2 * Copyright (c) 2007 The Hewlett-Packard Development Company
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 #include "arch/x86/emulenv.hh"
43 #include "base/misc.hh"
45 using namespace X86ISA
;
47 void EmulEnv::doModRM(const ExtMachInst
& machInst
)
49 assert(machInst
.modRM
.mod
!= 3);
50 //Use the SIB byte for addressing if the modrm byte calls for it.
51 if (machInst
.modRM
.rm
== 4 && machInst
.addrSize
!= 2) {
52 scale
= 1 << machInst
.sib
.scale
;
53 index
= machInst
.sib
.index
| (machInst
.rex
.x
<< 3);
54 base
= machInst
.sib
.base
| (machInst
.rex
.b
<< 3);
55 //In this special case, we don't use a base. The displacement also
56 //changes, but that's managed by the predecoder.
57 if (machInst
.sib
.base
== INTREG_RBP
&& machInst
.modRM
.mod
== 0)
59 //In -this- special case, we don't use an index.
60 if (index
== INTREG_RSP
)
63 if (machInst
.addrSize
== 2) {
64 unsigned rm
= machInst
.modRM
.rm
;
72 index
= (rm
% 2) ? INTREG_RDI
: INTREG_RSI
;
92 base
= machInst
.modRM
.rm
| (machInst
.rex
.b
<< 3);
93 if (machInst
.modRM
.mod
== 0 && machInst
.modRM
.rm
== 5) {
94 //Since we need to use a different encoding of this
95 //instruction anyway, just ignore the base in those cases
100 //Figure out what segment to use. This won't be entirely accurate since
101 //the presence of a displacement is supposed to make the instruction
102 //default to the data segment.
103 if ((base
!= INTREG_RBP
&& base
!= INTREG_RSP
) || machInst
.dispSize
) {
104 seg
= SEGMENT_REG_DS
;
105 //Handle any segment override that might have been in the instruction
106 int segFromInst
= machInst
.legacy
.seg
;
108 seg
= (SegmentRegIndex
)(segFromInst
- 1);
110 seg
= SEGMENT_REG_SS
;
114 void EmulEnv::setSeg(const ExtMachInst
& machInst
)
116 seg
= SEGMENT_REG_DS
;
117 //Handle any segment override that might have been in the instruction
118 int segFromInst
= machInst
.legacy
.seg
;
120 seg
= (SegmentRegIndex
)(segFromInst
- 1);