39be85f639e8372f64c238217dd8f160463661ca
[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 (('iand', 0xffff, ('ushr', a, 16)), ('ushr', a, 16)),
167 # Exponential/logarithmic identities
168 (('fexp2', ('flog2', a)), a), # 2^lg2(a) = a
169 (('flog2', ('fexp2', a)), a), # lg2(2^a) = a
170 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
171 (('fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
172 (('fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
173 ('fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
174 (('fpow', a, 1.0), a),
175 (('fpow', a, 2.0), ('fmul', a, a)),
176 (('fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
177 (('fpow', 2.0, a), ('fexp2', a)),
178 (('fpow', ('fpow', a, 2.2), 0.454545), a),
179 (('fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
180 (('fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
181 (('frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
182 (('frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
183 (('flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
184 (('flog2', ('frcp', a)), ('fneg', ('flog2', a))),
185 (('flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
186 (('flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
187 (('fadd', ('flog2', a), ('flog2', b)), ('flog2', ('fmul', a, b))),
188 (('fadd', ('flog2', a), ('fneg', ('flog2', b))), ('flog2', ('fdiv', a, b))),
189 (('fmul', ('fexp2', a), ('fexp2', b)), ('fexp2', ('fadd', a, b))),
190 # Division and reciprocal
191 (('fdiv', 1.0, a), ('frcp', a)),
192 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
193 (('frcp', ('frcp', a)), a),
194 (('frcp', ('fsqrt', a)), ('frsq', a)),
195 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
196 (('frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
197 # Boolean simplifications
198 (('ieq', 'a@bool', True), a),
199 (('ine', 'a@bool', True), ('inot', a)),
200 (('ine', 'a@bool', False), a),
201 (('ieq', 'a@bool', False), ('inot', 'a')),
202 (('bcsel', a, True, False), ('ine', a, 0)),
203 (('bcsel', a, False, True), ('ieq', a, 0)),
204 (('bcsel', True, b, c), b),
205 (('bcsel', False, b, c), c),
206 # The result of this should be hit by constant propagation and, in the
207 # next round of opt_algebraic, get picked up by one of the above two.
208 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
209
210 (('bcsel', a, b, b), b),
211 (('fcsel', a, b, b), b),
212
213 # Conversions
214 (('i2b', ('b2i', a)), a),
215 (('f2i', ('ftrunc', a)), ('f2i', a)),
216 (('f2u', ('ftrunc', a)), ('f2u', a)),
217
218 # Byte extraction
219 (('ushr', a, 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
220 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
221 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
222 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
223
224 # Word extraction
225 (('ushr', a, 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
226 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
227
228 # Subtracts
229 (('fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
230 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
231 (('ussub_4x8', a, 0), a),
232 (('ussub_4x8', a, ~0), 0),
233 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
234 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
235 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
236 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
237 (('fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
238 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
239 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
240 (('iabs', ('isub', 0, a)), ('iabs', a)),
241
242 # Misc. lowering
243 (('fmod', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'),
244 (('uadd_carry', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
245 (('usub_borrow', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
246
247 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
248 ('bcsel', ('ilt', 31, 'bits'), 'insert',
249 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
250 'options->lower_bitfield_insert'),
251
252 (('ibitfield_extract', 'value', 'offset', 'bits'),
253 ('bcsel', ('ilt', 31, 'bits'), 'value',
254 ('ibfe', 'value', 'offset', 'bits')),
255 'options->lower_bitfield_extract'),
256
257 (('ubitfield_extract', 'value', 'offset', 'bits'),
258 ('bcsel', ('ult', 31, 'bits'), 'value',
259 ('ubfe', 'value', 'offset', 'bits')),
260 'options->lower_bitfield_extract'),
261
262 (('extract_i8', a, b),
263 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
264 'options->lower_extract_byte'),
265
266 (('extract_u8', a, b),
267 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
268 'options->lower_extract_byte'),
269
270 (('extract_i16', a, b),
271 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
272 'options->lower_extract_word'),
273
274 (('extract_u16', a, b),
275 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
276 'options->lower_extract_word'),
277
278 (('pack_unorm_2x16', 'v'),
279 ('pack_uvec2_to_uint',
280 ('f2u', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
281 'options->lower_pack_unorm_2x16'),
282
283 (('pack_unorm_4x8', 'v'),
284 ('pack_uvec4_to_uint',
285 ('f2u', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
286 'options->lower_pack_unorm_4x8'),
287
288 (('pack_snorm_2x16', 'v'),
289 ('pack_uvec2_to_uint',
290 ('f2i', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
291 'options->lower_pack_snorm_2x16'),
292
293 (('pack_snorm_4x8', 'v'),
294 ('pack_uvec4_to_uint',
295 ('f2i', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
296 'options->lower_pack_snorm_4x8'),
297
298 (('unpack_unorm_2x16', 'v'),
299 ('fdiv', ('u2f', ('vec2', ('extract_u16', 'v', 0),
300 ('extract_u16', 'v', 1))),
301 65535.0),
302 'options->lower_unpack_unorm_2x16'),
303
304 (('unpack_unorm_4x8', 'v'),
305 ('fdiv', ('u2f', ('vec4', ('extract_u8', 'v', 0),
306 ('extract_u8', 'v', 1),
307 ('extract_u8', 'v', 2),
308 ('extract_u8', 'v', 3))),
309 255.0),
310 'options->lower_unpack_unorm_4x8'),
311
312 (('unpack_snorm_2x16', 'v'),
313 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
314 ('extract_i16', 'v', 1))),
315 32767.0))),
316 'options->lower_unpack_snorm_2x16'),
317
318 (('unpack_snorm_4x8', 'v'),
319 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
320 ('extract_i8', 'v', 1),
321 ('extract_i8', 'v', 2),
322 ('extract_i8', 'v', 3))),
323 127.0))),
324 'options->lower_unpack_snorm_4x8'),
325 ]
326
327 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
328 def bitfield_reverse(u):
329 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
330 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
331 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
332 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
333 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
334
335 return step5
336
337 optimizations += [(bitfield_reverse('x'), ('bitfield_reverse', 'x'))]
338
339
340 # Add optimizations to handle the case where the result of a ternary is
341 # compared to a constant. This way we can take things like
342 #
343 # (a ? 0 : 1) > 0
344 #
345 # and turn it into
346 #
347 # a ? (0 > 0) : (1 > 0)
348 #
349 # which constant folding will eat for lunch. The resulting ternary will
350 # further get cleaned up by the boolean reductions above and we will be
351 # left with just the original variable "a".
352 for op in ['flt', 'fge', 'feq', 'fne',
353 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
354 optimizations += [
355 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
356 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
357 ((op, '#d', ('bcsel', a, '#b', '#c')),
358 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
359 ]
360
361 # This section contains "late" optimizations that should be run after the
362 # regular optimizations have finished. Optimizations should go here if
363 # they help code generation but do not necessarily produce code that is
364 # more easily optimizable.
365 late_optimizations = [
366 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
367 (('fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
368 (('feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
369 (('fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
370 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
371 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
372 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
373 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
374 ]
375
376 print nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render()
377 print nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
378 late_optimizations).render()