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