dd26805e1a87aafe6c4a0de6f2a64c760180c553
[mesa.git] / src / compiler / nir / nir_opt_algebraic.py
1 #! /usr/bin/env python
2 #
3 # Copyright (C) 2014 Intel Corporation
4 #
5 # Permission is hereby granted, free of charge, to any person obtaining a
6 # copy of this software and associated documentation files (the "Software"),
7 # to deal in the Software without restriction, including without limitation
8 # the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 # and/or sell copies of the Software, and to permit persons to whom the
10 # Software is furnished to do so, subject to the following conditions:
11 #
12 # The above copyright notice and this permission notice (including the next
13 # paragraph) shall be included in all copies or substantial portions of the
14 # Software.
15 #
16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 # IN THE SOFTWARE.
23 #
24 # Authors:
25 # Jason Ekstrand (jason@jlekstrand.net)
26
27 import nir_algebraic
28
29 # Convenience variables
30 a = 'a'
31 b = 'b'
32 c = 'c'
33 d = 'd'
34
35 # Written in the form (<search>, <replace>) where <search> is an expression
36 # and <replace> is either an expression or a value. An expression is
37 # defined as a tuple of the form (<op>, <src0>, <src1>, <src2>, <src3>)
38 # where each source is either an expression or a value. A value can be
39 # either a numeric constant or a string representing a variable name.
40 #
41 # Variable names are specified as "[#]name[@type]" where "#" inicates that
42 # the given variable will only match constants and the type indicates that
43 # the given variable will only match values from ALU instructions with the
44 # given output type.
45 #
46 # For constants, you have to be careful to make sure that it is the right
47 # type because python is unaware of the source and destination types of the
48 # opcodes.
49
50 optimizations = [
51 (('fneg', ('fneg', a)), a),
52 (('ineg', ('ineg', a)), a),
53 (('fabs', ('fabs', a)), ('fabs', a)),
54 (('fabs', ('fneg', a)), ('fabs', a)),
55 (('iabs', ('iabs', a)), ('iabs', a)),
56 (('iabs', ('ineg', a)), ('iabs', a)),
57 (('fadd', a, 0.0), a),
58 (('iadd', a, 0), a),
59 (('usadd_4x8', a, 0), a),
60 (('usadd_4x8', a, ~0), ~0),
61 (('fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
62 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
63 (('fadd', ('fneg', a), a), 0.0),
64 (('iadd', ('ineg', a), a), 0),
65 (('iadd', ('ineg', a), ('iadd', a, b)), b),
66 (('iadd', a, ('iadd', ('ineg', a), b)), b),
67 (('fadd', ('fneg', a), ('fadd', a, b)), b),
68 (('fadd', a, ('fadd', ('fneg', a), b)), b),
69 (('fmul', a, 0.0), 0.0),
70 (('imul', a, 0), 0),
71 (('umul_unorm_4x8', a, 0), 0),
72 (('umul_unorm_4x8', a, ~0), a),
73 (('fmul', a, 1.0), a),
74 (('imul', a, 1), a),
75 (('fmul', a, -1.0), ('fneg', a)),
76 (('imul', a, -1), ('ineg', a)),
77 (('ffma', 0.0, a, b), b),
78 (('ffma', a, 0.0, b), b),
79 (('ffma', a, b, 0.0), ('fmul', a, b)),
80 (('ffma', a, 1.0, b), ('fadd', a, b)),
81 (('ffma', 1.0, a, b), ('fadd', a, b)),
82 (('flrp', a, b, 0.0), a),
83 (('flrp', a, b, 1.0), b),
84 (('flrp', a, a, b), a),
85 (('flrp', 0.0, a, b), ('fmul', a, b)),
86 (('flrp', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp'),
87 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
88 (('fadd', ('fmul', a, ('fadd', 1.0, ('fneg', c))), ('fmul', b, c)), ('flrp', a, b, c), '!options->lower_flrp'),
89 (('fadd', a, ('fmul', c, ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp'),
90 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
91 (('fadd', ('fmul', a, b), c), ('ffma', a, b, c), '!options->lower_ffma'),
92 # Comparison simplifications
93 (('inot', ('flt', a, b)), ('fge', a, b)),
94 (('inot', ('fge', a, b)), ('flt', a, b)),
95 (('inot', ('feq', a, b)), ('fne', a, b)),
96 (('inot', ('fne', a, b)), ('feq', a, b)),
97 (('inot', ('ilt', a, b)), ('ige', a, b)),
98 (('inot', ('ige', a, b)), ('ilt', a, b)),
99 (('inot', ('ieq', a, b)), ('ine', a, b)),
100 (('inot', ('ine', a, b)), ('ieq', a, b)),
101 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
102 (('bcsel', ('flt', a, b), a, b), ('fmin', a, b)),
103 (('bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
104 (('bcsel', ('inot', 'a@bool'), b, c), ('bcsel', a, c, b)),
105 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
106 (('fmin', a, a), a),
107 (('fmax', a, a), a),
108 (('imin', a, a), a),
109 (('imax', a, a), a),
110 (('umin', a, a), a),
111 (('umax', a, a), a),
112 (('fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
113 (('fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
114 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
115 (('fsat', ('fsat', a)), ('fsat', a)),
116 (('fmin', ('fmax', ('fmin', ('fmax', a, 0.0), 1.0), 0.0), 1.0), ('fmin', ('fmax', a, 0.0), 1.0)),
117 (('ior', ('flt', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
118 (('ior', ('flt', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
119 (('ior', ('fge', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
120 (('ior', ('fge', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
121 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
122 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
123 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
124 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
125 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
126 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
127 # Emulating booleans
128 (('imul', ('b2i', a), ('b2i', b)), ('b2i', ('iand', a, b))),
129 (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))),
130 (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))),
131 (('iand', 'a@bool', 1.0), ('b2f', a)),
132 (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
133 (('flt', ('fsub', 0.0, ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
134 # Comparison with the same args. Note that these are not done for
135 # the float versions because NaN always returns false on float
136 # inequalities.
137 (('ilt', a, a), False),
138 (('ige', a, a), True),
139 (('ieq', a, a), True),
140 (('ine', a, a), False),
141 (('ult', a, a), False),
142 (('uge', a, a), True),
143 # Logical and bit operations
144 (('fand', a, 0.0), 0.0),
145 (('iand', a, a), a),
146 (('iand', a, ~0), a),
147 (('iand', a, 0), 0),
148 (('ior', a, a), a),
149 (('ior', a, 0), a),
150 (('fxor', a, a), 0.0),
151 (('ixor', a, a), 0),
152 (('fxor', a, 0.0), a),
153 (('ixor', a, 0), a),
154 (('inot', ('inot', a)), a),
155 # DeMorgan's Laws
156 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
157 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
158 # Shift optimizations
159 (('ishl', 0, a), 0),
160 (('ishl', a, 0), a),
161 (('ishr', 0, a), 0),
162 (('ishr', a, 0), a),
163 (('ushr', 0, a), 0),
164 (('ushr', a, 0), a),
165 (('iand', 0xff, ('ushr', a, 24)), ('ushr', a, 24)),
166 # Exponential/logarithmic identities
167 (('fexp2', ('flog2', a)), a), # 2^lg2(a) = a
168 (('flog2', ('fexp2', a)), a), # lg2(2^a) = a
169 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
170 (('fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
171 (('fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
172 ('fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
173 (('fpow', a, 1.0), a),
174 (('fpow', a, 2.0), ('fmul', a, a)),
175 (('fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
176 (('fpow', 2.0, a), ('fexp2', a)),
177 (('fpow', ('fpow', a, 2.2), 0.454545), a),
178 (('fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
179 (('fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
180 (('frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
181 (('frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
182 (('flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
183 (('flog2', ('frcp', a)), ('fneg', ('flog2', a))),
184 (('flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
185 (('flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
186 (('fadd', ('flog2', a), ('flog2', b)), ('flog2', ('fmul', a, b))),
187 (('fadd', ('flog2', a), ('fneg', ('flog2', b))), ('flog2', ('fdiv', a, b))),
188 (('fmul', ('fexp2', a), ('fexp2', b)), ('fexp2', ('fadd', a, b))),
189 # Division and reciprocal
190 (('fdiv', 1.0, a), ('frcp', a)),
191 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
192 (('frcp', ('frcp', a)), a),
193 (('frcp', ('fsqrt', a)), ('frsq', a)),
194 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
195 (('frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
196 # Boolean simplifications
197 (('ieq', 'a@bool', True), a),
198 (('ine', 'a@bool', True), ('inot', a)),
199 (('ine', 'a@bool', False), a),
200 (('ieq', 'a@bool', False), ('inot', 'a')),
201 (('bcsel', a, True, False), ('ine', a, 0)),
202 (('bcsel', a, False, True), ('ieq', a, 0)),
203 (('bcsel', True, b, c), b),
204 (('bcsel', False, b, c), c),
205 # The result of this should be hit by constant propagation and, in the
206 # next round of opt_algebraic, get picked up by one of the above two.
207 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
208
209 (('bcsel', a, b, b), b),
210 (('fcsel', a, b, b), b),
211
212 # Conversions
213 (('i2b', ('b2i', a)), a),
214 (('f2i', ('ftrunc', a)), ('f2i', a)),
215 (('f2u', ('ftrunc', a)), ('f2u', a)),
216
217 # Byte extraction
218 (('ushr', a, 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
219 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
220 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
221 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
222
223 # Subtracts
224 (('fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
225 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
226 (('ussub_4x8', a, 0), a),
227 (('ussub_4x8', a, ~0), 0),
228 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
229 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
230 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
231 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
232 (('fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
233 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
234 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
235 (('iabs', ('isub', 0, a)), ('iabs', a)),
236
237 # Misc. lowering
238 (('fmod', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'),
239 (('uadd_carry', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
240 (('usub_borrow', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
241
242 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
243 ('bcsel', ('ilt', 31, 'bits'), 'insert',
244 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
245 'options->lower_bitfield_insert'),
246
247 (('ibitfield_extract', 'value', 'offset', 'bits'),
248 ('bcsel', ('ilt', 31, 'bits'), 'value',
249 ('ibfe', 'value', 'offset', 'bits')),
250 'options->lower_bitfield_extract'),
251
252 (('ubitfield_extract', 'value', 'offset', 'bits'),
253 ('bcsel', ('ult', 31, 'bits'), 'value',
254 ('ubfe', 'value', 'offset', 'bits')),
255 'options->lower_bitfield_extract'),
256
257 (('extract_i8', a, b),
258 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
259 'options->lower_extract_byte'),
260
261 (('extract_u8', a, b),
262 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
263 'options->lower_extract_byte'),
264
265 (('extract_i16', a, b),
266 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
267 'options->lower_extract_word'),
268
269 (('extract_u16', a, b),
270 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
271 'options->lower_extract_word'),
272
273 (('pack_unorm_2x16', 'v'),
274 ('pack_uvec2_to_uint',
275 ('f2u', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
276 'options->lower_pack_unorm_2x16'),
277
278 (('pack_unorm_4x8', 'v'),
279 ('pack_uvec4_to_uint',
280 ('f2u', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
281 'options->lower_pack_unorm_4x8'),
282
283 (('pack_snorm_2x16', 'v'),
284 ('pack_uvec2_to_uint',
285 ('f2i', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
286 'options->lower_pack_snorm_2x16'),
287
288 (('pack_snorm_4x8', 'v'),
289 ('pack_uvec4_to_uint',
290 ('f2i', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
291 'options->lower_pack_snorm_4x8'),
292
293 (('unpack_unorm_2x16', 'v'),
294 ('fdiv', ('u2f', ('vec2', ('extract_u16', 'v', 0),
295 ('extract_u16', 'v', 1))),
296 65535.0),
297 'options->lower_unpack_unorm_2x16'),
298
299 (('unpack_unorm_4x8', 'v'),
300 ('fdiv', ('u2f', ('vec4', ('extract_u8', 'v', 0),
301 ('extract_u8', 'v', 1),
302 ('extract_u8', 'v', 2),
303 ('extract_u8', 'v', 3))),
304 255.0),
305 'options->lower_unpack_unorm_4x8'),
306
307 (('unpack_snorm_2x16', 'v'),
308 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
309 ('extract_i16', 'v', 1))),
310 32767.0))),
311 'options->lower_unpack_snorm_2x16'),
312
313 (('unpack_snorm_4x8', 'v'),
314 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
315 ('extract_i8', 'v', 1),
316 ('extract_i8', 'v', 2),
317 ('extract_i8', 'v', 3))),
318 127.0))),
319 'options->lower_unpack_snorm_4x8'),
320 ]
321
322 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
323 def bitfield_reverse(u):
324 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
325 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
326 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
327 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
328 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
329
330 return step5
331
332 optimizations += [(bitfield_reverse('x'), ('bitfield_reverse', 'x'))]
333
334
335 # Add optimizations to handle the case where the result of a ternary is
336 # compared to a constant. This way we can take things like
337 #
338 # (a ? 0 : 1) > 0
339 #
340 # and turn it into
341 #
342 # a ? (0 > 0) : (1 > 0)
343 #
344 # which constant folding will eat for lunch. The resulting ternary will
345 # further get cleaned up by the boolean reductions above and we will be
346 # left with just the original variable "a".
347 for op in ['flt', 'fge', 'feq', 'fne',
348 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
349 optimizations += [
350 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
351 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
352 ((op, '#d', ('bcsel', a, '#b', '#c')),
353 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
354 ]
355
356 # This section contains "late" optimizations that should be run after the
357 # regular optimizations have finished. Optimizations should go here if
358 # they help code generation but do not necessarily produce code that is
359 # more easily optimizable.
360 late_optimizations = [
361 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
362 (('fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
363 (('feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
364 (('fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
365 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
366 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
367 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
368 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
369 ]
370
371 print nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render()
372 print nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
373 late_optimizations).render()