nir: Add lowering for find_lsb.
[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 import nir_algebraic
27 import itertools
28
29 # Convenience variables
30 a = 'a'
31 b = 'b'
32 c = 'c'
33 d = 'd'
34
35 # Written in the form (<search>, <replace>) where <search> is an expression
36 # and <replace> is either an expression or a value. An expression is
37 # defined as a tuple of the form ([~]<op>, <src0>, <src1>, <src2>, <src3>)
38 # where each source is either an expression or a value. A value can be
39 # either a numeric constant or a string representing a variable name.
40 #
41 # If the opcode in a search expression is prefixed by a '~' character, this
42 # indicates that the operation is inexact. Such operations will only get
43 # applied to SSA values that do not have the exact bit set. This should be
44 # used by by any optimizations that are not bit-for-bit exact. It should not,
45 # however, be used for backend-requested lowering operations as those need to
46 # happen regardless of precision.
47 #
48 # Variable names are specified as "[#]name[@type][(cond)]" where "#" inicates
49 # that the given variable will only match constants and the type indicates that
50 # the given variable will only match values from ALU instructions with the
51 # given output type, and (cond) specifies an additional condition function
52 # (see nir_search_helpers.h).
53 #
54 # For constants, you have to be careful to make sure that it is the right
55 # type because python is unaware of the source and destination types of the
56 # opcodes.
57 #
58 # All expression types can have a bit-size specified. For opcodes, this
59 # looks like "op@32", for variables it is "a@32" or "a@uint32" to specify a
60 # type and size, and for literals, you can write "2.0@32". In the search half
61 # of the expression this indicates that it should only match that particular
62 # bit-size. In the replace half of the expression this indicates that the
63 # constructed value should have that bit-size.
64
65 optimizations = [
66
67 (('imul', a, '#b@32(is_pos_power_of_two)'), ('ishl', a, ('find_lsb', b))),
68 (('imul', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('ishl', a, ('find_lsb', ('iabs', b))))),
69 (('udiv', a, 1), a),
70 (('idiv', a, 1), a),
71 (('umod', a, 1), 0),
72 (('imod', a, 1), 0),
73 (('udiv', a, '#b@32(is_pos_power_of_two)'), ('ushr', a, ('find_lsb', b))),
74 (('idiv', a, '#b@32(is_pos_power_of_two)'), ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', b))), 'options->lower_idiv'),
75 (('idiv', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', ('iabs', b))))), 'options->lower_idiv'),
76 (('umod', a, '#b(is_pos_power_of_two)'), ('iand', a, ('isub', b, 1))),
77
78 (('fneg', ('fneg', a)), a),
79 (('ineg', ('ineg', a)), a),
80 (('fabs', ('fabs', a)), ('fabs', a)),
81 (('fabs', ('fneg', a)), ('fabs', a)),
82 (('fabs', ('u2f32', a)), ('u2f32', a)),
83 (('iabs', ('iabs', a)), ('iabs', a)),
84 (('iabs', ('ineg', a)), ('iabs', a)),
85 (('~fadd', a, 0.0), a),
86 (('iadd', a, 0), a),
87 (('usadd_4x8', a, 0), a),
88 (('usadd_4x8', a, ~0), ~0),
89 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
90 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
91 (('~fadd', ('fneg', a), a), 0.0),
92 (('iadd', ('ineg', a), a), 0),
93 (('iadd', ('ineg', a), ('iadd', a, b)), b),
94 (('iadd', a, ('iadd', ('ineg', a), b)), b),
95 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
96 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
97 (('~fmul', a, 0.0), 0.0),
98 (('imul', a, 0), 0),
99 (('umul_unorm_4x8', a, 0), 0),
100 (('umul_unorm_4x8', a, ~0), a),
101 (('fmul', a, 1.0), a),
102 (('imul', a, 1), a),
103 (('fmul', a, -1.0), ('fneg', a)),
104 (('imul', a, -1), ('ineg', a)),
105 (('~ffma', 0.0, a, b), b),
106 (('~ffma', a, 0.0, b), b),
107 (('~ffma', a, b, 0.0), ('fmul', a, b)),
108 (('ffma', a, 1.0, b), ('fadd', a, b)),
109 (('ffma', 1.0, a, b), ('fadd', a, b)),
110 (('~flrp', a, b, 0.0), a),
111 (('~flrp', a, b, 1.0), b),
112 (('~flrp', a, a, b), a),
113 (('~flrp', 0.0, a, b), ('fmul', a, b)),
114 (('~flrp', a, b, ('b2f', c)), ('bcsel', c, b, a), 'options->lower_flrp32'),
115 (('~flrp', a, 0.0, c), ('fadd', ('fmul', ('fneg', a), c), a)),
116 (('flrp@32', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp32'),
117 (('flrp@64', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp64'),
118 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
119 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', c)))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'),
120 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'),
121 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'),
122 (('~fadd', a, ('fmul', ('b2f', c), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'),
123 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'),
124 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'),
125 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
126 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'),
127
128 (('fdot4', ('vec4', a, b, c, 1.0), d), ('fdph', ('vec3', a, b, c), d)),
129 (('fdot4', ('vec4', a, 0.0, 0.0, 0.0), b), ('fmul', a, b)),
130 (('fdot4', ('vec4', a, b, 0.0, 0.0), c), ('fdot2', ('vec2', a, b), c)),
131 (('fdot4', ('vec4', a, b, c, 0.0), d), ('fdot3', ('vec3', a, b, c), d)),
132
133 (('fdot3', ('vec3', a, 0.0, 0.0), b), ('fmul', a, b)),
134 (('fdot3', ('vec3', a, b, 0.0), c), ('fdot2', ('vec2', a, b), c)),
135
136 # (a * #b + #c) << #d
137 # ((a * #b) << #d) + (#c << #d)
138 # (a * (#b << #d)) + (#c << #d)
139 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'),
140 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))),
141
142 # (a * #b) << #c
143 # a * (#b << #c)
144 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))),
145
146 # Comparison simplifications
147 (('~inot', ('flt', a, b)), ('fge', a, b)),
148 (('~inot', ('fge', a, b)), ('flt', a, b)),
149 (('~inot', ('feq', a, b)), ('fne', a, b)),
150 (('~inot', ('fne', a, b)), ('feq', a, b)),
151 (('inot', ('ilt', a, b)), ('ige', a, b)),
152 (('inot', ('ult', a, b)), ('uge', a, b)),
153 (('inot', ('ige', a, b)), ('ilt', a, b)),
154 (('inot', ('uge', a, b)), ('ult', a, b)),
155 (('inot', ('ieq', a, b)), ('ine', a, b)),
156 (('inot', ('ine', a, b)), ('ieq', a, b)),
157
158 # 0.0 >= b2f(a)
159 # b2f(a) <= 0.0
160 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1
161 # inot(a)
162 (('fge', 0.0, ('b2f', a)), ('inot', a)),
163
164 (('fge', ('fneg', ('b2f', a)), 0.0), ('inot', a)),
165
166 (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)),
167 (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)),
168 (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)),
169 (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)),
170
171 # Cannot remove the addition from ilt or ige due to overflow.
172 (('ieq', ('iadd', a, b), a), ('ieq', b, 0)),
173 (('ine', ('iadd', a, b), a), ('ine', b, 0)),
174
175 # fmin(-b2f(a), b) >= 0.0
176 # -b2f(a) >= 0.0 && b >= 0.0
177 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0
178 # b2f(a) == 0.0 && b >= 0.0
179 # a == False && b >= 0.0
180 # !a && b >= 0.0
181 #
182 # The fge in the second replacement is not a typo. I leave the proof that
183 # "fmin(-b2f(a), b) >= 0 <=> fmin(-b2f(a), b) == 0" as an exercise for the
184 # reader.
185 (('fge', ('fmin', ('fneg', ('b2f', a)), b), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
186 (('feq', ('fmin', ('fneg', ('b2f', a)), b), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
187
188 (('feq', ('b2f', a), 0.0), ('inot', a)),
189 (('fne', ('b2f', a), 0.0), a),
190 (('ieq', ('b2i', a), 0), ('inot', a)),
191 (('ine', ('b2i', a), 0), a),
192
193 # 0.0 < fabs(a)
194 # fabs(a) > 0.0
195 # fabs(a) != 0.0 because fabs(a) must be >= 0
196 # a != 0.0
197 (('flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
198
199 (('fmax', ('b2f(is_used_once)', a), ('b2f', b)), ('b2f', ('ior', a, b))),
200 (('fmax', ('fneg(is_used_once)', ('b2f(is_used_once)', a)), ('fneg', ('b2f', b))), ('fneg', ('b2f', ('ior', a, b)))),
201 (('fmin', ('b2f(is_used_once)', a), ('b2f', b)), ('b2f', ('iand', a, b))),
202 (('fmin', ('fneg(is_used_once)', ('b2f(is_used_once)', a)), ('fneg', ('b2f', b))), ('fneg', ('b2f', ('iand', a, b)))),
203
204 # fmin(b2f(a), b)
205 # bcsel(a, fmin(b2f(a), b), fmin(b2f(a), b))
206 # bcsel(a, fmin(b2f(True), b), fmin(b2f(False), b))
207 # bcsel(a, fmin(1.0, b), fmin(0.0, b))
208 #
209 # Since b is a constant, constant folding will eliminate the fmin and the
210 # fmax. If b is > 1.0, the bcsel will be replaced with a b2f.
211 (('fmin', ('b2f', a), '#b'), ('bcsel', a, ('fmin', b, 1.0), ('fmin', b, 0.0))),
212
213 (('flt', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
214
215 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
216 (('~bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
217 (('~bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
218 (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)),
219 (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)),
220 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)),
221 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
222 (('bcsel', a, True, 'b@bool'), ('ior', a, b)),
223 (('fmin', a, a), a),
224 (('fmax', a, a), a),
225 (('imin', a, a), a),
226 (('imax', a, a), a),
227 (('umin', a, a), a),
228 (('umax', a, a), a),
229 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))),
230 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))),
231 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))),
232 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))),
233 (('fmin', a, ('fabs', a)), a),
234 (('imin', a, ('iabs', a)), a),
235 (('fmax', a, ('fneg', ('fabs', a))), a),
236 (('imax', a, ('ineg', ('iabs', a))), a),
237 (('fmax', a, ('fabs', a)), ('fabs', a)),
238 (('imax', a, ('iabs', a)), ('iabs', a)),
239 (('fmax', a, ('fneg', a)), ('fabs', a)),
240 (('imax', a, ('ineg', a)), ('iabs', a)),
241 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
242 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
243 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
244 (('fsat', ('fsat', a)), ('fsat', a)),
245 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)),
246 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)),
247 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)),
248 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))),
249 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))),
250 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
251 (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
252 (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
253 (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
254 (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
255 (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
256 (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
257 (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
258 (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
259 (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
260 (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
261 (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
262 (('~iand', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmin', a, b), c)),
263 (('~iand', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmin', b, c))),
264 (('~iand', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmax', a, b), c)),
265 (('~iand', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmax', b, c))),
266 (('~iand', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmin', a, b), c)),
267
268 (('ior', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imax', b, c))),
269 (('ior', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imin', a, b), c)),
270 (('ior', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imin', b, c))),
271 (('ior', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imax', a, b), c)),
272 (('ior', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umax', b, c))),
273 (('ior', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umin', a, b), c)),
274 (('ior', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umin', b, c))),
275 (('ior', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umax', a, b), c)),
276 (('iand', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imin', b, c))),
277 (('iand', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imax', a, b), c)),
278 (('iand', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imax', b, c))),
279 (('iand', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imin', a, b), c)),
280 (('iand', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umin', b, c))),
281 (('iand', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umax', a, b), c)),
282 (('iand', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umax', b, c))),
283 (('iand', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umin', a, b), c)),
284
285 (('iand', ('ieq', 'a@32', 0), ('ieq', 'b@32', 0)), ('ieq', ('ior', 'a@32', 'b@32'), 0)),
286
287 # These patterns can result when (a < b || a < c) => (a < min(b, c))
288 # transformations occur before constant propagation and loop-unrolling.
289 (('~flt', a, ('fmax', b, a)), ('flt', a, b)),
290 (('~flt', ('fmin', a, b), a), ('flt', b, a)),
291 (('~fge', a, ('fmin', b, a)), True),
292 (('~fge', ('fmax', a, b), a), True),
293 (('~flt', a, ('fmin', b, a)), False),
294 (('~flt', ('fmax', a, b), a), False),
295 (('~fge', a, ('fmax', b, a)), ('fge', a, b)),
296 (('~fge', ('fmin', a, b), a), ('fge', b, a)),
297
298 (('ilt', a, ('imax', b, a)), ('ilt', a, b)),
299 (('ilt', ('imin', a, b), a), ('ilt', b, a)),
300 (('ige', a, ('imin', b, a)), True),
301 (('ige', ('imax', a, b), a), True),
302 (('ult', a, ('umax', b, a)), ('ult', a, b)),
303 (('ult', ('umin', a, b), a), ('ult', b, a)),
304 (('uge', a, ('umin', b, a)), True),
305 (('uge', ('umax', a, b), a), True),
306 (('ilt', a, ('imin', b, a)), False),
307 (('ilt', ('imax', a, b), a), False),
308 (('ige', a, ('imax', b, a)), ('ige', a, b)),
309 (('ige', ('imin', a, b), a), ('ige', b, a)),
310 (('ult', a, ('umin', b, a)), False),
311 (('ult', ('umax', a, b), a), False),
312 (('uge', a, ('umax', b, a)), ('uge', a, b)),
313 (('uge', ('umin', a, b), a), ('uge', b, a)),
314
315 (('ilt', '#a', ('imax', '#b', c)), ('ior', ('ilt', a, b), ('ilt', a, c))),
316 (('ilt', ('imin', '#a', b), '#c'), ('ior', ('ilt', a, c), ('ilt', b, c))),
317 (('ige', '#a', ('imin', '#b', c)), ('ior', ('ige', a, b), ('ige', a, c))),
318 (('ige', ('imax', '#a', b), '#c'), ('ior', ('ige', a, c), ('ige', b, c))),
319 (('ult', '#a', ('umax', '#b', c)), ('ior', ('ult', a, b), ('ult', a, c))),
320 (('ult', ('umin', '#a', b), '#c'), ('ior', ('ult', a, c), ('ult', b, c))),
321 (('uge', '#a', ('umin', '#b', c)), ('ior', ('uge', a, b), ('uge', a, c))),
322 (('uge', ('umax', '#a', b), '#c'), ('ior', ('uge', a, c), ('uge', b, c))),
323 (('ilt', '#a', ('imin', '#b', c)), ('iand', ('ilt', a, b), ('ilt', a, c))),
324 (('ilt', ('imax', '#a', b), '#c'), ('iand', ('ilt', a, c), ('ilt', b, c))),
325 (('ige', '#a', ('imax', '#b', c)), ('iand', ('ige', a, b), ('ige', a, c))),
326 (('ige', ('imin', '#a', b), '#c'), ('iand', ('ige', a, c), ('ige', b, c))),
327 (('ult', '#a', ('umin', '#b', c)), ('iand', ('ult', a, b), ('ult', a, c))),
328 (('ult', ('umax', '#a', b), '#c'), ('iand', ('ult', a, c), ('ult', b, c))),
329 (('uge', '#a', ('umax', '#b', c)), ('iand', ('uge', a, b), ('uge', a, c))),
330 (('uge', ('umin', '#a', b), '#c'), ('iand', ('uge', a, c), ('uge', b, c))),
331
332 (('fabs', ('slt', a, b)), ('slt', a, b)),
333 (('fabs', ('sge', a, b)), ('sge', a, b)),
334 (('fabs', ('seq', a, b)), ('seq', a, b)),
335 (('fabs', ('sne', a, b)), ('sne', a, b)),
336 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
337 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
338 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
339 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
340 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
341 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
342 # Emulating booleans
343 (('imul', ('b2i', a), ('b2i', b)), ('b2i', ('iand', a, b))),
344 (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))),
345 (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))),
346 (('iand', 'a@bool', 1.0), ('b2f', a), '!options->lower_b2f'),
347 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True).
348 (('ineg', ('b2i@32', a)), a),
349 (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
350 (('flt', ('fsub', 0.0, ('b2f', a)), 0), a), # Generated by TGSI KILL_IF.
351 # Comparison with the same args. Note that these are not done for
352 # the float versions because NaN always returns false on float
353 # inequalities.
354 (('ilt', a, a), False),
355 (('ige', a, a), True),
356 (('ieq', a, a), True),
357 (('ine', a, a), False),
358 (('ult', a, a), False),
359 (('uge', a, a), True),
360 # Logical and bit operations
361 (('fand', a, 0.0), 0.0),
362 (('iand', a, a), a),
363 (('iand', a, ~0), a),
364 (('iand', a, 0), 0),
365 (('ior', a, a), a),
366 (('ior', a, 0), a),
367 (('ior', a, True), True),
368 (('fxor', a, a), 0.0),
369 (('ixor', a, a), 0),
370 (('ixor', a, 0), a),
371 (('inot', ('inot', a)), a),
372 # DeMorgan's Laws
373 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
374 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
375 # Shift optimizations
376 (('ishl', 0, a), 0),
377 (('ishl', a, 0), a),
378 (('ishr', 0, a), 0),
379 (('ishr', a, 0), a),
380 (('ushr', 0, a), 0),
381 (('ushr', a, 0), a),
382 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)),
383 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)),
384 # Exponential/logarithmic identities
385 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a
386 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a
387 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
388 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
389 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
390 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
391 (('~fexp2', ('fmul', ('flog2', a), 2.0)), ('fmul', a, a)),
392 (('~fexp2', ('fmul', ('flog2', a), 4.0)), ('fmul', ('fmul', a, a), ('fmul', a, a))),
393 (('~fpow', a, 1.0), a),
394 (('~fpow', a, 2.0), ('fmul', a, a)),
395 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
396 (('~fpow', 2.0, a), ('fexp2', a)),
397 (('~fpow', ('fpow', a, 2.2), 0.454545), a),
398 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
399 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
400 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
401 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
402 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
403 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))),
404 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
405 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
406 (('~fmul', ('fexp2(is_used_once)', a), ('fexp2(is_used_once)', b)), ('fexp2', ('fadd', a, b))),
407 # Division and reciprocal
408 (('~fdiv', 1.0, a), ('frcp', a)),
409 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
410 (('~frcp', ('frcp', a)), a),
411 (('~frcp', ('fsqrt', a)), ('frsq', a)),
412 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
413 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
414 # Boolean simplifications
415 (('ieq', 'a@bool', True), a),
416 (('ine(is_not_used_by_if)', 'a@bool', True), ('inot', a)),
417 (('ine', 'a@bool', False), a),
418 (('ieq(is_not_used_by_if)', 'a@bool', False), ('inot', 'a')),
419 (('bcsel', a, True, False), a),
420 (('bcsel', a, False, True), ('inot', a)),
421 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)),
422 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))),
423 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))),
424 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))),
425 (('bcsel', True, b, c), b),
426 (('bcsel', False, b, c), c),
427 (('bcsel', a, ('b2f(is_used_once)', b), ('b2f', c)), ('b2f', ('bcsel', a, b, c))),
428 # The result of this should be hit by constant propagation and, in the
429 # next round of opt_algebraic, get picked up by one of the above two.
430 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
431
432 (('bcsel', a, b, b), b),
433 (('fcsel', a, b, b), b),
434
435 # Conversions
436 (('i2b', ('b2i', a)), a),
437 (('i2b', 'a@bool'), a),
438 (('f2i32', ('ftrunc', a)), ('f2i32', a)),
439 (('f2u32', ('ftrunc', a)), ('f2u32', a)),
440 (('i2b', ('ineg', a)), ('i2b', a)),
441 (('i2b', ('iabs', a)), ('i2b', a)),
442 (('fabs', ('b2f', a)), ('b2f', a)),
443 (('iabs', ('b2i', a)), ('b2i', a)),
444 (('inot', ('f2b', a)), ('feq', a, 0.0)),
445
446 # Packing and then unpacking does nothing
447 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
448 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
449 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
450 ('unpack_64_2x32_split_y', a)), a),
451
452 # Byte extraction
453 (('ushr', a, 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
454 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
455 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
456 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
457
458 # Word extraction
459 (('ushr', a, 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
460 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
461
462 # Subtracts
463 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
464 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
465 (('ussub_4x8', a, 0), a),
466 (('ussub_4x8', a, ~0), 0),
467 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
468 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
469 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
470 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
471 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
472 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
473 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
474 (('iabs', ('isub', 0, a)), ('iabs', a)),
475
476 # Propagate negation up multiplication chains
477 (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))),
478 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
479
480 # Propagate constants up multiplication chains
481 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
482 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
483 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
484 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
485
486 # Reassociate constants in add/mul chains so they can be folded together.
487 # For now, we mostly only handle cases where the constants are separated by
488 # a single non-constant. We could do better eventually.
489 (('~fmul', '#a', ('fmul', b, '#c')), ('fmul', ('fmul', a, c), b)),
490 (('imul', '#a', ('imul', b, '#c')), ('imul', ('imul', a, c), b)),
491 (('~fadd', '#a', ('fadd', b, '#c')), ('fadd', ('fadd', a, c), b)),
492 (('~fadd', '#a', ('fneg', ('fadd', b, '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
493 (('iadd', '#a', ('iadd', b, '#c')), ('iadd', ('iadd', a, c), b)),
494
495 # By definition...
496 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
497 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
498 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
499
500 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
501 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
502 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
503
504 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
505
506 # Misc. lowering
507 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod32'),
508 (('fmod@64', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod64'),
509 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod32'),
510 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
511 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
512
513 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
514 ('bcsel', ('ilt', 31, 'bits'), 'insert',
515 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
516 'options->lower_bitfield_insert'),
517
518 # Alternative lowering that doesn't rely on bfi.
519 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
520 ('bcsel', ('ilt', 31, 'bits'),
521 'insert',
522 ('ior',
523 ('iand', 'base', ('inot', ('bfm', 'bits', 'offset'))),
524 ('iand', ('ishl', 'insert', 'offset'), ('bfm', 'bits', 'offset')))),
525 'options->lower_bitfield_insert_to_shifts'),
526
527 # bfm lowering -- note that the NIR opcode is undefined if either arg is 32.
528 (('bfm', 'bits', 'offset'),
529 ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'),
530 'options->lower_bfm'),
531
532 (('ibitfield_extract', 'value', 'offset', 'bits'),
533 ('bcsel', ('ilt', 31, 'bits'), 'value',
534 ('ibfe', 'value', 'offset', 'bits')),
535 'options->lower_bitfield_extract'),
536
537 (('ubitfield_extract', 'value', 'offset', 'bits'),
538 ('bcsel', ('ult', 31, 'bits'), 'value',
539 ('ubfe', 'value', 'offset', 'bits')),
540 'options->lower_bitfield_extract'),
541
542 (('ibitfield_extract', 'value', 'offset', 'bits'),
543 ('bcsel', ('ieq', 0, 'bits'),
544 0,
545 ('ishr',
546 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
547 ('isub', 32, 'bits'))),
548 'options->lower_bitfield_extract_to_shifts'),
549
550 (('ubitfield_extract', 'value', 'offset', 'bits'),
551 ('iand',
552 ('ushr', 'value', 'offset'),
553 ('bcsel', ('ieq', 'bits', 32),
554 0xffffffff,
555 ('bfm', 'bits', 0))),
556 'options->lower_bitfield_extract_to_shifts'),
557
558 (('ifind_msb', 'value'),
559 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
560 'options->lower_ifind_msb'),
561
562 (('find_lsb', 'value'),
563 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
564 'options->lower_find_lsb'),
565
566 (('extract_i8', a, 'b@32'),
567 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
568 'options->lower_extract_byte'),
569
570 (('extract_u8', a, 'b@32'),
571 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
572 'options->lower_extract_byte'),
573
574 (('extract_i16', a, 'b@32'),
575 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
576 'options->lower_extract_word'),
577
578 (('extract_u16', a, 'b@32'),
579 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
580 'options->lower_extract_word'),
581
582 (('pack_unorm_2x16', 'v'),
583 ('pack_uvec2_to_uint',
584 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
585 'options->lower_pack_unorm_2x16'),
586
587 (('pack_unorm_4x8', 'v'),
588 ('pack_uvec4_to_uint',
589 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
590 'options->lower_pack_unorm_4x8'),
591
592 (('pack_snorm_2x16', 'v'),
593 ('pack_uvec2_to_uint',
594 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
595 'options->lower_pack_snorm_2x16'),
596
597 (('pack_snorm_4x8', 'v'),
598 ('pack_uvec4_to_uint',
599 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
600 'options->lower_pack_snorm_4x8'),
601
602 (('unpack_unorm_2x16', 'v'),
603 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
604 ('extract_u16', 'v', 1))),
605 65535.0),
606 'options->lower_unpack_unorm_2x16'),
607
608 (('unpack_unorm_4x8', 'v'),
609 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
610 ('extract_u8', 'v', 1),
611 ('extract_u8', 'v', 2),
612 ('extract_u8', 'v', 3))),
613 255.0),
614 'options->lower_unpack_unorm_4x8'),
615
616 (('unpack_snorm_2x16', 'v'),
617 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f32', ('vec2', ('extract_i16', 'v', 0),
618 ('extract_i16', 'v', 1))),
619 32767.0))),
620 'options->lower_unpack_snorm_2x16'),
621
622 (('unpack_snorm_4x8', 'v'),
623 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f32', ('vec4', ('extract_i8', 'v', 0),
624 ('extract_i8', 'v', 1),
625 ('extract_i8', 'v', 2),
626 ('extract_i8', 'v', 3))),
627 127.0))),
628 'options->lower_unpack_snorm_4x8'),
629 ]
630
631 invert = {'feq': 'fne', 'fne': 'feq', 'fge': 'flt', 'flt': 'fge' }
632
633 for left, right in list(itertools.combinations(invert.keys(), 2)) + zip(invert.keys(), invert.keys()):
634 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
635 ('iand', (invert[left], a, b), (invert[right], c, d))))
636 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
637 ('ior', (invert[left], a, b), (invert[right], c, d))))
638
639 def fexp2i(exp, bits):
640 # We assume that exp is already in the right range.
641 if bits == 32:
642 return ('ishl', ('iadd', exp, 127), 23)
643 elif bits == 64:
644 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
645 else:
646 assert False
647
648 def ldexp(f, exp, bits):
649 # First, we clamp exp to a reasonable range. The maximum possible range
650 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
651 # a maximum range of [-149, 127]. This means that we can potentially have
652 # a swing of +-276. If you start with FLT_MAX, you actually have to do
653 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
654 # spec, on the other hand, only requires that we handle an exponent value
655 # in the range [-126, 128]. This implementation is *mostly* correct; it
656 # handles a range on exp of [-252, 254] which allows you to create any
657 # value (including denorms if the hardware supports it) and to adjust the
658 # exponent of any normal value to anything you want.
659 if bits == 32:
660 exp = ('imin', ('imax', exp, -252), 254)
661 elif bits == 64:
662 exp = ('imin', ('imax', exp, -2044), 2046)
663 else:
664 assert False
665
666 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
667 # (We use ishr which isn't the same for -1, but the -1 case still works
668 # since we use exp-exp/2 as the second exponent.) While the spec
669 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
670 # work with denormals and doesn't allow for the full swing in exponents
671 # that you can get with normalized values. Instead, we create two powers
672 # of two and multiply by them each in turn. That way the effective range
673 # of our exponent is doubled.
674 pow2_1 = fexp2i(('ishr', exp, 1), bits)
675 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
676 return ('fmul', ('fmul', f, pow2_1), pow2_2)
677
678 optimizations += [
679 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
680 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
681 ]
682
683 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
684 def bitfield_reverse(u):
685 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
686 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
687 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
688 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
689 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
690
691 return step5
692
693 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'))]
694
695 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
696 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
697 # and, if a is a NaN then the second comparison will fail anyway.
698 for op in ['flt', 'fge', 'feq']:
699 optimizations += [
700 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
701 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
702 ]
703
704 # Add optimizations to handle the case where the result of a ternary is
705 # compared to a constant. This way we can take things like
706 #
707 # (a ? 0 : 1) > 0
708 #
709 # and turn it into
710 #
711 # a ? (0 > 0) : (1 > 0)
712 #
713 # which constant folding will eat for lunch. The resulting ternary will
714 # further get cleaned up by the boolean reductions above and we will be
715 # left with just the original variable "a".
716 for op in ['flt', 'fge', 'feq', 'fne',
717 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
718 optimizations += [
719 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
720 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
721 ((op, '#d', ('bcsel', a, '#b', '#c')),
722 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
723 ]
724
725
726 # For example, this converts things like
727 #
728 # 1 + mix(0, a - 1, condition)
729 #
730 # into
731 #
732 # mix(1, (a-1)+1, condition)
733 #
734 # Other optimizations will rearrange the constants.
735 for op in ['fadd', 'fmul', 'iadd', 'imul']:
736 optimizations += [
737 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
738 ]
739
740 # This section contains "late" optimizations that should be run before
741 # creating ffmas and calling regular optimizations for the final time.
742 # Optimizations should go here if they help code generation and conflict
743 # with the regular optimizations.
744 before_ffma_optimizations = [
745 # Propagate constants down multiplication chains
746 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
747 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
748 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
749 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
750
751 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
752 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
753 (('~fadd', ('fneg', a), a), 0.0),
754 (('iadd', ('ineg', a), a), 0),
755 (('iadd', ('ineg', a), ('iadd', a, b)), b),
756 (('iadd', a, ('iadd', ('ineg', a), b)), b),
757 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
758 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
759 ]
760
761 # This section contains "late" optimizations that should be run after the
762 # regular optimizations have finished. Optimizations should go here if
763 # they help code generation but do not necessarily produce code that is
764 # more easily optimizable.
765 late_optimizations = [
766 # Most of these optimizations aren't quite safe when you get infinity or
767 # Nan involved but the first one should be fine.
768 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
769 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
770 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
771 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
772 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
773 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
774
775 (('~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)))),
776
777 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
778 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
779 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
780 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
781
782 (('b2f(is_used_more_than_once)', ('inot', a)), ('bcsel', a, 0.0, 1.0)),
783 (('fneg(is_used_more_than_once)', ('b2f', ('inot', a))), ('bcsel', a, -0.0, -1.0)),
784
785 # we do these late so that we don't get in the way of creating ffmas
786 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
787 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
788
789 # Lowered for backends without a dedicated b2f instruction
790 (('b2f@32', a), ('iand', a, 1.0), 'options->lower_b2f'),
791 ]
792
793 print nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render()
794 print nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
795 before_ffma_optimizations).render()
796 print nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
797 late_optimizations).render()