nir/algebraic: Optimize low 32 bit extraction
[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
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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 (('unpack_64_2x32_split_x', ('imul_2x32_64(is_used_once)', a, b)), ('imul', a, b)),
74 (('unpack_64_2x32_split_x', ('umul_2x32_64(is_used_once)', a, b)), ('imul', a, b)),
75 (('imul_2x32_64', a, b), ('pack_64_2x32_split', ('imul', a, b), ('imul_high', a, b)), 'options->lower_mul_2x32_64'),
76 (('umul_2x32_64', a, b), ('pack_64_2x32_split', ('imul', a, b), ('umul_high', a, b)), 'options->lower_mul_2x32_64'),
77 (('udiv', a, 1), a),
78 (('idiv', a, 1), a),
79 (('umod', a, 1), 0),
80 (('imod', a, 1), 0),
81 (('udiv', a, '#b@32(is_pos_power_of_two)'), ('ushr', a, ('find_lsb', b))),
82 (('idiv', a, '#b@32(is_pos_power_of_two)'), ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', b))), 'options->lower_idiv'),
83 (('idiv', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', ('iabs', b))))), 'options->lower_idiv'),
84 (('umod', a, '#b(is_pos_power_of_two)'), ('iand', a, ('isub', b, 1))),
85
86 (('fneg', ('fneg', a)), a),
87 (('ineg', ('ineg', a)), a),
88 (('fabs', ('fabs', a)), ('fabs', a)),
89 (('fabs', ('fneg', a)), ('fabs', a)),
90 (('fabs', ('u2f', a)), ('u2f', a)),
91 (('iabs', ('iabs', a)), ('iabs', a)),
92 (('iabs', ('ineg', a)), ('iabs', a)),
93 (('f2b', ('fneg', a)), ('f2b', a)),
94 (('i2b', ('ineg', a)), ('i2b', a)),
95 (('~fadd', a, 0.0), a),
96 (('iadd', a, 0), a),
97 (('usadd_4x8', a, 0), a),
98 (('usadd_4x8', a, ~0), ~0),
99 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
100 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
101 (('~fadd', ('fneg', a), a), 0.0),
102 (('iadd', ('ineg', a), a), 0),
103 (('iadd', ('ineg', a), ('iadd', a, b)), b),
104 (('iadd', a, ('iadd', ('ineg', a), b)), b),
105 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
106 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
107 (('~fmul', a, 0.0), 0.0),
108 (('imul', a, 0), 0),
109 (('umul_unorm_4x8', a, 0), 0),
110 (('umul_unorm_4x8', a, ~0), a),
111 (('fmul', a, 1.0), a),
112 (('imul', a, 1), a),
113 (('fmul', a, -1.0), ('fneg', a)),
114 (('imul', a, -1), ('ineg', a)),
115 # If a < 0: fsign(a)*a*a => -1*a*a => -a*a => abs(a)*a
116 # If a > 0: fsign(a)*a*a => 1*a*a => a*a => abs(a)*a
117 # If a == 0: fsign(a)*a*a => 0*0*0 => abs(0)*0
118 (('fmul', ('fsign', a), ('fmul', a, a)), ('fmul', ('fabs', a), a)),
119 (('fmul', ('fmul', ('fsign', a), a), a), ('fmul', ('fabs', a), a)),
120 (('~ffma', 0.0, a, b), b),
121 (('~ffma', a, 0.0, b), b),
122 (('~ffma', a, b, 0.0), ('fmul', a, b)),
123 (('ffma', a, 1.0, b), ('fadd', a, b)),
124 (('ffma', 1.0, a, b), ('fadd', a, b)),
125 (('~flrp', a, b, 0.0), a),
126 (('~flrp', a, b, 1.0), b),
127 (('~flrp', a, a, b), a),
128 (('~flrp', 0.0, a, b), ('fmul', a, b)),
129 (('~flrp', a, b, ('b2f', 'c@1')), ('bcsel', c, b, a), 'options->lower_flrp32'),
130 (('~flrp', a, 0.0, c), ('fadd', ('fmul', ('fneg', a), c), a)),
131 (('flrp@32', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp32'),
132 (('flrp@64', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp64'),
133 (('ffloor', a), ('fsub', a, ('ffract', a)), 'options->lower_ffloor'),
134 (('fadd', a, ('fneg', ('ffract', a))), ('ffloor', a), '!options->lower_ffloor'),
135 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
136 (('fceil', a), ('fneg', ('ffloor', ('fneg', a))), 'options->lower_fceil'),
137 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', 'c@1')))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'),
138 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'),
139 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'),
140 (('~fadd', a, ('fmul', ('b2f', 'c@1'), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'),
141 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'),
142 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'),
143 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
144 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'),
145
146 (('fdot4', ('vec4', a, b, c, 1.0), d), ('fdph', ('vec3', a, b, c), d)),
147 (('fdot4', ('vec4', a, 0.0, 0.0, 0.0), b), ('fmul', a, b)),
148 (('fdot4', ('vec4', a, b, 0.0, 0.0), c), ('fdot2', ('vec2', a, b), c)),
149 (('fdot4', ('vec4', a, b, c, 0.0), d), ('fdot3', ('vec3', a, b, c), d)),
150
151 (('fdot3', ('vec3', a, 0.0, 0.0), b), ('fmul', a, b)),
152 (('fdot3', ('vec3', a, b, 0.0), c), ('fdot2', ('vec2', a, b), c)),
153
154 # (a * #b + #c) << #d
155 # ((a * #b) << #d) + (#c << #d)
156 # (a * (#b << #d)) + (#c << #d)
157 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'),
158 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))),
159
160 # (a * #b) << #c
161 # a * (#b << #c)
162 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))),
163
164 # Comparison simplifications
165 (('~inot', ('flt', a, b)), ('fge', a, b)),
166 (('~inot', ('fge', a, b)), ('flt', a, b)),
167 (('~inot', ('feq', a, b)), ('fne', a, b)),
168 (('~inot', ('fne', a, b)), ('feq', a, b)),
169 (('inot', ('ilt', a, b)), ('ige', a, b)),
170 (('inot', ('ult', a, b)), ('uge', a, b)),
171 (('inot', ('ige', a, b)), ('ilt', a, b)),
172 (('inot', ('uge', a, b)), ('ult', a, b)),
173 (('inot', ('ieq', a, b)), ('ine', a, b)),
174 (('inot', ('ine', a, b)), ('ieq', a, b)),
175
176 # 0.0 >= b2f(a)
177 # b2f(a) <= 0.0
178 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1
179 # inot(a)
180 (('fge', 0.0, ('b2f', 'a@1')), ('inot', a)),
181
182 (('fge', ('fneg', ('b2f', 'a@1')), 0.0), ('inot', a)),
183
184 (('fne', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('ior', a, b)),
185 (('fne', ('fmax', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('ior', a, b)),
186 (('fne', ('bcsel', a, 1.0, ('b2f', 'b@1')) , 0.0), ('ior', a, b)),
187 (('fne', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), ('ior', a, b)),
188 (('fne', ('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('iand', a, b)),
189 (('fne', ('fmin', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('iand', a, b)),
190 (('fne', ('bcsel', a, ('b2f', 'b@1'), 0.0) , 0.0), ('iand', a, b)),
191 (('fne', ('fadd', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), 0.0), ('ixor', a, b)),
192 (('fne', ('b2f', 'a@1') , ('b2f', 'b@1') ), ('ixor', a, b)),
193 (('fne', ('fneg', ('b2f', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('ixor', a, b)),
194 (('feq', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('ior', a, b))),
195 (('feq', ('fmax', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('ior', a, b))),
196 (('feq', ('bcsel', a, 1.0, ('b2f', 'b@1')) , 0.0), ('inot', ('ior', a, b))),
197 (('feq', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), ('inot', ('ior', a, b))),
198 (('feq', ('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('iand', a, b))),
199 (('feq', ('fmin', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('iand', a, b))),
200 (('feq', ('bcsel', a, ('b2f', 'b@1'), 0.0) , 0.0), ('inot', ('iand', a, b))),
201 (('feq', ('fadd', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), 0.0), ('ieq', a, b)),
202 (('feq', ('b2f', 'a@1') , ('b2f', 'b@1') ), ('ieq', a, b)),
203 (('feq', ('fneg', ('b2f', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('ieq', a, b)),
204
205 # -(b2f(a) + b2f(b)) < 0
206 # 0 < b2f(a) + b2f(b)
207 # 0 != b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
208 # a || b
209 (('flt', ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), 0.0), ('ior', a, b)),
210 (('flt', 0.0, ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('ior', a, b)),
211
212 # -(b2f(a) + b2f(b)) >= 0
213 # 0 >= b2f(a) + b2f(b)
214 # 0 == b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
215 # !(a || b)
216 (('fge', ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), 0.0), ('inot', ('ior', a, b))),
217 (('fge', 0.0, ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('inot', ('ior', a, b))),
218
219 # Some optimizations (below) convert things like (a < b || c < b) into
220 # (min(a, c) < b). However, this interfers with the previous optimizations
221 # that try to remove comparisons with negated sums of b2f. This just
222 # breaks that apart.
223 (('flt', ('fmin', c, ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')))), 0.0),
224 ('ior', ('flt', c, 0.0), ('ior', a, b))),
225
226 (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)),
227 (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)),
228 (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)),
229 (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)),
230
231 # Cannot remove the addition from ilt or ige due to overflow.
232 (('ieq', ('iadd', a, b), a), ('ieq', b, 0)),
233 (('ine', ('iadd', a, b), a), ('ine', b, 0)),
234
235 # fmin(-b2f(a), b) >= 0.0
236 # -b2f(a) >= 0.0 && b >= 0.0
237 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0
238 # b2f(a) == 0.0 && b >= 0.0
239 # a == False && b >= 0.0
240 # !a && b >= 0.0
241 #
242 # The fge in the second replacement is not a typo. I leave the proof that
243 # "fmin(-b2f(a), b) >= 0 <=> fmin(-b2f(a), b) == 0" as an exercise for the
244 # reader.
245 (('fge', ('fmin', ('fneg', ('b2f', 'a@1')), 'b@1'), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
246 (('feq', ('fmin', ('fneg', ('b2f', 'a@1')), 'b@1'), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
247
248 (('feq', ('b2f', 'a@1'), 0.0), ('inot', a)),
249 (('fne', ('b2f', 'a@1'), 0.0), a),
250 (('ieq', ('b2i', 'a@1'), 0), ('inot', a)),
251 (('ine', ('b2i', 'a@1'), 0), a),
252
253 (('fne', ('u2f', a), 0.0), ('ine', a, 0)),
254 (('feq', ('u2f', a), 0.0), ('ieq', a, 0)),
255 (('fge', ('u2f', a), 0.0), True),
256 (('fge', 0.0, ('u2f', a)), ('uge', 0, a)), # ieq instead?
257 (('flt', ('u2f', a), 0.0), False),
258 (('flt', 0.0, ('u2f', a)), ('ult', 0, a)), # ine instead?
259 (('fne', ('i2f', a), 0.0), ('ine', a, 0)),
260 (('feq', ('i2f', a), 0.0), ('ieq', a, 0)),
261 (('fge', ('i2f', a), 0.0), ('ige', a, 0)),
262 (('fge', 0.0, ('i2f', a)), ('ige', 0, a)),
263 (('flt', ('i2f', a), 0.0), ('ilt', a, 0)),
264 (('flt', 0.0, ('i2f', a)), ('ilt', 0, a)),
265
266 # 0.0 < fabs(a)
267 # fabs(a) > 0.0
268 # fabs(a) != 0.0 because fabs(a) must be >= 0
269 # a != 0.0
270 (('~flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
271
272 # -fabs(a) < 0.0
273 # fabs(a) > 0.0
274 (('~flt', ('fneg', ('fabs', a)), 0.0), ('fne', a, 0.0)),
275
276 # 0.0 >= fabs(a)
277 # 0.0 == fabs(a) because fabs(a) must be >= 0
278 # 0.0 == a
279 (('fge', 0.0, ('fabs', a)), ('feq', a, 0.0)),
280
281 # -fabs(a) >= 0.0
282 # 0.0 >= fabs(a)
283 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
284
285 (('fmax', ('b2f(is_used_once)', 'a@1'), ('b2f', 'b@1')), ('b2f', ('ior', a, b))),
286 (('fmax', ('fneg(is_used_once)', ('b2f(is_used_once)', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('fneg', ('b2f', ('ior', a, b)))),
287 (('fmin', ('b2f(is_used_once)', 'a@1'), ('b2f', 'b@1')), ('b2f', ('iand', a, b))),
288 (('fmin', ('fneg(is_used_once)', ('b2f(is_used_once)', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('fneg', ('b2f', ('iand', a, b)))),
289
290 # fmin(b2f(a), b)
291 # bcsel(a, fmin(b2f(a), b), fmin(b2f(a), b))
292 # bcsel(a, fmin(b2f(True), b), fmin(b2f(False), b))
293 # bcsel(a, fmin(1.0, b), fmin(0.0, b))
294 #
295 # Since b is a constant, constant folding will eliminate the fmin and the
296 # fmax. If b is > 1.0, the bcsel will be replaced with a b2f.
297 (('fmin', ('b2f', 'a@1'), '#b'), ('bcsel', a, ('fmin', b, 1.0), ('fmin', b, 0.0))),
298
299 (('flt', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
300
301 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
302 (('~bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
303 (('~bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
304 (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)),
305 (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)),
306 (('bcsel', ('i2b', a), b, c), ('bcsel', ('ine', a, 0), b, c)),
307 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)),
308 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
309 (('bcsel', a, b, ('bcsel', a, c, d)), ('bcsel', a, b, d)),
310 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
311 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
312 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
313 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
314 (('bcsel', a, True, 'b@bool'), ('ior', a, b)),
315 (('fmin', a, a), a),
316 (('fmax', a, a), a),
317 (('imin', a, a), a),
318 (('imax', a, a), a),
319 (('umin', a, a), a),
320 (('umax', a, a), a),
321 (('fmax', ('fmax', a, b), b), ('fmax', a, b)),
322 (('umax', ('umax', a, b), b), ('umax', a, b)),
323 (('imax', ('imax', a, b), b), ('imax', a, b)),
324 (('fmin', ('fmin', a, b), b), ('fmin', a, b)),
325 (('umin', ('umin', a, b), b), ('umin', a, b)),
326 (('imin', ('imin', a, b), b), ('imin', a, b)),
327 (('fmax', a, ('fneg', a)), ('fabs', a)),
328 (('imax', a, ('ineg', a)), ('iabs', a)),
329 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))),
330 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))),
331 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))),
332 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))),
333 (('fmin', a, ('fabs', a)), a),
334 (('imin', a, ('iabs', a)), a),
335 (('fmax', a, ('fneg', ('fabs', a))), a),
336 (('imax', a, ('ineg', ('iabs', a))), a),
337 (('fmax', a, ('fabs', a)), ('fabs', a)),
338 (('imax', a, ('iabs', a)), ('iabs', a)),
339 (('fmax', a, ('fneg', a)), ('fabs', a)),
340 (('imax', a, ('ineg', a)), ('iabs', a)),
341 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
342 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
343 (('fsat', ('fsign', a)), ('b2f', ('flt', 0.0, a))),
344 (('fsat', ('b2f', a)), ('b2f', a)),
345 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
346 (('fsat', ('fsat', a)), ('fsat', a)),
347 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)),
348 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)),
349 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)),
350 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))),
351 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))),
352 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
353 (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
354 (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
355 (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
356 (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
357 (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
358 (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
359 (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
360 (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
361 (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
362 (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
363 (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
364 (('~iand', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmin', a, b), c)),
365 (('~iand', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmin', b, c))),
366 (('~iand', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmax', a, b), c)),
367 (('~iand', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmax', b, c))),
368 (('~iand', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmin', a, b), c)),
369
370 (('ior', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imax', b, c))),
371 (('ior', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imin', a, b), c)),
372 (('ior', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imin', b, c))),
373 (('ior', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imax', a, b), c)),
374 (('ior', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umax', b, c))),
375 (('ior', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umin', a, b), c)),
376 (('ior', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umin', b, c))),
377 (('ior', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umax', a, b), c)),
378 (('iand', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imin', b, c))),
379 (('iand', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imax', a, b), c)),
380 (('iand', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imax', b, c))),
381 (('iand', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imin', a, b), c)),
382 (('iand', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umin', b, c))),
383 (('iand', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umax', a, b), c)),
384 (('iand', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umax', b, c))),
385 (('iand', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umin', a, b), c)),
386
387 # Common pattern like 'if (i == 0 || i == 1 || ...)'
388 (('ior', ('ieq', a, 0), ('ieq', a, 1)), ('uge', 1, a)),
389 (('ior', ('uge', 1, a), ('ieq', a, 2)), ('uge', 2, a)),
390 (('ior', ('uge', 2, a), ('ieq', a, 3)), ('uge', 3, a)),
391
392 (('ior', 'a@bool', ('ieq', a, False)), True),
393 (('ior', a, ('inot', a)), -1),
394
395 (('iand', ('ieq', 'a@32', 0), ('ieq', 'b@32', 0)), ('ieq', ('ior', 'a@32', 'b@32'), 0)),
396
397 # These patterns can result when (a < b || a < c) => (a < min(b, c))
398 # transformations occur before constant propagation and loop-unrolling.
399 (('~flt', a, ('fmax', b, a)), ('flt', a, b)),
400 (('~flt', ('fmin', a, b), a), ('flt', b, a)),
401 (('~fge', a, ('fmin', b, a)), True),
402 (('~fge', ('fmax', a, b), a), True),
403 (('~flt', a, ('fmin', b, a)), False),
404 (('~flt', ('fmax', a, b), a), False),
405 (('~fge', a, ('fmax', b, a)), ('fge', a, b)),
406 (('~fge', ('fmin', a, b), a), ('fge', b, a)),
407
408 (('ilt', a, ('imax', b, a)), ('ilt', a, b)),
409 (('ilt', ('imin', a, b), a), ('ilt', b, a)),
410 (('ige', a, ('imin', b, a)), True),
411 (('ige', ('imax', a, b), a), True),
412 (('ult', a, ('umax', b, a)), ('ult', a, b)),
413 (('ult', ('umin', a, b), a), ('ult', b, a)),
414 (('uge', a, ('umin', b, a)), True),
415 (('uge', ('umax', a, b), a), True),
416 (('ilt', a, ('imin', b, a)), False),
417 (('ilt', ('imax', a, b), a), False),
418 (('ige', a, ('imax', b, a)), ('ige', a, b)),
419 (('ige', ('imin', a, b), a), ('ige', b, a)),
420 (('ult', a, ('umin', b, a)), False),
421 (('ult', ('umax', a, b), a), False),
422 (('uge', a, ('umax', b, a)), ('uge', a, b)),
423 (('uge', ('umin', a, b), a), ('uge', b, a)),
424
425 (('ilt', '#a', ('imax', '#b', c)), ('ior', ('ilt', a, b), ('ilt', a, c))),
426 (('ilt', ('imin', '#a', b), '#c'), ('ior', ('ilt', a, c), ('ilt', b, c))),
427 (('ige', '#a', ('imin', '#b', c)), ('ior', ('ige', a, b), ('ige', a, c))),
428 (('ige', ('imax', '#a', b), '#c'), ('ior', ('ige', a, c), ('ige', b, c))),
429 (('ult', '#a', ('umax', '#b', c)), ('ior', ('ult', a, b), ('ult', a, c))),
430 (('ult', ('umin', '#a', b), '#c'), ('ior', ('ult', a, c), ('ult', b, c))),
431 (('uge', '#a', ('umin', '#b', c)), ('ior', ('uge', a, b), ('uge', a, c))),
432 (('uge', ('umax', '#a', b), '#c'), ('ior', ('uge', a, c), ('uge', b, c))),
433 (('ilt', '#a', ('imin', '#b', c)), ('iand', ('ilt', a, b), ('ilt', a, c))),
434 (('ilt', ('imax', '#a', b), '#c'), ('iand', ('ilt', a, c), ('ilt', b, c))),
435 (('ige', '#a', ('imax', '#b', c)), ('iand', ('ige', a, b), ('ige', a, c))),
436 (('ige', ('imin', '#a', b), '#c'), ('iand', ('ige', a, c), ('ige', b, c))),
437 (('ult', '#a', ('umin', '#b', c)), ('iand', ('ult', a, b), ('ult', a, c))),
438 (('ult', ('umax', '#a', b), '#c'), ('iand', ('ult', a, c), ('ult', b, c))),
439 (('uge', '#a', ('umax', '#b', c)), ('iand', ('uge', a, b), ('uge', a, c))),
440 (('uge', ('umin', '#a', b), '#c'), ('iand', ('uge', a, c), ('uge', b, c))),
441
442 (('fabs', ('slt', a, b)), ('slt', a, b)),
443 (('fabs', ('sge', a, b)), ('sge', a, b)),
444 (('fabs', ('seq', a, b)), ('seq', a, b)),
445 (('fabs', ('sne', a, b)), ('sne', a, b)),
446 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
447 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
448 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
449 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
450 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
451 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
452 # Emulating booleans
453 (('imul', ('b2i', 'a@1'), ('b2i', 'b@1')), ('b2i', ('iand', a, b))),
454 (('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), ('b2f', ('iand', a, b))),
455 (('fsat', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('b2f', ('ior', a, b))),
456 (('iand', 'a@bool32', 1.0), ('b2f', a)),
457 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True).
458 (('ineg', ('b2i32', 'a@32')), a),
459 (('flt', ('fneg', ('b2f', 'a@1')), 0), a), # Generated by TGSI KILL_IF.
460 (('flt', ('fsub', 0.0, ('b2f', 'a@1')), 0), a), # Generated by TGSI KILL_IF.
461 # Comparison with the same args. Note that these are not done for
462 # the float versions because NaN always returns false on float
463 # inequalities.
464 (('ilt', a, a), False),
465 (('ige', a, a), True),
466 (('ieq', a, a), True),
467 (('ine', a, a), False),
468 (('ult', a, a), False),
469 (('uge', a, a), True),
470 # Logical and bit operations
471 (('fand', a, 0.0), 0.0),
472 (('iand', a, a), a),
473 (('iand', a, ~0), a),
474 (('iand', a, 0), 0),
475 (('ior', a, a), a),
476 (('ior', a, 0), a),
477 (('ior', a, True), True),
478 (('fxor', a, a), 0.0),
479 (('ixor', a, a), 0),
480 (('ixor', a, 0), a),
481 (('inot', ('inot', a)), a),
482 (('ior', ('iand', a, b), b), b),
483 (('ior', ('ior', a, b), b), ('ior', a, b)),
484 (('iand', ('ior', a, b), b), b),
485 (('iand', ('iand', a, b), b), ('iand', a, b)),
486 # DeMorgan's Laws
487 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
488 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
489 # Shift optimizations
490 (('ishl', 0, a), 0),
491 (('ishl', a, 0), a),
492 (('ishr', 0, a), 0),
493 (('ishr', a, 0), a),
494 (('ushr', 0, a), 0),
495 (('ushr', a, 0), a),
496 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)),
497 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)),
498 # Exponential/logarithmic identities
499 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a
500 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a
501 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
502 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
503 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
504 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
505 (('~fexp2', ('fmul', ('flog2', a), 2.0)), ('fmul', a, a)),
506 (('~fexp2', ('fmul', ('flog2', a), 4.0)), ('fmul', ('fmul', a, a), ('fmul', a, a))),
507 (('~fpow', a, 1.0), a),
508 (('~fpow', a, 2.0), ('fmul', a, a)),
509 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
510 (('~fpow', 2.0, a), ('fexp2', a)),
511 (('~fpow', ('fpow', a, 2.2), 0.454545), a),
512 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
513 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
514 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
515 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
516 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
517 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))),
518 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
519 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
520 (('~fmul', ('fexp2(is_used_once)', a), ('fexp2(is_used_once)', b)), ('fexp2', ('fadd', a, b))),
521 # Division and reciprocal
522 (('~fdiv', 1.0, a), ('frcp', a)),
523 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
524 (('~frcp', ('frcp', a)), a),
525 (('~frcp', ('fsqrt', a)), ('frsq', a)),
526 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
527 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
528 # Boolean simplifications
529 (('i2b32(is_used_by_if)', a), ('ine32', a, 0)),
530 (('i2b1(is_used_by_if)', a), ('ine', a, 0)),
531 (('ieq', 'a@bool', True), a),
532 (('ine(is_not_used_by_if)', 'a@bool', True), ('inot', a)),
533 (('ine', 'a@bool', False), a),
534 (('ieq(is_not_used_by_if)', 'a@bool', False), ('inot', 'a')),
535 (('bcsel', a, True, False), a),
536 (('bcsel', a, False, True), ('inot', a)),
537 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)),
538 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))),
539 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))),
540 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))),
541 (('bcsel', True, b, c), b),
542 (('bcsel', False, b, c), c),
543 (('bcsel', a, ('b2f(is_used_once)', 'b@32'), ('b2f', 'c@32')), ('b2f', ('bcsel', a, b, c))),
544 # The result of this should be hit by constant propagation and, in the
545 # next round of opt_algebraic, get picked up by one of the above two.
546 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
547
548 (('bcsel', a, b, b), b),
549 (('fcsel', a, b, b), b),
550
551 # D3D Boolean emulation
552 (('bcsel', a, -1, 0), ('ineg', ('b2i', 'a@1'))),
553 (('bcsel', a, 0, -1), ('ineg', ('b2i', ('inot', a)))),
554 (('iand', ('ineg', ('b2i', 'a@1')), ('ineg', ('b2i', 'b@1'))),
555 ('ineg', ('b2i', ('iand', a, b)))),
556 (('ior', ('ineg', ('b2i','a@1')), ('ineg', ('b2i', 'b@1'))),
557 ('ineg', ('b2i', ('ior', a, b)))),
558 (('ieq', ('ineg', ('b2i', 'a@1')), 0), ('inot', a)),
559 (('ieq', ('ineg', ('b2i', 'a@1')), -1), a),
560 (('ine', ('ineg', ('b2i', 'a@1')), 0), a),
561 (('ine', ('ineg', ('b2i', 'a@1')), -1), ('inot', a)),
562 (('iand', ('ineg', ('b2i', a)), 1.0), ('b2f', a)),
563
564 # SM5 32-bit shifts are defined to use the 5 least significant bits
565 (('ishl', 'a@32', ('iand', 31, b)), ('ishl', a, b)),
566 (('ishr', 'a@32', ('iand', 31, b)), ('ishr', a, b)),
567 (('ushr', 'a@32', ('iand', 31, b)), ('ushr', a, b)),
568
569 # Conversions
570 (('i2b32', ('b2i', 'a@32')), a),
571 (('f2i', ('ftrunc', a)), ('f2i', a)),
572 (('f2u', ('ftrunc', a)), ('f2u', a)),
573 (('i2b', ('ineg', a)), ('i2b', a)),
574 (('i2b', ('iabs', a)), ('i2b', a)),
575 (('fabs', ('b2f', a)), ('b2f', a)),
576 (('iabs', ('b2i', a)), ('b2i', a)),
577 (('inot', ('f2b1', a)), ('feq', a, 0.0)),
578
579 # Ironically, mark these as imprecise because removing the conversions may
580 # preserve more precision than doing the conversions (e.g.,
581 # uint(float(0x81818181u)) == 0x81818200).
582 (('~f2i32', ('i2f', 'a@32')), a),
583 (('~f2i32', ('u2f', 'a@32')), a),
584 (('~f2u32', ('i2f', 'a@32')), a),
585 (('~f2u32', ('u2f', 'a@32')), a),
586
587 # Section 5.4.1 (Conversion and Scalar Constructors) of the GLSL 4.60 spec
588 # says:
589 #
590 # It is undefined to convert a negative floating-point value to an
591 # uint.
592 #
593 # Assuming that (uint)some_float behaves like (uint)(int)some_float allows
594 # some optimizations in the i965 backend to proceed.
595 (('ige', ('f2u', a), b), ('ige', ('f2i', a), b)),
596 (('ige', b, ('f2u', a)), ('ige', b, ('f2i', a))),
597 (('ilt', ('f2u', a), b), ('ilt', ('f2i', a), b)),
598 (('ilt', b, ('f2u', a)), ('ilt', b, ('f2i', a))),
599
600 # Packing and then unpacking does nothing
601 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
602 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
603 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
604 ('unpack_64_2x32_split_y', a)), a),
605
606 # Byte extraction
607 (('ushr', ('ishl', 'a@32', 24), 24), ('extract_u8', a, 0), '!options->lower_extract_byte'),
608 (('ushr', ('ishl', 'a@32', 16), 24), ('extract_u8', a, 1), '!options->lower_extract_byte'),
609 (('ushr', ('ishl', 'a@32', 8), 24), ('extract_u8', a, 2), '!options->lower_extract_byte'),
610 (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
611 (('ishr', ('ishl', 'a@32', 24), 24), ('extract_i8', a, 0), '!options->lower_extract_byte'),
612 (('ishr', ('ishl', 'a@32', 16), 24), ('extract_i8', a, 1), '!options->lower_extract_byte'),
613 (('ishr', ('ishl', 'a@32', 8), 24), ('extract_i8', a, 2), '!options->lower_extract_byte'),
614 (('ishr', 'a@32', 24), ('extract_i8', a, 3), '!options->lower_extract_byte'),
615 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'),
616 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'),
617 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
618
619 # Word extraction
620 (('ushr', ('ishl', 'a@32', 16), 16), ('extract_u16', a, 0), '!options->lower_extract_word'),
621 (('ushr', 'a@32', 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
622 (('ishr', ('ishl', 'a@32', 16), 16), ('extract_i16', a, 0), '!options->lower_extract_word'),
623 (('ishr', 'a@32', 16), ('extract_i16', a, 1), '!options->lower_extract_word'),
624 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
625
626 # Subtracts
627 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
628 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
629 (('ussub_4x8', a, 0), a),
630 (('ussub_4x8', a, ~0), 0),
631 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
632 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
633 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
634 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
635 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
636 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
637 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
638 (('iabs', ('isub', 0, a)), ('iabs', a)),
639
640 # Propagate negation up multiplication chains
641 (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))),
642 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
643
644 # Propagate constants up multiplication chains
645 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
646 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
647 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
648 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
649
650 # Reassociate constants in add/mul chains so they can be folded together.
651 # For now, we mostly only handle cases where the constants are separated by
652 # a single non-constant. We could do better eventually.
653 (('~fmul', '#a', ('fmul', 'b(is_not_const)', '#c')), ('fmul', ('fmul', a, c), b)),
654 (('imul', '#a', ('imul', 'b(is_not_const)', '#c')), ('imul', ('imul', a, c), b)),
655 (('~fadd', '#a', ('fadd', 'b(is_not_const)', '#c')), ('fadd', ('fadd', a, c), b)),
656 (('~fadd', '#a', ('fneg', ('fadd', 'b(is_not_const)', '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
657 (('iadd', '#a', ('iadd', 'b(is_not_const)', '#c')), ('iadd', ('iadd', a, c), b)),
658
659 # By definition...
660 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
661 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
662 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
663
664 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
665 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
666 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
667
668 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
669
670 # Misc. lowering
671 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod32'),
672 (('fmod@64', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod64'),
673 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod32'),
674 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
675 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
676
677 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
678 ('bcsel', ('ilt', 31, 'bits'), 'insert',
679 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
680 'options->lower_bitfield_insert'),
681
682 # Alternative lowering that doesn't rely on bfi.
683 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
684 ('bcsel', ('ilt', 31, 'bits'),
685 'insert',
686 ('ior',
687 ('iand', 'base', ('inot', ('bfm', 'bits', 'offset'))),
688 ('iand', ('ishl', 'insert', 'offset'), ('bfm', 'bits', 'offset')))),
689 'options->lower_bitfield_insert_to_shifts'),
690
691 # bfm lowering -- note that the NIR opcode is undefined if either arg is 32.
692 (('bfm', 'bits', 'offset'),
693 ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'),
694 'options->lower_bfm'),
695
696 (('ibitfield_extract', 'value', 'offset', 'bits'),
697 ('bcsel', ('ilt', 31, 'bits'), 'value',
698 ('ibfe', 'value', 'offset', 'bits')),
699 'options->lower_bitfield_extract'),
700
701 (('ubitfield_extract', 'value', 'offset', 'bits'),
702 ('bcsel', ('ult', 31, 'bits'), 'value',
703 ('ubfe', 'value', 'offset', 'bits')),
704 'options->lower_bitfield_extract'),
705
706 (('ibitfield_extract', 'value', 'offset', 'bits'),
707 ('bcsel', ('ieq', 0, 'bits'),
708 0,
709 ('ishr',
710 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
711 ('isub', 32, 'bits'))),
712 'options->lower_bitfield_extract_to_shifts'),
713
714 (('ubitfield_extract', 'value', 'offset', 'bits'),
715 ('iand',
716 ('ushr', 'value', 'offset'),
717 ('bcsel', ('ieq', 'bits', 32),
718 0xffffffff,
719 ('bfm', 'bits', 0))),
720 'options->lower_bitfield_extract_to_shifts'),
721
722 (('ifind_msb', 'value'),
723 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
724 'options->lower_ifind_msb'),
725
726 (('find_lsb', 'value'),
727 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
728 'options->lower_find_lsb'),
729
730 (('extract_i8', a, 'b@32'),
731 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
732 'options->lower_extract_byte'),
733
734 (('extract_u8', a, 'b@32'),
735 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
736 'options->lower_extract_byte'),
737
738 (('extract_i16', a, 'b@32'),
739 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
740 'options->lower_extract_word'),
741
742 (('extract_u16', a, 'b@32'),
743 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
744 'options->lower_extract_word'),
745
746 (('pack_unorm_2x16', 'v'),
747 ('pack_uvec2_to_uint',
748 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
749 'options->lower_pack_unorm_2x16'),
750
751 (('pack_unorm_4x8', 'v'),
752 ('pack_uvec4_to_uint',
753 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
754 'options->lower_pack_unorm_4x8'),
755
756 (('pack_snorm_2x16', 'v'),
757 ('pack_uvec2_to_uint',
758 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
759 'options->lower_pack_snorm_2x16'),
760
761 (('pack_snorm_4x8', 'v'),
762 ('pack_uvec4_to_uint',
763 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
764 'options->lower_pack_snorm_4x8'),
765
766 (('unpack_unorm_2x16', 'v'),
767 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
768 ('extract_u16', 'v', 1))),
769 65535.0),
770 'options->lower_unpack_unorm_2x16'),
771
772 (('unpack_unorm_4x8', 'v'),
773 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
774 ('extract_u8', 'v', 1),
775 ('extract_u8', 'v', 2),
776 ('extract_u8', 'v', 3))),
777 255.0),
778 'options->lower_unpack_unorm_4x8'),
779
780 (('unpack_snorm_2x16', 'v'),
781 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
782 ('extract_i16', 'v', 1))),
783 32767.0))),
784 'options->lower_unpack_snorm_2x16'),
785
786 (('unpack_snorm_4x8', 'v'),
787 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
788 ('extract_i8', 'v', 1),
789 ('extract_i8', 'v', 2),
790 ('extract_i8', 'v', 3))),
791 127.0))),
792 'options->lower_unpack_snorm_4x8'),
793
794 (('isign', a), ('imin', ('imax', a, -1), 1), 'options->lower_isign'),
795 ]
796
797 invert = OrderedDict([('feq', 'fne'), ('fne', 'feq'), ('fge', 'flt'), ('flt', 'fge')])
798
799 for left, right in itertools.combinations_with_replacement(invert.keys(), 2):
800 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
801 ('iand', (invert[left], a, b), (invert[right], c, d))))
802 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
803 ('ior', (invert[left], a, b), (invert[right], c, d))))
804
805 # Optimize x2bN(b2x(x)) -> x
806 for size in type_sizes('bool'):
807 aN = 'a@' + str(size)
808 f2bN = 'f2b' + str(size)
809 i2bN = 'i2b' + str(size)
810 optimizations.append(((f2bN, ('b2f', aN)), a))
811 optimizations.append(((i2bN, ('b2i', aN)), a))
812
813 # Optimize x2yN(b2x(x)) -> b2y
814 for x, y in itertools.product(['f', 'u', 'i'], ['f', 'u', 'i']):
815 if x != 'f' and y != 'f' and x != y:
816 continue
817
818 b2x = 'b2f' if x == 'f' else 'b2i'
819 b2y = 'b2f' if y == 'f' else 'b2i'
820 x2yN = '{}2{}'.format(x, y)
821 optimizations.append(((x2yN, (b2x, a)), (b2y, a)))
822
823 def fexp2i(exp, bits):
824 # We assume that exp is already in the right range.
825 if bits == 32:
826 return ('ishl', ('iadd', exp, 127), 23)
827 elif bits == 64:
828 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
829 else:
830 assert False
831
832 def ldexp(f, exp, bits):
833 # First, we clamp exp to a reasonable range. The maximum possible range
834 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
835 # a maximum range of [-149, 127]. This means that we can potentially have
836 # a swing of +-276. If you start with FLT_MAX, you actually have to do
837 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
838 # spec, on the other hand, only requires that we handle an exponent value
839 # in the range [-126, 128]. This implementation is *mostly* correct; it
840 # handles a range on exp of [-252, 254] which allows you to create any
841 # value (including denorms if the hardware supports it) and to adjust the
842 # exponent of any normal value to anything you want.
843 if bits == 32:
844 exp = ('imin', ('imax', exp, -252), 254)
845 elif bits == 64:
846 exp = ('imin', ('imax', exp, -2044), 2046)
847 else:
848 assert False
849
850 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
851 # (We use ishr which isn't the same for -1, but the -1 case still works
852 # since we use exp-exp/2 as the second exponent.) While the spec
853 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
854 # work with denormals and doesn't allow for the full swing in exponents
855 # that you can get with normalized values. Instead, we create two powers
856 # of two and multiply by them each in turn. That way the effective range
857 # of our exponent is doubled.
858 pow2_1 = fexp2i(('ishr', exp, 1), bits)
859 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
860 return ('fmul', ('fmul', f, pow2_1), pow2_2)
861
862 optimizations += [
863 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
864 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
865 ]
866
867 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
868 def bitfield_reverse(u):
869 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
870 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
871 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
872 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
873 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
874
875 return step5
876
877 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'))]
878
879 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
880 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
881 # and, if a is a NaN then the second comparison will fail anyway.
882 for op in ['flt', 'fge', 'feq']:
883 optimizations += [
884 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
885 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
886 ]
887
888 # Add optimizations to handle the case where the result of a ternary is
889 # compared to a constant. This way we can take things like
890 #
891 # (a ? 0 : 1) > 0
892 #
893 # and turn it into
894 #
895 # a ? (0 > 0) : (1 > 0)
896 #
897 # which constant folding will eat for lunch. The resulting ternary will
898 # further get cleaned up by the boolean reductions above and we will be
899 # left with just the original variable "a".
900 for op in ['flt', 'fge', 'feq', 'fne',
901 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
902 optimizations += [
903 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
904 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
905 ((op, '#d', ('bcsel', a, '#b', '#c')),
906 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
907 ]
908
909
910 # For example, this converts things like
911 #
912 # 1 + mix(0, a - 1, condition)
913 #
914 # into
915 #
916 # mix(1, (a-1)+1, condition)
917 #
918 # Other optimizations will rearrange the constants.
919 for op in ['fadd', 'fmul', 'iadd', 'imul']:
920 optimizations += [
921 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
922 ]
923
924 # This section contains "late" optimizations that should be run before
925 # creating ffmas and calling regular optimizations for the final time.
926 # Optimizations should go here if they help code generation and conflict
927 # with the regular optimizations.
928 before_ffma_optimizations = [
929 # Propagate constants down multiplication chains
930 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
931 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
932 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
933 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
934
935 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
936 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
937 (('~fadd', ('fneg', a), a), 0.0),
938 (('iadd', ('ineg', a), a), 0),
939 (('iadd', ('ineg', a), ('iadd', a, b)), b),
940 (('iadd', a, ('iadd', ('ineg', a), b)), b),
941 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
942 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
943 ]
944
945 # This section contains "late" optimizations that should be run after the
946 # regular optimizations have finished. Optimizations should go here if
947 # they help code generation but do not necessarily produce code that is
948 # more easily optimizable.
949 late_optimizations = [
950 # Most of these optimizations aren't quite safe when you get infinity or
951 # Nan involved but the first one should be fine.
952 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
953 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
954 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
955 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
956 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
957 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
958
959 (('~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)))),
960
961 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
962 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
963 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
964 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
965
966 (('b2f(is_used_more_than_once)', ('inot', 'a@1')), ('bcsel', a, 0.0, 1.0)),
967 (('fneg(is_used_more_than_once)', ('b2f', ('inot', 'a@1'))), ('bcsel', a, -0.0, -1.0)),
968
969 # we do these late so that we don't get in the way of creating ffmas
970 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
971 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
972
973 (('bcsel', 'a@bool', 0, ('b2f32', ('inot', 'b@bool'))), ('b2f32', ('inot', ('ior', a, b)))),
974 ]
975
976 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render())
977 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
978 before_ffma_optimizations).render())
979 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
980 late_optimizations).render())