2 /*--------------------------------------------------------------------*/
3 /*--- Asm-only TransTab stuff. pub_core_transtab_asm.h ---*/
4 /*--------------------------------------------------------------------*/
7 This file is part of Valgrind, a dynamic binary instrumentation
10 Copyright (C) 2000-2010 Julian Seward
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.
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.
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
28 The GNU General Public License is contained in the file COPYING.
31 #ifndef __PUB_CORE_TRANSTAB_ASM_H
32 #define __PUB_CORE_TRANSTAB_ASM_H
34 /* Constants for the fast translation lookup cache. It is a direct
35 mapped cache, with 2^VG_TT_FAST_BITS entries.
37 On x86/amd64, the cache index is computed as
38 'address[VG_TT_FAST_BITS-1 : 0]'.
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.
45 On ARM we do like ppc32/ppc64, although that will have to be
46 revisited when we come to implement Thumb.
48 On s390x the rightmost bit of an instruction address is zero.
49 For best table utilization shift the address to the right by 1 bit. */
51 #define VG_TT_FAST_BITS 15
52 #define VG_TT_FAST_SIZE (1 << VG_TT_FAST_BITS)
53 #define VG_TT_FAST_MASK ((VG_TT_FAST_SIZE) - 1)
55 /* This macro isn't usable in asm land; nevertheless this seems
56 like a good place to put it. */
58 #if defined(VGA_x86) || defined(VGA_amd64)
59 # define VG_TT_FAST_HASH(_addr) ((((UWord)(_addr)) ) & VG_TT_FAST_MASK)
61 #elif defined(VGA_s390x) || defined(VGA_arm)
62 # define VG_TT_FAST_HASH(_addr) ((((UWord)(_addr)) >> 1) & VG_TT_FAST_MASK)
64 #elif defined(VGA_ppc32) || defined(VGA_ppc64)
65 # define VG_TT_FAST_HASH(_addr) ((((UWord)(_addr)) >> 2) & VG_TT_FAST_MASK)
68 # error "VG_TT_FAST_HASH: unknown platform"
71 #endif // __PUB_CORE_TRANSTAB_ASM_H
73 /*--------------------------------------------------------------------*/
75 /*--------------------------------------------------------------------*/