Miles Bader implemented a new mmap based malloc which is much

smarter than the old "malloc-simple", and actually works, unlike
the old "malloc".  So kill the old "malloc-simple" and the old
"malloc" and replace them with Miles' new malloc implementation.
Update Config files to match.  Thanks Miles!

16 files changed, 740 insertions, 1392 deletions

diff --git a/libc/stdlib/malloc-simple/.indent.pro b/libc/stdlib/malloc-simple/.indent.pro
deleted file mode 100644
index 492ecf1c7..000000000
--- a/libc/stdlib/malloc-simple/.indent.pro
+++ /dev/null
@@ -1,33 +0,0 @@
---blank-lines-after-declarations
---blank-lines-after-procedures
---break-before-boolean-operator
---no-blank-lines-after-commas
---braces-on-if-line
---braces-on-struct-decl-line
---comment-indentation25
---declaration-comment-column25
---no-comment-delimiters-on-blank-lines
---cuddle-else
---continuation-indentation4
---case-indentation0
---else-endif-column33
---space-after-cast
---line-comments-indentation0
---declaration-indentation1
---dont-format-first-column-comments
---dont-format-comments
---honour-newlines
---indent-level4
-/* changed from 0 to 4 */
---parameter-indentation4
---line-length78 /* changed from 75 */
---continue-at-parentheses
---no-space-after-function-call-names
---dont-break-procedure-type
---dont-star-comments
---leave-optional-blank-lines
---dont-space-special-semicolon
---tab-size4
-/* additions by Mark */
---case-brace-indentation0
---leave-preprocessor-space
diff --git a/libc/stdlib/malloc-simple/Makefile b/libc/stdlib/malloc-simple/Makefile
deleted file mode 100644
index f8fe3520d..000000000
--- a/libc/stdlib/malloc-simple/Makefile
+++ /dev/null
@@ -1,49 +0,0 @@
-# Makefile for uClibc
-#
-# Copyright (C) 2000 by Lineo, inc.
-# Copyright (C) 2000,2001 Erik Andersen <andersen@uclibc.org>
-#
-# This program is free software; you can redistribute it and/or modify it under
-# the terms of the GNU Library General Public License as published by the Free
-# Software Foundation; either version 2 of the License, or (at your option) any
-# later version.
-#
-# This program is distributed in the hope that it will be useful, but WITHOUT
-# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-# FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more
-# details.
-#
-# You should have received a copy of the GNU Library General Public License
-# along with this program; if not, write to the Free Software Foundation, Inc.,
-# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-#
-# Derived in part from the Linux-8086 C library, the GNU C Library, and several
-# other sundry sources.  Files within this library are copyright by their
-# respective copyright holders.
-
-TOPDIR=../../../
-include $(TOPDIR)Rules.mak
-
-MSRC=alloc.c
-MOBJ=malloc.o realloc.o free.o calloc.o #malloc_dbg.o free_dbg.o calloc_dbg.o
-OBJS=$(MOBJ)
-
-
-all: $(OBJS) $(LIBC)
-
-$(LIBC): ar-target
-
-ar-target: $(OBJS)
-	$(AR) $(ARFLAGS) $(LIBC) $(OBJS)
-
-$(MOBJ): $(MSRC)
-	$(CC) $(CFLAGS) -DL_$* $< -c -o $*.o
-	$(STRIPTOOL) -x -R .note -R .comment $*.o
-
-$(COBJS): %.o : %.c
-	$(CC) $(CFLAGS) -c $< -o $@
-	$(STRIPTOOL) -x -R .note -R .comment $*.o
-
-clean:
-	rm -f *.[oa] *~ core
-
diff --git a/libc/stdlib/malloc-simple/alloc.c b/libc/stdlib/malloc-simple/alloc.c
deleted file mode 100644
index 1824507eb..000000000
--- a/libc/stdlib/malloc-simple/alloc.c
+++ /dev/null
@@ -1,141 +0,0 @@
-
-/*
- *	For MMU hosts we need to track the size of the allocations otherwise
- *	munmap will fail to free the memory (EINVAL).
- */
-
-#include <features.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/mman.h>
-
-
-#ifdef L_calloc_dbg
-
-void *calloc_dbg(size_t num, size_t size, char *function, char *file,
-				 int line)
-{
-	void *ptr;
-
-	fprintf(stderr, "calloc of %d bytes at %s @%s:%d = ", (int) (num * size),
-			function, file, line);
-	ptr = calloc(num, size);
-	fprintf(stderr, "%p\n", ptr);
-	return ptr;
-}
-
-#endif
-
-#ifdef L_malloc_dbg
-
-void *malloc_dbg(size_t size, char *function, char *file, int line)
-{
-	void *result;
-
-	fprintf(stderr, "malloc of %d bytes at %s @%s:%d = ", (int) size, function,
-			file, line);
-	result = malloc(size);
-	fprintf(stderr, "%p\n", result);
-	return result;
-}
-
-#endif
-
-#ifdef L_free_dbg
-
-void free_dbg(void *ptr, char *function, char *file, int line)
-{
-	fprintf(stderr, "free of %p at %s @%s:%d\n", ptr, function, file,
-			line);
-	free(ptr);
-}
-
-#endif
-
-
-#ifdef L_calloc
-
-void *calloc(size_t num, size_t size)
-{
-	void *ptr = malloc(num * size);
-
-	if (ptr)
-		memset(ptr, 0, num * size);
-	return ptr;
-}
-
-#endif
-
-#ifdef L_malloc
-
-void *malloc(size_t size)
-{
-	void *result;
-
-    /* Some programs will call malloc (0).  Lets be strict and return NULL */
-    if (size == 0)
-		return NULL;
-
-#ifdef __UCLIBC_HAS_MMU__
-	result = mmap((void *) 0, size + sizeof(size_t), PROT_READ | PROT_WRITE,
-						MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
-#else
-	result = mmap((void *) 0, size, PROT_READ | PROT_WRITE,
-						MAP_SHARED | MAP_ANONYMOUS, 0, 0);
-#endif
-
-	if (result == MAP_FAILED)
-		return 0;
-	
-#ifdef __UCLIBC_HAS_MMU__
-	* (size_t *) result = size;
-	return(result + sizeof(size_t));
-#else
-	return(result);
-#endif
-}
-
-#endif
-
-#ifdef L_free
-
-void free(void *ptr)
-{
-#ifdef __UCLIBC_HAS_MMU__
-	if (ptr) {
-		ptr -= sizeof(size_t);
-		munmap(ptr, * (size_t *) ptr + sizeof(size_t));
-	}
-#else
-	munmap(ptr, 0);
-#endif
-}
-
-#endif
-
-#ifdef L_realloc
-
-void *realloc(void *ptr, size_t size)
-{
-	void *newptr = NULL;
-
-	if (size > 0) {
-		newptr = malloc(size);
-		if (newptr && ptr) {
-#ifdef __UCLIBC_HAS_MMU__
-			memcpy(newptr, ptr, * ((size_t *) (ptr - sizeof(size_t))));
-#else
-			memcpy(newptr, ptr, size);
-#endif
-			free(ptr);
-		}
-	}
-	else
-		free(ptr);
-	return newptr;
-}
-
-#endif
diff --git a/libc/stdlib/malloc/Makefile b/libc/stdlib/malloc/Makefile
index 64aad319a..710f70297 100644
--- a/libc/stdlib/malloc/Makefile
+++ b/libc/stdlib/malloc/Makefile
@@ -1,7 +1,7 @@
 # Makefile for uClibc
 #
-# Copyright (C) 2000 by Lineo, inc.
-# Copyright (C) 2000,2001 Erik Andersen <andersen@uclibc.org>
+# Copyright (C) 2002  NEC Corporation
+# Copyright (C) 2002  Miles Bader <miles@gnu.org>
 #
 # This program is free software; you can redistribute it and/or modify it under
 # the terms of the GNU Library General Public License as published by the Free
@@ -24,14 +24,10 @@
 TOPDIR=../../../
 include $(TOPDIR)Rules.mak
 
-#MSRC=alloc.c
-#MOBJ=malloc_dbg.o free_dbg.o calloc_dbg.o realloc_dbg.o
-
-MSRC1=malloc.c
-MOBJ1=_avl_support.o _free_support.o _malloc_init.o _realloc_no_move.o calloc.o \
-	 free.o malloc.o realloc.o
-
-OBJS=$(MOBJ) $(MOBJ1)
+CSRC = malloc.o free.o realloc.o calloc.o heap_alloc.o \
+	heap_alloc_at.o heap_free.o heap_append_free.o
+COBJS=$(patsubst %.c,%.o, $(CSRC))
+OBJS=$(COBJS)
 
 all: $(OBJS) $(LIBC)
 
@@ -40,12 +36,8 @@ $(LIBC): ar-target
 ar-target: $(OBJS)
 	$(AR) $(ARFLAGS) $(LIBC) $(OBJS)
 
-$(MOBJ): $(MSRC)
-	$(CC) $(CFLAGS) -DL_$* $< -c -o $*.o
-	$(STRIPTOOL) -x -R .note -R .comment $*.o
-
-$(MOBJ1): $(MSRC1)
-	$(CC) $(CFLAGS) -DL_$* $< -c -o $*.o
+$(COBJS): %.o : %.c
+	$(CC) $(CFLAGS) -c $< -o $@
 	$(STRIPTOOL) -x -R .note -R .comment $*.o
 
 clean:
diff --git a/libc/stdlib/malloc/alloc.c b/libc/stdlib/malloc/alloc.c
deleted file mode 100644
index 99537a35d..000000000
--- a/libc/stdlib/malloc/alloc.c
+++ /dev/null
@@ -1,60 +0,0 @@
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/mman.h>
-
-
-#ifdef L_calloc_dbg
-
-void *calloc_dbg(size_t num, size_t size, char *function, char *file,
-				 int line)
-{
-	void *ptr;
-
-	fprintf(stderr, "calloc of %ld bytes at %s @%s:%d = ",
-			(long) (num * size), function, file, line);
-	ptr = calloc(num, size);
-	fprintf(stderr, "%p\n", ptr);
-	return ptr;
-}
-
-#endif
-
-#ifdef L_malloc_dbg
-
-void *malloc_dbg(size_t len, char *function, char *file, int line)
-{
-	void *result;
-
-	fprintf(stderr, "malloc of %ld bytes at %s @%s:%d = ", (long) len,
-			function, file, line);
-	result = malloc(len);
-	fprintf(stderr, "%p\n", result);
-	return result;
-}
-
-#endif
-
-#ifdef L_free_dbg
-
-void free_dbg(void *ptr, char *function, char *file, int line)
-{
-	fprintf(stderr, "free of %p at %s @%s:%d\n", ptr, function, file,
-			line);
-	free(ptr);
-}
-
-#endif
-
-#ifdef L_realloc_dbg
-void *realloc_dbg(void *ptr, size_t size, char *function, char *file, int line)
-{
-	fprintf(stderr, "realloc of %p to %ld bytes at %s @%s;%d = ", ptr,
-			(long)size, function, file, line);
-	ptr = realloc(ptr, size);
-	fprintf(stderr, "%p\n", ptr);
-	return ptr;
-}
-#endif
diff --git a/libc/stdlib/malloc/avlmacro.h b/libc/stdlib/malloc/avlmacro.h
deleted file mode 100644
index cce2c38f3..000000000
--- a/libc/stdlib/malloc/avlmacro.h
+++ /dev/null
@@ -1,226 +0,0 @@
-/* MACRO-CODED FAST FIXED AVL TREES IMPLEMENTATION IN C              */
-/* COPYRIGHT (C) 1998 VALERY SHCHEDRIN                               */
-/* IT IS DISTRIBUTED UNDER GLPL (GNU GENERAL LIBRARY PUBLIC LICENSE) */
-
-/*
- * Manuel Novoa III       Jan 2001
- *
- * Modified to decrease object size.
- *   Tree balancing is now done in a fuction rather than inline.
- *   Removed common code in balance by use of a goto.
- *   Added macro Avl_Tree_no_replace since ptrs_replace was not used.
- *   Prepended may symbols with "__" for possible conversion to extern.
- */
-
-#define __Avl_balance_proto(objname, pr, root) \
-  static int __Avl_##objname##pr##balance(objname **root) \
-  { \
-    objname *p; \
-    int ht_changed; \
-    p = *root; \
-    if (p->bal_##pr < -1) \
-    { \
-      if (p->l_##pr->bal_##pr == 1) \
-      { \
-	objname *pp; \
-	pp=p->l_##pr; *root=p->l_##pr->r_##pr; p->l_##pr = (*root)->r_##pr; \
-	(*root)->r_##pr = p; pp->r_##pr = (*root)->l_##pr; \
-	p = *root; p->l_##pr = pp; \
-    goto pr_common_ht_changed; \
-      } \
-      else \
-      { \
-	ht_changed = (p->l_##pr ->bal_##pr)?1:0; \
-	*root = p->l_##pr ; \
-	p->l_##pr = (*root)->r_##pr ; (*root)->r_##pr = p; \
-	p->bal_##pr = - (++((*root)->bal_##pr )); \
-      } \
-    } \
-    else if (p->bal_##pr > 1) \
-    { \
-      if (p->r_##pr->bal_##pr == -1) \
-      { \
-	objname *pp; \
-	pp=p->r_##pr ; *root=p->r_##pr ->l_##pr ; p->r_##pr =(*root)->l_##pr ; \
-	(*root)->l_##pr = p; pp->l_##pr = (*root)->r_##pr ; \
-	p = *root; p->r_##pr = pp; \
-    pr_common_ht_changed: \
-	if (p->bal_##pr > 0) p->l_##pr ->bal_##pr = -p->bal_##pr ; \
-	else p->l_##pr ->bal_##pr = 0; \
-	if (p->bal_##pr < 0) p->r_##pr ->bal_##pr = -p->bal_##pr ; \
-	else p->r_##pr ->bal_##pr = 0; \
-	p->bal_##pr = 0; \
-	ht_changed = 1; \
-      } \
-      else \
-      { \
-	ht_changed = (p->r_##pr ->bal_##pr)?1:0; \
-	*root = p->r_##pr ; \
-	p->r_##pr = (*root)->l_##pr ; (*root)->l_##pr = p; \
-	p->bal_##pr = - (--((*root)->bal_##pr )); \
-      } \
-    } else ht_changed = 0; \
-   return ht_changed; \
-  }
-
-#define balance(objname, pr, root) \
-  __Avl_##objname##pr##balance(root)
-
-#define __Avl_r_insert_proto(objname, pr, COMPARE) \
-  static int __Avl_##objname##pr##_r_insert(objname **root) \
-  { \
-    int i; /* height increase */ \
-    if (!*root) \
-    { \
-      *root = __Avl_##objname##pr##_new_node; \
-      __Avl_##objname##pr##_new_node = NULL; \
-      return 1; \
-    } \
-    COMPARE(i, __Avl_##objname##pr##_new_node, *root); \
-    \
-    if (i < 0) \
-    { /* insert into the left subtree */ \
-      i = -__Avl_##objname##pr##_r_insert(&((*root)->l_##pr)); \
-      if (__Avl_##objname##pr##_new_node != NULL) return 0; /* already there */ \
-    } \
-    else if (i > 0) \
-    { /* insert into the right subtree */ \
-      i = __Avl_##objname##pr##_r_insert(&((*root)->r_##pr)); \
-      if (__Avl_##objname##pr##_new_node != NULL) return 0; /* already there */ \
-    } \
-    else \
-    { /* found */ \
-      __Avl_##objname##pr##_new_node = *root; \
-      return 0; \
-    } \
-    if (!i) return 0; \
-    (*root)->bal_##pr += i; /* update balance factor */ \
-    if ((*root)->bal_##pr) \
-    { \
-      return 1 - balance(objname,pr,root); \
-    } \
-    else return 0; \
-  }
-
-#define __Avl_r_delete_proto(objname,pr,COMPARE) \
-  static int __Avl_##objname##pr##_r_delete(objname **root) \
-  { \
-    int i; /* height decrease */ \
-    \
-    if (!*root) return 0; /* not found */ \
-    \
-    COMPARE(i, __Avl_##objname##pr##_new_node, *root); \
-    \
-    if (i < 0) \
-      i = -__Avl_##objname##pr##_r_delete(&((*root)->l_##pr)); \
-    else if (i > 0) \
-      i =  __Avl_##objname##pr##_r_delete(&((*root)->r_##pr)); \
-    else \
-    { \
-      if (!(*root)->l_##pr) \
-      { \
-	*root = (*root)->r_##pr; \
-	return 1; \
-      } \
-      else if (!(*root)->r_##pr) \
-      { \
-	*root = (*root)->l_##pr; \
-	return 1; \
-      } \
-      else \
-      { \
-	i = __Avl_##objname##pr##_r_delfix(&((*root)->r_##pr)); \
-	__Avl_##objname##pr##_new_node->l_##pr = (*root)->l_##pr; \
-	__Avl_##objname##pr##_new_node->r_##pr = (*root)->r_##pr; \
-	__Avl_##objname##pr##_new_node->bal_##pr = (*root)->bal_##pr; \
-	*root = __Avl_##objname##pr##_new_node; \
-      } \
-    } \
-    if (!i) return 0; \
-    (*root)->bal_##pr -= i; \
-    if ((*root)->bal_##pr) \
-    { \
-      return balance(objname,pr,root); \
-    } \
-    return 1; \
-  }
-
-#define __Avl_r_delfix_proto(objname,pr) \
-  static int __Avl_##objname##pr##_r_delfix(objname **root) \
-  { \
-    int i; /* height decrease */ \
-    \
-    if (!(*root)->l_##pr) \
-    { \
-      __Avl_##objname##pr##_new_node = *root; \
-      *root = (*root)->r_##pr; \
-      return 1; \
-    } \
-    i = -__Avl_##objname##pr##_r_delfix(&((*root)->l_##pr)); \
-    if (!i) return 0; \
-    (*root)->bal_##pr -= i; \
-    if ((*root)->bal_##pr) \
-    { \
-      return balance(objname,pr,root); \
-    } \
-    return 1; \
-  }
-
-#define __Avl_ins_proto(alias,objname,pr) \
-  objname *__##alias##_ins(objname *data) \
-  { \
-    __Avl_##objname##pr##_new_node = data; \
-    (data)->l_##pr = NULL; \
-    (data)->r_##pr = NULL; \
-    (data)->bal_##pr = 0; \
-    __Avl_##objname##pr##_r_insert(&__Avl_##objname##pr##_tree); \
-    if (__Avl_##objname##pr##_new_node) \
-      return __Avl_##objname##pr##_new_node; \
-    return NULL; \
-  }
-
-#define __Avl_del_proto(alias,objname,pr) \
-  void __##alias##_del(objname *data) \
-  { \
-    __Avl_##objname##pr##_new_node = data; \
-    __Avl_##objname##pr##_r_delete(&__Avl_##objname##pr##_tree); \
-  }
-
-#define __Avl_replace_proto(alias,objname,pr,COMPARE) \
-  void __##alias##_replace(objname *data) \
-  { \
-    objname **p = &__Avl_##objname##pr##_tree; \
-    int cmp; \
-    while (*p) \
-    { \
-      COMPARE(cmp, data, *p); \
-      if (cmp < 0) \
-	p = &((*p)->l_##pr); \
-      else if (cmp > 0) \
-	p = &((*p)->r_##pr); \
-      else \
-      { \
-	(data)->l_##pr = (*p)->l_##pr; \
-	(data)->r_##pr = (*p)->r_##pr; \
-	(data)->bal_##pr = (*p)->bal_##pr; \
-	*p = data; \
-	return; \
-      } \
-    } \
-  }
-
-#define Avl_Root(objname,pr) __Avl_##objname##pr##_tree
-
-#define Avl_Tree_no_replace(alias,objname,pr,COMPARE) \
-objname *__Avl_##objname##pr##_tree = NULL; \
-static objname *__Avl_##objname##pr##_new_node; \
-__Avl_balance_proto(objname, pr, root) \
-__Avl_r_insert_proto(objname,pr,COMPARE) \
-__Avl_r_delfix_proto(objname,pr) \
-__Avl_r_delete_proto(objname,pr,COMPARE) \
-__Avl_ins_proto(alias,objname,pr) \
-__Avl_del_proto(alias,objname,pr)
-
-#define Avl_Tree(alias,objname,pr,COMPARE) \
-Avl_Tree_no_replace(alias,objname,pr,COMPARE) \
-__Avl_replace_proto(alias,objname,pr,COMPARE)
diff --git a/libc/stdlib/malloc/calloc.c b/libc/stdlib/malloc/calloc.c
new file mode 100644
index 000000000..6231edb46
--- /dev/null
+++ b/libc/stdlib/malloc/calloc.c
@@ -0,0 +1,32 @@
+/*
+ * libc/stdlib/malloc-zarg/calloc.c -- calloc function
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "malloc.h"
+
+
+void *
+calloc (size_t size, size_t num)
+{
+  void *mem;
+
+  size *= num;
+
+  mem = malloc (size);
+  if (mem)
+    memset (mem, 0, size);
+
+  return mem;
+}
diff --git a/libc/stdlib/malloc/free.c b/libc/stdlib/malloc/free.c
new file mode 100644
index 000000000..5d5b8f033
--- /dev/null
+++ b/libc/stdlib/malloc/free.c
@@ -0,0 +1,35 @@
+/*
+ * libc/stdlib/malloc-zarg/free.c -- free function
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+#include <sys/mman.h>
+
+#include "malloc.h"
+#include "heap.h"
+
+
+void free (void *mem)
+{
+  size_t size;
+
+  mem = (size_t *)mem - 1;
+  size = *(size_t *)mem;
+
+  MALLOC_DEBUG ("free: 0x%lx (base = 0x%lx, total_size = %d)\n",
+		(long)mem + sizeof (size_t), (long)mem, size);
+
+  if (size >= MALLOC_MMAP_THRESHOLD)
+    munmap (mem, size);
+  else
+    __heap_free (&__malloc_heap, mem, size);
+}
diff --git a/libc/stdlib/malloc/heap.h b/libc/stdlib/malloc/heap.h
new file mode 100644
index 000000000..74b56603b
--- /dev/null
+++ b/libc/stdlib/malloc/heap.h
@@ -0,0 +1,146 @@
+/*
+ * libc/stdlib/malloc-zarg/heap.h -- heap allocator used for malloc
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <features.h>
+
+
+#ifdef __UCLIBC_HAS_THREADS__
+#include <pthread.h>
+typedef pthread_mutex_t mutex_t;
+# define MUTEX_INITIALIZER  PTHREAD_MUTEX_INITIALIZER
+# define mutex_lock(x)	    pthread_mutex_lock(&(x))
+# define mutex_unlock(x)    pthread_mutex_unlock(&(x));
+#else
+/* Mutex operations are currently a nop.  */
+typedef int mutex_t;
+# define MUTEX_INITIALIZER 0
+# define mutex_lock(x)
+# define mutex_unlock(x)
+#endif
+
+
+
+/* The unit in which allocation is done, due to alignment constraints, etc.
+   All allocation requests are rounded up to a multiple of this size.
+   Must be a power of 2.  */
+#define HEAP_GRANULARITY	(sizeof (double))
+
+
+struct heap
+{
+  struct heap_free_area *free_areas;
+  mutex_t lock;
+};
+
+#define HEAP_INIT 	{ 0, MUTEX_INITIALIZER }
+
+
+/* A free-list area `header'.  These are actually stored at the _ends_ of
+   free areas (to make allocating from the beginning of the area simpler),
+   so one might call it a `footer'.  */
+struct heap_free_area
+{
+	size_t size;
+	struct heap_free_area *next, *prev;
+};
+
+/* Return the address of the end of the frea area FA.  */
+#define HEAP_FREE_AREA_END(fa) ((void *)(fa + 1))
+/* Return the address of the beginning of the frea area FA.  FA is
+   evaulated multiple times.  */
+#define HEAP_FREE_AREA_START(fa) ((void *)((char *)(fa + 1) - (fa)->size))
+
+
+/* Rounds SZ up to be a multiple of HEAP_GRANULARITY.  */
+#define HEAP_ADJUST_SIZE(sz)  \
+   (((sz) + HEAP_GRANULARITY - 1) & ~(HEAP_GRANULARITY - 1))
+
+/* The minimum size of a free area.  It must include at least enough room
+   to hold a struct heap_free_area, plus enough extra to be usefully
+   allocated.  */
+#define HEAP_MIN_FREE_AREA_SIZE  \
+  (sizeof (struct heap_free_area) + HEAP_ADJUST_SIZE (1))
+
+
+#if 0
+#include <stdio.h>
+static void HEAP_DEBUG (struct heap *heap, const char *str)
+{
+  static int recursed = 0;
+  if (! recursed)
+    {
+      struct heap_free_area *fa;
+      recursed = 1;
+      fprintf (stderr, "  %s: heap @0x%lx:\n", str, (long)heap);
+      for (fa = heap->free_areas; fa; fa = fa->next)
+	fprintf (stderr,
+		 "    0x%lx:  0x%lx - 0x%lx  (%d)\tN=0x%lx, P=0x%lx\n",
+		 (long)fa,
+		 (long)HEAP_FREE_AREA_START (fa),
+		 (long)HEAP_FREE_AREA_END (fa),
+		 fa->size,
+		 (long)fa->prev,
+		 (long)fa->next);
+      recursed = 0;
+    }
+}
+#else
+#define HEAP_DEBUG(heap, str) (void)0
+#endif
+
+
+/* Allocate SIZE bytes from the front of the free-area FA in HEAP, and
+   return the amount actually allocated (which may be more than SIZE).  */
+extern inline size_t
+__heap_free_area_alloc (struct heap *heap,
+			struct heap_free_area *fa, size_t size)
+{
+  size_t fa_size = fa->size;
+
+  if (fa_size < size + HEAP_MIN_FREE_AREA_SIZE)
+    /* There's not enough room left over in FA after allocating the block, so
+       just use the whole thing, removing it from the list of free areas.  */
+    {
+      if (fa->next)
+	fa->next->prev = fa->prev;
+      if (fa->prev)
+	fa->prev->next = fa->next;
+      else
+	heap->free_areas = fa->next;
+      /* Remember that we've alloced the whole area.  */
+      size = fa_size;
+    }
+  else
+    /* Reduce size of FA to account for this allocation.  */
+    fa->size = fa_size - size;
+
+  return size;
+}
+
+
+/* Allocate and return a block at least *SIZE bytes long from HEAP.
+   *SIZE is adjusted to reflect the actual amount allocated (which may be
+   greater than requested).  */
+extern void *__heap_alloc (struct heap *heap, size_t *size);
+
+/* Allocate SIZE bytes at address MEM in HEAP.  Return the actual size
+   allocated, or 0 if we failed.  */
+extern size_t __heap_alloc_at (struct heap *heap, void *mem, size_t size);
+
+/* Return the memory area MEM of size SIZE to HEAP.  */
+extern void __heap_free (struct heap *heap, void *mem, size_t size);
+
+/* If the memory area MEM, of size SIZE, immediately follows an existing
+   free-area in HEAP, use it to extend that free-area, and return true;
+   otherwise return false.  */
+extern int __heap_append_free (struct heap *heap, void *mem, size_t size);
diff --git a/libc/stdlib/malloc/heap_alloc.c b/libc/stdlib/malloc/heap_alloc.c
new file mode 100644
index 000000000..22591d613
--- /dev/null
+++ b/libc/stdlib/malloc/heap_alloc.c
@@ -0,0 +1,55 @@
+/*
+ * libc/stdlib/malloc-zarg/heap_alloc.c -- allocate from a heap
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+
+#include "heap.h"
+
+
+/* Allocate and return a block at least *SIZE bytes long from HEAP.
+   *SIZE is adjusted to reflect the actual amount allocated (which may be
+   greater than requested).  */
+void *
+__heap_alloc (struct heap *heap, size_t *size)
+{
+  struct heap_free_area *fa;
+  size_t _size = *size;
+  void *mem = 0;
+
+  _size = HEAP_ADJUST_SIZE (_size);
+  
+  if (_size < sizeof (struct heap_free_area))
+    /* Because we sometimes must use a freed block to hold a free-area node,
+       we must make sure that every allocated block can hold one.  */
+    _size = HEAP_ADJUST_SIZE (sizeof (struct heap_free_area));
+
+  mutex_lock (heap->lock);
+
+  HEAP_DEBUG (heap, "before __heap_alloc");
+
+  /* Look for a free area that can contain _SIZE bytes.  */
+  for (fa = heap->free_areas; fa; fa = fa->next)
+    if (fa->size >= _size)
+      {
+	/* Found one!  */
+	mem = HEAP_FREE_AREA_START (fa);
+	*size = __heap_free_area_alloc (heap, fa, _size);
+	break;
+      }
+
+  HEAP_DEBUG (heap, "after __heap_alloc");
+
+  mutex_unlock (heap->lock);
+
+  return mem;
+}
diff --git a/libc/stdlib/malloc/heap_alloc_at.c b/libc/stdlib/malloc/heap_alloc_at.c
new file mode 100644
index 000000000..8ee925488
--- /dev/null
+++ b/libc/stdlib/malloc/heap_alloc_at.c
@@ -0,0 +1,51 @@
+/*
+ * libc/stdlib/malloc-zarg/heap_alloc_at.c -- allocate at a specific address
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+
+#include "heap.h"
+
+
+/* Allocate SIZE bytes at address MEM in HEAP.  Return the actual size
+   allocated, or 0 if we failed.  */
+size_t
+__heap_alloc_at (struct heap *heap, void *mem, size_t size)
+{
+  struct heap_free_area *fa;
+  size_t alloced = 0;
+
+  size = HEAP_ADJUST_SIZE (size);
+
+  mutex_lock (heap->lock);
+
+  HEAP_DEBUG (heap, "before __heap_alloc_at");
+
+  /* Look for a free area that can contain SIZE bytes.  */
+  for (fa = heap->free_areas; fa; fa = fa->next)
+    {
+      void *fa_mem = HEAP_FREE_AREA_START (fa);
+      if (fa_mem <= mem) 
+	{
+	  if (fa_mem == mem && fa->size >= size)
+	    /* FA has the right addr, and is big enough! */
+	    alloced = __heap_free_area_alloc (heap, fa, size);
+	  break;
+	}
+    }
+
+  HEAP_DEBUG (heap, "after __heap_alloc_at");
+
+  mutex_unlock (heap->lock);
+
+  return alloced;
+}
diff --git a/libc/stdlib/malloc/heap_append_free.c b/libc/stdlib/malloc/heap_append_free.c
new file mode 100644
index 000000000..42f0cf5bb
--- /dev/null
+++ b/libc/stdlib/malloc/heap_append_free.c
@@ -0,0 +1,71 @@
+/*
+ * libc/stdlib/malloc-zarg/heap_append_free.c -- append to heap free area
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+
+#include "heap.h"
+
+
+/* If the block MEM, of size SIZE, immediately follows an existing free-area
+   in HEAP, use it to extend that free-area, and return true; otherwise return
+   false.  */
+int
+__heap_append_free (struct heap *heap, void *mem, size_t size)
+{
+  int success = 0;
+  struct heap_free_area *fa;
+
+  mutex_lock (heap->lock);
+
+  HEAP_DEBUG (heap, "before __heap_append_free");
+
+  /* Find an adjacent free-list entry.  */
+  for (fa = heap->free_areas; fa; fa = fa->next)
+    if (HEAP_FREE_AREA_END (fa) == mem)
+      /* MEM follows FA, extend FA to include it.  Since the descriptor for FA
+	 is located at the end, we must actually write a new descriptor.  Note
+	 that we _don't_ handle the case where the extended FA can be merged
+	 with a following free area; this is because this function is
+	 generally only used in cases were we believe that usually won't
+	 happen (it doesn't cause any incorrectness, and the two blocks can be
+	 merged by __heap_free later).  */
+      {
+	struct heap_free_area *next_fa = fa->next;
+	struct heap_free_area *prev_fa = fa->prev;
+	size_t fa_size = fa->size;
+	struct heap_free_area *new_fa =
+	  (struct heap_free_area *)((char *)fa + size);
+
+	/* Update surrounding free-areas to point to FA's new address.  */
+	if (prev_fa)
+	  prev_fa->next = new_fa;
+	else
+	  heap->free_areas = new_fa;
+	if (next_fa)
+	  next_fa->prev = new_fa;
+
+	/* Fill in the moved descriptor.  */
+	new_fa->prev = prev_fa;
+	new_fa->next = next_fa;
+	new_fa->size = fa_size + size;
+
+	success = 1;
+	break;
+      }
+
+  HEAP_DEBUG (heap, "after __heap_append_free");
+
+  mutex_unlock (heap->lock);
+
+  return success;
+}
diff --git a/libc/stdlib/malloc/heap_free.c b/libc/stdlib/malloc/heap_free.c
new file mode 100644
index 000000000..20ef65572
--- /dev/null
+++ b/libc/stdlib/malloc/heap_free.c
@@ -0,0 +1,127 @@
+/*
+ * libc/stdlib/malloc-zarg/heap_free.c -- return memory to a heap
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+
+#include "heap.h"
+
+
+/* Return the memory area MEM of size SIZE to HEAP.  */
+void
+__heap_free (struct heap *heap, void *mem, size_t size)
+{
+  struct heap_free_area *prev_fa, *fa, *new_fa;
+  void *end = (char *)mem + size;
+
+  mutex_lock (heap->lock);
+
+  HEAP_DEBUG (heap, "before __heap_free");
+
+  /* Find an adjacent free-list entry.  */
+  for (prev_fa = 0, fa = heap->free_areas; fa; prev_fa = fa, fa = fa->next)
+    {
+      size_t fa_size = fa->size;
+      void *fa_end = HEAP_FREE_AREA_END (fa);
+      void *fa_mem = HEAP_FREE_AREA_START (fa);
+
+      if (fa_mem == end)
+	/* FA is just after MEM, grow down to encompass it. */
+	{
+	  fa_size += size;
+
+	  /* See if FA can now be merged with its predecessor. */
+	  if (prev_fa && fa_mem - size == HEAP_FREE_AREA_END (prev_fa))
+	    /* Yup; merge PREV_FA's info into FA.  */
+	    {
+	      struct heap_free_area *pp = prev_fa->prev;
+	      fa_size += prev_fa->size;
+	      if (pp)
+		pp->next = fa;
+	      else
+		heap->free_areas = fa;
+	      fa->prev = pp;
+	    }
+
+	  fa->size = fa_size;
+
+	  goto done;
+	}
+      else if (fa_end == mem)
+	/* FA is just before MEM, expand to encompass it. */
+	{
+	  struct heap_free_area *next_fa = fa->next;
+
+	  fa_size += size;
+
+	  /* See if FA can now be merged with its successor. */
+	  if (next_fa && fa_end + size == HEAP_FREE_AREA_START (next_fa))
+	    {
+	      /* Yup; merge FA's info into NEXT_FA.  */
+	      fa_size += next_fa->size;
+	      if (prev_fa)
+		prev_fa->next = next_fa;
+	      else
+		heap->free_areas = next_fa;
+	      next_fa->prev = prev_fa;
+	      fa = next_fa;
+	    }
+	  else
+	    /* FA can't be merged; move the descriptor for it to the tail-end
+	       of the memory block.  */
+	    {
+	      new_fa = (struct heap_free_area *)((char *)fa + size);
+	      /* Update surrounding free-areas to point to FA's new address. */
+	      if (prev_fa)
+		prev_fa->next = new_fa;
+	      else
+		heap->free_areas = new_fa;
+	      if (next_fa)
+		next_fa->prev = new_fa;
+	      /* Fill in the moved descriptor.  */
+	      new_fa->prev = prev_fa;
+	      new_fa->next = next_fa;
+	      fa = new_fa;
+	    }
+
+	  fa->size = fa_size;
+
+	  goto done;
+	}
+      else if (fa_mem > mem)
+	/* We've reached the right spot in the free-list without finding an
+	   adjacent free-area, so add a new free area to hold MEM. */
+	break;
+    }
+
+  /* Make a new free-list entry.  */
+
+  /* NEW_FA initially holds only MEM.  */
+  new_fa = (struct heap_free_area *)
+    ((char *)mem + size - sizeof (struct heap_free_area));
+  new_fa->size = size;
+  new_fa->next = fa;
+  new_fa->prev = prev_fa;
+
+  /* Insert NEW_FA in the free-list between PREV_FA and FA. */
+  if (prev_fa)
+    prev_fa->next = new_fa;
+  else
+    heap->free_areas = new_fa;
+  if (fa)
+    fa->prev = new_fa;
+
+ done:
+  HEAP_DEBUG (heap, "after __heap_free");
+
+  mutex_unlock (heap->lock);
+}
diff --git a/libc/stdlib/malloc/malloc.c b/libc/stdlib/malloc/malloc.c
index 9a3bbb332..317b10840 100644
--- a/libc/stdlib/malloc/malloc.c
+++ b/libc/stdlib/malloc/malloc.c
@@ -1,880 +1,107 @@
 /*
-  malloc - heap manager based on heavy use of virtual memory management.
-  Copyright (C) 1998   Valery Shchedrin
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Library General Public
-  License as published by the Free Software Foundation; either
-  version 2 of the License, or (at your option) any later version.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Library General Public License for more details.
-
-  You should have received a copy of the GNU Library General Public
-  License along with this library; if not, write to the Free
-  Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
-  MA 02111-1307, USA
-  
-  Public Functions:
-  
-  void *malloc(size_t size);
-  
-    Allocates `size` bytes
-    returns NULL if no free memory available
-  
-  void *calloc(size_t unit, size_t quantity);
-  
-    Allocates `quantity*unit` zeroed bytes via internal malloc call
-  
-  void *realloc(void *ptr, size_t size);
-  
-    Reallocates already allocated block `ptr`, if `ptr` is not valid block
-    then it works as malloc. NULL is returned if no free memory available
-  
-  void *_realloc_no_move(void *ptr, size_t size);
-  
-    Reallocates already allocated block `ptr`, if `ptr` is not valid block
-    or if reallocation can't be done with shrinking/expanding already
-    allocated block NULL is returned
-  
-  void free(void *ptr);
-  
-    Frees already allocated block, if `ptr` is incorrect one nothing will
-    happen.
-*/
-
-/*
- * Manuel Novoa III         Jan 2001
+ * libc/stdlib/malloc-zarg/malloc.c -- malloc function
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
  *
- * Modified to decrease object sizes.
- *   Broke into independent object files.
- *   Converted INIT_BLOCK() and FREE_MEM_DEL_BLOCK() from macros to functions.
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
  */
 
-#include <features.h>
-#ifndef _XOPEN_SOURCE
-#define _XOPEN_SOURCE
-#endif
-#include <sys/types.h>
-#include <unistd.h>
-#include <limits.h>
-#include <sys/time.h>
-#include <asm/page.h>
-#include <unistd.h>
+#include <stdlib.h>
 #include <sys/mman.h>
-#include <string.h>
-#include "malloc.h"
-#include <stdio.h>
-
-#define M_DOTRIMMING 1
-#define M_MULTITHREADED 0
-
-#define VALLOC_MSTART  ((void*)0x1c000000)
-#define LARGE_MSTART   ((void*)0x19000000)
-#define HUNK_MSTART    ((void*)0x18000000)
-#define HUNK_MSIZE     M_PAGESIZE
-#define HUNK_ID        0x99171713
-
-/* alignment of allocations > HUNK_THRESHOLD */
-#define MALLOC_ALIGN    4
-
-/* allocations < HUNK_THRESHOLD will not be aligned */
-#define HUNK_THRESHOLD  4
-
-/*up to HUNK_MAXSIZE blocks will be joined together to decrease memory waste*/
-#define HUNK_MAXSIZE 128
-
-/* returns value not less than size, aligned to MALLOC_ALIGN */
-#define ALIGN(size) (((size)+(MALLOC_ALIGN)-1)&(~((MALLOC_ALIGN)-1)))
-
-/* aligns s or p to page boundaries */
-#define PAGE_ALIGN(s) (((s)+M_PAGESIZE-1)&(~(M_PAGESIZE-1)))
-#define PAGE_ALIGNP(p) ((char*)PAGE_ALIGN((unsigned)(p)))
-#define PAGE_DOWNALIGNP(p) ((char*)(((unsigned)(p))&(~(M_PAGESIZE-1))))
-
-/* returns v * 2 for your machine (speed-up) */
-#define MUL2(v)  ((v)*2)
-
-/* does v *= 8 for your machine (speed-up) */
-#define EMUL8(v) v*=8
-
-/* does v/8 for your machind (speed-up) */
-#define DIV8(v)  ((v)/8)
-
-#if M_MULTITHREADED
-#error This version does not support threads
-#else
-typedef int mutex_t;
-
-#define mutex_lock(x)
-#define mutex_unlock(x)
-#define mutex_init(x)
-#define MUTEX_INITIALIZER 0
-//static mutex_t malloc_lock = MUTEX_INITIALIZER;
-#endif
-
-extern int __malloc_initialized;
-
-#ifdef L__malloc_init
-int __malloc_initialized = -1;
-
- /* -1 == uninitialized, 0 == initializing, 1 == initialized */
-#endif
-
-#ifndef MAP_FAILED
-#define MAP_FAILED ((void*)-1)
-#endif
-
-#if defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
-#define MAP_ANON MAP_ANONYMOUS
-#endif
-
-#ifndef NULL
-#define NULL ((void*)0)
-#endif
-
-/* guess pagesize */
-#define M_PAGESIZE getpagesize()
-
-/* HUNK MANAGER */
-
-typedef struct Hunk_s Hunk_t;
-
-struct Hunk_s {					/* Hunked block - 8 byte overhead */
-	int id;						/* unique id */
-	unsigned int total:12, used:12, size:8;
-	Hunk_t *next;				/* next free in __free_h */
-};
-
-#define usagemap(h) (((unsigned char *)(h))+sizeof(Hunk_t))
-#define hunk_ptr(h) (((char*)(h))+sizeof(Hunk_t)+ALIGN(DIV8(h->total+7)))
-#define hunk(h)  ((Hunk_t*)(h))
-
-extern Hunk_t *__free_h[HUNK_MAXSIZE + 1];
-extern int __total_h[HUNK_MAXSIZE + 1];
-
-#ifdef L__malloc_init
-Hunk_t *__free_h[HUNK_MAXSIZE + 1];	/* free hash */
-int __total_h[HUNK_MAXSIZE + 1];	/* Hunk_t's `total` member */
-#endif
-
-extern void *__hunk_alloc(int size);
-
-#ifdef L_malloc
-/* __hunk_alloc allocates <= HUNK_MAXSIZE blocks */
-void *__hunk_alloc(int size)
-{
-	Hunk_t *p;
-	unsigned long *cpl;
-	int i, c;
-
-	//	if (size >= HUNK_THRESHOLD)
-	size = ALIGN(size);
-
-	/* Look for already allocated hunkblocks */
-	if ((p = __free_h[size]) == NULL) {
-		if (
-			(p =
-			 (Hunk_t *) mmap(HUNK_MSTART, HUNK_MSIZE,
-							 PROT_READ | PROT_WRITE,
-#ifdef __UCLIBC_HAS_MMU__
-							 MAP_PRIVATE | MAP_ANONYMOUS
-#else
-							 MAP_SHARED | MAP_ANONYMOUS
-#endif
-							 , 0, 0)) == (Hunk_t *) MAP_FAILED)
-		  // {
-		  //  printf("hunk_alloc failed: %d, %d\n", size, errno);
-			return NULL;
-		  // }
-		memset(p, 0, HUNK_MSIZE);
-		p->id = HUNK_ID;
-		p->total = __total_h[size];
-		/* p->used = 0; */
-		p->size = size;
-		/* p->next = (Hunk_t*)NULL; */
-		/* memset(usagemap(p), 0, bound); */
-		__free_h[size] = p;
-	}
-
-	/* Locate free point in usagemap */
-	
-	/* First find a word where not all the bits are set */
-	for (cpl = (unsigned long *) usagemap(p); *cpl == 0xFFFFFFFF; cpl++);
-
-	/* Remember the byte position of that word */
-	i = ((unsigned char *) cpl) - usagemap(p);
-
-	/* Now find find a free bit in the word using binary search */
-	if (*(unsigned short *) cpl != 0xFFFF) {
-
-		if (*(unsigned char *) cpl == 0xFF) {
-			c = *(((unsigned char *) cpl) + 1);
-			i++;
-		}
-		else
-		  {
-		    c = *(unsigned char *) cpl;
-		  }
-	} else {
-		i += 2;
-		c = *(((unsigned char *) cpl) + 2);
-		if (c == 0xFF) {
-			c = *(((unsigned char *) cpl) + 3);
-			i++;
-		}
-	}
-	
-	/*
-	 * Multiply i by 8 for the bit position
-	 * Further down, we divide by 8 again to find the byte position
-	 */
-	EMUL8(i);
-	
-	/* If bottom nibble is set, shift down the top nibble */
-	if ((c & 0xF) == 0xF) {
-		c >>= 4;
-		i += 4;
-	}
-	
-	/* If bottom 2 bits are set, shift down the top two */
-	if ((c & 0x3) == 0x3) {
-		c >>= 2;
-		i += 2;
-	}
-	
-	/* Check which one of the two bits is set */
-	if (c & 1)
-		i++;
-
-	usagemap(p)[DIV8(i)] |= (1 << (i & 7));	/* set bit */
 
-	/* Increment counter and update hashes */
-	if (++p->used == p->total) {
-		__free_h[p->size] = p->next;
-		p->next = NULL;
-	}
-	
-	// fprintf(stderr, "hunk_alloc: i=%d, p->size=%d, p=%p\n", i, p->size, p);
-	return hunk_ptr(p) + i * p->size;
-}
-#endif							/* L_malloc */
-
-extern void __hunk_free(char *ptr);
-
-#ifdef L__free_support
-/* __hunk_free frees blocks allocated by __hunk_alloc */
-void __hunk_free(char *ptr)
-{
-	unsigned char *up;
-	int i, v;
-	Hunk_t *h;
-
-	if (!ptr)
-		return;
-
-	h = (Hunk_t *) PAGE_DOWNALIGNP(ptr);
-
-	/* Validate `ptr` */
-	if (h->id != HUNK_ID)
-		return;
-	v = ptr - hunk_ptr(h);
-	i = v / h->size;
-	if (v % h->size != 0 || i < 0 || i >= h->total)
-		return;
-
-	/* Update `usagemap` */
-	up = &(usagemap(h)[DIV8(i)]);
-	i = 1 << (i & 7);
-	if (!(*up & i))
-		return;
-	*up ^= i;
-
-	/* Update hunk counters */
-	if (h->used == h->total) {
-		if (--h->used) {		/* insert into __free_h */
-			h->next = __free_h[h->size];
-			__free_h[h->size] = h;
-		}						/* else - it will be unmapped */
-	} else {
-		if (!--h->used) {		/* delete from __free_h - will be __bl_freed */
-			Hunk_t *p, *pp;
-
-			for (p = __free_h[h->size], pp = NULL; p != h;
-				 pp = p, p = p->next);
-			if (!pp)
-				__free_h[h->size] = p->next;
-			else
-				pp->next = p->next;
-		}
-	}
-
-	/* Unmap empty Hunk_t */
-	if (!h->used)
-		munmap((void *) h, HUNK_MSIZE);
-}
-#endif							/* L__free_support */
-
-/* BLOCK MANAGER */
-
-typedef struct Block_s Block_t;
-
-struct Block_s {				/* 32-bytes long control structure (if 4-byte aligned) */
-	char *ptr;					/* pointer to related data */
-	Block_t *next;				/* next in free_mem list */
-	Block_t *l_free_mem, *r_free_mem;	/* left & right subtrees of <free_mem> */
-	Block_t *l_ptrs, *r_ptrs;	/* left & right subtrees of <ptrs> */
-	size_t size;				/* size - divided by align */
-
-	/* packed 4-byte attributes */
-/* { */
-	signed char bal_free_mem:8;	/* balance of <free_mem> subtree */
-	signed char bal_ptrs:8;		/* balance of <ptrs> subtree */
-	unsigned int used:1;		/* used/free state of the block */
-	unsigned int broken:1;		/* 1 if previous block can't be merged with it */
-/* } */
-};
-
-extern Block_t *__bl_last;		/* last mmapped block */
-
-#ifdef L__malloc_init
-Block_t *__bl_last;				/* last mmapped block */
-#endif
-
-#define bl_get() __hunk_alloc(sizeof(Block_t))
-#define bl_rel(p) __hunk_free((char*)p)
-
-extern Block_t *__Avl_Block_tfree_mem_tree;
-extern Block_t *__free_mem_ins(Block_t * data);
-extern void __free_mem_del(Block_t * data);
-extern void __free_mem_replace(Block_t * data);
-extern Block_t *__Avl_Block_tptrs_tree;
-extern Block_t *__ptrs_ins(Block_t * data);
-extern void __ptrs_del(Block_t * data);
-
-extern void __bl_uncommit(Block_t * b);
-extern void __bl_free(Block_t * b);
-
-/* like C++ templates ;-) */
-#include "avlmacro.h"
-
-#define FREE_MEM_COMPARE(i,a,b) \
-{ \
-  if ( (a)->size < (b)->size ) { \
-     i = -1; \
-  } else if ( (a)->size > (b)->size ) { \
-     i = 1; \
-  } else { \
-     i = 0; \
-  } \
-}
-
-#define PTRS_COMPARE(i,a,b) \
-{ \
-  if ( (a)->ptr < (b)->ptr ) { \
-     i = -1; \
-  } else if ( (a)->ptr > (b)->ptr ) { \
-     i = 1; \
-  } else { \
-     i = 0; \
-  } \
-}
-
-#ifdef L__avl_support
-Avl_Tree(free_mem, Block_t, free_mem, FREE_MEM_COMPARE)
-	Avl_Tree_no_replace(ptrs, Block_t, ptrs, PTRS_COMPARE)
-#endif
-#define free_mem_root Avl_Root(Block_t, free_mem)
-#define ptrs_root Avl_Root(Block_t, ptrs)
-/* pp is freed block */
-#define FREE_MEM_DEL_BLOCK(pp,p) {p = __free_mem_del_block(pp,p);}
-extern Block_t *__free_mem_del_block(Block_t * pp, Block_t * p);
-
-#ifdef L_malloc
-Block_t *__free_mem_del_block(Block_t * pp, Block_t * p)
-{
-	for (p = free_mem_root;;)
-		if (p->size > pp->size)
-			p = p->l_free_mem;
-		else if (p->size < pp->size)
-			p = p->r_free_mem;
-		else
-			break;
-	if (p == pp) {
-		if (pp->next)
-			__free_mem_replace(pp->next);
-		else
-			__free_mem_del(pp);
-	} else {
-		for (; p->next != pp; p = p->next);
-		p->next = pp->next;
-	}
-	return p;
-}
-#endif							/* L_malloc */
-
-#define FREE_MEM_INS_BLOCK(pp) \
-{ \
-  if ((p = __free_mem_ins(pp)) != NULL)\
-  {\
-    pp->next = p->next;\
-    p->next = pp;\
-  }\
-  else pp->next = NULL; \
-}
-
-/* `b` is current block, `pp` is next block */
-#define COMBINE_BLOCKS(b,pp) \
-{\
-  __ptrs_del(pp); \
-  b->size += pp->size; \
-  if (pp == __bl_last) __bl_last = b; \
-  bl_rel(pp); \
-}
-
-/* initializes new block b */
-#define INIT_BLOCK(b, pppp, sz) { p = __init_block(b, pppp, sz); }
-
-extern Block_t *__init_block(Block_t * b, char *pppp, size_t sz);
-
-#ifdef L_malloc
-Block_t *__init_block(Block_t * b, char *pppp, size_t sz)
-{
-	Block_t *p;
-
-	memset(b, 0, sizeof(Block_t));
-	b->ptr = pppp;
-	b->size = sz;
-	__ptrs_ins(b);
-	FREE_MEM_INS_BLOCK(b);
-	return p;
-}
-#endif							/* L_malloc */
-
-/* `b` is current block, `sz` its new size */
-/* block `b` will be splitted to one busy & one free block */
-#define SPLIT_BLOCK(b,sz) \
-{\
-  Block_t *bt; \
-  bt = bl_get(); \
-  INIT_BLOCK(bt, b->ptr + sz, b->size - sz); \
-  b->size = sz; \
-  if (__bl_last == b) __bl_last = bt; \
-  __bl_uncommit(bt);\
-}
-
-/* `b` is current block, `pp` is next free block, `sz` is needed size */
-#define SHRINK_BLOCK(b,pp,sz) \
-{\
-  FREE_MEM_DEL_BLOCK(pp,p); \
-  pp->ptr = b->ptr + sz; \
-  pp->size += b->size - sz; \
-  b->size = sz; \
-  FREE_MEM_INS_BLOCK(pp); \
-  __bl_uncommit(pp); \
-}
-
-#ifdef L_malloc
-static Block_t *bl_mapnew(size_t size)
-{
-	size_t map_size;
-	Block_t *pp, *p;
-	void *pt;
-
-	map_size = PAGE_ALIGN(size);
-	pt = mmap(LARGE_MSTART, map_size, PROT_READ | PROT_WRITE | PROT_EXEC,
-#ifdef __UCLIBC_HAS_MMU__
-							 MAP_PRIVATE | MAP_ANONYMOUS
-#else
-							 MAP_SHARED | MAP_ANONYMOUS
-#endif
-							 , 0, 0);
-
-	if (pt == MAP_FAILED)
-		return (Block_t *) NULL;
-
-	__bl_last = pp = bl_get();
-	INIT_BLOCK(pp, (char *) pt, map_size);
-	pp->broken = 1;
-
-	return pp;
-}
-
-void __bl_uncommit(Block_t * b)
-{
-	char *u_start, *u_end;
-
-	u_start = PAGE_ALIGNP(b->ptr);
-	u_end = PAGE_DOWNALIGNP(b->ptr + b->size);
-	if (u_end <= u_start)
-		return;
-
-#if M_DOTRIMMING
-	mmap(u_start, u_end - u_start, PROT_READ | PROT_WRITE | PROT_EXEC,
-#ifdef __UCLIBC_HAS_MMU__
-							 MAP_PRIVATE | MAP_ANONYMOUS |MAP_FIXED
-#else
-							 MAP_SHARED | MAP_ANONYMOUS |MAP_FIXED
-#endif
-							 , 0, 0);
-#endif
-}
-
-/* requested size must be aligned to ALIGNMENT */
-static Block_t *bl_alloc(size_t size)
-{
-	Block_t *p, *pp;
-
-	/* try to find needed space in existing memory */
-	for (p = free_mem_root, pp = NULL; p;) {
-		if (p->size > size) {
-			pp = p;
-			p = p->l_free_mem;
-		} else if (p->size < size)
-			p = p->r_free_mem;
-		else {
-			pp = p;
-			break;
-		}
-	}
-
-	if (!pp) {					/* map some memory */
-		if (!__bl_last) {		/* just do initial mmap */
-			pp = bl_mapnew(size);
-			if (!pp)
-				return NULL;
-		} else if (!__bl_last->used) {	/* try growing last unused */
-			if (mremap(PAGE_DOWNALIGNP(__bl_last->ptr),
-					   PAGE_ALIGNP(__bl_last->ptr + __bl_last->size) -
-					   PAGE_DOWNALIGNP(__bl_last->ptr),
-					   PAGE_ALIGNP(__bl_last->ptr + size) -
-					   PAGE_DOWNALIGNP(__bl_last->ptr), 0) == MAP_FAILED) {	/* unable to grow -- initiate new block */
-				pp = bl_mapnew(size);
-				if (!pp)
-					return NULL;
-			} else {
-				pp = __bl_last;
-				FREE_MEM_DEL_BLOCK(pp, p);
-				pp->size = PAGE_ALIGNP(pp->ptr + size) - pp->ptr;
-				FREE_MEM_INS_BLOCK(pp);
-			}
-		} else {				/* __bl_last is used block */
-			if (mremap(PAGE_DOWNALIGNP(__bl_last->ptr),
-					   PAGE_ALIGNP(__bl_last->ptr + __bl_last->size) -
-					   PAGE_DOWNALIGNP(__bl_last->ptr),
-					   PAGE_ALIGNP(__bl_last->ptr + __bl_last->size +
-								   size) - PAGE_DOWNALIGNP(__bl_last->ptr),
-					   0) == MAP_FAILED) {
-				pp = bl_mapnew(size);
-				if (!pp)
-					return NULL;
-			} else {
-				pp = bl_get();
-				INIT_BLOCK(pp, __bl_last->ptr + __bl_last->size,
-						   PAGE_ALIGNP(__bl_last->ptr + __bl_last->size +
-									   size) - __bl_last->ptr -
-						   __bl_last->size);
-				__bl_last = pp;
-			}
-		}
-	}
-
-	/* just delete this node from free_mem tree */
-	if (pp->next)
-		__free_mem_replace(pp->next);
-	else
-		__free_mem_del(pp);
-	pp->used = 1;
-
-	if (pp->size - size > MALLOC_ALIGN) {	/* this block can be splitted (it is unused,not_broken) */
-		SPLIT_BLOCK(pp, size);
-	}
-
-	return pp;
-}
-#endif							/* L_malloc */
-
-#ifdef L__free_support
-void __bl_free(Block_t * b)
-{
-	Block_t *p, *bl_next, *bl_prev;
-
-	/* Look for blocks before & after `b` */
-	for (p = ptrs_root, bl_next = NULL, bl_prev = NULL; p;) {
-		if (p->ptr > b->ptr) {
-			bl_next = p;
-			p = p->l_ptrs;
-		} else if (p->ptr < b->ptr) {
-			bl_prev = p;
-			p = p->r_ptrs;
-		} else
-			break;
-	}
-	if (b->l_ptrs)
-		for (bl_prev = b->l_ptrs; bl_prev->r_ptrs;
-			 bl_prev = bl_prev->r_ptrs);
-	if (b->r_ptrs)
-		for (bl_next = b->r_ptrs; bl_next->l_ptrs;
-			 bl_next = bl_next->l_ptrs);
-
-	if (bl_next && !bl_next->broken && !bl_next->used) {
-		FREE_MEM_DEL_BLOCK(bl_next, p)
-			COMBINE_BLOCKS(b, bl_next)
-	}
-
-	if (bl_prev && !b->broken && !bl_prev->used) {
-		FREE_MEM_DEL_BLOCK(bl_prev, p)
-			COMBINE_BLOCKS(bl_prev, b)
-			b = bl_prev;
-	}
-
-	b->used = 0;
-	FREE_MEM_INS_BLOCK(b)
-		__bl_uncommit(b);
-}
-#endif							/* L__free_support */
-
-extern void __malloc_init(void);
-
-#ifdef L__malloc_init
-void __malloc_init(void)
-{
-	int i, mapsize, x, old_x, gcount;
-
-	mapsize = M_PAGESIZE;
-
-	__malloc_initialized = 0;
-	__bl_last = NULL;
-	free_mem_root = NULL;
-	ptrs_root = NULL;
-	mapsize -= sizeof(Hunk_t);
-	for (i = 1; i <= HUNK_MAXSIZE; i++) {
-		__free_h[i] = (Hunk_t *) NULL;
-		for (x = mapsize / i, gcount = 0, old_x = 0; old_x != x;) {
-			old_x = x;
-			x = (mapsize - ALIGN(DIV8(old_x + 7))) / i;
-			if (gcount > 1 && x * i + ALIGN(DIV8(x + 7)) <= mapsize)
-				break;
-			if (x * i + ALIGN(DIV8(x + 7)) > mapsize)
-				gcount++;
-		}
-		__total_h[i] = x;
-	}
-	mutex_init(&malloc_lock);
-	__malloc_initialized = 1;
-	// fprintf(stderr, "malloc_init: hunk_t=%d\n", sizeof(Hunk_t));
-}
-#endif							/* L__malloc_init */
-
-#ifdef L_malloc
-void *malloc(size_t size)
-{
-	void *p;
-
-	if (size == 0)
-		return NULL;
-
-	if (__malloc_initialized < 0)
-		__malloc_init();
-	if (__malloc_initialized)
-		mutex_lock(&malloc_lock);
-
-	if (size <= HUNK_MAXSIZE)
-		p = __hunk_alloc(size);
-	else {
-		if ((p = bl_alloc(ALIGN(size))) != NULL)
-			p = ((Block_t *) p)->ptr;
-	}
-
-	if (__malloc_initialized)
-		mutex_unlock(&malloc_lock);
-
-	// fprintf(stderr, "malloc returning: s=%d, p=%p\n", size, p);
-	return p;
-}
-#endif							/* L_malloc */
-
-#ifdef L_free
-void free(void *ptr)
-{
-	Block_t *p, *best;
-
-	if (__malloc_initialized < 0)
-		return;
-	if (__malloc_initialized)
-		mutex_lock(&malloc_lock);
-
-	for (p = ptrs_root, best = NULL; p;) {
-		if (p->ptr > (char *) ptr)
-			p = p->l_ptrs;
-		else {
-			best = p;
-			p = p->r_ptrs;
-		}
-	}
-
-	if (!best || !best->used || best->ptr != (char *) ptr) {
-		__hunk_free(ptr);
-		if (__malloc_initialized)
-			mutex_unlock(&malloc_lock);
-		return;
-	}
-
-	__bl_free(best);
-
-	if (__malloc_initialized)
-		mutex_unlock(&malloc_lock);
-}
-#endif							/* L_free */
-
-extern void *_realloc_no_move(void *ptr, size_t size);
-
-#ifdef L__realloc_no_move
-void *_realloc_no_move(void *ptr, size_t size)
-{
-	Block_t *p, *best, *next;
-
-	if (size <= HUNK_MAXSIZE)
-		return NULL;
-
-	if (__malloc_initialized <= 0)
-		return malloc(size);
-
-	mutex_lock(&malloc_lock);
-
-	/* Locate block */
-	for (p = ptrs_root, best = NULL; p;) {
-		if (p->ptr > (char *) ptr)
-			p = p->l_ptrs;
-		else {
-			best = p;
-			p = p->r_ptrs;
-		}
-	}
-
-	if (!best || !best->used || best->ptr != (char *) ptr) {
-		mutex_unlock(&malloc_lock);
-		return NULL;
-	}
-
-	size = ALIGN(size);
-
-	if (size == best->size) {
-		mutex_unlock(&malloc_lock);
-		return ptr;
-	}
-
-	if (best->r_ptrs)			/* get block just after */
-		for (next = best->r_ptrs; next->l_ptrs; next = next->l_ptrs);
-	else
-		for (p = ptrs_root, next = NULL; p;) {
-			if (p->ptr > best->ptr) {
-				next = p;
-				p = p->l_ptrs;
-			} else if (p->ptr < best->ptr)
-				p = p->r_ptrs;
-			else
-				break;
-		}
-
-	if (size < best->size) {	/* shrink block */
-		if (!next || next->used || next->broken) {
-			if (best->size - size > MALLOC_ALIGN) {	/* do split */
-				SPLIT_BLOCK(best, size);
-			}
-		} else {				/* just move border of next block */
-			SHRINK_BLOCK(best, next, size);
-		}
-	} else if (next && !next->broken && !next->used) {	/* can expand */
-		if (best->size + next->size > size + HUNK_MAXSIZE) {	/* shrink next free block */
-			SHRINK_BLOCK(best, next, size);
-		} else if (best->size + next->size >= size) {	/* combine blocks (eat next one) */
-			FREE_MEM_DEL_BLOCK(next, p);
-			COMBINE_BLOCKS(best, next);
-		} else {				/* not enough memory in next block */
-			mutex_unlock(&malloc_lock);
-			return NULL;
-		}
-	} else {					/* no next block */
-		mutex_unlock(&malloc_lock);
-		return NULL;
-	}
-	mutex_unlock(&malloc_lock);
-	return best->ptr;
-}
-#endif							/* L__realloc_no_move */
-
-#ifdef L_realloc
-void *realloc(void *ptr, size_t size)
-{
-	void *tmp;
-
-	tmp = _realloc_no_move(ptr, size);
-
-	if (!tmp) {
-		Block_t *p, *best;
-
-		mutex_lock(&malloc_lock);
-
-		for (p = ptrs_root, best = NULL; p;) {
-			if (p->ptr > (char *) ptr)
-				p = p->l_ptrs;
-			else {
-				best = p;
-				p = p->r_ptrs;
-			}
-		}
-
-		if (!best || !best->used || best->ptr != (char *) ptr) {
-			if (ptr) {
-				Hunk_t *h;
+#include "malloc.h"
+#include "heap.h"
 
-				h = (Hunk_t *) PAGE_DOWNALIGNP(ptr);
-				if (h->id == HUNK_ID) {
-					mutex_unlock(&malloc_lock);
-					if ((size >= HUNK_THRESHOLD && ALIGN(size) == h->size)
-						|| size == h->size)
-						return ptr;
-					if ((tmp = malloc(size)) == NULL)
-						return NULL;
-					mutex_lock(&malloc_lock);
-					memcpy(tmp, ptr, ((size < h->size) ? size : h->size));
-					__hunk_free(ptr);
-					mutex_unlock(&malloc_lock);
-					return tmp;
-				}
-			}
-			mutex_unlock(&malloc_lock);
-			return malloc(size);
-		}
 
-		mutex_unlock(&malloc_lock);
+/* When we give memory to the heap, start this many bytes after the
+   beginning of the mmaped block.  This is because we must ensure that
+   malloc return values are aligned to MALLOC_ALIGNMENT, but since we need
+   to use one word _before_ the beginning of that, we actually want the heap
+   to return values that are MALLOC_ALIGNMENT aligned - sizeof (size_t).
+   Since the heap always allocates in multiples of HEAP_GRANULARITY, we can
+   do this by (1) ensuring that HEAP_GRANULARITY is a multiple of
+   MALLOC_ALIGNMENT, and (2) making sure that the heap's free areas start
+   sizeof(size_t) bytes before our required alignment.  */
+#define MALLOC_HEAP_BLOCK_SHIM	(MALLOC_ALIGNMENT - sizeof (size_t))
 
-		/* copy whole block */
-		if ((tmp = malloc(size)) == NULL)
-			return NULL;
-		memcpy(tmp, ptr, ((size < best->size) ? size : best->size));
 
-		mutex_lock(&malloc_lock);
-		__bl_free(best);
-		mutex_unlock(&malloc_lock);
-	}
-	return tmp;
-}
-#endif							/* L_realloc */
+/* The heap used for small allocations.  */
+struct heap __malloc_heap = HEAP_INIT;
 
-#ifdef L_calloc
-void *calloc(size_t unit, size_t quantity)
+
+void *malloc (size_t size)
 {
-	void *p;
-
-	unit *= quantity;
-
-	if ((p = malloc(unit)) == NULL)
-		return NULL;
-	memset(p, 0, unit);
-	return p;
+  void *mem;
+
+  MALLOC_DEBUG ("malloc: %d bytes\n", size);
+
+  /* Include an extra word to record the size of the allocated block.  */
+  size += sizeof (size_t);
+
+  if (size >= MALLOC_MMAP_THRESHOLD)
+    /* Use mmap for large allocations.  */
+    {
+      /* Make sure we request enough memory to align the result correctly,
+	 and that SIZE reflects that mmap hands back whole pages.  */
+      size += MALLOC_ROUND_UP_TO_PAGE_SIZE (MALLOC_ALIGNMENT - sizeof(size_t));
+
+      mem = mmap (0, size, PROT_READ | PROT_WRITE,
+		  MAP_SHARED | MAP_ANONYMOUS, 0, 0);
+      if (mem == MAP_FAILED)
+	return 0;
+    }
+  else
+    /* Use the heap for small allocations.  */
+    {
+      mem = __heap_alloc (&__malloc_heap, &size);
+
+      if (! mem) 
+	/* We couldn't allocate from the heap, so get some more memory
+	   from the system, add it to the heap, and try again.  */
+	{
+	  /* If we're trying to allocate a block bigger than the default
+	     MALLOC_HEAP_EXTEND_SIZE, make sure we get enough to hold it. */
+	  size_t block_size = (size < MALLOC_HEAP_EXTEND_SIZE
+			       ? MALLOC_HEAP_EXTEND_SIZE
+			       : MALLOC_ROUND_UP_TO_PAGE_SIZE (size));
+	  /* Allocate the new heap block.  */
+	  void *block = mmap (0, block_size,
+			      PROT_READ | PROT_WRITE,
+			      MAP_SHARED | MAP_ANONYMOUS, 0, 0);
+
+	  if (block != MAP_FAILED) 
+	    {
+	      /* Put BLOCK into the heap.  We first try to append BLOCK to
+		 an existing free area, which is more efficient because it
+		 doesn't require using a `shim' at the beginning (which
+		 would prevent merging free-areas); since mmap often returns
+		 contiguous areas, this is worth it.  */
+	      if (! __heap_append_free (&__malloc_heap, block, block_size))
+		/* Couldn't append, just add BLOCK as a new free-area.  */
+		__heap_free (&__malloc_heap,
+			     block + MALLOC_HEAP_BLOCK_SHIM,
+			     block_size - MALLOC_HEAP_BLOCK_SHIM);
+
+	      /* Try again to allocate.  */
+	      mem = __heap_alloc (&__malloc_heap, &size);
+	    }
+	}
+    }
+
+  if (mem)
+    /* Record the size of this block just before the returned address.  */
+    {
+      *(size_t *)mem = size;
+      mem = (size_t *)mem + 1;
+
+      MALLOC_DEBUG ("  malloc: returning 0x%lx (base:0x%lx, total_size:%d)\n",
+		    (long)mem, (long)mem - sizeof (size_t), size);
+    }
+
+  return mem;
 }
-#endif							/* L_calloc */
diff --git a/libc/stdlib/malloc/malloc.h b/libc/stdlib/malloc/malloc.h
new file mode 100644
index 000000000..96c8de6c2
--- /dev/null
+++ b/libc/stdlib/malloc/malloc.h
@@ -0,0 +1,45 @@
+/*
+ * libc/stdlib/malloc-zarg/malloc.h -- small malloc implementation
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+/* The alignment we guarantee for malloc return values.  */
+#define MALLOC_ALIGNMENT	(sizeof (double))
+
+/* The system pagesize we assume; we really ought to get it with
+   getpagesize, but gee, how annoying.  */
+#define MALLOC_PAGE_SIZE	4096
+
+/* The minimum size of block we request from the the system to extend the
+   heap for small allocations (we may request a bigger block if necessary to
+   satisfy a particularly big request).  */
+#define MALLOC_HEAP_EXTEND_SIZE	MALLOC_PAGE_SIZE
+
+/* The threshold above which blocks are allocated/freed with mmap/munmap,
+   rather than using the heap.  */
+#define MALLOC_MMAP_THRESHOLD	(8*MALLOC_PAGE_SIZE)
+
+
+#if 0
+#include <stdio.h>
+#define MALLOC_DEBUG(fmt, args...) fprintf (stderr, fmt , ##args)
+#else
+#define MALLOC_DEBUG(fmt, args...) (void)0
+#endif
+
+
+/* Return SZ rounded up to a multiple MALLOC_PAGE_SIZE.  */
+#define MALLOC_ROUND_UP_TO_PAGE_SIZE(sz)  \
+  (((sz) + (MALLOC_PAGE_SIZE - 1)) & ~(MALLOC_PAGE_SIZE - 1))
+
+
+/* The heap used for small allocations.  */
+extern struct heap __malloc_heap;
diff --git a/libc/stdlib/malloc/realloc.c b/libc/stdlib/malloc/realloc.c
new file mode 100644
index 000000000..faf7ac2f8
--- /dev/null
+++ b/libc/stdlib/malloc/realloc.c
@@ -0,0 +1,76 @@
+/*
+ * libc/stdlib/malloc-zarg/realloc.c -- realloc function
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ * 
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include "malloc.h"
+#include "heap.h"
+
+
+void *realloc (void *mem, size_t new_size)
+{
+  if (! mem)
+    return malloc (new_size);
+  else
+    {
+      void *base_mem = (size_t *)mem - 1;
+      size_t size = *(size_t *)base_mem;
+
+      MALLOC_DEBUG ("realloc: 0x%lx, %d (base = 0x%lx, total_size = %d)\n",
+		    (long)mem, new_size, (long)base_mem, size);
+
+      if (new_size <= size)
+	return mem;
+      else
+	{
+	  void *new_mem = 0;
+	  size_t ext_size = new_size - size;
+	  void *ext_addr = (char *)base_mem + ext_size;
+
+	  if (size >= MALLOC_MMAP_THRESHOLD)
+	    /* Try to extend this block in place using mmap.  */
+	    {
+	      ext_size += MALLOC_ROUND_UP_TO_PAGE_SIZE (ext_size);
+
+	      new_mem = mmap (ext_addr, ext_size, PROT_READ | PROT_WRITE,
+			      MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, 0, 0);
+	      if (new_mem == MAP_FAILED)
+		/* Can't do it.  */
+		ext_size = 0;
+	    }
+	  else
+	    ext_size = __heap_alloc_at (&__malloc_heap, ext_addr, ext_size);
+
+	  if (! ext_size)
+	    /* Our attempts to extend MEM in place failed, just
+	       allocate-and-copy.  */
+	    {
+	      new_mem = malloc (new_size);
+	      if (new_mem)
+		{
+		  memcpy (new_mem, mem, size);
+		  free (mem);
+		}
+	    }
+
+	  if (new_mem)
+	    MALLOC_DEBUG ("  realloc: returning 0x%lx"
+			  " (base:0x%lx, total_size:%d)\n",
+			  (long)new_mem, (long)new_mem - sizeof(size_t), size);
+
+	  return new_mem;
+	}
+    }
+}