1 #!/usr/bin/python3
2 # Copyright (C) 2014-2023 Free Software Foundation, Inc.
3 # This file is part of the GNU C Library.
4 #
5 # The GNU C Library is free software; you can redistribute it and/or
6 # modify it under the terms of the GNU Lesser General Public
7 # License as published by the Free Software Foundation; either
8 # version 2.1 of the License, or (at your option) any later version.
9 #
10 # The GNU C Library is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 # Lesser General Public License for more details.
14 #
15 # You should have received a copy of the GNU Lesser General Public
16 # License along with the GNU C Library; if not, see
17 # <https://www.gnu.org/licenses/>.
18
19 """Benchmark program generator script
20
21 This script takes a function name as input and generates a program using
22 an input file located in the benchtests directory. The name of the
23 input file should be of the form foo-inputs where 'foo' is the name of
24 the function.
25 """
26
27 from __future__ import print_function
28 import sys
29 import os
30 import itertools
31
32 # Macro definitions for functions that take no arguments. For functions
33 # that take arguments, the STRUCT_TEMPLATE, ARGS_TEMPLATE and
34 # VARIANTS_TEMPLATE are used instead.
35 DEFINES_TEMPLATE = '''
36 #define CALL_BENCH_FUNC(v, i) %(func)s ()
37 #define NUM_VARIANTS (1)
38 #define NUM_SAMPLES(v) (1)
39 #define VARIANT(v) FUNCNAME "()"
40 '''
41
42 # Structures to store arguments for the function call. A function may
43 # have its inputs partitioned to represent distinct performance
44 # characteristics or distinct flavors of the function. Each such
45 # variant is represented by the _VARIANT structure. The ARGS structure
46 # represents a single set of arguments.
47 STRUCT_TEMPLATE = '''
48 #define CALL_BENCH_FUNC(v, i, x) %(func)s (x %(func_args)s)
49
50 struct args
51 {
52 %(args)s
53 double timing;
54 };
55
56 struct _variants
57 {
58 const char *name;
59 int count;
60 struct args *in;
61 };
62 '''
63
64 # The actual input arguments.
65 ARGS_TEMPLATE = '''
66 struct args in%(argnum)d[%(num_args)d] = {
67 %(args)s
68 };
69 '''
70
71 # The actual variants, along with macros defined to access the variants.
72 VARIANTS_TEMPLATE = '''
73 struct _variants variants[%(num_variants)d] = {
74 %(variants)s
75 };
76
77 #define NUM_VARIANTS %(num_variants)d
78 #define NUM_SAMPLES(i) (variants[i].count)
79 #define VARIANT(i) (variants[i].name)
80 '''
81
82 # Epilogue for the generated source file.
83 EPILOGUE = '''
84 #define RESULT(__v, __i) (variants[(__v)].in[(__i)].timing)
85 #define RESULT_ACCUM(r, v, i, old, new) \\
86 ((RESULT ((v), (i))) = (RESULT ((v), (i)) * (old) + (r)) / ((new) + 1))
87 #define BENCH_FUNC(i, j) ({%(getret)s CALL_BENCH_FUNC (i, j, );})
88 #define BENCH_FUNC_LAT(i, j) ({%(getret)s CALL_BENCH_FUNC (i, j, %(latarg)s);})
89 #define BENCH_VARS %(defvar)s
90 #define FUNCNAME "%(func)s"
91 #include "bench-skeleton.c"'''
92
93
94 def gen_source(func, directives, all_vals):
95 """Generate source for the function
96
97 Generate the C source for the function from the values and
98 directives.
99
100 Args:
101 func: The function name
102 directives: A dictionary of directives applicable to this function
103 all_vals: A dictionary input values
104 """
105 # The includes go in first.
106 for header in directives['includes']:
107 print('#include <%s>' % header)
108
109 for header in directives['include-sources']:
110 print('#include "%s"' % header)
111
112 # Print macros. This branches out to a separate routine if
113 # the function takes arguments.
114 if not directives['args']:
115 print(DEFINES_TEMPLATE % {'func': func})
116 outargs = []
117 else:
118 outargs = _print_arg_data(func, directives, all_vals)
119
120 # Print the output variable definitions if necessary.
121 for out in outargs:
122 print(out)
123
124 # If we have a return value from the function, make sure it is
125 # assigned to prevent the compiler from optimizing out the
126 # call.
127 getret = ''
128 latarg = ''
129 defvar = ''
130
131 if directives['ret']:
132 print('static %s volatile ret;' % directives['ret'])
133 print('static %s zero __attribute__((used)) = 0;' % directives['ret'])
134 getret = 'ret = func_res = '
135 # Note this may not work if argument and result type are incompatible.
136 latarg = 'func_res * zero +'
137 defvar = '%s func_res = 0;' % directives['ret']
138
139 # Test initialization.
140 if directives['init']:
141 print('#define BENCH_INIT %s' % directives['init'])
142
143 print(EPILOGUE % {'getret': getret, 'func': func, 'latarg': latarg, 'defvar': defvar })
144
145
146 def _print_arg_data(func, directives, all_vals):
147 """Print argument data
148
149 This is a helper function for gen_source that prints structure and
150 values for arguments and their variants and returns output arguments
151 if any are found.
152
153 Args:
154 func: Function name
155 directives: A dictionary of directives applicable to this function
156 all_vals: A dictionary input values
157
158 Returns:
159 Returns a list of definitions for function arguments that act as
160 output parameters.
161 """
162 # First, all of the definitions. We process writing of
163 # CALL_BENCH_FUNC, struct args and also the output arguments
164 # together in a single traversal of the arguments list.
165 func_args = []
166 arg_struct = []
167 outargs = []
168
169 for arg, i in zip(directives['args'], itertools.count()):
170 if arg[0] == '<' and arg[-1] == '>':
171 pos = arg.rfind('*')
172 if pos == -1:
173 die('Output argument must be a pointer type')
174
175 outargs.append('static %s out%d __attribute__((used));' % (arg[1:pos], i))
176 func_args.append(' &out%d' % i)
177 else:
178 arg_struct.append(' %s volatile arg%d;' % (arg, i))
179 func_args.append('variants[v].in[i].arg%d' % i)
180
181 print(STRUCT_TEMPLATE % {'args' : '\n'.join(arg_struct), 'func': func,
182 'func_args': ', '.join(func_args)})
183
184 # Now print the values.
185 variants = []
186 for (k, vals), i in zip(all_vals.items(), itertools.count()):
187 out = [' {%s, 0},' % v for v in vals]
188
189 # Members for the variants structure list that we will
190 # print later.
191 variants.append(' {"%s", %d, in%d},' % (k, len(vals), i))
192 print(ARGS_TEMPLATE % {'argnum': i, 'num_args': len(vals),
193 'args': '\n'.join(out)})
194
195 # Print the variants and the last set of macros.
196 print(VARIANTS_TEMPLATE % {'num_variants': len(all_vals),
197 'variants': '\n'.join(variants)})
198 return outargs
199
200
201 def _process_directive(d_name, d_val):
202 """Process a directive.
203
204 Evaluate the directive name and value passed and return the
205 processed value. This is a helper function for parse_file.
206
207 Args:
208 d_name: Name of the directive
209 d_val: The string value to process
210
211 Returns:
212 The processed value, which may be the string as it is or an object
213 that describes the directive.
214 """
215 # Process the directive values if necessary. name and ret don't
216 # need any processing.
217 if d_name.startswith('include'):
218 d_val = d_val.split(',')
219 elif d_name == 'args':
220 d_val = d_val.split(':')
221
222 # Return the values.
223 return d_val
224
225
226 def parse_file(func):
227 """Parse an input file
228
229 Given a function name, open and parse an input file for the function
230 and get the necessary parameters for the generated code and the list
231 of inputs.
232
233 Args:
234 func: The function name
235
236 Returns:
237 A tuple of two elements, one a dictionary of directives and the
238 other a dictionary of all input values.
239 """
240 all_vals = {}
241 # Valid directives.
242 directives = {
243 'name': '',
244 'args': [],
245 'includes': [],
246 'include-sources': [],
247 'ret': '',
248 'init': ''
249 }
250
251 try:
252 with open('%s-inputs' % func) as f:
253 for line in f:
254 # Look for directives and parse it if found.
255 if line.startswith('##'):
256 try:
257 d_name, d_val = line[2:].split(':', 1)
258 d_name = d_name.strip()
259 d_val = d_val.strip()
260 directives[d_name] = _process_directive(d_name, d_val)
261 except (IndexError, KeyError):
262 die('Invalid directive: %s' % line[2:])
263
264 # Skip blank lines and comments.
265 line = line.split('#', 1)[0].rstrip()
266 if not line:
267 continue
268
269 # Otherwise, we're an input. Add to the appropriate
270 # input set.
271 cur_name = directives['name']
272 all_vals.setdefault(cur_name, [])
273 all_vals[cur_name].append(line)
274 except IOError as ex:
275 die("Failed to open input file (%s): %s" % (ex.filename, ex.strerror))
276
277 return directives, all_vals
278
279
280 def die(msg):
281 """Exit with an error
282
283 Prints an error message to the standard error stream and exits with
284 a non-zero status.
285
286 Args:
287 msg: The error message to print to standard error
288 """
289 print('%s\n' % msg, file=sys.stderr)
290 sys.exit(os.EX_DATAERR)
291
292
293 def main(args):
294 """Main function
295
296 Use the first command line argument as function name and parse its
297 input file to generate C source that calls the function repeatedly
298 for the input.
299
300 Args:
301 args: The command line arguments with the program name dropped
302
303 Returns:
304 os.EX_USAGE on error and os.EX_OK on success.
305 """
306 if len(args) != 1:
307 print('Usage: %s <function>' % sys.argv[0])
308 return os.EX_USAGE
309
310 directives, all_vals = parse_file(args[0])
311 gen_source(args[0], directives, all_vals)
312 return os.EX_OK
313
314
315 if __name__ == '__main__':
316 sys.exit(main(sys.argv[1:]))