c482bde8b3bbead39696ae4818693c123e4b81f2
[mesa.git] / src / compiler / nir / nir_opt_algebraic.py
1 #
2 # Copyright (C) 2014 Intel Corporation
3 #
4 # Permission is hereby granted, free of charge, to any person obtaining a
5 # copy of this software and associated documentation files (the "Software"),
6 # to deal in the Software without restriction, including without limitation
7 # the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 # and/or sell copies of the Software, and to permit persons to whom the
9 # Software is furnished to do so, subject to the following conditions:
10 #
11 # The above copyright notice and this permission notice (including the next
12 # paragraph) shall be included in all copies or substantial portions of the
13 # Software.
14 #
15 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 # IN THE SOFTWARE.
22 #
23 # Authors:
24 # Jason Ekstrand (jason@jlekstrand.net)
25
26 from __future__ import print_function
27
28 from collections import OrderedDict
29 import nir_algebraic
30 import itertools
31
32 # Convenience variables
33 a = 'a'
34 b = 'b'
35 c = 'c'
36 d = 'd'
37
38 # Written in the form (<search>, <replace>) where <search> is an expression
39 # and <replace> is either an expression or a value. An expression is
40 # defined as a tuple of the form ([~]<op>, <src0>, <src1>, <src2>, <src3>)
41 # where each source is either an expression or a value. A value can be
42 # either a numeric constant or a string representing a variable name.
43 #
44 # If the opcode in a search expression is prefixed by a '~' character, this
45 # indicates that the operation is inexact. Such operations will only get
46 # applied to SSA values that do not have the exact bit set. This should be
47 # used by by any optimizations that are not bit-for-bit exact. It should not,
48 # however, be used for backend-requested lowering operations as those need to
49 # happen regardless of precision.
50 #
51 # Variable names are specified as "[#]name[@type][(cond)]" where "#" inicates
52 # that the given variable will only match constants and the type indicates that
53 # the given variable will only match values from ALU instructions with the
54 # given output type, and (cond) specifies an additional condition function
55 # (see nir_search_helpers.h).
56 #
57 # For constants, you have to be careful to make sure that it is the right
58 # type because python is unaware of the source and destination types of the
59 # opcodes.
60 #
61 # All expression types can have a bit-size specified. For opcodes, this
62 # looks like "op@32", for variables it is "a@32" or "a@uint32" to specify a
63 # type and size, and for literals, you can write "2.0@32". In the search half
64 # of the expression this indicates that it should only match that particular
65 # bit-size. In the replace half of the expression this indicates that the
66 # constructed value should have that bit-size.
67
68 optimizations = [
69
70 (('imul', a, '#b@32(is_pos_power_of_two)'), ('ishl', a, ('find_lsb', b))),
71 (('imul', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('ishl', a, ('find_lsb', ('iabs', b))))),
72 (('udiv', a, 1), a),
73 (('idiv', a, 1), a),
74 (('umod', a, 1), 0),
75 (('imod', a, 1), 0),
76 (('udiv', a, '#b@32(is_pos_power_of_two)'), ('ushr', a, ('find_lsb', b))),
77 (('idiv', a, '#b@32(is_pos_power_of_two)'), ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', b))), 'options->lower_idiv'),
78 (('idiv', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', ('iabs', b))))), 'options->lower_idiv'),
79 (('umod', a, '#b(is_pos_power_of_two)'), ('iand', a, ('isub', b, 1))),
80
81 (('fneg', ('fneg', a)), a),
82 (('ineg', ('ineg', a)), a),
83 (('fabs', ('fabs', a)), ('fabs', a)),
84 (('fabs', ('fneg', a)), ('fabs', a)),
85 (('fabs', ('u2f', a)), ('u2f', a)),
86 (('iabs', ('iabs', a)), ('iabs', a)),
87 (('iabs', ('ineg', a)), ('iabs', a)),
88 (('~fadd', a, 0.0), a),
89 (('iadd', a, 0), a),
90 (('usadd_4x8', a, 0), a),
91 (('usadd_4x8', a, ~0), ~0),
92 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
93 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
94 (('~fadd', ('fneg', a), a), 0.0),
95 (('iadd', ('ineg', a), a), 0),
96 (('iadd', ('ineg', a), ('iadd', a, b)), b),
97 (('iadd', a, ('iadd', ('ineg', a), b)), b),
98 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
99 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
100 (('~fmul', a, 0.0), 0.0),
101 (('imul', a, 0), 0),
102 (('umul_unorm_4x8', a, 0), 0),
103 (('umul_unorm_4x8', a, ~0), a),
104 (('fmul', a, 1.0), a),
105 (('imul', a, 1), a),
106 (('fmul', a, -1.0), ('fneg', a)),
107 (('imul', a, -1), ('ineg', a)),
108 # If a < 0: fsign(a)*a*a => -1*a*a => -a*a => abs(a)*a
109 # If a > 0: fsign(a)*a*a => 1*a*a => a*a => abs(a)*a
110 # If a == 0: fsign(a)*a*a => 0*0*0 => abs(0)*0
111 (('fmul', ('fsign', a), ('fmul', a, a)), ('fmul', ('fabs', a), a)),
112 (('fmul', ('fmul', ('fsign', a), a), a), ('fmul', ('fabs', a), a)),
113 (('~ffma', 0.0, a, b), b),
114 (('~ffma', a, 0.0, b), b),
115 (('~ffma', a, b, 0.0), ('fmul', a, b)),
116 (('ffma', a, 1.0, b), ('fadd', a, b)),
117 (('ffma', 1.0, a, b), ('fadd', a, b)),
118 (('~flrp', a, b, 0.0), a),
119 (('~flrp', a, b, 1.0), b),
120 (('~flrp', a, a, b), a),
121 (('~flrp', 0.0, a, b), ('fmul', a, b)),
122 (('~flrp', a, b, ('b2f', c)), ('bcsel', c, b, a), 'options->lower_flrp32'),
123 (('~flrp', a, 0.0, c), ('fadd', ('fmul', ('fneg', a), c), a)),
124 (('flrp@32', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp32'),
125 (('flrp@64', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp64'),
126 (('ffloor', a), ('fsub', a, ('ffract', a)), 'options->lower_ffloor'),
127 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
128 (('fceil', a), ('fneg', ('ffloor', ('fneg', a))), 'options->lower_fceil'),
129 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', c)))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'),
130 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'),
131 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'),
132 (('~fadd', a, ('fmul', ('b2f', c), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'),
133 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'),
134 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'),
135 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
136 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'),
137
138 (('fdot4', ('vec4', a, b, c, 1.0), d), ('fdph', ('vec3', a, b, c), d)),
139 (('fdot4', ('vec4', a, 0.0, 0.0, 0.0), b), ('fmul', a, b)),
140 (('fdot4', ('vec4', a, b, 0.0, 0.0), c), ('fdot2', ('vec2', a, b), c)),
141 (('fdot4', ('vec4', a, b, c, 0.0), d), ('fdot3', ('vec3', a, b, c), d)),
142
143 (('fdot3', ('vec3', a, 0.0, 0.0), b), ('fmul', a, b)),
144 (('fdot3', ('vec3', a, b, 0.0), c), ('fdot2', ('vec2', a, b), c)),
145
146 # (a * #b + #c) << #d
147 # ((a * #b) << #d) + (#c << #d)
148 # (a * (#b << #d)) + (#c << #d)
149 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'),
150 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))),
151
152 # (a * #b) << #c
153 # a * (#b << #c)
154 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))),
155
156 # Comparison simplifications
157 (('~inot', ('flt', a, b)), ('fge', a, b)),
158 (('~inot', ('fge', a, b)), ('flt', a, b)),
159 (('~inot', ('feq', a, b)), ('fne', a, b)),
160 (('~inot', ('fne', a, b)), ('feq', a, b)),
161 (('inot', ('ilt', a, b)), ('ige', a, b)),
162 (('inot', ('ult', a, b)), ('uge', a, b)),
163 (('inot', ('ige', a, b)), ('ilt', a, b)),
164 (('inot', ('uge', a, b)), ('ult', a, b)),
165 (('inot', ('ieq', a, b)), ('ine', a, b)),
166 (('inot', ('ine', a, b)), ('ieq', a, b)),
167
168 # 0.0 >= b2f(a)
169 # b2f(a) <= 0.0
170 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1
171 # inot(a)
172 (('fge', 0.0, ('b2f', a)), ('inot', a)),
173
174 (('fge', ('fneg', ('b2f', a)), 0.0), ('inot', a)),
175
176 (('fne', ('fadd', ('b2f', a), ('b2f', b)), 0.0), ('ior', a, b)),
177 (('fne', ('fmax', ('b2f', a), ('b2f', b)), 0.0), ('ior', a, b)),
178 (('fne', ('bcsel', a, 1.0, ('b2f', b)) , 0.0), ('ior', a, b)),
179 (('fne', ('b2f', a), ('fneg', ('b2f', b))), ('ior', a, b)),
180 (('fne', ('fmul', ('b2f', a), ('b2f', b)), 0.0), ('iand', a, b)),
181 (('fne', ('fmin', ('b2f', a), ('b2f', b)), 0.0), ('iand', a, b)),
182 (('fne', ('bcsel', a, ('b2f', b), 0.0) , 0.0), ('iand', a, b)),
183 (('fne', ('fadd', ('b2f', a), ('fneg', ('b2f', b))), 0.0), ('ixor', a, b)),
184 (('fne', ('b2f', a) , ('b2f', b) ), ('ixor', a, b)),
185 (('fne', ('fneg', ('b2f', a)), ('fneg', ('b2f', b))), ('ixor', a, b)),
186 (('feq', ('fadd', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('ior', a, b))),
187 (('feq', ('fmax', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('ior', a, b))),
188 (('feq', ('bcsel', a, 1.0, ('b2f', b)) , 0.0), ('inot', ('ior', a, b))),
189 (('feq', ('b2f', a), ('fneg', ('b2f', b))), ('inot', ('ior', a, b))),
190 (('feq', ('fmul', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('iand', a, b))),
191 (('feq', ('fmin', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('iand', a, b))),
192 (('feq', ('bcsel', a, ('b2f', b), 0.0) , 0.0), ('inot', ('iand', a, b))),
193 (('feq', ('fadd', ('b2f', a), ('fneg', ('b2f', b))), 0.0), ('ieq', a, b)),
194 (('feq', ('b2f', a) , ('b2f', b) ), ('ieq', a, b)),
195 (('feq', ('fneg', ('b2f', a)), ('fneg', ('b2f', b))), ('ieq', a, b)),
196
197 # -(b2f(a) + b2f(b)) < 0
198 # 0 < b2f(a) + b2f(b)
199 # 0 != b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
200 # a || b
201 (('flt', ('fneg', ('fadd', ('b2f', a), ('b2f', b))), 0.0), ('ior', a, b)),
202 (('flt', 0.0, ('fadd', ('b2f', a), ('b2f', b))), ('ior', a, b)),
203
204 # -(b2f(a) + b2f(b)) >= 0
205 # 0 >= b2f(a) + b2f(b)
206 # 0 == b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
207 # !(a || b)
208 (('fge', ('fneg', ('fadd', ('b2f', a), ('b2f', b))), 0.0), ('inot', ('ior', a, b))),
209 (('fge', 0.0, ('fadd', ('b2f', a), ('b2f', b))), ('inot', ('ior', a, b))),
210
211 # Some optimizations (below) convert things like (a < b || c < b) into
212 # (min(a, c) < b). However, this interfers with the previous optimizations
213 # that try to remove comparisons with negated sums of b2f. This just
214 # breaks that apart.
215 (('flt', ('fmin', c, ('fneg', ('fadd', ('b2f', a), ('b2f', b)))), 0.0),
216 ('ior', ('flt', c, 0.0), ('ior', a, b))),
217
218 (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)),
219 (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)),
220 (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)),
221 (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)),
222
223 # Cannot remove the addition from ilt or ige due to overflow.
224 (('ieq', ('iadd', a, b), a), ('ieq', b, 0)),
225 (('ine', ('iadd', a, b), a), ('ine', b, 0)),
226
227 # fmin(-b2f(a), b) >= 0.0
228 # -b2f(a) >= 0.0 && b >= 0.0
229 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0
230 # b2f(a) == 0.0 && b >= 0.0
231 # a == False && b >= 0.0
232 # !a && b >= 0.0
233 #
234 # The fge in the second replacement is not a typo. I leave the proof that
235 # "fmin(-b2f(a), b) >= 0 <=> fmin(-b2f(a), b) == 0" as an exercise for the
236 # reader.
237 (('fge', ('fmin', ('fneg', ('b2f', a)), b), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
238 (('feq', ('fmin', ('fneg', ('b2f', a)), b), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
239
240 (('feq', ('b2f', a), 0.0), ('inot', a)),
241 (('fne', ('b2f', a), 0.0), a),
242 (('ieq', ('b2i', a), 0), ('inot', a)),
243 (('ine', ('b2i', a), 0), a),
244
245 (('fne', ('u2f', a), 0.0), ('ine', a, 0)),
246 (('feq', ('u2f', a), 0.0), ('ieq', a, 0)),
247 (('fge', ('u2f', a), 0.0), True),
248 (('fge', 0.0, ('u2f', a)), ('uge', 0, a)), # ieq instead?
249 (('flt', ('u2f', a), 0.0), False),
250 (('flt', 0.0, ('u2f', a)), ('ult', 0, a)), # ine instead?
251 (('fne', ('i2f', a), 0.0), ('ine', a, 0)),
252 (('feq', ('i2f', a), 0.0), ('ieq', a, 0)),
253 (('fge', ('i2f', a), 0.0), ('ige', a, 0)),
254 (('fge', 0.0, ('i2f', a)), ('ige', 0, a)),
255 (('flt', ('i2f', a), 0.0), ('ilt', a, 0)),
256 (('flt', 0.0, ('i2f', a)), ('ilt', 0, a)),
257
258 # 0.0 < fabs(a)
259 # fabs(a) > 0.0
260 # fabs(a) != 0.0 because fabs(a) must be >= 0
261 # a != 0.0
262 (('~flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
263
264 # -fabs(a) < 0.0
265 # fabs(a) > 0.0
266 (('~flt', ('fneg', ('fabs', a)), 0.0), ('fne', a, 0.0)),
267
268 # 0.0 >= fabs(a)
269 # 0.0 == fabs(a) because fabs(a) must be >= 0
270 # 0.0 == a
271 (('fge', 0.0, ('fabs', a)), ('feq', a, 0.0)),
272
273 # -fabs(a) >= 0.0
274 # 0.0 >= fabs(a)
275 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
276
277 (('fmax', ('b2f(is_used_once)', a), ('b2f', b)), ('b2f', ('ior', a, b))),
278 (('fmax', ('fneg(is_used_once)', ('b2f(is_used_once)', a)), ('fneg', ('b2f', b))), ('fneg', ('b2f', ('ior', a, b)))),
279 (('fmin', ('b2f(is_used_once)', a), ('b2f', b)), ('b2f', ('iand', a, b))),
280 (('fmin', ('fneg(is_used_once)', ('b2f(is_used_once)', a)), ('fneg', ('b2f', b))), ('fneg', ('b2f', ('iand', a, b)))),
281
282 # fmin(b2f(a), b)
283 # bcsel(a, fmin(b2f(a), b), fmin(b2f(a), b))
284 # bcsel(a, fmin(b2f(True), b), fmin(b2f(False), b))
285 # bcsel(a, fmin(1.0, b), fmin(0.0, b))
286 #
287 # Since b is a constant, constant folding will eliminate the fmin and the
288 # fmax. If b is > 1.0, the bcsel will be replaced with a b2f.
289 (('fmin', ('b2f', a), '#b'), ('bcsel', a, ('fmin', b, 1.0), ('fmin', b, 0.0))),
290
291 (('flt', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
292
293 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
294 (('~bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
295 (('~bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
296 (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)),
297 (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)),
298 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)),
299 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
300 (('bcsel', a, b, ('bcsel', a, c, d)), ('bcsel', a, b, d)),
301 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
302 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
303 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
304 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
305 (('bcsel', a, True, 'b@bool'), ('ior', a, b)),
306 (('fmin', a, a), a),
307 (('fmax', a, a), a),
308 (('imin', a, a), a),
309 (('imax', a, a), a),
310 (('umin', a, a), a),
311 (('umax', a, a), a),
312 (('fmax', ('fmax', a, b), b), ('fmax', a, b)),
313 (('umax', ('umax', a, b), b), ('umax', a, b)),
314 (('imax', ('imax', a, b), b), ('imax', a, b)),
315 (('fmin', ('fmin', a, b), b), ('fmin', a, b)),
316 (('umin', ('umin', a, b), b), ('umin', a, b)),
317 (('imin', ('imin', a, b), b), ('imin', a, b)),
318 (('fmax', a, ('fneg', a)), ('fabs', a)),
319 (('imax', a, ('ineg', a)), ('iabs', a)),
320 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))),
321 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))),
322 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))),
323 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))),
324 (('fmin', a, ('fabs', a)), a),
325 (('imin', a, ('iabs', a)), a),
326 (('fmax', a, ('fneg', ('fabs', a))), a),
327 (('imax', a, ('ineg', ('iabs', a))), a),
328 (('fmax', a, ('fabs', a)), ('fabs', a)),
329 (('imax', a, ('iabs', a)), ('iabs', a)),
330 (('fmax', a, ('fneg', a)), ('fabs', a)),
331 (('imax', a, ('ineg', a)), ('iabs', a)),
332 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
333 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
334 (('fsat', ('fsign', a)), ('b2f', ('flt', 0.0, a))),
335 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
336 (('fsat', ('fsat', a)), ('fsat', a)),
337 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)),
338 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)),
339 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)),
340 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))),
341 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))),
342 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
343 (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
344 (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
345 (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
346 (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
347 (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
348 (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
349 (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
350 (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
351 (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
352 (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
353 (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
354 (('~iand', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmin', a, b), c)),
355 (('~iand', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmin', b, c))),
356 (('~iand', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmax', a, b), c)),
357 (('~iand', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmax', b, c))),
358 (('~iand', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmin', a, b), c)),
359
360 (('ior', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imax', b, c))),
361 (('ior', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imin', a, b), c)),
362 (('ior', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imin', b, c))),
363 (('ior', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imax', a, b), c)),
364 (('ior', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umax', b, c))),
365 (('ior', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umin', a, b), c)),
366 (('ior', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umin', b, c))),
367 (('ior', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umax', a, b), c)),
368 (('iand', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imin', b, c))),
369 (('iand', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imax', a, b), c)),
370 (('iand', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imax', b, c))),
371 (('iand', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imin', a, b), c)),
372 (('iand', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umin', b, c))),
373 (('iand', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umax', a, b), c)),
374 (('iand', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umax', b, c))),
375 (('iand', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umin', a, b), c)),
376
377 (('ior', 'a@bool', ('ieq', a, False)), True),
378 (('ior', a, ('inot', a)), -1),
379
380 (('iand', ('ieq', 'a@32', 0), ('ieq', 'b@32', 0)), ('ieq', ('ior', 'a@32', 'b@32'), 0)),
381
382 # These patterns can result when (a < b || a < c) => (a < min(b, c))
383 # transformations occur before constant propagation and loop-unrolling.
384 (('~flt', a, ('fmax', b, a)), ('flt', a, b)),
385 (('~flt', ('fmin', a, b), a), ('flt', b, a)),
386 (('~fge', a, ('fmin', b, a)), True),
387 (('~fge', ('fmax', a, b), a), True),
388 (('~flt', a, ('fmin', b, a)), False),
389 (('~flt', ('fmax', a, b), a), False),
390 (('~fge', a, ('fmax', b, a)), ('fge', a, b)),
391 (('~fge', ('fmin', a, b), a), ('fge', b, a)),
392
393 (('ilt', a, ('imax', b, a)), ('ilt', a, b)),
394 (('ilt', ('imin', a, b), a), ('ilt', b, a)),
395 (('ige', a, ('imin', b, a)), True),
396 (('ige', ('imax', a, b), a), True),
397 (('ult', a, ('umax', b, a)), ('ult', a, b)),
398 (('ult', ('umin', a, b), a), ('ult', b, a)),
399 (('uge', a, ('umin', b, a)), True),
400 (('uge', ('umax', a, b), a), True),
401 (('ilt', a, ('imin', b, a)), False),
402 (('ilt', ('imax', a, b), a), False),
403 (('ige', a, ('imax', b, a)), ('ige', a, b)),
404 (('ige', ('imin', a, b), a), ('ige', b, a)),
405 (('ult', a, ('umin', b, a)), False),
406 (('ult', ('umax', a, b), a), False),
407 (('uge', a, ('umax', b, a)), ('uge', a, b)),
408 (('uge', ('umin', a, b), a), ('uge', b, a)),
409
410 (('ilt', '#a', ('imax', '#b', c)), ('ior', ('ilt', a, b), ('ilt', a, c))),
411 (('ilt', ('imin', '#a', b), '#c'), ('ior', ('ilt', a, c), ('ilt', b, c))),
412 (('ige', '#a', ('imin', '#b', c)), ('ior', ('ige', a, b), ('ige', a, c))),
413 (('ige', ('imax', '#a', b), '#c'), ('ior', ('ige', a, c), ('ige', b, c))),
414 (('ult', '#a', ('umax', '#b', c)), ('ior', ('ult', a, b), ('ult', a, c))),
415 (('ult', ('umin', '#a', b), '#c'), ('ior', ('ult', a, c), ('ult', b, c))),
416 (('uge', '#a', ('umin', '#b', c)), ('ior', ('uge', a, b), ('uge', a, c))),
417 (('uge', ('umax', '#a', b), '#c'), ('ior', ('uge', a, c), ('uge', b, c))),
418 (('ilt', '#a', ('imin', '#b', c)), ('iand', ('ilt', a, b), ('ilt', a, c))),
419 (('ilt', ('imax', '#a', b), '#c'), ('iand', ('ilt', a, c), ('ilt', b, c))),
420 (('ige', '#a', ('imax', '#b', c)), ('iand', ('ige', a, b), ('ige', a, c))),
421 (('ige', ('imin', '#a', b), '#c'), ('iand', ('ige', a, c), ('ige', b, c))),
422 (('ult', '#a', ('umin', '#b', c)), ('iand', ('ult', a, b), ('ult', a, c))),
423 (('ult', ('umax', '#a', b), '#c'), ('iand', ('ult', a, c), ('ult', b, c))),
424 (('uge', '#a', ('umax', '#b', c)), ('iand', ('uge', a, b), ('uge', a, c))),
425 (('uge', ('umin', '#a', b), '#c'), ('iand', ('uge', a, c), ('uge', b, c))),
426
427 (('fabs', ('slt', a, b)), ('slt', a, b)),
428 (('fabs', ('sge', a, b)), ('sge', a, b)),
429 (('fabs', ('seq', a, b)), ('seq', a, b)),
430 (('fabs', ('sne', a, b)), ('sne', a, b)),
431 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
432 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
433 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
434 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
435 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
436 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
437 # Emulating booleans
438 (('imul', ('b2i', a), ('b2i', b)), ('b2i', ('iand', a, b))),
439 (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))),
440 (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))),
441 (('iand', 'a@bool', 1.0), ('b2f', a), '!options->lower_b2f'),
442 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True).
443 (('ineg', ('b2i@32', a)), a),
444 (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
445 (('flt', ('fsub', 0.0, ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
446 # Comparison with the same args. Note that these are not done for
447 # the float versions because NaN always returns false on float
448 # inequalities.
449 (('ilt', a, a), False),
450 (('ige', a, a), True),
451 (('ieq', a, a), True),
452 (('ine', a, a), False),
453 (('ult', a, a), False),
454 (('uge', a, a), True),
455 # Logical and bit operations
456 (('fand', a, 0.0), 0.0),
457 (('iand', a, a), a),
458 (('iand', a, ~0), a),
459 (('iand', a, 0), 0),
460 (('ior', a, a), a),
461 (('ior', a, 0), a),
462 (('ior', a, True), True),
463 (('fxor', a, a), 0.0),
464 (('ixor', a, a), 0),
465 (('ixor', a, 0), a),
466 (('inot', ('inot', a)), a),
467 (('ior', ('iand', a, b), b), b),
468 (('ior', ('ior', a, b), b), ('ior', a, b)),
469 (('iand', ('ior', a, b), b), b),
470 (('iand', ('iand', a, b), b), ('iand', a, b)),
471 # DeMorgan's Laws
472 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
473 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
474 # Shift optimizations
475 (('ishl', 0, a), 0),
476 (('ishl', a, 0), a),
477 (('ishr', 0, a), 0),
478 (('ishr', a, 0), a),
479 (('ushr', 0, a), 0),
480 (('ushr', a, 0), a),
481 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)),
482 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)),
483 # Exponential/logarithmic identities
484 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a
485 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a
486 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
487 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
488 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
489 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
490 (('~fexp2', ('fmul', ('flog2', a), 2.0)), ('fmul', a, a)),
491 (('~fexp2', ('fmul', ('flog2', a), 4.0)), ('fmul', ('fmul', a, a), ('fmul', a, a))),
492 (('~fpow', a, 1.0), a),
493 (('~fpow', a, 2.0), ('fmul', a, a)),
494 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
495 (('~fpow', 2.0, a), ('fexp2', a)),
496 (('~fpow', ('fpow', a, 2.2), 0.454545), a),
497 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
498 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
499 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
500 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
501 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
502 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))),
503 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
504 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
505 (('~fmul', ('fexp2(is_used_once)', a), ('fexp2(is_used_once)', b)), ('fexp2', ('fadd', a, b))),
506 # Division and reciprocal
507 (('~fdiv', 1.0, a), ('frcp', a)),
508 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
509 (('~frcp', ('frcp', a)), a),
510 (('~frcp', ('fsqrt', a)), ('frsq', a)),
511 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
512 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
513 # Boolean simplifications
514 (('ieq', 'a@bool', True), a),
515 (('ine(is_not_used_by_if)', 'a@bool', True), ('inot', a)),
516 (('ine', 'a@bool', False), a),
517 (('ieq(is_not_used_by_if)', 'a@bool', False), ('inot', 'a')),
518 (('bcsel', a, True, False), a),
519 (('bcsel', a, False, True), ('inot', a)),
520 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)),
521 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))),
522 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))),
523 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))),
524 (('bcsel', True, b, c), b),
525 (('bcsel', False, b, c), c),
526 (('bcsel', a, ('b2f(is_used_once)', b), ('b2f', c)), ('b2f', ('bcsel', a, b, c))),
527 # The result of this should be hit by constant propagation and, in the
528 # next round of opt_algebraic, get picked up by one of the above two.
529 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
530
531 (('bcsel', a, b, b), b),
532 (('fcsel', a, b, b), b),
533
534 # Conversions
535 (('i2b', ('b2i', a)), a),
536 (('i2b', 'a@bool'), a),
537 (('f2i', ('ftrunc', a)), ('f2i', a)),
538 (('f2u', ('ftrunc', a)), ('f2u', a)),
539 (('i2b', ('ineg', a)), ('i2b', a)),
540 (('i2b', ('iabs', a)), ('i2b', a)),
541 (('fabs', ('b2f', a)), ('b2f', a)),
542 (('iabs', ('b2i', a)), ('b2i', a)),
543 (('inot', ('f2b', a)), ('feq', a, 0.0)),
544
545 # Ironically, mark these as imprecise because removing the conversions may
546 # preserve more precision than doing the conversions (e.g.,
547 # uint(float(0x81818181u)) == 0x81818200).
548 (('~f2i32', ('i2f', 'a@32')), a),
549 (('~f2i32', ('u2f', 'a@32')), a),
550 (('~f2u32', ('i2f', 'a@32')), a),
551 (('~f2u32', ('u2f', 'a@32')), a),
552
553 # Packing and then unpacking does nothing
554 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
555 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
556 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
557 ('unpack_64_2x32_split_y', a)), a),
558
559 # Byte extraction
560 (('ushr', ('ishl', 'a@32', 24), 24), ('extract_u8', a, 0), '!options->lower_extract_byte'),
561 (('ushr', ('ishl', 'a@32', 16), 24), ('extract_u8', a, 1), '!options->lower_extract_byte'),
562 (('ushr', ('ishl', 'a@32', 8), 24), ('extract_u8', a, 2), '!options->lower_extract_byte'),
563 (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
564 (('ishr', ('ishl', 'a@32', 24), 24), ('extract_i8', a, 0), '!options->lower_extract_byte'),
565 (('ishr', ('ishl', 'a@32', 16), 24), ('extract_i8', a, 1), '!options->lower_extract_byte'),
566 (('ishr', ('ishl', 'a@32', 8), 24), ('extract_i8', a, 2), '!options->lower_extract_byte'),
567 (('ishr', 'a@32', 24), ('extract_i8', a, 3), '!options->lower_extract_byte'),
568 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
569 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
570 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
571
572 # Word extraction
573 (('ushr', ('ishl', 'a@32', 16), 16), ('extract_u16', a, 0), '!options->lower_extract_word'),
574 (('ushr', 'a@32', 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
575 (('ishr', ('ishl', 'a@32', 16), 16), ('extract_i16', a, 0), '!options->lower_extract_word'),
576 (('ishr', 'a@32', 16), ('extract_i16', a, 1), '!options->lower_extract_word'),
577 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
578
579 # Subtracts
580 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
581 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
582 (('ussub_4x8', a, 0), a),
583 (('ussub_4x8', a, ~0), 0),
584 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
585 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
586 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
587 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
588 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
589 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
590 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
591 (('iabs', ('isub', 0, a)), ('iabs', a)),
592
593 # Propagate negation up multiplication chains
594 (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))),
595 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
596
597 # Propagate constants up multiplication chains
598 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
599 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
600 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
601 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
602
603 # Reassociate constants in add/mul chains so they can be folded together.
604 # For now, we mostly only handle cases where the constants are separated by
605 # a single non-constant. We could do better eventually.
606 (('~fmul', '#a', ('fmul', b, '#c')), ('fmul', ('fmul', a, c), b)),
607 (('imul', '#a', ('imul', b, '#c')), ('imul', ('imul', a, c), b)),
608 (('~fadd', '#a', ('fadd', b, '#c')), ('fadd', ('fadd', a, c), b)),
609 (('~fadd', '#a', ('fneg', ('fadd', b, '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
610 (('iadd', '#a', ('iadd', b, '#c')), ('iadd', ('iadd', a, c), b)),
611
612 # By definition...
613 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
614 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
615 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
616
617 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
618 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
619 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
620
621 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
622
623 # Misc. lowering
624 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod32'),
625 (('fmod@64', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod64'),
626 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod32'),
627 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
628 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
629
630 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
631 ('bcsel', ('ilt', 31, 'bits'), 'insert',
632 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
633 'options->lower_bitfield_insert'),
634
635 # Alternative lowering that doesn't rely on bfi.
636 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
637 ('bcsel', ('ilt', 31, 'bits'),
638 'insert',
639 ('ior',
640 ('iand', 'base', ('inot', ('bfm', 'bits', 'offset'))),
641 ('iand', ('ishl', 'insert', 'offset'), ('bfm', 'bits', 'offset')))),
642 'options->lower_bitfield_insert_to_shifts'),
643
644 # bfm lowering -- note that the NIR opcode is undefined if either arg is 32.
645 (('bfm', 'bits', 'offset'),
646 ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'),
647 'options->lower_bfm'),
648
649 (('ibitfield_extract', 'value', 'offset', 'bits'),
650 ('bcsel', ('ilt', 31, 'bits'), 'value',
651 ('ibfe', 'value', 'offset', 'bits')),
652 'options->lower_bitfield_extract'),
653
654 (('ubitfield_extract', 'value', 'offset', 'bits'),
655 ('bcsel', ('ult', 31, 'bits'), 'value',
656 ('ubfe', 'value', 'offset', 'bits')),
657 'options->lower_bitfield_extract'),
658
659 (('ibitfield_extract', 'value', 'offset', 'bits'),
660 ('bcsel', ('ieq', 0, 'bits'),
661 0,
662 ('ishr',
663 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
664 ('isub', 32, 'bits'))),
665 'options->lower_bitfield_extract_to_shifts'),
666
667 (('ubitfield_extract', 'value', 'offset', 'bits'),
668 ('iand',
669 ('ushr', 'value', 'offset'),
670 ('bcsel', ('ieq', 'bits', 32),
671 0xffffffff,
672 ('bfm', 'bits', 0))),
673 'options->lower_bitfield_extract_to_shifts'),
674
675 (('ifind_msb', 'value'),
676 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
677 'options->lower_ifind_msb'),
678
679 (('find_lsb', 'value'),
680 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
681 'options->lower_find_lsb'),
682
683 (('extract_i8', a, 'b@32'),
684 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
685 'options->lower_extract_byte'),
686
687 (('extract_u8', a, 'b@32'),
688 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
689 'options->lower_extract_byte'),
690
691 (('extract_i16', a, 'b@32'),
692 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
693 'options->lower_extract_word'),
694
695 (('extract_u16', a, 'b@32'),
696 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
697 'options->lower_extract_word'),
698
699 (('pack_unorm_2x16', 'v'),
700 ('pack_uvec2_to_uint',
701 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
702 'options->lower_pack_unorm_2x16'),
703
704 (('pack_unorm_4x8', 'v'),
705 ('pack_uvec4_to_uint',
706 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
707 'options->lower_pack_unorm_4x8'),
708
709 (('pack_snorm_2x16', 'v'),
710 ('pack_uvec2_to_uint',
711 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
712 'options->lower_pack_snorm_2x16'),
713
714 (('pack_snorm_4x8', 'v'),
715 ('pack_uvec4_to_uint',
716 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
717 'options->lower_pack_snorm_4x8'),
718
719 (('unpack_unorm_2x16', 'v'),
720 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
721 ('extract_u16', 'v', 1))),
722 65535.0),
723 'options->lower_unpack_unorm_2x16'),
724
725 (('unpack_unorm_4x8', 'v'),
726 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
727 ('extract_u8', 'v', 1),
728 ('extract_u8', 'v', 2),
729 ('extract_u8', 'v', 3))),
730 255.0),
731 'options->lower_unpack_unorm_4x8'),
732
733 (('unpack_snorm_2x16', 'v'),
734 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
735 ('extract_i16', 'v', 1))),
736 32767.0))),
737 'options->lower_unpack_snorm_2x16'),
738
739 (('unpack_snorm_4x8', 'v'),
740 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
741 ('extract_i8', 'v', 1),
742 ('extract_i8', 'v', 2),
743 ('extract_i8', 'v', 3))),
744 127.0))),
745 'options->lower_unpack_snorm_4x8'),
746 ]
747
748 invert = OrderedDict([('feq', 'fne'), ('fne', 'feq'), ('fge', 'flt'), ('flt', 'fge')])
749
750 for left, right in itertools.combinations_with_replacement(invert.keys(), 2):
751 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
752 ('iand', (invert[left], a, b), (invert[right], c, d))))
753 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
754 ('ior', (invert[left], a, b), (invert[right], c, d))))
755
756 # Optimize x2yN(b2x(x)) -> b2y
757 optimizations.append((('f2b', ('b2f', a)), a))
758 optimizations.append((('i2b', ('b2i', a)), a))
759 for x, y in itertools.product(['f', 'u', 'i'], ['f', 'u', 'i']):
760 if x != 'f' and y != 'f' and x != y:
761 continue
762
763 b2x = 'b2f' if x == 'f' else 'b2i'
764 b2y = 'b2f' if y == 'f' else 'b2i'
765 x2yN = '{}2{}'.format(x, y)
766 optimizations.append(((x2yN, (b2x, a)), (b2y, a)))
767
768 def fexp2i(exp, bits):
769 # We assume that exp is already in the right range.
770 if bits == 32:
771 return ('ishl', ('iadd', exp, 127), 23)
772 elif bits == 64:
773 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
774 else:
775 assert False
776
777 def ldexp(f, exp, bits):
778 # First, we clamp exp to a reasonable range. The maximum possible range
779 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
780 # a maximum range of [-149, 127]. This means that we can potentially have
781 # a swing of +-276. If you start with FLT_MAX, you actually have to do
782 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
783 # spec, on the other hand, only requires that we handle an exponent value
784 # in the range [-126, 128]. This implementation is *mostly* correct; it
785 # handles a range on exp of [-252, 254] which allows you to create any
786 # value (including denorms if the hardware supports it) and to adjust the
787 # exponent of any normal value to anything you want.
788 if bits == 32:
789 exp = ('imin', ('imax', exp, -252), 254)
790 elif bits == 64:
791 exp = ('imin', ('imax', exp, -2044), 2046)
792 else:
793 assert False
794
795 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
796 # (We use ishr which isn't the same for -1, but the -1 case still works
797 # since we use exp-exp/2 as the second exponent.) While the spec
798 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
799 # work with denormals and doesn't allow for the full swing in exponents
800 # that you can get with normalized values. Instead, we create two powers
801 # of two and multiply by them each in turn. That way the effective range
802 # of our exponent is doubled.
803 pow2_1 = fexp2i(('ishr', exp, 1), bits)
804 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
805 return ('fmul', ('fmul', f, pow2_1), pow2_2)
806
807 optimizations += [
808 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
809 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
810 ]
811
812 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
813 def bitfield_reverse(u):
814 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
815 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
816 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
817 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
818 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
819
820 return step5
821
822 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'))]
823
824 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
825 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
826 # and, if a is a NaN then the second comparison will fail anyway.
827 for op in ['flt', 'fge', 'feq']:
828 optimizations += [
829 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
830 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
831 ]
832
833 # Add optimizations to handle the case where the result of a ternary is
834 # compared to a constant. This way we can take things like
835 #
836 # (a ? 0 : 1) > 0
837 #
838 # and turn it into
839 #
840 # a ? (0 > 0) : (1 > 0)
841 #
842 # which constant folding will eat for lunch. The resulting ternary will
843 # further get cleaned up by the boolean reductions above and we will be
844 # left with just the original variable "a".
845 for op in ['flt', 'fge', 'feq', 'fne',
846 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
847 optimizations += [
848 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
849 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
850 ((op, '#d', ('bcsel', a, '#b', '#c')),
851 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
852 ]
853
854
855 # For example, this converts things like
856 #
857 # 1 + mix(0, a - 1, condition)
858 #
859 # into
860 #
861 # mix(1, (a-1)+1, condition)
862 #
863 # Other optimizations will rearrange the constants.
864 for op in ['fadd', 'fmul', 'iadd', 'imul']:
865 optimizations += [
866 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
867 ]
868
869 # This section contains "late" optimizations that should be run before
870 # creating ffmas and calling regular optimizations for the final time.
871 # Optimizations should go here if they help code generation and conflict
872 # with the regular optimizations.
873 before_ffma_optimizations = [
874 # Propagate constants down multiplication chains
875 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
876 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
877 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
878 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
879
880 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
881 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
882 (('~fadd', ('fneg', a), a), 0.0),
883 (('iadd', ('ineg', a), a), 0),
884 (('iadd', ('ineg', a), ('iadd', a, b)), b),
885 (('iadd', a, ('iadd', ('ineg', a), b)), b),
886 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
887 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
888 ]
889
890 # This section contains "late" optimizations that should be run after the
891 # regular optimizations have finished. Optimizations should go here if
892 # they help code generation but do not necessarily produce code that is
893 # more easily optimizable.
894 late_optimizations = [
895 # Most of these optimizations aren't quite safe when you get infinity or
896 # Nan involved but the first one should be fine.
897 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
898 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
899 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
900 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
901 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
902 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
903
904 (('~fge', ('fmin(is_used_once)', ('fadd(is_used_once)', a, b), ('fadd', c, d)), 0.0), ('iand', ('fge', a, ('fneg', b)), ('fge', c, ('fneg', d)))),
905
906 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
907 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
908 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
909 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
910
911 (('b2f(is_used_more_than_once)', ('inot', a)), ('bcsel', a, 0.0, 1.0)),
912 (('fneg(is_used_more_than_once)', ('b2f', ('inot', a))), ('bcsel', a, -0.0, -1.0)),
913
914 # we do these late so that we don't get in the way of creating ffmas
915 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
916 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
917
918 # Lowered for backends without a dedicated b2f instruction
919 (('b2f@32', a), ('iand', a, 1.0), 'options->lower_b2f'),
920 ]
921
922 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render())
923 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
924 before_ffma_optimizations).render())
925 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
926 late_optimizations).render())