diff options
Diffstat (limited to 'newlib/libc')
| -rw-r--r-- | newlib/libc/sys/mmixware/sbrk.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/newlib/libc/sys/mmixware/sbrk.c b/newlib/libc/sys/mmixware/sbrk.c index de5ce5dac..f50886df8 100644 --- a/newlib/libc/sys/mmixware/sbrk.c +++ b/newlib/libc/sys/mmixware/sbrk.c @@ -1,6 +1,6 @@ /* 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 @@ -34,10 +34,26 @@ __asm__ (" .global _Sbrk_high\n" 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; } |