1 /* vm interpreter wrapper
2
3 Copyright (C) 2001,2002,2003,2007 Free Software Foundation, Inc.
4
5 This file is part of Gforth.
6
7 Gforth is free software; you can redistribute it and/or
8 modify it under the terms of the GNU General Public License
9 as published by the Free Software Foundation, either version 3
10 of the License, or (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, see http://www.gnu.org/licenses/.
19 */
20
21 #include "mini.h"
22
23 #define USE_spTOS 1
24
25 #ifdef USE_spTOS
26 #define IF_spTOS(x) x
27 #else
28 #define IF_spTOS(x)
29 #endif
30
31 #ifdef VM_DEBUG
32 #define NAME(_x) if (vm_debug) {fprintf(vm_out, "%p: %-20s, ", ip-1, _x); fprintf(vm_out,"fp=%p, sp=%p", fp, sp);}
33 #else
34 #define NAME(_x)
35 #endif
36
37 /* different threading schemes for different architectures; the sparse
38 numbering is there for historical reasons */
39
40 /* here you select the threading scheme; I have only set this up for
41 386 and generic, because I don't know what preprocessor macros to
42 test for (Gforth uses config.guess instead). Anyway, it's probably
43 best to build them all and select the fastest instead of hardwiring
44 a specific scheme for an architecture. E.g., scheme 8 is fastest
45 for Gforth "make bench" on a 486, whereas scheme 5 is fastest for
46 "mini fib.mini" on an Athlon */
47 #ifndef THREADING_SCHEME
48 #define THREADING_SCHEME 5
49 #endif /* defined(THREADING_SCHEME) */
50
51 #ifdef __GNUC__
52 #if THREADING_SCHEME==1
53 /* direct threading scheme 1: autoinc, long latency (HPPA, Sharc) */
54 # define NEXT_P0 ({cfa=*ip++;})
55 # define IP (ip-1)
56 # define SET_IP(p) ({ip=(p); NEXT_P0;})
57 # define NEXT_INST (cfa)
58 # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);})
59 # define DEF_CA
60 # define NEXT_P1
61 # define NEXT_P2 ({goto *(cfa.inst);})
62 #endif
63
64 #if THREADING_SCHEME==3
65 /* direct threading scheme 3: autoinc, low latency (68K) */
66 # define NEXT_P0
67 # define IP (ip)
68 # define SET_IP(p) ({ip=(p); NEXT_P0;})
69 # define NEXT_INST (*ip)
70 # define INC_IP(const_inc) ({ip+=(const_inc);})
71 # define DEF_CA
72 # define NEXT_P1 ({cfa=*ip++;})
73 # define NEXT_P2 ({goto *(cfa.inst);})
74 #endif
75
76 #if THREADING_SCHEME==5
77 /* direct threading scheme 5: early fetching (Alpha, MIPS) */
78 # define CFA_NEXT
79 # define NEXT_P0 ({cfa=*ip;})
80 # define IP (ip)
81 # define SET_IP(p) ({ip=(Inst *)(p); NEXT_P0;})
82 # define NEXT_INST (cfa)
83 # define INC_IP(const_inc) ({cfa=ip[const_inc]; ip+=(const_inc);})
84 # define DEF_CA
85 # define NEXT_P1 (ip++)
86 # define NEXT_P2 ({goto *(cfa.inst);})
87 #endif
88
89 #if THREADING_SCHEME==8
90 /* direct threading scheme 8: i386 hack */
91 # define NEXT_P0
92 # define IP (ip)
93 # define SET_IP(p) ({ip=(p); NEXT_P0;})
94 # define NEXT_INST (*IP)
95 # define INC_IP(const_inc) ({ ip+=(const_inc);})
96 # define DEF_CA
97 # define NEXT_P1 (ip++)
98 # define NEXT_P2 ({goto *((*(ip-1)).inst);})
99 #endif
100
101 #if THREADING_SCHEME==9
102 /* direct threading scheme 9: prefetching (for PowerPC) */
103 /* note that the "cfa=next_cfa;" occurs only in NEXT_P1, because this
104 works out better with the capabilities of gcc to introduce and
105 schedule the mtctr instruction. */
106 # define NEXT_P0
107 # define IP ip
108 # define SET_IP(p) ({ip=(p); next_cfa=*ip; NEXT_P0;})
109 # define NEXT_INST (next_cfa)
110 # define INC_IP(const_inc) ({next_cfa=IP[const_inc]; ip+=(const_inc);})
111 # define DEF_CA
112 # define NEXT_P1 ({cfa=next_cfa; ip++; next_cfa=*ip;})
113 # define NEXT_P2 ({goto *(cfa.inst);})
114 # define MORE_VARS Cell next_cfa;
115 #endif
116
117 #if THREADING_SCHEME==10
118 /* direct threading scheme 10: plain (no attempt at scheduling) */
119 # define NEXT_P0
120 # define IP (ip)
121 # define SET_IP(p) ({ip=(p); NEXT_P0;})
122 # define NEXT_INST (*ip)
123 # define INC_IP(const_inc) ({ip+=(const_inc);})
124 # define DEF_CA
125 # define NEXT_P1
126 # define NEXT_P2 ({cfa=*ip++; goto *(cfa.inst);})
127 #endif
128
129
130 #define NEXT ({DEF_CA NEXT_P1; NEXT_P2;})
131 #define IPTOS ((NEXT_INST))
132
133 #define INST_ADDR(name) (Label)&&I_##name
134 #define LABEL(name) I_##name:
135 #else /* !defined(__GNUC__) */
136 /* use switch dispatch */
137 #define DEF_CA
138 #define NEXT_P0
139 #define NEXT_P1
140 #define NEXT_P2 goto next_inst;
141 #define SET_IP(p) (ip=(p))
142 #define IP ip
143 #define NEXT_INST (*ip)
144 #define INC_IP(const_inc) (ip+=(const_inc))
145 #define IPTOS NEXT_INST
146 #define INST_ADDR(name) I_##name
147 #define LABEL(name) case I_##name:
148
149 #endif /* !defined(__GNUC__) */
150
151 #define LABEL2(x)
152
153 #ifdef VM_PROFILING
154 #define SUPER_END vm_count_block(IP)
155 #else
156 #define SUPER_END
157 #endif
158
159 #ifndef __GNUC__
160 enum {
161 #include "mini-labels.i"
162 };
163 #endif
164
165 #if defined(__GNUC__) && ((__GNUC__==2 && defined(__GNUC_MINOR__) && __GNUC_MINOR__>=7)||(__GNUC__>2))
166 #define MAYBE_UNUSED __attribute__((unused))
167 #else
168 #define MAYBE_UNUSED
169 #endif
170
171 /* the return type can be anything you want it to */
engine(Cell * ip0,Cell * sp,char * fp)172 long engine(Cell *ip0, Cell *sp, char *fp)
173 {
174 /* VM registers (you may want to use gcc's "Explicit Reg Vars" here) */
175 Cell * ip;
176 Cell cfa;
177 #ifdef USE_spTOS
178 Cell spTOS;
179 #else
180 #define spTOS (sp[0])
181 #endif
182 static Label labels[] = {
183 #include "mini-labels.i"
184 };
185 #ifdef MORE_VARS
186 MORE_VARS
187 #endif
188
189 if (vm_debug)
190 fprintf(vm_out,"entering engine(%p,%p,%p)\n",ip0,sp,fp);
191 if (ip0 == NULL) {
192 vm_prim = labels;
193 return 0;
194 }
195
196 /* I don't have a clue where these things come from,
197 but I've put them in macros.h for the moment */
198 IF_spTOS(spTOS = sp[0]);
199
200 SET_IP(ip0);
201 SUPER_END; /* count the BB starting at ip0 */
202
203 #ifdef __GNUC__
204 NEXT;
205 #include "mini-vm.i"
206 #else
207 next_inst:
208 switch((*ip++).inst) {
209 #include "mini-vm.i"
210 default:
211 fprintf(stderr,"unknown instruction %d at %p\n", ip[-1], ip-1);
212 exit(1);
213 }
214 #endif
215 }
216