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1 
2 /*---------------------------------------------------------------*/
3 /*--- begin                                  guest_arm_defs.h ---*/
4 /*---------------------------------------------------------------*/
5 /*
6    This file is part of Valgrind, a dynamic binary instrumentation
7    framework.
8 
9    Copyright (C) 2004-2013 OpenWorks LLP
10       info@open-works.net
11 
12    This program is free software; you can redistribute it and/or
13    modify it under the terms of the GNU General Public License as
14    published by the Free Software Foundation; either version 2 of the
15    License, or (at your option) any later version.
16 
17    This program is distributed in the hope that it will be useful, but
18    WITHOUT ANY WARRANTY; without even the implied warranty of
19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20    General Public License for more details.
21 
22    You should have received a copy of the GNU General Public License
23    along with this program; if not, write to the Free Software
24    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
25    02110-1301, USA.
26 
27    The GNU General Public License is contained in the file COPYING.
28 */
29 
30 /* Only to be used within the guest-arm directory. */
31 
32 #ifndef __VEX_GUEST_ARM_DEFS_H
33 #define __VEX_GUEST_ARM_DEFS_H
34 
35 #include "libvex_basictypes.h"
36 #include "guest_generic_bb_to_IR.h"     // DisResult
37 
38 /*---------------------------------------------------------*/
39 /*--- arm to IR conversion                              ---*/
40 /*---------------------------------------------------------*/
41 
42 /* Convert one ARM insn to IR.  See the type DisOneInstrFn in
43    bb_to_IR.h. */
44 extern
45 DisResult disInstr_ARM ( IRSB*        irbb,
46                          Bool         (*resteerOkFn) ( void*, Addr64 ),
47                          Bool         resteerCisOk,
48                          void*        callback_opaque,
49                          UChar*       guest_code,
50                          Long         delta,
51                          Addr64       guest_IP,
52                          VexArch      guest_arch,
53                          VexArchInfo* archinfo,
54                          VexAbiInfo*  abiinfo,
55                          Bool         host_bigendian,
56                          Bool         sigill_diag );
57 
58 /* Used by the optimiser to specialise calls to helpers. */
59 extern
60 IRExpr* guest_arm_spechelper ( const HChar* function_name,
61                                IRExpr** args,
62                                IRStmt** precedingStmts,
63                                Int      n_precedingStmts );
64 
65 /* Describes to the optimser which part of the guest state require
66    precise memory exceptions.  This is logically part of the guest
67    state description. */
68 extern
69 Bool guest_arm_state_requires_precise_mem_exns ( Int, Int );
70 
71 extern
72 VexGuestLayout armGuest_layout;
73 
74 
75 /*---------------------------------------------------------*/
76 /*--- arm guest helpers                                 ---*/
77 /*---------------------------------------------------------*/
78 
79 /* --- CLEAN HELPERS --- */
80 
81 /* Calculate NZCV from the supplied thunk components, in the positions
82    they appear in the CPSR, viz bits 31:28 for N Z V C respectively.
83    Returned bits 27:0 are zero. */
84 extern
85 UInt armg_calculate_flags_nzcv ( UInt cc_op, UInt cc_dep1,
86                                  UInt cc_dep2, UInt cc_dep3 );
87 
88 /* Calculate the C flag from the thunk components, in the lowest bit
89    of the word (bit 0). */
90 extern
91 UInt armg_calculate_flag_c ( UInt cc_op, UInt cc_dep1,
92                              UInt cc_dep2, UInt cc_dep3 );
93 
94 /* Calculate the V flag from the thunk components, in the lowest bit
95    of the word (bit 0). */
96 extern
97 UInt armg_calculate_flag_v ( UInt cc_op, UInt cc_dep1,
98                              UInt cc_dep2, UInt cc_dep3 );
99 
100 /* Calculate the specified condition from the thunk components, in the
101    lowest bit of the word (bit 0). */
102 extern
103 UInt armg_calculate_condition ( UInt cond_n_op /* ARMCondcode << 4 | cc_op */,
104                                 UInt cc_dep1,
105                                 UInt cc_dep2, UInt cc_dep3 );
106 
107 /* Calculate the QC flag from the thunk components, in the lowest bit
108    of the word (bit 0). */
109 extern
110 UInt armg_calculate_flag_qc ( UInt resL1, UInt resL2,
111                               UInt resR1, UInt resR2 );
112 
113 
114 /*---------------------------------------------------------*/
115 /*--- Condition code stuff                              ---*/
116 /*---------------------------------------------------------*/
117 
118 /* Flags masks.  Defines positions of flags bits in the CPSR. */
119 #define ARMG_CC_SHIFT_N  31
120 #define ARMG_CC_SHIFT_Z  30
121 #define ARMG_CC_SHIFT_C  29
122 #define ARMG_CC_SHIFT_V  28
123 #define ARMG_CC_SHIFT_Q  27
124 
125 #define ARMG_CC_MASK_N    (1 << ARMG_CC_SHIFT_N)
126 #define ARMG_CC_MASK_Z    (1 << ARMG_CC_SHIFT_Z)
127 #define ARMG_CC_MASK_C    (1 << ARMG_CC_SHIFT_C)
128 #define ARMG_CC_MASK_V    (1 << ARMG_CC_SHIFT_V)
129 #define ARMG_CC_MASK_Q    (1 << ARMG_CC_SHIFT_Q)
130 
131 /* Flag thunk descriptors.  A four-word thunk is used to record
132    details of the most recent flag-setting operation, so NZCV can
133    be computed later if needed.
134 
135    The four words are:
136 
137       CC_OP, which describes the operation.
138 
139       CC_DEP1, CC_DEP2, CC_DEP3.  These are arguments to the
140          operation.  We want set up the mcx_masks in flag helper calls
141          involving these fields so that Memcheck "believes" that the
142          resulting flags are data-dependent on both CC_DEP1 and
143          CC_DEP2.  Hence the name DEP.
144 
145    When building the thunk, it is always necessary to write words into
146    CC_DEP1/2/3, even if those args are not used given the
147    CC_OP field.  This is important because otherwise Memcheck could
148    give false positives as it does not understand the relationship
149    between the CC_OP field and CC_DEP1/2/3, and so believes
150    that the definedness of the stored flags always depends on
151    all 3 DEP values.
152 
153    Fields carrying only 1 or 2 bits of useful information (old_C,
154    shifter_co, old_V, oldC:oldV) must have their top 31 or 30 bits
155    (respectively) zero.  The text "31x0:" or "30x0:" denotes this.
156 
157    A summary of the field usages is:
158 
159    OP                DEP1              DEP2              DEP3
160    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
161 
162    OP_COPY           curr_NZCV:28x0    unused            unused
163    OP_ADD            argL              argR              unused
164    OP_SUB            argL              argR              unused
165    OP_ADC            argL              argR              31x0:old_C
166    OP_SBB            argL              argR              31x0:old_C
167    OP_LOGIC          result            31x0:shifter_co   31x0:old_V
168    OP_MUL            result            unused            30x0:old_C:old_V
169    OP_MULL           resLO32           resHI32           30x0:old_C:old_V
170 */
171 
172 enum {
173    ARMG_CC_OP_COPY=0,  /* DEP1 = NZCV in 31:28, DEP2 = 0, DEP3 = 0
174                           just copy DEP1 to output */
175 
176    ARMG_CC_OP_ADD,     /* DEP1 = argL (Rn), DEP2 = argR (shifter_op),
177                           DEP3 = 0 */
178 
179    ARMG_CC_OP_SUB,     /* DEP1 = argL (Rn), DEP2 = argR (shifter_op),
180                           DEP3 = 0 */
181 
182    ARMG_CC_OP_ADC,     /* DEP1 = argL (Rn), DEP2 = arg2 (shifter_op),
183                           DEP3 = oldC (in LSB) */
184 
185    ARMG_CC_OP_SBB,     /* DEP1 = argL (Rn), DEP2 = arg2 (shifter_op),
186                           DEP3 = oldC (in LSB) */
187 
188    ARMG_CC_OP_LOGIC,   /* DEP1 = result, DEP2 = shifter_carry_out (in LSB),
189                           DEP3 = old V flag (in LSB) */
190 
191    ARMG_CC_OP_MUL,     /* DEP1 = result, DEP2 = 0, DEP3 = oldC:old_V
192                           (in bits 1:0) */
193 
194    ARMG_CC_OP_MULL,    /* DEP1 = resLO32, DEP2 = resHI32, DEP3 = oldC:old_V
195                           (in bits 1:0) */
196 
197    ARMG_CC_OP_NUMBER
198 };
199 
200 /* XXXX because of the calling conventions for
201    armg_calculate_condition, all this OP values MUST be in the range
202    0 .. 15 only (viz, 4-bits). */
203 
204 
205 
206 /* Defines conditions which we can ask for (ARM ARM 2e page A3-6) */
207 
208 typedef
209    enum {
210       ARMCondEQ     = 0,  /* equal                         : Z=1 */
211       ARMCondNE     = 1,  /* not equal                     : Z=0 */
212 
213       ARMCondHS     = 2,  /* >=u (higher or same)          : C=1 */
214       ARMCondLO     = 3,  /* <u  (lower)                   : C=0 */
215 
216       ARMCondMI     = 4,  /* minus (negative)              : N=1 */
217       ARMCondPL     = 5,  /* plus (zero or +ve)            : N=0 */
218 
219       ARMCondVS     = 6,  /* overflow                      : V=1 */
220       ARMCondVC     = 7,  /* no overflow                   : V=0 */
221 
222       ARMCondHI     = 8,  /* >u   (higher)                 : C=1 && Z=0 */
223       ARMCondLS     = 9,  /* <=u  (lower or same)          : C=0 || Z=1 */
224 
225       ARMCondGE     = 10, /* >=s (signed greater or equal) : N=V */
226       ARMCondLT     = 11, /* <s  (signed less than)        : N!=V */
227 
228       ARMCondGT     = 12, /* >s  (signed greater)          : Z=0 && N=V */
229       ARMCondLE     = 13, /* <=s (signed less or equal)    : Z=1 || N!=V */
230 
231       ARMCondAL     = 14, /* always (unconditional)        : 1 */
232       ARMCondNV     = 15  /* never (unconditional):        : 0 */
233       /* NB: ARM have deprecated the use of the NV condition code.
234          You are now supposed to use MOV R0,R0 as a noop rather than
235          MOVNV R0,R0 as was previously recommended.  Future processors
236          may have the NV condition code reused to do other things.  */
237    }
238    ARMCondcode;
239 
240 #endif /* ndef __VEX_GUEST_ARM_DEFS_H */
241 
242 /*---------------------------------------------------------------*/
243 /*--- end                                    guest_arm_defs.h ---*/
244 /*---------------------------------------------------------------*/
245