diff: fix bug with memory profiling and interactive queries

[Fergus Henderson]

It turns out that the following additional fix is needed.

--------------------

Estimated hours taken: 0.25

runtime/mercury_prof_mem.h:
runtime/mercury_prof_mem.c:
	Change MR_prof_malloc() to ensure that the memory that it
	allocates will be Word-aligned.  This change is needed
	as a result of my previous change to mercury_heap_profile.c
	which made it allocate strings using MR_prof_malloc().

Index: runtime/mercury_prof_mem.c
===================================================================
RCS file: /home/mercury1/repository/mercury/runtime/mercury_prof_mem.c,v
retrieving revision 1.3
diff -u -r1.3 mercury_prof_mem.c
--- mercury_prof_mem.c	1997/12/05 15:56:45	1.3
+++ mercury_prof_mem.c	1999/04/01 07:48:44
@@ -22,6 +22,7 @@
 #include "mercury_prof_mem.h"
 
 #include "mercury_std.h"	/* for newmem() */
+#include "mercury_types.h"	/* for Word */
 
 /*----------------------------------------------------------------------------*/
 
@@ -53,6 +54,18 @@
 MR_prof_malloc(size_t size)
 {
 	register void *p;
+
+	/*
+	** Ensure all allocations are word-aligned, by rounding size
+	** up to the nearest multiple of the word size.
+	**
+	** Note that the current implementation of MR_prof_malloc only
+	** guarantees that the memory will be Word-aligned; if you want to
+	** allocate types that contain data types (e.g. `double') which might
+	** require stricter alignment than that, then you will need to
+	** change this to round the size up accordingly.
+	*/
+	size = (size + sizeof(Word) - 1) / sizeof(Word);
 
 	/* Here we waste a bit of space but hopefully not to much */
 	if (mem_left < size) {
Index: runtime/mercury_prof_mem.h
===================================================================
RCS file: /home/mercury1/repository/mercury/runtime/mercury_prof_mem.h,v
retrieving revision 1.3
diff -u -r1.3 mercury_prof_mem.h
--- mercury_prof_mem.h	1997/12/05 15:56:46	1.3
+++ mercury_prof_mem.h	1999/04/01 06:02:07
@@ -17,11 +17,17 @@
 #include <stddef.h>	/* for size_t */
 
 /*
-** prof_malloc() allocates memory in large chunks using newmem(),
+** MR_prof_malloc() allocates memory in large chunks using newmem(),
 ** and then doles out portions of these chunks one at a time.
 ** We use prof_malloc() to reduce the chance of calling newmem()
 ** from a profiling interrupt that interrupted another call to newmem().
 ** Doing that is bad news, because newmem() is not re-entrant.
+**
+** Note that the current implementation of MR_prof_malloc only guarantees
+** that the memory will be Word-aligned; if you want to allocate types
+** that contain data types (e.g. `double') which might require stricter
+** alignment than that, then you will need to change the implementation of
+** MR_prof_malloc().
 */
 extern void *MR_prof_malloc(size_t);
 
-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3        |     -- the last words of T. S. Garp.