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