3267e93a583d9683ab1ecbbb021eb8bb8e66ff35
[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', ('u2f32', a)), ('u2f32', 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 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
127 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', c)))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'),
128 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'),
129 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'),
130 (('~fadd', a, ('fmul', ('b2f', c), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'),
131 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'),
132 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'),
133 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
134 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'),
135
136 (('fdot4', ('vec4', a, b, c, 1.0), d), ('fdph', ('vec3', a, b, c), d)),
137 (('fdot4', ('vec4', a, 0.0, 0.0, 0.0), b), ('fmul', a, b)),
138 (('fdot4', ('vec4', a, b, 0.0, 0.0), c), ('fdot2', ('vec2', a, b), c)),
139 (('fdot4', ('vec4', a, b, c, 0.0), d), ('fdot3', ('vec3', a, b, c), d)),
140
141 (('fdot3', ('vec3', a, 0.0, 0.0), b), ('fmul', a, b)),
142 (('fdot3', ('vec3', a, b, 0.0), c), ('fdot2', ('vec2', a, b), c)),
143
144 # (a * #b + #c) << #d
145 # ((a * #b) << #d) + (#c << #d)
146 # (a * (#b << #d)) + (#c << #d)
147 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'),
148 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))),
149
150 # (a * #b) << #c
151 # a * (#b << #c)
152 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))),
153
154 # Comparison simplifications
155 (('~inot', ('flt', a, b)), ('fge', a, b)),
156 (('~inot', ('fge', a, b)), ('flt', a, b)),
157 (('~inot', ('feq', a, b)), ('fne', a, b)),
158 (('~inot', ('fne', a, b)), ('feq', a, b)),
159 (('inot', ('ilt', a, b)), ('ige', a, b)),
160 (('inot', ('ult', a, b)), ('uge', a, b)),
161 (('inot', ('ige', a, b)), ('ilt', a, b)),
162 (('inot', ('uge', a, b)), ('ult', a, b)),
163 (('inot', ('ieq', a, b)), ('ine', a, b)),
164 (('inot', ('ine', a, b)), ('ieq', a, b)),
165
166 # 0.0 >= b2f(a)
167 # b2f(a) <= 0.0
168 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1
169 # inot(a)
170 (('fge', 0.0, ('b2f', a)), ('inot', a)),
171
172 (('fge', ('fneg', ('b2f', a)), 0.0), ('inot', a)),
173
174 (('fne', ('fadd', ('b2f', a), ('b2f', b)), 0.0), ('ior', a, b)),
175 (('fne', ('fmax', ('b2f', a), ('b2f', b)), 0.0), ('ior', a, b)),
176 (('fne', ('bcsel', a, 1.0, ('b2f', b)) , 0.0), ('ior', a, b)),
177 (('fne', ('b2f', a), ('fneg', ('b2f', b))), ('ior', a, b)),
178 (('fne', ('fmul', ('b2f', a), ('b2f', b)), 0.0), ('iand', a, b)),
179 (('fne', ('fmin', ('b2f', a), ('b2f', b)), 0.0), ('iand', a, b)),
180 (('fne', ('bcsel', a, ('b2f', b), 0.0) , 0.0), ('iand', a, b)),
181 (('fne', ('fadd', ('b2f', a), ('fneg', ('b2f', b))), 0.0), ('ixor', a, b)),
182 (('fne', ('b2f', a) , ('b2f', b) ), ('ixor', a, b)),
183 (('fne', ('fneg', ('b2f', a)), ('fneg', ('b2f', b))), ('ixor', a, b)),
184 (('feq', ('fadd', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('ior', a, b))),
185 (('feq', ('fmax', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('ior', a, b))),
186 (('feq', ('bcsel', a, 1.0, ('b2f', b)) , 0.0), ('inot', ('ior', a, b))),
187 (('feq', ('b2f', a), ('fneg', ('b2f', b))), ('inot', ('ior', a, b))),
188 (('feq', ('fmul', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('iand', a, b))),
189 (('feq', ('fmin', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('iand', a, b))),
190 (('feq', ('bcsel', a, ('b2f', b), 0.0) , 0.0), ('inot', ('iand', a, b))),
191 (('feq', ('fadd', ('b2f', a), ('fneg', ('b2f', b))), 0.0), ('ieq', a, b)),
192 (('feq', ('b2f', a) , ('b2f', b) ), ('ieq', a, b)),
193 (('feq', ('fneg', ('b2f', a)), ('fneg', ('b2f', b))), ('ieq', a, b)),
194
195 # -(b2f(a) + b2f(b)) < 0
196 # 0 < b2f(a) + b2f(b)
197 # 0 != b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
198 # a || b
199 (('flt', ('fneg', ('fadd', ('b2f', a), ('b2f', b))), 0.0), ('ior', a, b)),
200 (('flt', 0.0, ('fadd', ('b2f', a), ('b2f', b))), ('ior', a, b)),
201
202 # -(b2f(a) + b2f(b)) >= 0
203 # 0 >= b2f(a) + b2f(b)
204 # 0 == b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
205 # !(a || b)
206 (('fge', ('fneg', ('fadd', ('b2f', a), ('b2f', b))), 0.0), ('inot', ('ior', a, b))),
207 (('fge', 0.0, ('fadd', ('b2f', a), ('b2f', b))), ('inot', ('ior', a, b))),
208
209 # Some optimizations (below) convert things like (a < b || c < b) into
210 # (min(a, c) < b). However, this interfers with the previous optimizations
211 # that try to remove comparisons with negated sums of b2f. This just
212 # breaks that apart.
213 (('flt', ('fmin', c, ('fneg', ('fadd', ('b2f', a), ('b2f', b)))), 0.0),
214 ('ior', ('flt', c, 0.0), ('ior', a, b))),
215
216 (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)),
217 (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)),
218 (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)),
219 (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)),
220
221 # Cannot remove the addition from ilt or ige due to overflow.
222 (('ieq', ('iadd', a, b), a), ('ieq', b, 0)),
223 (('ine', ('iadd', a, b), a), ('ine', b, 0)),
224
225 # fmin(-b2f(a), b) >= 0.0
226 # -b2f(a) >= 0.0 && b >= 0.0
227 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0
228 # b2f(a) == 0.0 && b >= 0.0
229 # a == False && b >= 0.0
230 # !a && b >= 0.0
231 #
232 # The fge in the second replacement is not a typo. I leave the proof that
233 # "fmin(-b2f(a), b) >= 0 <=> fmin(-b2f(a), b) == 0" as an exercise for the
234 # reader.
235 (('fge', ('fmin', ('fneg', ('b2f', a)), b), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
236 (('feq', ('fmin', ('fneg', ('b2f', a)), b), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
237
238 (('feq', ('b2f', a), 0.0), ('inot', a)),
239 (('fne', ('b2f', a), 0.0), a),
240 (('ieq', ('b2i', a), 0), ('inot', a)),
241 (('ine', ('b2i', a), 0), a),
242
243 (('fne', ('u2f32', a), 0.0), ('ine', a, 0)),
244 (('feq', ('u2f32', a), 0.0), ('ieq', a, 0)),
245 (('fge', ('u2f32', a), 0.0), True),
246 (('fge', 0.0, ('u2f32', a)), ('uge', 0, a)), # ieq instead?
247 (('flt', ('u2f32', a), 0.0), False),
248 (('flt', 0.0, ('u2f32', a)), ('ult', 0, a)), # ine instead?
249 (('fne', ('i2f32', a), 0.0), ('ine', a, 0)),
250 (('feq', ('i2f32', a), 0.0), ('ieq', a, 0)),
251 (('fge', ('i2f32', a), 0.0), ('ige', a, 0)),
252 (('fge', 0.0, ('i2f32', a)), ('ige', 0, a)),
253 (('flt', ('i2f32', a), 0.0), ('ilt', a, 0)),
254 (('flt', 0.0, ('i2f32', a)), ('ilt', 0, a)),
255
256 # 0.0 < fabs(a)
257 # fabs(a) > 0.0
258 # fabs(a) != 0.0 because fabs(a) must be >= 0
259 # a != 0.0
260 (('~flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
261
262 # -fabs(a) < 0.0
263 # fabs(a) > 0.0
264 (('~flt', ('fneg', ('fabs', a)), 0.0), ('fne', a, 0.0)),
265
266 # 0.0 >= fabs(a)
267 # 0.0 == fabs(a) because fabs(a) must be >= 0
268 # 0.0 == a
269 (('fge', 0.0, ('fabs', a)), ('feq', a, 0.0)),
270
271 # -fabs(a) >= 0.0
272 # 0.0 >= fabs(a)
273 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
274
275 (('fmax', ('b2f(is_used_once)', a), ('b2f', b)), ('b2f', ('ior', a, b))),
276 (('fmax', ('fneg(is_used_once)', ('b2f(is_used_once)', a)), ('fneg', ('b2f', b))), ('fneg', ('b2f', ('ior', a, b)))),
277 (('fmin', ('b2f(is_used_once)', a), ('b2f', b)), ('b2f', ('iand', a, b))),
278 (('fmin', ('fneg(is_used_once)', ('b2f(is_used_once)', a)), ('fneg', ('b2f', b))), ('fneg', ('b2f', ('iand', a, b)))),
279
280 # fmin(b2f(a), b)
281 # bcsel(a, fmin(b2f(a), b), fmin(b2f(a), b))
282 # bcsel(a, fmin(b2f(True), b), fmin(b2f(False), b))
283 # bcsel(a, fmin(1.0, b), fmin(0.0, b))
284 #
285 # Since b is a constant, constant folding will eliminate the fmin and the
286 # fmax. If b is > 1.0, the bcsel will be replaced with a b2f.
287 (('fmin', ('b2f', a), '#b'), ('bcsel', a, ('fmin', b, 1.0), ('fmin', b, 0.0))),
288
289 (('flt', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
290
291 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
292 (('~bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
293 (('~bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
294 (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)),
295 (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)),
296 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)),
297 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
298 (('bcsel', a, b, ('bcsel', a, c, d)), ('bcsel', a, b, d)),
299 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
300 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
301 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
302 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
303 (('bcsel', a, True, 'b@bool'), ('ior', a, b)),
304 (('fmin', a, a), a),
305 (('fmax', a, a), a),
306 (('imin', a, a), a),
307 (('imax', a, a), a),
308 (('umin', a, a), a),
309 (('umax', a, a), a),
310 (('fmax', ('fmax', a, b), b), ('fmax', a, b)),
311 (('umax', ('umax', a, b), b), ('umax', a, b)),
312 (('imax', ('imax', a, b), b), ('imax', a, b)),
313 (('fmin', ('fmin', a, b), b), ('fmin', a, b)),
314 (('umin', ('umin', a, b), b), ('umin', a, b)),
315 (('imin', ('imin', a, b), b), ('imin', a, b)),
316 (('fmax', a, ('fneg', a)), ('fabs', a)),
317 (('imax', a, ('ineg', a)), ('iabs', a)),
318 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))),
319 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))),
320 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))),
321 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))),
322 (('fmin', a, ('fabs', a)), a),
323 (('imin', a, ('iabs', a)), a),
324 (('fmax', a, ('fneg', ('fabs', a))), a),
325 (('imax', a, ('ineg', ('iabs', a))), a),
326 (('fmax', a, ('fabs', a)), ('fabs', a)),
327 (('imax', a, ('iabs', a)), ('iabs', a)),
328 (('fmax', a, ('fneg', a)), ('fabs', a)),
329 (('imax', a, ('ineg', a)), ('iabs', a)),
330 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
331 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
332 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
333 (('fsat', ('fsat', a)), ('fsat', a)),
334 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)),
335 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)),
336 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)),
337 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))),
338 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))),
339 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
340 (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
341 (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
342 (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
343 (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
344 (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
345 (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
346 (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
347 (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
348 (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
349 (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
350 (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
351 (('~iand', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmin', a, b), c)),
352 (('~iand', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmin', b, c))),
353 (('~iand', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmax', a, b), c)),
354 (('~iand', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmax', b, c))),
355 (('~iand', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmin', a, b), c)),
356
357 (('ior', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imax', b, c))),
358 (('ior', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imin', a, b), c)),
359 (('ior', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imin', b, c))),
360 (('ior', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imax', a, b), c)),
361 (('ior', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umax', b, c))),
362 (('ior', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umin', a, b), c)),
363 (('ior', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umin', b, c))),
364 (('ior', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umax', a, b), c)),
365 (('iand', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imin', b, c))),
366 (('iand', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imax', a, b), c)),
367 (('iand', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imax', b, c))),
368 (('iand', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imin', a, b), c)),
369 (('iand', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umin', b, c))),
370 (('iand', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umax', a, b), c)),
371 (('iand', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umax', b, c))),
372 (('iand', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umin', a, b), c)),
373
374 (('ior', 'a@bool', ('ieq', a, False)), True),
375 (('ior', 'a@bool', ('inot', a)), True),
376
377 (('iand', ('ieq', 'a@32', 0), ('ieq', 'b@32', 0)), ('ieq', ('ior', 'a@32', 'b@32'), 0)),
378
379 # These patterns can result when (a < b || a < c) => (a < min(b, c))
380 # transformations occur before constant propagation and loop-unrolling.
381 (('~flt', a, ('fmax', b, a)), ('flt', a, b)),
382 (('~flt', ('fmin', a, b), a), ('flt', b, a)),
383 (('~fge', a, ('fmin', b, a)), True),
384 (('~fge', ('fmax', a, b), a), True),
385 (('~flt', a, ('fmin', b, a)), False),
386 (('~flt', ('fmax', a, b), a), False),
387 (('~fge', a, ('fmax', b, a)), ('fge', a, b)),
388 (('~fge', ('fmin', a, b), a), ('fge', b, a)),
389
390 (('ilt', a, ('imax', b, a)), ('ilt', a, b)),
391 (('ilt', ('imin', a, b), a), ('ilt', b, a)),
392 (('ige', a, ('imin', b, a)), True),
393 (('ige', ('imax', a, b), a), True),
394 (('ult', a, ('umax', b, a)), ('ult', a, b)),
395 (('ult', ('umin', a, b), a), ('ult', b, a)),
396 (('uge', a, ('umin', b, a)), True),
397 (('uge', ('umax', a, b), a), True),
398 (('ilt', a, ('imin', b, a)), False),
399 (('ilt', ('imax', a, b), a), False),
400 (('ige', a, ('imax', b, a)), ('ige', a, b)),
401 (('ige', ('imin', a, b), a), ('ige', b, a)),
402 (('ult', a, ('umin', b, a)), False),
403 (('ult', ('umax', a, b), a), False),
404 (('uge', a, ('umax', b, a)), ('uge', a, b)),
405 (('uge', ('umin', a, b), a), ('uge', b, a)),
406
407 (('ilt', '#a', ('imax', '#b', c)), ('ior', ('ilt', a, b), ('ilt', a, c))),
408 (('ilt', ('imin', '#a', b), '#c'), ('ior', ('ilt', a, c), ('ilt', b, c))),
409 (('ige', '#a', ('imin', '#b', c)), ('ior', ('ige', a, b), ('ige', a, c))),
410 (('ige', ('imax', '#a', b), '#c'), ('ior', ('ige', a, c), ('ige', b, c))),
411 (('ult', '#a', ('umax', '#b', c)), ('ior', ('ult', a, b), ('ult', a, c))),
412 (('ult', ('umin', '#a', b), '#c'), ('ior', ('ult', a, c), ('ult', b, c))),
413 (('uge', '#a', ('umin', '#b', c)), ('ior', ('uge', a, b), ('uge', a, c))),
414 (('uge', ('umax', '#a', b), '#c'), ('ior', ('uge', a, c), ('uge', b, c))),
415 (('ilt', '#a', ('imin', '#b', c)), ('iand', ('ilt', a, b), ('ilt', a, c))),
416 (('ilt', ('imax', '#a', b), '#c'), ('iand', ('ilt', a, c), ('ilt', b, c))),
417 (('ige', '#a', ('imax', '#b', c)), ('iand', ('ige', a, b), ('ige', a, c))),
418 (('ige', ('imin', '#a', b), '#c'), ('iand', ('ige', a, c), ('ige', b, c))),
419 (('ult', '#a', ('umin', '#b', c)), ('iand', ('ult', a, b), ('ult', a, c))),
420 (('ult', ('umax', '#a', b), '#c'), ('iand', ('ult', a, c), ('ult', b, c))),
421 (('uge', '#a', ('umax', '#b', c)), ('iand', ('uge', a, b), ('uge', a, c))),
422 (('uge', ('umin', '#a', b), '#c'), ('iand', ('uge', a, c), ('uge', b, c))),
423
424 (('fabs', ('slt', a, b)), ('slt', a, b)),
425 (('fabs', ('sge', a, b)), ('sge', a, b)),
426 (('fabs', ('seq', a, b)), ('seq', a, b)),
427 (('fabs', ('sne', a, b)), ('sne', a, b)),
428 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
429 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
430 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
431 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
432 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
433 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
434 # Emulating booleans
435 (('imul', ('b2i', a), ('b2i', b)), ('b2i', ('iand', a, b))),
436 (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))),
437 (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))),
438 (('iand', 'a@bool', 1.0), ('b2f', a), '!options->lower_b2f'),
439 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True).
440 (('ineg', ('b2i@32', a)), a),
441 (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
442 (('flt', ('fsub', 0.0, ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
443 # Comparison with the same args. Note that these are not done for
444 # the float versions because NaN always returns false on float
445 # inequalities.
446 (('ilt', a, a), False),
447 (('ige', a, a), True),
448 (('ieq', a, a), True),
449 (('ine', a, a), False),
450 (('ult', a, a), False),
451 (('uge', a, a), True),
452 # Logical and bit operations
453 (('fand', a, 0.0), 0.0),
454 (('iand', a, a), a),
455 (('iand', a, ~0), a),
456 (('iand', a, 0), 0),
457 (('ior', a, a), a),
458 (('ior', a, 0), a),
459 (('ior', a, True), True),
460 (('fxor', a, a), 0.0),
461 (('ixor', a, a), 0),
462 (('ixor', a, 0), a),
463 (('inot', ('inot', a)), a),
464 (('ior', ('iand', a, b), b), b),
465 (('ior', ('ior', a, b), b), ('ior', a, b)),
466 (('iand', ('ior', a, b), b), b),
467 (('iand', ('iand', a, b), b), ('iand', a, b)),
468 # DeMorgan's Laws
469 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
470 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
471 # Shift optimizations
472 (('ishl', 0, a), 0),
473 (('ishl', a, 0), a),
474 (('ishr', 0, a), 0),
475 (('ishr', a, 0), a),
476 (('ushr', 0, a), 0),
477 (('ushr', a, 0), a),
478 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)),
479 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)),
480 # Exponential/logarithmic identities
481 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a
482 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a
483 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
484 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
485 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
486 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
487 (('~fexp2', ('fmul', ('flog2', a), 2.0)), ('fmul', a, a)),
488 (('~fexp2', ('fmul', ('flog2', a), 4.0)), ('fmul', ('fmul', a, a), ('fmul', a, a))),
489 (('~fpow', a, 1.0), a),
490 (('~fpow', a, 2.0), ('fmul', a, a)),
491 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
492 (('~fpow', 2.0, a), ('fexp2', a)),
493 (('~fpow', ('fpow', a, 2.2), 0.454545), a),
494 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
495 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
496 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
497 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
498 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
499 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))),
500 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
501 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
502 (('~fmul', ('fexp2(is_used_once)', a), ('fexp2(is_used_once)', b)), ('fexp2', ('fadd', a, b))),
503 # Division and reciprocal
504 (('~fdiv', 1.0, a), ('frcp', a)),
505 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
506 (('~frcp', ('frcp', a)), a),
507 (('~frcp', ('fsqrt', a)), ('frsq', a)),
508 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
509 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
510 # Boolean simplifications
511 (('ieq', 'a@bool', True), a),
512 (('ine(is_not_used_by_if)', 'a@bool', True), ('inot', a)),
513 (('ine', 'a@bool', False), a),
514 (('ieq(is_not_used_by_if)', 'a@bool', False), ('inot', 'a')),
515 (('bcsel', a, True, False), a),
516 (('bcsel', a, False, True), ('inot', a)),
517 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)),
518 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))),
519 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))),
520 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))),
521 (('bcsel', True, b, c), b),
522 (('bcsel', False, b, c), c),
523 (('bcsel', a, ('b2f(is_used_once)', b), ('b2f', c)), ('b2f', ('bcsel', a, b, c))),
524 # The result of this should be hit by constant propagation and, in the
525 # next round of opt_algebraic, get picked up by one of the above two.
526 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
527
528 (('bcsel', a, b, b), b),
529 (('fcsel', a, b, b), b),
530
531 # Conversions
532 (('i2b', ('b2i', a)), a),
533 (('i2b', 'a@bool'), a),
534 (('f2i32', ('ftrunc', a)), ('f2i32', a)),
535 (('f2u32', ('ftrunc', a)), ('f2u32', a)),
536 (('i2b', ('ineg', a)), ('i2b', a)),
537 (('i2b', ('iabs', a)), ('i2b', a)),
538 (('fabs', ('b2f', a)), ('b2f', a)),
539 (('iabs', ('b2i', a)), ('b2i', a)),
540 (('inot', ('f2b', a)), ('feq', a, 0.0)),
541
542 # Ironically, mark these as imprecise because removing the conversions may
543 # preserve more precision than doing the conversions (e.g.,
544 # uint(float(0x81818181u)) == 0x81818200).
545 (('~f2i32', ('i2f32', 'a@32')), a),
546 (('~f2i32', ('u2f32', 'a@32')), a),
547 (('~f2u32', ('i2f32', 'a@32')), a),
548 (('~f2u32', ('u2f32', 'a@32')), a),
549
550 # Packing and then unpacking does nothing
551 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
552 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
553 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
554 ('unpack_64_2x32_split_y', a)), a),
555
556 # Byte extraction
557 (('ushr', ('ishl', 'a@32', 24), 24), ('extract_u8', a, 0), '!options->lower_extract_byte'),
558 (('ushr', ('ishl', 'a@32', 16), 24), ('extract_u8', a, 1), '!options->lower_extract_byte'),
559 (('ushr', ('ishl', 'a@32', 8), 24), ('extract_u8', a, 2), '!options->lower_extract_byte'),
560 (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
561 (('ishr', ('ishl', 'a@32', 24), 24), ('extract_i8', a, 0), '!options->lower_extract_byte'),
562 (('ishr', ('ishl', 'a@32', 16), 24), ('extract_i8', a, 1), '!options->lower_extract_byte'),
563 (('ishr', ('ishl', 'a@32', 8), 24), ('extract_i8', a, 2), '!options->lower_extract_byte'),
564 (('ishr', 'a@32', 24), ('extract_i8', a, 3), '!options->lower_extract_byte'),
565 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
566 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
567 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
568
569 # Word extraction
570 (('ushr', ('ishl', 'a@32', 16), 16), ('extract_u16', a, 0), '!options->lower_extract_word'),
571 (('ushr', 'a@32', 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
572 (('ishr', ('ishl', 'a@32', 16), 16), ('extract_i16', a, 0), '!options->lower_extract_word'),
573 (('ishr', 'a@32', 16), ('extract_i16', a, 1), '!options->lower_extract_word'),
574 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
575
576 # Subtracts
577 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
578 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
579 (('ussub_4x8', a, 0), a),
580 (('ussub_4x8', a, ~0), 0),
581 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
582 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
583 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
584 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
585 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
586 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
587 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
588 (('iabs', ('isub', 0, a)), ('iabs', a)),
589
590 # Propagate negation up multiplication chains
591 (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))),
592 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
593
594 # Propagate constants up multiplication chains
595 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
596 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
597 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
598 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
599
600 # Reassociate constants in add/mul chains so they can be folded together.
601 # For now, we mostly only handle cases where the constants are separated by
602 # a single non-constant. We could do better eventually.
603 (('~fmul', '#a', ('fmul', b, '#c')), ('fmul', ('fmul', a, c), b)),
604 (('imul', '#a', ('imul', b, '#c')), ('imul', ('imul', a, c), b)),
605 (('~fadd', '#a', ('fadd', b, '#c')), ('fadd', ('fadd', a, c), b)),
606 (('~fadd', '#a', ('fneg', ('fadd', b, '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
607 (('iadd', '#a', ('iadd', b, '#c')), ('iadd', ('iadd', a, c), b)),
608
609 # By definition...
610 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
611 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
612 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
613
614 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
615 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
616 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
617
618 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
619
620 # Misc. lowering
621 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod32'),
622 (('fmod@64', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod64'),
623 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod32'),
624 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
625 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
626
627 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
628 ('bcsel', ('ilt', 31, 'bits'), 'insert',
629 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
630 'options->lower_bitfield_insert'),
631
632 # Alternative lowering that doesn't rely on bfi.
633 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
634 ('bcsel', ('ilt', 31, 'bits'),
635 'insert',
636 ('ior',
637 ('iand', 'base', ('inot', ('bfm', 'bits', 'offset'))),
638 ('iand', ('ishl', 'insert', 'offset'), ('bfm', 'bits', 'offset')))),
639 'options->lower_bitfield_insert_to_shifts'),
640
641 # bfm lowering -- note that the NIR opcode is undefined if either arg is 32.
642 (('bfm', 'bits', 'offset'),
643 ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'),
644 'options->lower_bfm'),
645
646 (('ibitfield_extract', 'value', 'offset', 'bits'),
647 ('bcsel', ('ilt', 31, 'bits'), 'value',
648 ('ibfe', 'value', 'offset', 'bits')),
649 'options->lower_bitfield_extract'),
650
651 (('ubitfield_extract', 'value', 'offset', 'bits'),
652 ('bcsel', ('ult', 31, 'bits'), 'value',
653 ('ubfe', 'value', 'offset', 'bits')),
654 'options->lower_bitfield_extract'),
655
656 (('ibitfield_extract', 'value', 'offset', 'bits'),
657 ('bcsel', ('ieq', 0, 'bits'),
658 0,
659 ('ishr',
660 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
661 ('isub', 32, 'bits'))),
662 'options->lower_bitfield_extract_to_shifts'),
663
664 (('ubitfield_extract', 'value', 'offset', 'bits'),
665 ('iand',
666 ('ushr', 'value', 'offset'),
667 ('bcsel', ('ieq', 'bits', 32),
668 0xffffffff,
669 ('bfm', 'bits', 0))),
670 'options->lower_bitfield_extract_to_shifts'),
671
672 (('ifind_msb', 'value'),
673 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
674 'options->lower_ifind_msb'),
675
676 (('find_lsb', 'value'),
677 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
678 'options->lower_find_lsb'),
679
680 (('extract_i8', a, 'b@32'),
681 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
682 'options->lower_extract_byte'),
683
684 (('extract_u8', a, 'b@32'),
685 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
686 'options->lower_extract_byte'),
687
688 (('extract_i16', a, 'b@32'),
689 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
690 'options->lower_extract_word'),
691
692 (('extract_u16', a, 'b@32'),
693 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
694 'options->lower_extract_word'),
695
696 (('pack_unorm_2x16', 'v'),
697 ('pack_uvec2_to_uint',
698 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
699 'options->lower_pack_unorm_2x16'),
700
701 (('pack_unorm_4x8', 'v'),
702 ('pack_uvec4_to_uint',
703 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
704 'options->lower_pack_unorm_4x8'),
705
706 (('pack_snorm_2x16', 'v'),
707 ('pack_uvec2_to_uint',
708 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
709 'options->lower_pack_snorm_2x16'),
710
711 (('pack_snorm_4x8', 'v'),
712 ('pack_uvec4_to_uint',
713 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
714 'options->lower_pack_snorm_4x8'),
715
716 (('unpack_unorm_2x16', 'v'),
717 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
718 ('extract_u16', 'v', 1))),
719 65535.0),
720 'options->lower_unpack_unorm_2x16'),
721
722 (('unpack_unorm_4x8', 'v'),
723 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
724 ('extract_u8', 'v', 1),
725 ('extract_u8', 'v', 2),
726 ('extract_u8', 'v', 3))),
727 255.0),
728 'options->lower_unpack_unorm_4x8'),
729
730 (('unpack_snorm_2x16', 'v'),
731 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f32', ('vec2', ('extract_i16', 'v', 0),
732 ('extract_i16', 'v', 1))),
733 32767.0))),
734 'options->lower_unpack_snorm_2x16'),
735
736 (('unpack_snorm_4x8', 'v'),
737 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f32', ('vec4', ('extract_i8', 'v', 0),
738 ('extract_i8', 'v', 1),
739 ('extract_i8', 'v', 2),
740 ('extract_i8', 'v', 3))),
741 127.0))),
742 'options->lower_unpack_snorm_4x8'),
743 ]
744
745 invert = OrderedDict([('feq', 'fne'), ('fne', 'feq'), ('fge', 'flt'), ('flt', 'fge')])
746
747 for left, right in itertools.combinations_with_replacement(invert.keys(), 2):
748 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
749 ('iand', (invert[left], a, b), (invert[right], c, d))))
750 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
751 ('ior', (invert[left], a, b), (invert[right], c, d))))
752
753 def fexp2i(exp, bits):
754 # We assume that exp is already in the right range.
755 if bits == 32:
756 return ('ishl', ('iadd', exp, 127), 23)
757 elif bits == 64:
758 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
759 else:
760 assert False
761
762 def ldexp(f, exp, bits):
763 # First, we clamp exp to a reasonable range. The maximum possible range
764 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
765 # a maximum range of [-149, 127]. This means that we can potentially have
766 # a swing of +-276. If you start with FLT_MAX, you actually have to do
767 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
768 # spec, on the other hand, only requires that we handle an exponent value
769 # in the range [-126, 128]. This implementation is *mostly* correct; it
770 # handles a range on exp of [-252, 254] which allows you to create any
771 # value (including denorms if the hardware supports it) and to adjust the
772 # exponent of any normal value to anything you want.
773 if bits == 32:
774 exp = ('imin', ('imax', exp, -252), 254)
775 elif bits == 64:
776 exp = ('imin', ('imax', exp, -2044), 2046)
777 else:
778 assert False
779
780 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
781 # (We use ishr which isn't the same for -1, but the -1 case still works
782 # since we use exp-exp/2 as the second exponent.) While the spec
783 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
784 # work with denormals and doesn't allow for the full swing in exponents
785 # that you can get with normalized values. Instead, we create two powers
786 # of two and multiply by them each in turn. That way the effective range
787 # of our exponent is doubled.
788 pow2_1 = fexp2i(('ishr', exp, 1), bits)
789 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
790 return ('fmul', ('fmul', f, pow2_1), pow2_2)
791
792 optimizations += [
793 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
794 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
795 ]
796
797 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
798 def bitfield_reverse(u):
799 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
800 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
801 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
802 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
803 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
804
805 return step5
806
807 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'))]
808
809 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
810 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
811 # and, if a is a NaN then the second comparison will fail anyway.
812 for op in ['flt', 'fge', 'feq']:
813 optimizations += [
814 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
815 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
816 ]
817
818 # Add optimizations to handle the case where the result of a ternary is
819 # compared to a constant. This way we can take things like
820 #
821 # (a ? 0 : 1) > 0
822 #
823 # and turn it into
824 #
825 # a ? (0 > 0) : (1 > 0)
826 #
827 # which constant folding will eat for lunch. The resulting ternary will
828 # further get cleaned up by the boolean reductions above and we will be
829 # left with just the original variable "a".
830 for op in ['flt', 'fge', 'feq', 'fne',
831 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
832 optimizations += [
833 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
834 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
835 ((op, '#d', ('bcsel', a, '#b', '#c')),
836 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
837 ]
838
839
840 # For example, this converts things like
841 #
842 # 1 + mix(0, a - 1, condition)
843 #
844 # into
845 #
846 # mix(1, (a-1)+1, condition)
847 #
848 # Other optimizations will rearrange the constants.
849 for op in ['fadd', 'fmul', 'iadd', 'imul']:
850 optimizations += [
851 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
852 ]
853
854 # This section contains "late" optimizations that should be run before
855 # creating ffmas and calling regular optimizations for the final time.
856 # Optimizations should go here if they help code generation and conflict
857 # with the regular optimizations.
858 before_ffma_optimizations = [
859 # Propagate constants down multiplication chains
860 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
861 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
862 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
863 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
864
865 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
866 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
867 (('~fadd', ('fneg', a), a), 0.0),
868 (('iadd', ('ineg', a), a), 0),
869 (('iadd', ('ineg', a), ('iadd', a, b)), b),
870 (('iadd', a, ('iadd', ('ineg', a), b)), b),
871 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
872 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
873 ]
874
875 # This section contains "late" optimizations that should be run after the
876 # regular optimizations have finished. Optimizations should go here if
877 # they help code generation but do not necessarily produce code that is
878 # more easily optimizable.
879 late_optimizations = [
880 # Most of these optimizations aren't quite safe when you get infinity or
881 # Nan involved but the first one should be fine.
882 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
883 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
884 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
885 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
886 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
887 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
888
889 (('~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)))),
890
891 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
892 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
893 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
894 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
895
896 (('b2f(is_used_more_than_once)', ('inot', a)), ('bcsel', a, 0.0, 1.0)),
897 (('fneg(is_used_more_than_once)', ('b2f', ('inot', a))), ('bcsel', a, -0.0, -1.0)),
898
899 # we do these late so that we don't get in the way of creating ffmas
900 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
901 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
902
903 # Lowered for backends without a dedicated b2f instruction
904 (('b2f@32', a), ('iand', a, 1.0), 'options->lower_b2f'),
905 ]
906
907 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render())
908 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
909 before_ffma_optimizations).render())
910 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
911 late_optimizations).render())