONV MEM_SIZE	Perl_malloc_good_size(size_t nbytes)
+			__attribute__warn_unused_result__;
+
 #endif
 
 PERL_CALLCONV void*	Perl_get_context(void)