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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/*-----------------------------------------------------------------*-C-*---
* File: handc/runtime/applyg.c
*
* Copyright (C)1997 Donovan Kolbly <d.kolbly@rscheme.org>
* as part of the RScheme project, licensed for free use.
* See <http://www.rscheme.org/> for the latest information.
*
* File version: 1.5
* File mod date: 1997.11.29 23:10:51
* System build: v0.7.2, 97.12.21
*
* Purpose: Generic function dispatch code (using a tiny hash table cache)
*------------------------------------------------------------------------*/
#include <rscheme/vinsns.h>
#include <rscheme/runtime.h>
#include <rscheme/linktype.h>
#include <rscheme/scheme.h>
#include <rscheme/allocns.h>
#define CLASS_HASH_CODE SLOT(5)
#define GF_CACHE_0_K SLOT(4)
#define GF_VICTIM_K SLOT(12)
#define GF_VICTIM_V SLOT(13)
#define GF_CACHE_OVERFLOW SLOT(14)
#ifdef GF_DEBUG
FILE *foo = NULL;
static void gf_stat( obj gf )
{
int i;
obj p, k;
fprintf( foo, "%s status: ",
symbol_text( gvec_ref( gf, SLOT(3) ) ) );
for (i=0; i<4; i++)
{
k = gvec_ref( gf, SLOT(i*2) + GF_CACHE_0_K );
if (truish(k))
fprintf( foo, " %s", symbol_text(class_name(k)) );
else
fprintf( foo, " #f" );
}
fprintf( foo, " |" );
k = gvec_ref( gf, GF_VICTIM_K );
if (truish(k))
fprintf( foo, " %s", symbol_text(class_name(k)) );
else
fprintf( foo, " #f" );
fprintf( foo, " |" );
for (p=gvec_ref(gf,GF_CACHE_OVERFLOW);truish(p);p=gvec_ref(p,0))
{
k = gvec_ref(p,SLOT(1));
fprintf( foo, " %s", symbol_text(class_name(k)) );
}
fprintf( foo, "\n" );
}
#endif /* GF_DEBUG */
obj rs_gf_find_method( obj gf, obj rcvr )
{
obj c, m, impl, h, k;
UINT_32 k_ix, v_ix;
#ifdef GF_DEBUG
if (!foo)
foo = fopen( "/tmp/gf.trc", "w" );
#endif /* GF_DEBUG */
c = object_class(rcvr);
h = FX_AND(gvec_ref(c, CLASS_HASH_CODE),int2fx(3*2));
k_ix = GF_CACHE_0_K + FXWORDS_TO_RIBYTES(h);
v_ix = k_ix + SLOT(1);
k = gvec_ref( gf, k_ix );
#ifdef GF_DEBUG
gf_stat(gf);
#endif /* GF_DEBUG */
if (EQ(k,c))
return gvec_ref( gf, v_ix );
else
{
/* check the victim entry */
k = gvec_ref( gf, GF_VICTIM_K );
if (EQ(k,c))
{
m = gvec_ref( gf, GF_VICTIM_V );
/* a hit -- victimize the primary entry
* (note: there is no way you can hit in the victim cache
* if your primary entry is #f)
*/
gvec_write_ptr( gf, GF_VICTIM_K, gvec_ref( gf, k_ix ) );
gvec_write_ptr( gf, GF_VICTIM_V, gvec_ref( gf, v_ix ) );
gvec_write_ptr( gf, k_ix, k );
gvec_write_ptr( gf, v_ix, m );
return m;
}
else
{
obj ov, new_ov, prev = ZERO;
#ifdef GF_DEBUG
fprintf( foo, "%s: check overflow for key = %s\n",
symbol_text( gvec_ref( gf, SLOT(3) ) ),
symbol_text( class_name( c ) ) );
if (truish( gvec_ref( gf, k_ix ) ))
fprintf( foo, " primary[%d] => %s\n",
fx2int(h),
symbol_text( class_name( gvec_ref( gf, k_ix ) ) ) );
if (truish(k))
fprintf( foo, " victim => %s\n",
symbol_text( class_name( k ) ) );
#endif /* GF_DEBUG */
/* a primary miss -- check the overflow list */
for (ov = gvec_ref( gf, GF_CACHE_OVERFLOW );
!EQ(ov,FALSE_OBJ);
ov = gvec_ref( ov, SLOT(0) ) )
{
k = gvec_ref( ov, SLOT(1) );
#ifdef GF_DEBUG
fprintf( foo, " overflow {%#x} => %s\n", ov,
symbol_text( class_name( k ) ) );
#endif /* GF_DEBUG */
if (EQ(k,c))
{
#ifdef GF_DEBUG
fprintf( foo, " HIT (prev = {%#x})\n", prev );
#endif /* GF_DEBUG */
m = gvec_ref( ov, SLOT(2) );
/* found it in the overflow list... move this entry
* to the primary cache area and spill the victim cache
*/
new_ov = make3( vector_class,
(EQ(prev,ZERO)
? gvec_ref( ov, SLOT(0) )
: gvec_ref( gf, GF_CACHE_OVERFLOW )),
gvec_ref( gf, GF_VICTIM_K ),
gvec_ref( gf, GF_VICTIM_V ) );
gvec_write_ptr( gf, GF_VICTIM_K, gvec_ref( gf, k_ix ) );
gvec_write_ptr( gf, GF_VICTIM_V, gvec_ref( gf, v_ix ) );
if (!EQ(prev,ZERO))
gvec_write( prev, SLOT(0), gvec_ref( ov, SLOT(0) ) );
gvec_write_ptr( gf, GF_CACHE_OVERFLOW, new_ov );
gvec_write_ptr( gf, k_ix, k );
gvec_write_ptr( gf, v_ix, m );
#ifdef GF_DEBUG
gf_stat(gf);
#endif /* GF_DEBUG */
return m;
}
prev = ov;
}
#ifdef GF_DEBUG
fprintf( foo, " MISS\n" );
#endif /* GF_DEBUG */
return FALSE_OBJ;
}
}
}
jump_addr rs_gf_dispatch( obj gf )
{
obj m;
if (arg_count_reg < 1)
{
scheme_error( "GF ~s called with no arguments", 1, gf );
}
m = rs_gf_find_method( gf, REG0 );
if (EQ(m,FALSE_OBJ))
{
/* a miss -- call the fallback function */
COLLECT0();
REG1 = REG0;
REG0 = gf;
arg_count_reg = 2;
return apply( load_cache_and_call_proc );
}
else
{
return apply(m);
}
}
jump_addr applyg( obj gf )
{
/* if the template has been changed, call the full procedure
* (this is for debugging, tracing, and introspection purposes...
* we want to keep the protocol that pretends like the template
* is always called, even if we optimize away that call in certain
* cases
*/
if (!EQ(gvec_ref(gf,SLOT(0)),gf_dispatch_template))
return apply(gf);
else
return rs_gf_dispatch(gf);
}
|
