+2012-10-21 Hans-Peter Nilsson <hp@bitrange.com>
+
+ * libc/sys/mmixware/sbrk.c (_sbrk): Drop unused extern declaration
+ of "end". Mark allocated memory by applying PRELD.
+
2012-10-16 Gregory Pietsch <gpietsch@comcast.net>
* libc/stdlib/getopt.c (getopt_internal): Align handling of colon to
/* sbrk for MMIXware.
- Copyright (C) 2001 Hans-Peter Nilsson
+ Copyright (C) 2001, 2012 Hans-Peter Nilsson
Permission to use, copy, modify, and distribute this software is
freely granted, provided that the above copyright notice, this notice
caddr_t
_sbrk (size_t incr)
{
- extern char end; /* Defined by the linker */
char *prev_heap_end;
prev_heap_end = _Sbrk_high;
+
+ /* A simulator that requires explicit memory allocation is expected
+ to hook that to the PRELD data prefetch insn, which is otherwise
+ typically a nop. */
+ if ((long) incr > 0)
+ {
+ size_t n = incr;
+ char *p = prev_heap_end;
+#define A(N) __asm__ ("preld " #N ",%0,0" : : "r" (p))
+#define PRELDOWNTO(N) while (n >= N + 1) { A(N); n -= N + 1; p += N + 1; }
+
+ PRELDOWNTO (255);
+ PRELDOWNTO (31);
+ PRELDOWNTO (3);
+ PRELDOWNTO (0);
+ }
+
_Sbrk_high += incr;
return (caddr_t) prev_heap_end;
}