1
2/*--------------------------------------------------------------------*/
3/*--- Asm-only TransTab stuff.             pub_core_transtab_asm.h ---*/
4/*--------------------------------------------------------------------*/
5
6/*
7   This file is part of Valgrind, a dynamic binary instrumentation
8   framework.
9
10   Copyright (C) 2000-2010 Julian Seward
11      jseward@acm.org
12
13   This program is free software; you can redistribute it and/or
14   modify it under the terms of the GNU General Public License as
15   published by the Free Software Foundation; either version 2 of the
16   License, or (at your option) any later version.
17
18   This program is distributed in the hope that it will be useful, but
19   WITHOUT ANY WARRANTY; without even the implied warranty of
20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21   General Public License for more details.
22
23   You should have received a copy of the GNU General Public License
24   along with this program; if not, write to the Free Software
25   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26   02111-1307, USA.
27
28   The GNU General Public License is contained in the file COPYING.
29*/
30
31#ifndef __PUB_CORE_TRANSTAB_ASM_H
32#define __PUB_CORE_TRANSTAB_ASM_H
33
34/* Constants for the fast translation lookup cache.  It is a direct
35   mapped cache, with 2^VG_TT_FAST_BITS entries.
36
37   On x86/amd64, the cache index is computed as
38   'address[VG_TT_FAST_BITS-1 : 0]'.
39
40   On ppc32/ppc64, the bottom two bits of instruction addresses are
41   zero, which means that function causes only 1/4 of the entries to
42   ever be used.  So instead the function is '(address >>u
43   2)[VG_TT_FAST_BITS-1 : 0]' on those targets.
44
45   On ARM we do like ppc32/ppc64, although that will have to be
46   revisited when we come to implement Thumb. */
47
48#define VG_TT_FAST_BITS 15
49#define VG_TT_FAST_SIZE (1 << VG_TT_FAST_BITS)
50#define VG_TT_FAST_MASK ((VG_TT_FAST_SIZE) - 1)
51
52/* This macro isn't usable in asm land; nevertheless this seems
53   like a good place to put it. */
54#if defined(VGA_x86) || defined(VGA_amd64)
55#  define VG_TT_FAST_HASH(_addr)  ((((UWord)(_addr))     ) & VG_TT_FAST_MASK)
56#elif defined(VGA_ppc32) || defined(VGA_ppc64) || defined(VGA_arm)
57#  define VG_TT_FAST_HASH(_addr)  ((((UWord)(_addr)) >> 2) & VG_TT_FAST_MASK)
58#else
59#  error "VG_TT_FAST_HASH: unknown platform"
60#endif
61
62#endif   // __PUB_CORE_TRANSTAB_ASM_H
63
64/*--------------------------------------------------------------------*/
65/*--- end                                                          ---*/
66/*--------------------------------------------------------------------*/
67