789a57e38b63944a0811e2db3cb926a897023a92
[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 from nir_opcodes import type_sizes
31 import itertools
32
33 # Convenience variables
34 a = 'a'
35 b = 'b'
36 c = 'c'
37 d = 'd'
38
39 # Written in the form (<search>, <replace>) where <search> is an expression
40 # and <replace> is either an expression or a value. An expression is
41 # defined as a tuple of the form ([~]<op>, <src0>, <src1>, <src2>, <src3>)
42 # where each source is either an expression or a value. A value can be
43 # either a numeric constant or a string representing a variable name.
44 #
45 # If the opcode in a search expression is prefixed by a '~' character, this
46 # indicates that the operation is inexact. Such operations will only get
47 # applied to SSA values that do not have the exact bit set. This should be
48 # used by by any optimizations that are not bit-for-bit exact. It should not,
49 # however, be used for backend-requested lowering operations as those need to
50 # happen regardless of precision.
51 #
52 # Variable names are specified as "[#]name[@type][(cond)]" where "#" inicates
53 # that the given variable will only match constants and the type indicates that
54 # the given variable will only match values from ALU instructions with the
55 # given output type, and (cond) specifies an additional condition function
56 # (see nir_search_helpers.h).
57 #
58 # For constants, you have to be careful to make sure that it is the right
59 # type because python is unaware of the source and destination types of the
60 # opcodes.
61 #
62 # All expression types can have a bit-size specified. For opcodes, this
63 # looks like "op@32", for variables it is "a@32" or "a@uint32" to specify a
64 # type and size. In the search half of the expression this indicates that it
65 # should only match that particular bit-size. In the replace half of the
66 # expression this indicates that the constructed value should have that
67 # bit-size.
68
69 optimizations = [
70
71 (('imul', a, '#b@32(is_pos_power_of_two)'), ('ishl', a, ('find_lsb', b))),
72 (('imul', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('ishl', a, ('find_lsb', ('iabs', b))))),
73 (('udiv', a, 1), a),
74 (('idiv', a, 1), a),
75 (('umod', a, 1), 0),
76 (('imod', a, 1), 0),
77 (('udiv', a, '#b@32(is_pos_power_of_two)'), ('ushr', a, ('find_lsb', b))),
78 (('idiv', a, '#b@32(is_pos_power_of_two)'), ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', b))), 'options->lower_idiv'),
79 (('idiv', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', ('iabs', b))))), 'options->lower_idiv'),
80 (('umod', a, '#b(is_pos_power_of_two)'), ('iand', a, ('isub', b, 1))),
81
82 (('fneg', ('fneg', a)), a),
83 (('ineg', ('ineg', a)), a),
84 (('fabs', ('fabs', a)), ('fabs', a)),
85 (('fabs', ('fneg', a)), ('fabs', a)),
86 (('fabs', ('u2f', a)), ('u2f', a)),
87 (('iabs', ('iabs', a)), ('iabs', a)),
88 (('iabs', ('ineg', a)), ('iabs', a)),
89 (('f2b', ('fneg', a)), ('f2b', a)),
90 (('i2b', ('ineg', a)), ('i2b', a)),
91 (('~fadd', a, 0.0), a),
92 (('iadd', a, 0), a),
93 (('usadd_4x8', a, 0), a),
94 (('usadd_4x8', a, ~0), ~0),
95 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
96 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
97 (('~fadd', ('fneg', a), a), 0.0),
98 (('iadd', ('ineg', a), a), 0),
99 (('iadd', ('ineg', a), ('iadd', a, b)), b),
100 (('iadd', a, ('iadd', ('ineg', a), b)), b),
101 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
102 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
103 (('~fmul', a, 0.0), 0.0),
104 (('imul', a, 0), 0),
105 (('umul_unorm_4x8', a, 0), 0),
106 (('umul_unorm_4x8', a, ~0), a),
107 (('fmul', a, 1.0), a),
108 (('imul', a, 1), a),
109 (('fmul', a, -1.0), ('fneg', a)),
110 (('imul', a, -1), ('ineg', a)),
111 # If a < 0: fsign(a)*a*a => -1*a*a => -a*a => abs(a)*a
112 # If a > 0: fsign(a)*a*a => 1*a*a => a*a => abs(a)*a
113 # If a == 0: fsign(a)*a*a => 0*0*0 => abs(0)*0
114 (('fmul', ('fsign', a), ('fmul', a, a)), ('fmul', ('fabs', a), a)),
115 (('fmul', ('fmul', ('fsign', a), a), a), ('fmul', ('fabs', a), a)),
116 (('~ffma', 0.0, a, b), b),
117 (('~ffma', a, 0.0, b), b),
118 (('~ffma', a, b, 0.0), ('fmul', a, b)),
119 (('ffma', a, 1.0, b), ('fadd', a, b)),
120 (('ffma', 1.0, a, b), ('fadd', a, b)),
121 (('~flrp', a, b, 0.0), a),
122 (('~flrp', a, b, 1.0), b),
123 (('~flrp', a, a, b), a),
124 (('~flrp', 0.0, a, b), ('fmul', a, b)),
125 (('~flrp', a, b, ('b2f', 'c@1')), ('bcsel', c, b, a), 'options->lower_flrp32'),
126 (('~flrp', a, 0.0, c), ('fadd', ('fmul', ('fneg', a), c), a)),
127 (('flrp@32', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp32'),
128 (('flrp@64', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp64'),
129 (('ffloor', a), ('fsub', a, ('ffract', a)), 'options->lower_ffloor'),
130 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
131 (('fceil', a), ('fneg', ('ffloor', ('fneg', a))), 'options->lower_fceil'),
132 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', 'c@1')))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'),
133 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'),
134 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'),
135 (('~fadd', a, ('fmul', ('b2f', 'c@1'), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'),
136 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'),
137 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'),
138 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
139 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'),
140
141 (('fdot4', ('vec4', a, b, c, 1.0), d), ('fdph', ('vec3', a, b, c), d)),
142 (('fdot4', ('vec4', a, 0.0, 0.0, 0.0), b), ('fmul', a, b)),
143 (('fdot4', ('vec4', a, b, 0.0, 0.0), c), ('fdot2', ('vec2', a, b), c)),
144 (('fdot4', ('vec4', a, b, c, 0.0), d), ('fdot3', ('vec3', a, b, c), d)),
145
146 (('fdot3', ('vec3', a, 0.0, 0.0), b), ('fmul', a, b)),
147 (('fdot3', ('vec3', a, b, 0.0), c), ('fdot2', ('vec2', a, b), c)),
148
149 # (a * #b + #c) << #d
150 # ((a * #b) << #d) + (#c << #d)
151 # (a * (#b << #d)) + (#c << #d)
152 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'),
153 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))),
154
155 # (a * #b) << #c
156 # a * (#b << #c)
157 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))),
158
159 # Comparison simplifications
160 (('~inot', ('flt', a, b)), ('fge', a, b)),
161 (('~inot', ('fge', a, b)), ('flt', a, b)),
162 (('~inot', ('feq', a, b)), ('fne', a, b)),
163 (('~inot', ('fne', a, b)), ('feq', a, b)),
164 (('inot', ('ilt', a, b)), ('ige', a, b)),
165 (('inot', ('ult', a, b)), ('uge', a, b)),
166 (('inot', ('ige', a, b)), ('ilt', a, b)),
167 (('inot', ('uge', a, b)), ('ult', a, b)),
168 (('inot', ('ieq', a, b)), ('ine', a, b)),
169 (('inot', ('ine', a, b)), ('ieq', a, b)),
170
171 # 0.0 >= b2f(a)
172 # b2f(a) <= 0.0
173 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1
174 # inot(a)
175 (('fge', 0.0, ('b2f', 'a@1')), ('inot', a)),
176
177 (('fge', ('fneg', ('b2f', 'a@1')), 0.0), ('inot', a)),
178
179 (('fne', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('ior', a, b)),
180 (('fne', ('fmax', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('ior', a, b)),
181 (('fne', ('bcsel', a, 1.0, ('b2f', 'b@1')) , 0.0), ('ior', a, b)),
182 (('fne', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), ('ior', a, b)),
183 (('fne', ('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('iand', a, b)),
184 (('fne', ('fmin', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('iand', a, b)),
185 (('fne', ('bcsel', a, ('b2f', 'b@1'), 0.0) , 0.0), ('iand', a, b)),
186 (('fne', ('fadd', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), 0.0), ('ixor', a, b)),
187 (('fne', ('b2f', 'a@1') , ('b2f', 'b@1') ), ('ixor', a, b)),
188 (('fne', ('fneg', ('b2f', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('ixor', a, b)),
189 (('feq', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('ior', a, b))),
190 (('feq', ('fmax', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('ior', a, b))),
191 (('feq', ('bcsel', a, 1.0, ('b2f', 'b@1')) , 0.0), ('inot', ('ior', a, b))),
192 (('feq', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), ('inot', ('ior', a, b))),
193 (('feq', ('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('iand', a, b))),
194 (('feq', ('fmin', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('iand', a, b))),
195 (('feq', ('bcsel', a, ('b2f', 'b@1'), 0.0) , 0.0), ('inot', ('iand', a, b))),
196 (('feq', ('fadd', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), 0.0), ('ieq', a, b)),
197 (('feq', ('b2f', 'a@1') , ('b2f', 'b@1') ), ('ieq', a, b)),
198 (('feq', ('fneg', ('b2f', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('ieq', a, b)),
199
200 # -(b2f(a) + b2f(b)) < 0
201 # 0 < b2f(a) + b2f(b)
202 # 0 != b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
203 # a || b
204 (('flt', ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), 0.0), ('ior', a, b)),
205 (('flt', 0.0, ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('ior', a, b)),
206
207 # -(b2f(a) + b2f(b)) >= 0
208 # 0 >= b2f(a) + b2f(b)
209 # 0 == b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
210 # !(a || b)
211 (('fge', ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), 0.0), ('inot', ('ior', a, b))),
212 (('fge', 0.0, ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('inot', ('ior', a, b))),
213
214 # Some optimizations (below) convert things like (a < b || c < b) into
215 # (min(a, c) < b). However, this interfers with the previous optimizations
216 # that try to remove comparisons with negated sums of b2f. This just
217 # breaks that apart.
218 (('flt', ('fmin', c, ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')))), 0.0),
219 ('ior', ('flt', c, 0.0), ('ior', a, b))),
220
221 (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)),
222 (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)),
223 (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)),
224 (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)),
225
226 # Cannot remove the addition from ilt or ige due to overflow.
227 (('ieq', ('iadd', a, b), a), ('ieq', b, 0)),
228 (('ine', ('iadd', a, b), a), ('ine', b, 0)),
229
230 # fmin(-b2f(a), b) >= 0.0
231 # -b2f(a) >= 0.0 && b >= 0.0
232 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0
233 # b2f(a) == 0.0 && b >= 0.0
234 # a == False && b >= 0.0
235 # !a && b >= 0.0
236 #
237 # The fge in the second replacement is not a typo. I leave the proof that
238 # "fmin(-b2f(a), b) >= 0 <=> fmin(-b2f(a), b) == 0" as an exercise for the
239 # reader.
240 (('fge', ('fmin', ('fneg', ('b2f', 'a@1')), 'b@1'), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
241 (('feq', ('fmin', ('fneg', ('b2f', 'a@1')), 'b@1'), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
242
243 (('feq', ('b2f', 'a@1'), 0.0), ('inot', a)),
244 (('fne', ('b2f', 'a@1'), 0.0), a),
245 (('ieq', ('b2i', 'a@1'), 0), ('inot', a)),
246 (('ine', ('b2i', 'a@1'), 0), a),
247
248 (('fne', ('u2f', a), 0.0), ('ine', a, 0)),
249 (('feq', ('u2f', a), 0.0), ('ieq', a, 0)),
250 (('fge', ('u2f', a), 0.0), True),
251 (('fge', 0.0, ('u2f', a)), ('uge', 0, a)), # ieq instead?
252 (('flt', ('u2f', a), 0.0), False),
253 (('flt', 0.0, ('u2f', a)), ('ult', 0, a)), # ine instead?
254 (('fne', ('i2f', a), 0.0), ('ine', a, 0)),
255 (('feq', ('i2f', a), 0.0), ('ieq', a, 0)),
256 (('fge', ('i2f', a), 0.0), ('ige', a, 0)),
257 (('fge', 0.0, ('i2f', a)), ('ige', 0, a)),
258 (('flt', ('i2f', a), 0.0), ('ilt', a, 0)),
259 (('flt', 0.0, ('i2f', a)), ('ilt', 0, a)),
260
261 # 0.0 < fabs(a)
262 # fabs(a) > 0.0
263 # fabs(a) != 0.0 because fabs(a) must be >= 0
264 # a != 0.0
265 (('~flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
266
267 # -fabs(a) < 0.0
268 # fabs(a) > 0.0
269 (('~flt', ('fneg', ('fabs', a)), 0.0), ('fne', a, 0.0)),
270
271 # 0.0 >= fabs(a)
272 # 0.0 == fabs(a) because fabs(a) must be >= 0
273 # 0.0 == a
274 (('fge', 0.0, ('fabs', a)), ('feq', a, 0.0)),
275
276 # -fabs(a) >= 0.0
277 # 0.0 >= fabs(a)
278 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
279
280 (('fmax', ('b2f(is_used_once)', 'a@1'), ('b2f', 'b@1')), ('b2f', ('ior', a, b))),
281 (('fmax', ('fneg(is_used_once)', ('b2f(is_used_once)', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('fneg', ('b2f', ('ior', a, b)))),
282 (('fmin', ('b2f(is_used_once)', 'a@1'), ('b2f', 'b@1')), ('b2f', ('iand', a, b))),
283 (('fmin', ('fneg(is_used_once)', ('b2f(is_used_once)', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('fneg', ('b2f', ('iand', a, b)))),
284
285 # fmin(b2f(a), b)
286 # bcsel(a, fmin(b2f(a), b), fmin(b2f(a), b))
287 # bcsel(a, fmin(b2f(True), b), fmin(b2f(False), b))
288 # bcsel(a, fmin(1.0, b), fmin(0.0, b))
289 #
290 # Since b is a constant, constant folding will eliminate the fmin and the
291 # fmax. If b is > 1.0, the bcsel will be replaced with a b2f.
292 (('fmin', ('b2f', 'a@1'), '#b'), ('bcsel', a, ('fmin', b, 1.0), ('fmin', b, 0.0))),
293
294 (('flt', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
295
296 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
297 (('~bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
298 (('~bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
299 (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)),
300 (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)),
301 (('bcsel', ('i2b', a), b, c), ('bcsel', ('ine', a, 0), b, c)),
302 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)),
303 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
304 (('bcsel', a, b, ('bcsel', a, c, d)), ('bcsel', a, b, d)),
305 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
306 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
307 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
308 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
309 (('bcsel', a, True, 'b@bool'), ('ior', a, b)),
310 (('fmin', a, a), a),
311 (('fmax', a, a), a),
312 (('imin', a, a), a),
313 (('imax', a, a), a),
314 (('umin', a, a), a),
315 (('umax', a, a), a),
316 (('fmax', ('fmax', a, b), b), ('fmax', a, b)),
317 (('umax', ('umax', a, b), b), ('umax', a, b)),
318 (('imax', ('imax', a, b), b), ('imax', a, b)),
319 (('fmin', ('fmin', a, b), b), ('fmin', a, b)),
320 (('umin', ('umin', a, b), b), ('umin', a, b)),
321 (('imin', ('imin', a, b), b), ('imin', a, b)),
322 (('fmax', a, ('fneg', a)), ('fabs', a)),
323 (('imax', a, ('ineg', a)), ('iabs', a)),
324 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))),
325 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))),
326 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))),
327 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))),
328 (('fmin', a, ('fabs', a)), a),
329 (('imin', a, ('iabs', a)), a),
330 (('fmax', a, ('fneg', ('fabs', a))), a),
331 (('imax', a, ('ineg', ('iabs', a))), a),
332 (('fmax', a, ('fabs', a)), ('fabs', a)),
333 (('imax', a, ('iabs', a)), ('iabs', a)),
334 (('fmax', a, ('fneg', a)), ('fabs', a)),
335 (('imax', a, ('ineg', a)), ('iabs', a)),
336 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
337 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
338 (('fsat', ('fsign', a)), ('b2f', ('flt', 0.0, a))),
339 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
340 (('fsat', ('fsat', a)), ('fsat', a)),
341 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)),
342 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)),
343 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)),
344 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))),
345 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))),
346 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
347 (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
348 (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
349 (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
350 (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
351 (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
352 (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
353 (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
354 (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
355 (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
356 (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
357 (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
358 (('~iand', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmin', a, b), c)),
359 (('~iand', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmin', b, c))),
360 (('~iand', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmax', a, b), c)),
361 (('~iand', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmax', b, c))),
362 (('~iand', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmin', a, b), c)),
363
364 (('ior', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imax', b, c))),
365 (('ior', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imin', a, b), c)),
366 (('ior', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imin', b, c))),
367 (('ior', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imax', a, b), c)),
368 (('ior', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umax', b, c))),
369 (('ior', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umin', a, b), c)),
370 (('ior', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umin', b, c))),
371 (('ior', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umax', a, b), c)),
372 (('iand', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imin', b, c))),
373 (('iand', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imax', a, b), c)),
374 (('iand', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imax', b, c))),
375 (('iand', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imin', a, b), c)),
376 (('iand', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umin', b, c))),
377 (('iand', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umax', a, b), c)),
378 (('iand', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umax', b, c))),
379 (('iand', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umin', a, b), c)),
380
381 # Common pattern like 'if (i == 0 || i == 1 || ...)'
382 (('ior', ('ieq', a, 0), ('ieq', a, 1)), ('uge', 1, a)),
383 (('ior', ('uge', 1, a), ('ieq', a, 2)), ('uge', 2, a)),
384 (('ior', ('uge', 2, a), ('ieq', a, 3)), ('uge', 3, a)),
385
386 (('ior', 'a@bool', ('ieq', a, False)), True),
387 (('ior', a, ('inot', a)), -1),
388
389 (('iand', ('ieq', 'a@32', 0), ('ieq', 'b@32', 0)), ('ieq', ('ior', 'a@32', 'b@32'), 0)),
390
391 # These patterns can result when (a < b || a < c) => (a < min(b, c))
392 # transformations occur before constant propagation and loop-unrolling.
393 (('~flt', a, ('fmax', b, a)), ('flt', a, b)),
394 (('~flt', ('fmin', a, b), a), ('flt', b, a)),
395 (('~fge', a, ('fmin', b, a)), True),
396 (('~fge', ('fmax', a, b), a), True),
397 (('~flt', a, ('fmin', b, a)), False),
398 (('~flt', ('fmax', a, b), a), False),
399 (('~fge', a, ('fmax', b, a)), ('fge', a, b)),
400 (('~fge', ('fmin', a, b), a), ('fge', b, a)),
401
402 (('ilt', a, ('imax', b, a)), ('ilt', a, b)),
403 (('ilt', ('imin', a, b), a), ('ilt', b, a)),
404 (('ige', a, ('imin', b, a)), True),
405 (('ige', ('imax', a, b), a), True),
406 (('ult', a, ('umax', b, a)), ('ult', a, b)),
407 (('ult', ('umin', a, b), a), ('ult', b, a)),
408 (('uge', a, ('umin', b, a)), True),
409 (('uge', ('umax', a, b), a), True),
410 (('ilt', a, ('imin', b, a)), False),
411 (('ilt', ('imax', a, b), a), False),
412 (('ige', a, ('imax', b, a)), ('ige', a, b)),
413 (('ige', ('imin', a, b), a), ('ige', b, a)),
414 (('ult', a, ('umin', b, a)), False),
415 (('ult', ('umax', a, b), a), False),
416 (('uge', a, ('umax', b, a)), ('uge', a, b)),
417 (('uge', ('umin', a, b), a), ('uge', b, a)),
418
419 (('ilt', '#a', ('imax', '#b', c)), ('ior', ('ilt', a, b), ('ilt', a, c))),
420 (('ilt', ('imin', '#a', b), '#c'), ('ior', ('ilt', a, c), ('ilt', b, c))),
421 (('ige', '#a', ('imin', '#b', c)), ('ior', ('ige', a, b), ('ige', a, c))),
422 (('ige', ('imax', '#a', b), '#c'), ('ior', ('ige', a, c), ('ige', b, c))),
423 (('ult', '#a', ('umax', '#b', c)), ('ior', ('ult', a, b), ('ult', a, c))),
424 (('ult', ('umin', '#a', b), '#c'), ('ior', ('ult', a, c), ('ult', b, c))),
425 (('uge', '#a', ('umin', '#b', c)), ('ior', ('uge', a, b), ('uge', a, c))),
426 (('uge', ('umax', '#a', b), '#c'), ('ior', ('uge', a, c), ('uge', b, c))),
427 (('ilt', '#a', ('imin', '#b', c)), ('iand', ('ilt', a, b), ('ilt', a, c))),
428 (('ilt', ('imax', '#a', b), '#c'), ('iand', ('ilt', a, c), ('ilt', b, c))),
429 (('ige', '#a', ('imax', '#b', c)), ('iand', ('ige', a, b), ('ige', a, c))),
430 (('ige', ('imin', '#a', b), '#c'), ('iand', ('ige', a, c), ('ige', b, c))),
431 (('ult', '#a', ('umin', '#b', c)), ('iand', ('ult', a, b), ('ult', a, c))),
432 (('ult', ('umax', '#a', b), '#c'), ('iand', ('ult', a, c), ('ult', b, c))),
433 (('uge', '#a', ('umax', '#b', c)), ('iand', ('uge', a, b), ('uge', a, c))),
434 (('uge', ('umin', '#a', b), '#c'), ('iand', ('uge', a, c), ('uge', b, c))),
435
436 (('fabs', ('slt', a, b)), ('slt', a, b)),
437 (('fabs', ('sge', a, b)), ('sge', a, b)),
438 (('fabs', ('seq', a, b)), ('seq', a, b)),
439 (('fabs', ('sne', a, b)), ('sne', a, b)),
440 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
441 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
442 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
443 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
444 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
445 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
446 # Emulating booleans
447 (('imul', ('b2i', 'a@1'), ('b2i', 'b@1')), ('b2i', ('iand', a, b))),
448 (('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), ('b2f', ('iand', a, b))),
449 (('fsat', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('b2f', ('ior', a, b))),
450 (('iand', 'a@bool32', 1.0), ('b2f', a)),
451 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True).
452 (('ineg', ('b2i32', 'a@32')), a),
453 (('flt', ('fneg', ('b2f', 'a@1')), 0), a), # Generated by TGSI KILL_IF.
454 (('flt', ('fsub', 0.0, ('b2f', 'a@1')), 0), a), # Generated by TGSI KILL_IF.
455 # Comparison with the same args. Note that these are not done for
456 # the float versions because NaN always returns false on float
457 # inequalities.
458 (('ilt', a, a), False),
459 (('ige', a, a), True),
460 (('ieq', a, a), True),
461 (('ine', a, a), False),
462 (('ult', a, a), False),
463 (('uge', a, a), True),
464 # Logical and bit operations
465 (('fand', a, 0.0), 0.0),
466 (('iand', a, a), a),
467 (('iand', a, ~0), a),
468 (('iand', a, 0), 0),
469 (('ior', a, a), a),
470 (('ior', a, 0), a),
471 (('ior', a, True), True),
472 (('fxor', a, a), 0.0),
473 (('ixor', a, a), 0),
474 (('ixor', a, 0), a),
475 (('inot', ('inot', a)), a),
476 (('ior', ('iand', a, b), b), b),
477 (('ior', ('ior', a, b), b), ('ior', a, b)),
478 (('iand', ('ior', a, b), b), b),
479 (('iand', ('iand', a, b), b), ('iand', a, b)),
480 # DeMorgan's Laws
481 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
482 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
483 # Shift optimizations
484 (('ishl', 0, a), 0),
485 (('ishl', a, 0), a),
486 (('ishr', 0, a), 0),
487 (('ishr', a, 0), a),
488 (('ushr', 0, a), 0),
489 (('ushr', a, 0), a),
490 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)),
491 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)),
492 # Exponential/logarithmic identities
493 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a
494 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a
495 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
496 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
497 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
498 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
499 (('~fexp2', ('fmul', ('flog2', a), 2.0)), ('fmul', a, a)),
500 (('~fexp2', ('fmul', ('flog2', a), 4.0)), ('fmul', ('fmul', a, a), ('fmul', a, a))),
501 (('~fpow', a, 1.0), a),
502 (('~fpow', a, 2.0), ('fmul', a, a)),
503 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
504 (('~fpow', 2.0, a), ('fexp2', a)),
505 (('~fpow', ('fpow', a, 2.2), 0.454545), a),
506 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
507 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
508 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
509 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
510 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
511 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))),
512 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
513 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
514 (('~fmul', ('fexp2(is_used_once)', a), ('fexp2(is_used_once)', b)), ('fexp2', ('fadd', a, b))),
515 # Division and reciprocal
516 (('~fdiv', 1.0, a), ('frcp', a)),
517 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
518 (('~frcp', ('frcp', a)), a),
519 (('~frcp', ('fsqrt', a)), ('frsq', a)),
520 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
521 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
522 # Boolean simplifications
523 (('i2b32(is_used_by_if)', a), ('ine32', a, 0)),
524 (('i2b1(is_used_by_if)', a), ('ine', a, 0)),
525 (('ieq', 'a@bool', True), a),
526 (('ine(is_not_used_by_if)', 'a@bool', True), ('inot', a)),
527 (('ine', 'a@bool', False), a),
528 (('ieq(is_not_used_by_if)', 'a@bool', False), ('inot', 'a')),
529 (('bcsel', a, True, False), a),
530 (('bcsel', a, False, True), ('inot', a)),
531 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)),
532 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))),
533 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))),
534 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))),
535 (('bcsel', True, b, c), b),
536 (('bcsel', False, b, c), c),
537 (('bcsel', a, ('b2f(is_used_once)', 'b@32'), ('b2f', 'c@32')), ('b2f', ('bcsel', a, b, c))),
538 # The result of this should be hit by constant propagation and, in the
539 # next round of opt_algebraic, get picked up by one of the above two.
540 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
541
542 (('bcsel', a, b, b), b),
543 (('fcsel', a, b, b), b),
544
545 # D3D Boolean emulation
546 (('bcsel', a, -1, 0), ('ineg', ('b2i', 'a@1'))),
547 (('bcsel', a, 0, -1), ('ineg', ('b2i', ('inot', a)))),
548 (('iand', ('ineg', ('b2i', 'a@1')), ('ineg', ('b2i', 'b@1'))),
549 ('ineg', ('b2i', ('iand', a, b)))),
550 (('ior', ('ineg', ('b2i','a@1')), ('ineg', ('b2i', 'b@1'))),
551 ('ineg', ('b2i', ('ior', a, b)))),
552 (('ieq', ('ineg', ('b2i', 'a@1')), 0), ('inot', a)),
553 (('ieq', ('ineg', ('b2i', 'a@1')), -1), a),
554 (('ine', ('ineg', ('b2i', 'a@1')), 0), a),
555 (('ine', ('ineg', ('b2i', 'a@1')), -1), ('inot', a)),
556 (('iand', ('ineg', ('b2i', a)), 1.0), ('b2f', a)),
557
558 # SM5 32-bit shifts are defined to use the 5 least significant bits
559 (('ishl', 'a@32', ('iand', 31, b)), ('ishl', a, b)),
560 (('ishr', 'a@32', ('iand', 31, b)), ('ishr', a, b)),
561 (('ushr', 'a@32', ('iand', 31, b)), ('ushr', a, b)),
562
563 # Conversions
564 (('i2b32', ('b2i', 'a@32')), a),
565 (('f2i', ('ftrunc', a)), ('f2i', a)),
566 (('f2u', ('ftrunc', a)), ('f2u', a)),
567 (('i2b', ('ineg', a)), ('i2b', a)),
568 (('i2b', ('iabs', a)), ('i2b', a)),
569 (('fabs', ('b2f', a)), ('b2f', a)),
570 (('iabs', ('b2i', a)), ('b2i', a)),
571 (('inot', ('f2b1', a)), ('feq', a, 0.0)),
572
573 # Ironically, mark these as imprecise because removing the conversions may
574 # preserve more precision than doing the conversions (e.g.,
575 # uint(float(0x81818181u)) == 0x81818200).
576 (('~f2i32', ('i2f', 'a@32')), a),
577 (('~f2i32', ('u2f', 'a@32')), a),
578 (('~f2u32', ('i2f', 'a@32')), a),
579 (('~f2u32', ('u2f', 'a@32')), a),
580
581 # Section 5.4.1 (Conversion and Scalar Constructors) of the GLSL 4.60 spec
582 # says:
583 #
584 # It is undefined to convert a negative floating-point value to an
585 # uint.
586 #
587 # Assuming that (uint)some_float behaves like (uint)(int)some_float allows
588 # some optimizations in the i965 backend to proceed.
589 (('ige', ('f2u', a), b), ('ige', ('f2i', a), b)),
590 (('ige', b, ('f2u', a)), ('ige', b, ('f2i', a))),
591 (('ilt', ('f2u', a), b), ('ilt', ('f2i', a), b)),
592 (('ilt', b, ('f2u', a)), ('ilt', b, ('f2i', a))),
593
594 # Packing and then unpacking does nothing
595 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
596 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
597 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
598 ('unpack_64_2x32_split_y', a)), a),
599
600 # Byte extraction
601 (('ushr', ('ishl', 'a@32', 24), 24), ('extract_u8', a, 0), '!options->lower_extract_byte'),
602 (('ushr', ('ishl', 'a@32', 16), 24), ('extract_u8', a, 1), '!options->lower_extract_byte'),
603 (('ushr', ('ishl', 'a@32', 8), 24), ('extract_u8', a, 2), '!options->lower_extract_byte'),
604 (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
605 (('ishr', ('ishl', 'a@32', 24), 24), ('extract_i8', a, 0), '!options->lower_extract_byte'),
606 (('ishr', ('ishl', 'a@32', 16), 24), ('extract_i8', a, 1), '!options->lower_extract_byte'),
607 (('ishr', ('ishl', 'a@32', 8), 24), ('extract_i8', a, 2), '!options->lower_extract_byte'),
608 (('ishr', 'a@32', 24), ('extract_i8', a, 3), '!options->lower_extract_byte'),
609 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
610 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
611 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
612
613 # Word extraction
614 (('ushr', ('ishl', 'a@32', 16), 16), ('extract_u16', a, 0), '!options->lower_extract_word'),
615 (('ushr', 'a@32', 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
616 (('ishr', ('ishl', 'a@32', 16), 16), ('extract_i16', a, 0), '!options->lower_extract_word'),
617 (('ishr', 'a@32', 16), ('extract_i16', a, 1), '!options->lower_extract_word'),
618 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
619
620 # Subtracts
621 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
622 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
623 (('ussub_4x8', a, 0), a),
624 (('ussub_4x8', a, ~0), 0),
625 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
626 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
627 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
628 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
629 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
630 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
631 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
632 (('iabs', ('isub', 0, a)), ('iabs', a)),
633
634 # Propagate negation up multiplication chains
635 (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))),
636 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
637
638 # Propagate constants up multiplication chains
639 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
640 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
641 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
642 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
643
644 # Reassociate constants in add/mul chains so they can be folded together.
645 # For now, we mostly only handle cases where the constants are separated by
646 # a single non-constant. We could do better eventually.
647 (('~fmul', '#a', ('fmul', 'b(is_not_const)', '#c')), ('fmul', ('fmul', a, c), b)),
648 (('imul', '#a', ('imul', 'b(is_not_const)', '#c')), ('imul', ('imul', a, c), b)),
649 (('~fadd', '#a', ('fadd', 'b(is_not_const)', '#c')), ('fadd', ('fadd', a, c), b)),
650 (('~fadd', '#a', ('fneg', ('fadd', 'b(is_not_const)', '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
651 (('iadd', '#a', ('iadd', 'b(is_not_const)', '#c')), ('iadd', ('iadd', a, c), b)),
652
653 # By definition...
654 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
655 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
656 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
657
658 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
659 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
660 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
661
662 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
663
664 # Misc. lowering
665 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod32'),
666 (('fmod@64', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod64'),
667 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod32'),
668 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
669 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
670
671 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
672 ('bcsel', ('ilt', 31, 'bits'), 'insert',
673 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
674 'options->lower_bitfield_insert'),
675
676 # Alternative lowering that doesn't rely on bfi.
677 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
678 ('bcsel', ('ilt', 31, 'bits'),
679 'insert',
680 ('ior',
681 ('iand', 'base', ('inot', ('bfm', 'bits', 'offset'))),
682 ('iand', ('ishl', 'insert', 'offset'), ('bfm', 'bits', 'offset')))),
683 'options->lower_bitfield_insert_to_shifts'),
684
685 # bfm lowering -- note that the NIR opcode is undefined if either arg is 32.
686 (('bfm', 'bits', 'offset'),
687 ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'),
688 'options->lower_bfm'),
689
690 (('ibitfield_extract', 'value', 'offset', 'bits'),
691 ('bcsel', ('ilt', 31, 'bits'), 'value',
692 ('ibfe', 'value', 'offset', 'bits')),
693 'options->lower_bitfield_extract'),
694
695 (('ubitfield_extract', 'value', 'offset', 'bits'),
696 ('bcsel', ('ult', 31, 'bits'), 'value',
697 ('ubfe', 'value', 'offset', 'bits')),
698 'options->lower_bitfield_extract'),
699
700 (('ibitfield_extract', 'value', 'offset', 'bits'),
701 ('bcsel', ('ieq', 0, 'bits'),
702 0,
703 ('ishr',
704 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
705 ('isub', 32, 'bits'))),
706 'options->lower_bitfield_extract_to_shifts'),
707
708 (('ubitfield_extract', 'value', 'offset', 'bits'),
709 ('iand',
710 ('ushr', 'value', 'offset'),
711 ('bcsel', ('ieq', 'bits', 32),
712 0xffffffff,
713 ('bfm', 'bits', 0))),
714 'options->lower_bitfield_extract_to_shifts'),
715
716 (('ifind_msb', 'value'),
717 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
718 'options->lower_ifind_msb'),
719
720 (('find_lsb', 'value'),
721 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
722 'options->lower_find_lsb'),
723
724 (('extract_i8', a, 'b@32'),
725 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
726 'options->lower_extract_byte'),
727
728 (('extract_u8', a, 'b@32'),
729 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
730 'options->lower_extract_byte'),
731
732 (('extract_i16', a, 'b@32'),
733 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
734 'options->lower_extract_word'),
735
736 (('extract_u16', a, 'b@32'),
737 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
738 'options->lower_extract_word'),
739
740 (('pack_unorm_2x16', 'v'),
741 ('pack_uvec2_to_uint',
742 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
743 'options->lower_pack_unorm_2x16'),
744
745 (('pack_unorm_4x8', 'v'),
746 ('pack_uvec4_to_uint',
747 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
748 'options->lower_pack_unorm_4x8'),
749
750 (('pack_snorm_2x16', 'v'),
751 ('pack_uvec2_to_uint',
752 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
753 'options->lower_pack_snorm_2x16'),
754
755 (('pack_snorm_4x8', 'v'),
756 ('pack_uvec4_to_uint',
757 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
758 'options->lower_pack_snorm_4x8'),
759
760 (('unpack_unorm_2x16', 'v'),
761 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
762 ('extract_u16', 'v', 1))),
763 65535.0),
764 'options->lower_unpack_unorm_2x16'),
765
766 (('unpack_unorm_4x8', 'v'),
767 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
768 ('extract_u8', 'v', 1),
769 ('extract_u8', 'v', 2),
770 ('extract_u8', 'v', 3))),
771 255.0),
772 'options->lower_unpack_unorm_4x8'),
773
774 (('unpack_snorm_2x16', 'v'),
775 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
776 ('extract_i16', 'v', 1))),
777 32767.0))),
778 'options->lower_unpack_snorm_2x16'),
779
780 (('unpack_snorm_4x8', 'v'),
781 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
782 ('extract_i8', 'v', 1),
783 ('extract_i8', 'v', 2),
784 ('extract_i8', 'v', 3))),
785 127.0))),
786 'options->lower_unpack_snorm_4x8'),
787
788 (('isign', a), ('imin', ('imax', a, -1), 1), 'options->lower_isign'),
789 ]
790
791 invert = OrderedDict([('feq', 'fne'), ('fne', 'feq'), ('fge', 'flt'), ('flt', 'fge')])
792
793 for left, right in itertools.combinations_with_replacement(invert.keys(), 2):
794 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
795 ('iand', (invert[left], a, b), (invert[right], c, d))))
796 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
797 ('ior', (invert[left], a, b), (invert[right], c, d))))
798
799 # Optimize x2bN(b2x(x)) -> x
800 for size in type_sizes('bool'):
801 aN = 'a@' + str(size)
802 f2bN = 'f2b' + str(size)
803 i2bN = 'i2b' + str(size)
804 optimizations.append(((f2bN, ('b2f', aN)), a))
805 optimizations.append(((i2bN, ('b2i', aN)), a))
806
807 # Optimize x2yN(b2x(x)) -> b2y
808 for x, y in itertools.product(['f', 'u', 'i'], ['f', 'u', 'i']):
809 if x != 'f' and y != 'f' and x != y:
810 continue
811
812 b2x = 'b2f' if x == 'f' else 'b2i'
813 b2y = 'b2f' if y == 'f' else 'b2i'
814 x2yN = '{}2{}'.format(x, y)
815 optimizations.append(((x2yN, (b2x, a)), (b2y, a)))
816
817 def fexp2i(exp, bits):
818 # We assume that exp is already in the right range.
819 if bits == 32:
820 return ('ishl', ('iadd', exp, 127), 23)
821 elif bits == 64:
822 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
823 else:
824 assert False
825
826 def ldexp(f, exp, bits):
827 # First, we clamp exp to a reasonable range. The maximum possible range
828 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
829 # a maximum range of [-149, 127]. This means that we can potentially have
830 # a swing of +-276. If you start with FLT_MAX, you actually have to do
831 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
832 # spec, on the other hand, only requires that we handle an exponent value
833 # in the range [-126, 128]. This implementation is *mostly* correct; it
834 # handles a range on exp of [-252, 254] which allows you to create any
835 # value (including denorms if the hardware supports it) and to adjust the
836 # exponent of any normal value to anything you want.
837 if bits == 32:
838 exp = ('imin', ('imax', exp, -252), 254)
839 elif bits == 64:
840 exp = ('imin', ('imax', exp, -2044), 2046)
841 else:
842 assert False
843
844 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
845 # (We use ishr which isn't the same for -1, but the -1 case still works
846 # since we use exp-exp/2 as the second exponent.) While the spec
847 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
848 # work with denormals and doesn't allow for the full swing in exponents
849 # that you can get with normalized values. Instead, we create two powers
850 # of two and multiply by them each in turn. That way the effective range
851 # of our exponent is doubled.
852 pow2_1 = fexp2i(('ishr', exp, 1), bits)
853 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
854 return ('fmul', ('fmul', f, pow2_1), pow2_2)
855
856 optimizations += [
857 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
858 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
859 ]
860
861 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
862 def bitfield_reverse(u):
863 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
864 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
865 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
866 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
867 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
868
869 return step5
870
871 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'))]
872
873 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
874 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
875 # and, if a is a NaN then the second comparison will fail anyway.
876 for op in ['flt', 'fge', 'feq']:
877 optimizations += [
878 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
879 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
880 ]
881
882 # Add optimizations to handle the case where the result of a ternary is
883 # compared to a constant. This way we can take things like
884 #
885 # (a ? 0 : 1) > 0
886 #
887 # and turn it into
888 #
889 # a ? (0 > 0) : (1 > 0)
890 #
891 # which constant folding will eat for lunch. The resulting ternary will
892 # further get cleaned up by the boolean reductions above and we will be
893 # left with just the original variable "a".
894 for op in ['flt', 'fge', 'feq', 'fne',
895 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
896 optimizations += [
897 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
898 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
899 ((op, '#d', ('bcsel', a, '#b', '#c')),
900 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
901 ]
902
903
904 # For example, this converts things like
905 #
906 # 1 + mix(0, a - 1, condition)
907 #
908 # into
909 #
910 # mix(1, (a-1)+1, condition)
911 #
912 # Other optimizations will rearrange the constants.
913 for op in ['fadd', 'fmul', 'iadd', 'imul']:
914 optimizations += [
915 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
916 ]
917
918 # This section contains "late" optimizations that should be run before
919 # creating ffmas and calling regular optimizations for the final time.
920 # Optimizations should go here if they help code generation and conflict
921 # with the regular optimizations.
922 before_ffma_optimizations = [
923 # Propagate constants down multiplication chains
924 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
925 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
926 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
927 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
928
929 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
930 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
931 (('~fadd', ('fneg', a), a), 0.0),
932 (('iadd', ('ineg', a), a), 0),
933 (('iadd', ('ineg', a), ('iadd', a, b)), b),
934 (('iadd', a, ('iadd', ('ineg', a), b)), b),
935 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
936 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
937 ]
938
939 # This section contains "late" optimizations that should be run after the
940 # regular optimizations have finished. Optimizations should go here if
941 # they help code generation but do not necessarily produce code that is
942 # more easily optimizable.
943 late_optimizations = [
944 # Most of these optimizations aren't quite safe when you get infinity or
945 # Nan involved but the first one should be fine.
946 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
947 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
948 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
949 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
950 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
951 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
952
953 (('~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)))),
954
955 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
956 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
957 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
958 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
959
960 (('b2f(is_used_more_than_once)', ('inot', 'a@1')), ('bcsel', a, 0.0, 1.0)),
961 (('fneg(is_used_more_than_once)', ('b2f', ('inot', 'a@1'))), ('bcsel', a, -0.0, -1.0)),
962
963 # we do these late so that we don't get in the way of creating ffmas
964 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
965 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
966
967 (('bcsel', 'a@bool', 0, ('b2f32', ('inot', 'b@bool'))), ('b2f32', ('inot', ('ior', a, b)))),
968 ]
969
970 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render())
971 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
972 before_ffma_optimizations).render())
973 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
974 late_optimizations).render())