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