blob: f580158917960d01b9795a58d22362e57f55d070 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - subx/016index_addressing.cc</title>
<meta name="Generator" content="Vim/8.0">
<meta name="plugin-version" content="vim7.4_v2">
<meta name="syntax" content="cpp">
<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #aaaaaa; background-color: #080808; }
body { font-size: 12pt; font-family: monospace; color: #aaaaaa; background-color: #080808; }
a { color:#eeeeee; text-decoration: none; }
a:hover { text-decoration: underline; }
* { font-size: 12pt; font-size: 1em; }
.Error { color: #ffffff; background-color: #ff6060; padding-bottom: 1px; }
.traceContains { color: #008000; }
.LineNr { color: #444444; }
.Constant { color: #00a0a0; }
.Delimiter { color: #800080; }
.Special { color: #c00000; }
.Identifier { color: #c0a020; }
.Normal { color: #aaaaaa; background-color: #080808; padding-bottom: 1px; }
.Comment { color: #9090ff; }
.Comment a { color:#0000ee; text-decoration:underline; }
.PreProc { color: #800080; }
-->
</style>
<script type='text/javascript'>
<!--
/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
var lineNum;
lineNum = window.location.hash;
lineNum = lineNum.substr(1); /* strip off '#' */
if (lineNum.indexOf('L') == -1) {
lineNum = 'L'+lineNum;
}
lineElem = document.getElementById(lineNum);
/* Always jump to new location even if the line was hidden inside a fold, or
* we corrected the raw number to a line ID.
*/
if (lineElem) {
lineElem.scrollIntoView(true);
}
return true;
}
if ('onhashchange' in window) {
window.onhashchange = JumpToLine;
}
-->
</script>
</head>
<body onload='JumpToLine();'>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="Comment">//: operating on memory at the address provided by some register plus optional scale and offset</span>
<span id="L2" class="LineNr"> 2 </span>
<span id="L3" class="LineNr"> 3 </span><span class="Delimiter">:(scenario add_r32_to_mem_at_r32_with_sib)</span>
<span id="L4" class="LineNr"> 4 </span><span class="Special">% Reg[EBX].i = 0x10;</span>
<span id="L5" class="LineNr"> 5 </span><span class="Special">% Reg[EAX].i = 0x2000;</span>
<span id="L6" class="LineNr"> 6 </span>== <span class="Constant">0x1</span> <span class="Comment"># code segment</span>
<span id="L7" class="LineNr"> 7 </span><span class="Comment"># op ModR/M SIB displacement immediate</span>
<span id="L8" class="LineNr"> 8 </span> <span class="PreProc">0</span><span class="Constant">1</span> 1c <span class="Constant">20</span> <span class="Comment"># add EBX to *EAX</span>
<span id="L9" class="LineNr"> 9 </span><span class="Comment"># ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB)</span>
<span id="L10" class="LineNr"> 10 </span><span class="Comment"># SIB in binary: 00 (scale 1) 100 (no index) 000 (base EAX)</span>
<span id="L11" class="LineNr"> 11 </span>== <span class="Constant">0x2000</span> <span class="Comment"># data segment</span>
<span id="L12" class="LineNr"> 12 </span><span class="PreProc">0</span><span class="Constant">1</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># 1</span>
<span id="L13" class="LineNr"> 13 </span><span class="traceContains">+run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32</span>
<span id="L14" class="LineNr"> 14 </span><span class="traceContains">+run: effective address is initially 0x2000 (EAX)</span>
<span id="L15" class="LineNr"> 15 </span><span class="traceContains">+run: effective address is 0x2000</span>
<span id="L16" class="LineNr"> 16 </span><span class="traceContains">+run: storing 0x00000011</span>
<span id="L17" class="LineNr"> 17 </span>
<span id="L18" class="LineNr"> 18 </span><span class="Delimiter">:(before "End Mod 0 Special-cases(addr)")</span>
<span id="L19" class="LineNr"> 19 </span><span class="Normal">case</span> <span class="Constant">4</span>: <span class="Comment">// exception: mod 0b00 rm 0b100 => incoming SIB (scale-index-base) byte</span>
<span id="L20" class="LineNr"> 20 </span> addr = <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a><span class="Delimiter">(</span>mod<span class="Delimiter">);</span>
<span id="L21" class="LineNr"> 21 </span> <span class="Identifier">break</span><span class="Delimiter">;</span>
<span id="L22" class="LineNr"> 22 </span><span class="Delimiter">:(code)</span>
<span id="L23" class="LineNr"> 23 </span><span class="Normal">uint32_t</span> <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a><span class="Delimiter">(</span><span class="Normal">uint8_t</span> mod<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span id="L24" class="LineNr"> 24 </span> <span class="Normal">uint8_t</span> sib = <a href='010---vm.cc.html#L322'>next</a><span class="Delimiter">();</span>
<span id="L25" class="LineNr"> 25 </span> <span class="Normal">uint8_t</span> base = sib&<span class="Constant">0x7</span><span class="Delimiter">;</span>
<span id="L26" class="LineNr"> 26 </span> <span class="Normal">uint32_t</span> addr = <span class="Constant">0</span><span class="Delimiter">;</span>
<span id="L27" class="LineNr"> 27 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>base != <a href='010---vm.cc.html#L18'>EBP</a> || mod != <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span id="L28" class="LineNr"> 28 </span> addr = Reg[base]<span class="Delimiter">.</span>u<span class="Delimiter">;</span>
<span id="L29" class="LineNr"> 29 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">90</span><span class="Delimiter">,</span> <span class="Constant">"run"</span><span class="Delimiter">)</span> << <span class="Constant">"effective address is initially 0x"</span> << std::hex << addr << <span class="Constant">" ("</span> << <a href='013direct_addressing.cc.html#L62'>rname</a><span class="Delimiter">(</span>base<span class="Delimiter">)</span> << <span class="Constant">")"</span> << end<span class="Delimiter">();</span>
<span id="L30" class="LineNr"> 30 </span> <span class="Delimiter">}</span>
<span id="L31" class="LineNr"> 31 </span> <span class="Normal">else</span> <span class="Delimiter">{</span>
<span id="L32" class="LineNr"> 32 </span> <span class="Comment">// base == EBP && mod == 0</span>
<span id="L33" class="LineNr"> 33 </span> addr = <a href='011run.cc.html#L343'>next32</a><span class="Delimiter">();</span> <span class="Comment">// ignore base</span>
<span id="L34" class="LineNr"> 34 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">90</span><span class="Delimiter">,</span> <span class="Constant">"run"</span><span class="Delimiter">)</span> << <span class="Constant">"effective address is initially 0x"</span> << std::hex << addr << <span class="Constant">" (disp32)"</span> << end<span class="Delimiter">();</span>
<span id="L35" class="LineNr"> 35 </span> <span class="Delimiter">}</span>
<span id="L36" class="LineNr"> 36 </span> <span class="Normal">uint8_t</span> index = <span class="Delimiter">(</span>sib>><span class="Constant">3</span><span class="Delimiter">)</span>&<span class="Constant">0x7</span><span class="Delimiter">;</span>
<span id="L37" class="LineNr"> 37 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>index == <a href='010---vm.cc.html#L17'>ESP</a><span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span id="L38" class="LineNr"> 38 </span> <span class="Comment">// ignore index and scale</span>
<span id="L39" class="LineNr"> 39 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">90</span><span class="Delimiter">,</span> <span class="Constant">"run"</span><span class="Delimiter">)</span> << <span class="Constant">"effective address is 0x"</span> << std::hex << addr << end<span class="Delimiter">();</span>
<span id="L40" class="LineNr"> 40 </span> <span class="Delimiter">}</span>
<span id="L41" class="LineNr"> 41 </span> <span class="Normal">else</span> <span class="Delimiter">{</span>
<span id="L42" class="LineNr"> 42 </span> <span class="Normal">uint8_t</span> scale = <span class="Delimiter">(</span><span class="Constant">1</span> << <span class="Delimiter">(</span>sib>><span class="Constant">6</span><span class="Delimiter">));</span>
<span id="L43" class="LineNr"> 43 </span> addr += Reg[index]<span class="Delimiter">.</span>i*scale<span class="Delimiter">;</span> <span class="Comment">// treat index register as signed. Maybe base as well? But we'll always ensure it's non-negative.</span>
<span id="L44" class="LineNr"> 44 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">90</span><span class="Delimiter">,</span> <span class="Constant">"run"</span><span class="Delimiter">)</span> << <span class="Constant">"effective address is 0x"</span> << std::hex << addr << <span class="Constant">" (after adding "</span> << <a href='013direct_addressing.cc.html#L62'>rname</a><span class="Delimiter">(</span>index<span class="Delimiter">)</span> << <span class="Constant">"*"</span> << <a href='010---vm.cc.html#L370'>NUM</a><span class="Delimiter">(</span>scale<span class="Delimiter">)</span> << <span class="Constant">")"</span> << end<span class="Delimiter">();</span>
<span id="L45" class="LineNr"> 45 </span> <span class="Delimiter">}</span>
<span id="L46" class="LineNr"> 46 </span> <span class="Identifier">return</span> addr<span class="Delimiter">;</span>
<span id="L47" class="LineNr"> 47 </span><span class="Delimiter">}</span>
<span id="L48" class="LineNr"> 48 </span>
<span id="L49" class="LineNr"> 49 </span><span class="Delimiter">:(scenario add_r32_to_mem_at_base_r32_index_r32)</span>
<span id="L50" class="LineNr"> 50 </span><span class="Special">% Reg[EBX].i = 0x10; // source</span>
<span id="L51" class="LineNr"> 51 </span><span class="Special">% Reg[EAX].i = 0x1ffe; // dest base</span>
<span id="L52" class="LineNr"> 52 </span><span class="Special">% Reg[ECX].i = 0x2; // dest index</span>
<span id="L53" class="LineNr"> 53 </span>== <span class="Constant">0x1</span> <span class="Comment"># code segment</span>
<span id="L54" class="LineNr"> 54 </span><span class="Comment"># op ModR/M SIB displacement immediate</span>
<span id="L55" class="LineNr"> 55 </span> <span class="PreProc">0</span><span class="Constant">1</span> 1c <span class="Error">08</span> <span class="Comment"># add EBX to *(EAX+ECX)</span>
<span id="L56" class="LineNr"> 56 </span><span class="Comment"># ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB)</span>
<span id="L57" class="LineNr"> 57 </span><span class="Comment"># SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX)</span>
<span id="L58" class="LineNr"> 58 </span>== <span class="Constant">0x2000</span> <span class="Comment"># data segment</span>
<span id="L59" class="LineNr"> 59 </span><span class="PreProc">0</span><span class="Constant">1</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># 1</span>
<span id="L60" class="LineNr"> 60 </span><span class="traceContains">+run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32</span>
<span id="L61" class="LineNr"> 61 </span><span class="traceContains">+run: effective address is initially 0x1ffe (EAX)</span>
<span id="L62" class="LineNr"> 62 </span><span class="traceContains">+run: effective address is 0x2000 (after adding ECX*1)</span>
<span id="L63" class="LineNr"> 63 </span><span class="traceContains">+run: storing 0x00000011</span>
<span id="L64" class="LineNr"> 64 </span>
<span id="L65" class="LineNr"> 65 </span><span class="Delimiter">:(scenario add_r32_to_mem_at_displacement_using_sib)</span>
<span id="L66" class="LineNr"> 66 </span><span class="Special">% Reg[EBX].i = 0x10; // source</span>
<span id="L67" class="LineNr"> 67 </span>== <span class="Constant">0x1</span> <span class="Comment"># code segment</span>
<span id="L68" class="LineNr"> 68 </span><span class="Comment"># op ModR/M SIB displacement immediate</span>
<span id="L69" class="LineNr"> 69 </span> <span class="PreProc">0</span><span class="Constant">1</span> 1c <span class="Constant">25</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Constant">20</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># add EBX to *0x2000</span>
<span id="L70" class="LineNr"> 70 </span><span class="Comment"># ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB)</span>
<span id="L71" class="LineNr"> 71 </span><span class="Comment"># SIB in binary: 00 (scale 1) 100 (no index) 101 (not EBP but disp32)</span>
<span id="L72" class="LineNr"> 72 </span>== <span class="Constant">0x2000</span> <span class="Comment"># data segment</span>
<span id="L73" class="LineNr"> 73 </span><span class="PreProc">0</span><span class="Constant">1</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># 1</span>
<span id="L74" class="LineNr"> 74 </span><span class="traceContains">+run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32</span>
<span id="L75" class="LineNr"> 75 </span><span class="traceContains">+run: effective address is initially 0x2000 (disp32)</span>
<span id="L76" class="LineNr"> 76 </span><span class="traceContains">+run: effective address is 0x2000</span>
<span id="L77" class="LineNr"> 77 </span><span class="traceContains">+run: storing 0x00000011</span>
<span id="L78" class="LineNr"> 78 </span>
<span id="L79" class="LineNr"> 79 </span><span class="Comment">//:</span>
<span id="L80" class="LineNr"> 80 </span>
<span id="L81" class="LineNr"> 81 </span><span class="Delimiter">:(scenario add_r32_to_mem_at_base_r32_index_r32_plus_disp8)</span>
<span id="L82" class="LineNr"> 82 </span><span class="Special">% Reg[EBX].i = 0x10; // source</span>
<span id="L83" class="LineNr"> 83 </span><span class="Special">% Reg[EAX].i = 0x1ff9; // dest base</span>
<span id="L84" class="LineNr"> 84 </span><span class="Special">% Reg[ECX].i = 0x5; // dest index</span>
<span id="L85" class="LineNr"> 85 </span>== <span class="Constant">0x1</span> <span class="Comment"># code segment</span>
<span id="L86" class="LineNr"> 86 </span><span class="Comment"># op ModR/M SIB displacement immediate</span>
<span id="L87" class="LineNr"> 87 </span> <span class="PreProc">0</span><span class="Constant">1</span> 5c <span class="Error">08</span> <span class="PreProc">0</span><span class="Constant">2</span> <span class="Comment"># add EBX to *(EAX+ECX+2)</span>
<span id="L88" class="LineNr"> 88 </span><span class="Comment"># ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 100 (dest in SIB)</span>
<span id="L89" class="LineNr"> 89 </span><span class="Comment"># SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX)</span>
<span id="L90" class="LineNr"> 90 </span>== <span class="Constant">0x2000</span> <span class="Comment"># data segment</span>
<span id="L91" class="LineNr"> 91 </span><span class="PreProc">0</span><span class="Constant">1</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># 1</span>
<span id="L92" class="LineNr"> 92 </span><span class="traceContains">+run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32</span>
<span id="L93" class="LineNr"> 93 </span><span class="traceContains">+run: effective address is initially 0x1ff9 (EAX)</span>
<span id="L94" class="LineNr"> 94 </span><span class="traceContains">+run: effective address is 0x1ffe (after adding ECX*1)</span>
<span id="L95" class="LineNr"> 95 </span><span class="traceContains">+run: effective address is 0x2000 (after adding disp8)</span>
<span id="L96" class="LineNr"> 96 </span><span class="traceContains">+run: storing 0x00000011</span>
<span id="L97" class="LineNr"> 97 </span>
<span id="L98" class="LineNr"> 98 </span><span class="Delimiter">:(before "End Mod 1 Special-cases(addr)")</span>
<span id="L99" class="LineNr"> 99 </span><span class="Normal">case</span> <span class="Constant">4</span>: <span class="Comment">// exception: mod 0b01 rm 0b100 => incoming SIB (scale-index-base) byte</span>
<span id="L100" class="LineNr">100 </span> addr = <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a><span class="Delimiter">(</span>mod<span class="Delimiter">);</span>
<span id="L101" class="LineNr">101 </span> <span class="Identifier">break</span><span class="Delimiter">;</span>
<span id="L102" class="LineNr">102 </span>
<span id="L103" class="LineNr">103 </span><span class="Comment">//:</span>
<span id="L104" class="LineNr">104 </span>
<span id="L105" class="LineNr">105 </span><span class="Delimiter">:(scenario add_r32_to_mem_at_base_r32_index_r32_plus_disp32)</span>
<span id="L106" class="LineNr">106 </span><span class="Special">% Reg[EBX].i = 0x10; // source</span>
<span id="L107" class="LineNr">107 </span><span class="Special">% Reg[EAX].i = 0x1ff9; // dest base</span>
<span id="L108" class="LineNr">108 </span><span class="Special">% Reg[ECX].i = 0x5; // dest index</span>
<span id="L109" class="LineNr">109 </span>== <span class="Constant">0x1</span> <span class="Comment"># code segment</span>
<span id="L110" class="LineNr">110 </span><span class="Comment"># op ModR/M SIB displacement immediate</span>
<span id="L111" class="LineNr">111 </span> <span class="PreProc">0</span><span class="Constant">1</span> 9c <span class="Error">08</span> <span class="PreProc">0</span><span class="Constant">2</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># add EBX to *(EAX+ECX+2)</span>
<span id="L112" class="LineNr">112 </span><span class="Comment"># ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 100 (dest in SIB)</span>
<span id="L113" class="LineNr">113 </span><span class="Comment"># SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX)</span>
<span id="L114" class="LineNr">114 </span>== <span class="Constant">0x2000</span> <span class="Comment"># data segment</span>
<span id="L115" class="LineNr">115 </span><span class="PreProc">0</span><span class="Constant">1</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="Comment"># 1</span>
<span id="L116" class="LineNr">116 </span><span class="traceContains">+run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32</span>
<span id="L117" class="LineNr">117 </span><span class="traceContains">+run: effective address is initially 0x1ff9 (EAX)</span>
<span id="L118" class="LineNr">118 </span><span class="traceContains">+run: effective address is 0x1ffe (after adding ECX*1)</span>
<span id="L119" class="LineNr">119 </span><span class="traceContains">+run: effective address is 0x2000 (after adding disp32)</span>
<span id="L120" class="LineNr">120 </span><span class="traceContains">+run: storing 0x00000011</span>
<span id="L121" class="LineNr">121 </span>
<span id="L122" class="LineNr">122 </span><span class="Delimiter">:(before "End Mod 2 Special-cases(addr)")</span>
<span id="L123" class="LineNr">123 </span><span class="Normal">case</span> <span class="Constant">4</span>: <span class="Comment">// exception: mod 0b10 rm 0b100 => incoming SIB (scale-index-base) byte</span>
<span id="L124" class="LineNr">124 </span> addr = <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a><span class="Delimiter">(</span>mod<span class="Delimiter">);</span>
<span id="L125" class="LineNr">125 </span> <span class="Identifier">break</span><span class="Delimiter">;</span>
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->
|