nir/algebraic: Mark some value range analysis-based optimizations imprecise
[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 from math import pi
33
34 # Convenience variables
35 a = 'a'
36 b = 'b'
37 c = 'c'
38 d = 'd'
39 e = 'e'
40
41 # Written in the form (<search>, <replace>) where <search> is an expression
42 # and <replace> is either an expression or a value. An expression is
43 # defined as a tuple of the form ([~]<op>, <src0>, <src1>, <src2>, <src3>)
44 # where each source is either an expression or a value. A value can be
45 # either a numeric constant or a string representing a variable name.
46 #
47 # If the opcode in a search expression is prefixed by a '~' character, this
48 # indicates that the operation is inexact. Such operations will only get
49 # applied to SSA values that do not have the exact bit set. This should be
50 # used by by any optimizations that are not bit-for-bit exact. It should not,
51 # however, be used for backend-requested lowering operations as those need to
52 # happen regardless of precision.
53 #
54 # Variable names are specified as "[#]name[@type][(cond)][.swiz]" where:
55 # "#" indicates that the given variable will only match constants,
56 # type indicates that the given variable will only match values from ALU
57 # instructions with the given output type,
58 # (cond) specifies an additional condition function (see nir_search_helpers.h),
59 # swiz is a swizzle applied to the variable (only in the <replace> expression)
60 #
61 # For constants, you have to be careful to make sure that it is the right
62 # type because python is unaware of the source and destination types of the
63 # opcodes.
64 #
65 # All expression types can have a bit-size specified. For opcodes, this
66 # looks like "op@32", for variables it is "a@32" or "a@uint32" to specify a
67 # type and size. In the search half of the expression this indicates that it
68 # should only match that particular bit-size. In the replace half of the
69 # expression this indicates that the constructed value should have that
70 # bit-size.
71 #
72 # A special condition "many-comm-expr" can be used with expressions to note
73 # that the expression and its subexpressions have more commutative expressions
74 # than nir_replace_instr can handle. If this special condition is needed with
75 # another condition, the two can be separated by a comma (e.g.,
76 # "(many-comm-expr,is_used_once)").
77
78 # based on https://web.archive.org/web/20180105155939/http://forum.devmaster.net/t/fast-and-accurate-sine-cosine/9648
79 def lowered_sincos(c):
80 x = ('fsub', ('fmul', 2.0, ('ffract', ('fadd', ('fmul', 0.5 / pi, a), c))), 1.0)
81 x = ('fmul', ('fsub', x, ('fmul', x, ('fabs', x))), 4.0)
82 return ('ffma', ('ffma', x, ('fabs', x), ('fneg', x)), 0.225, x)
83
84 optimizations = [
85
86 (('imul', a, '#b@32(is_pos_power_of_two)'), ('ishl', a, ('find_lsb', b)), '!options->lower_bitops'),
87 (('imul', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('ishl', a, ('find_lsb', ('iabs', b)))), '!options->lower_bitops'),
88 (('ishl', a, '#b@32'), ('imul', a, ('ishl', 1, b)), 'options->lower_bitops'),
89
90 (('unpack_64_2x32_split_x', ('imul_2x32_64(is_used_once)', a, b)), ('imul', a, b)),
91 (('unpack_64_2x32_split_x', ('umul_2x32_64(is_used_once)', a, b)), ('imul', a, b)),
92 (('imul_2x32_64', a, b), ('pack_64_2x32_split', ('imul', a, b), ('imul_high', a, b)), 'options->lower_mul_2x32_64'),
93 (('umul_2x32_64', a, b), ('pack_64_2x32_split', ('imul', a, b), ('umul_high', a, b)), 'options->lower_mul_2x32_64'),
94 (('udiv', a, 1), a),
95 (('idiv', a, 1), a),
96 (('umod', a, 1), 0),
97 (('imod', a, 1), 0),
98 (('udiv', a, '#b@32(is_pos_power_of_two)'), ('ushr', a, ('find_lsb', b)), '!options->lower_bitops'),
99 (('idiv', a, '#b@32(is_pos_power_of_two)'), ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', b))), 'options->lower_idiv'),
100 (('idiv', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', ('iabs', b))))), 'options->lower_idiv'),
101 (('umod', a, '#b(is_pos_power_of_two)'), ('iand', a, ('isub', b, 1))),
102
103 (('fneg', ('fneg', a)), a),
104 (('ineg', ('ineg', a)), a),
105 (('fabs', ('fabs', a)), ('fabs', a)),
106 (('fabs', ('fneg', a)), ('fabs', a)),
107 (('fabs', ('u2f', a)), ('u2f', a)),
108 (('iabs', ('iabs', a)), ('iabs', a)),
109 (('iabs', ('ineg', a)), ('iabs', a)),
110 (('f2b', ('fneg', a)), ('f2b', a)),
111 (('i2b', ('ineg', a)), ('i2b', a)),
112 (('~fadd', a, 0.0), a),
113 (('iadd', a, 0), a),
114 (('usadd_4x8', a, 0), a),
115 (('usadd_4x8', a, ~0), ~0),
116 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
117 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
118 (('~fadd', ('fneg', a), a), 0.0),
119 (('iadd', ('ineg', a), a), 0),
120 (('iadd', ('ineg', a), ('iadd', a, b)), b),
121 (('iadd', a, ('iadd', ('ineg', a), b)), b),
122 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
123 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
124 (('fadd', ('fsat', a), ('fsat', ('fneg', a))), ('fsat', ('fabs', a))),
125 (('~fmul', a, 0.0), 0.0),
126 (('imul', a, 0), 0),
127 (('umul_unorm_4x8', a, 0), 0),
128 (('umul_unorm_4x8', a, ~0), a),
129 (('fmul', a, 1.0), a),
130 (('imul', a, 1), a),
131 (('fmul', a, -1.0), ('fneg', a)),
132 (('imul', a, -1), ('ineg', a)),
133 # If a < 0: fsign(a)*a*a => -1*a*a => -a*a => abs(a)*a
134 # If a > 0: fsign(a)*a*a => 1*a*a => a*a => abs(a)*a
135 # If a == 0: fsign(a)*a*a => 0*0*0 => abs(0)*0
136 (('fmul', ('fsign', a), ('fmul', a, a)), ('fmul', ('fabs', a), a)),
137 (('fmul', ('fmul', ('fsign', a), a), a), ('fmul', ('fabs', a), a)),
138 (('~ffma', 0.0, a, b), b),
139 (('~ffma', a, b, 0.0), ('fmul', a, b)),
140 (('ffma', 1.0, a, b), ('fadd', a, b)),
141 (('ffma', -1.0, a, b), ('fadd', ('fneg', a), b)),
142 (('~flrp', a, b, 0.0), a),
143 (('~flrp', a, b, 1.0), b),
144 (('~flrp', a, a, b), a),
145 (('~flrp', 0.0, a, b), ('fmul', a, b)),
146
147 # flrp(a, a + b, c) => a + flrp(0, b, c) => a + (b * c)
148 (('~flrp', a, ('fadd(is_used_once)', a, b), c), ('fadd', ('fmul', b, c), a)),
149 (('~flrp@32', a, ('fadd', a, b), c), ('fadd', ('fmul', b, c), a), 'options->lower_flrp32'),
150 (('~flrp@64', a, ('fadd', a, b), c), ('fadd', ('fmul', b, c), a), 'options->lower_flrp64'),
151
152 (('~flrp@32', ('fadd', a, b), ('fadd', a, c), d), ('fadd', ('flrp', b, c, d), a), 'options->lower_flrp32'),
153 (('~flrp@64', ('fadd', a, b), ('fadd', a, c), d), ('fadd', ('flrp', b, c, d), a), 'options->lower_flrp64'),
154
155 (('~flrp@32', a, ('fmul(is_used_once)', a, b), c), ('fmul', ('flrp', 1.0, b, c), a), 'options->lower_flrp32'),
156 (('~flrp@64', a, ('fmul(is_used_once)', a, b), c), ('fmul', ('flrp', 1.0, b, c), a), 'options->lower_flrp64'),
157
158 (('~flrp', ('fmul(is_used_once)', a, b), ('fmul(is_used_once)', a, c), d), ('fmul', ('flrp', b, c, d), a)),
159
160 (('~flrp', a, b, ('b2f', 'c@1')), ('bcsel', c, b, a), 'options->lower_flrp32'),
161 (('~flrp', a, 0.0, c), ('fadd', ('fmul', ('fneg', a), c), a)),
162 (('ftrunc', a), ('bcsel', ('flt', a, 0.0), ('fneg', ('ffloor', ('fabs', a))), ('ffloor', ('fabs', a))), 'options->lower_ftrunc'),
163 (('ffloor', a), ('fsub', a, ('ffract', a)), 'options->lower_ffloor'),
164 (('fadd', a, ('fneg', ('ffract', a))), ('ffloor', a), '!options->lower_ffloor'),
165 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
166 (('fceil', a), ('fneg', ('ffloor', ('fneg', a))), 'options->lower_fceil'),
167 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', 'c@1')))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'),
168 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ) )), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'),
169 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ) )), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'),
170 # These are the same as the previous three rules, but it depends on
171 # 1-fsat(x) <=> fsat(1-x). See below.
172 (('~fadd@32', ('fmul', a, ('fsat', ('fadd', 1.0, ('fneg', c )))), ('fmul', b, ('fsat', c))), ('flrp', a, b, ('fsat', c)), '!options->lower_flrp32'),
173 (('~fadd@64', ('fmul', a, ('fsat', ('fadd', 1.0, ('fneg', c )))), ('fmul', b, ('fsat', c))), ('flrp', a, b, ('fsat', c)), '!options->lower_flrp64'),
174
175 (('~fadd', a, ('fmul', ('b2f', 'c@1'), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'),
176 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'),
177 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'),
178 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
179 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'),
180
181 (('~fmul', ('fadd', ('iand', ('ineg', ('b2i32', 'a@bool')), ('fmul', b, c)), '#d'), '#e'),
182 ('bcsel', a, ('fmul', ('fadd', ('fmul', b, c), d), e), ('fmul', d, e))),
183
184 (('fdph', a, b), ('fdot4', ('vec4', 'a.x', 'a.y', 'a.z', 1.0), b), 'options->lower_fdph'),
185
186 (('fdot4', ('vec4', a, b, c, 1.0), d), ('fdph', ('vec3', a, b, c), d), '!options->lower_fdph'),
187 (('fdot4', ('vec4', a, 0.0, 0.0, 0.0), b), ('fmul', a, b)),
188 (('fdot4', ('vec4', a, b, 0.0, 0.0), c), ('fdot2', ('vec2', a, b), c)),
189 (('fdot4', ('vec4', a, b, c, 0.0), d), ('fdot3', ('vec3', a, b, c), d)),
190
191 (('fdot3', ('vec3', a, 0.0, 0.0), b), ('fmul', a, b)),
192 (('fdot3', ('vec3', a, b, 0.0), c), ('fdot2', ('vec2', a, b), c)),
193
194 (('fdot2', ('vec2', a, 0.0), b), ('fmul', a, b)),
195 (('fdot2', a, 1.0), ('fadd', 'a.x', 'a.y')),
196
197 # Lower fdot to fsum when it is available
198 (('fdot2', a, b), ('fsum2', ('fmul', a, b)), 'options->lower_fdot'),
199 (('fdot3', a, b), ('fsum3', ('fmul', a, b)), 'options->lower_fdot'),
200 (('fdot4', a, b), ('fsum4', ('fmul', a, b)), 'options->lower_fdot'),
201 (('fsum2', a), ('fadd', 'a.x', 'a.y'), 'options->lower_fdot'),
202
203 # If x >= 0 and x <= 1: fsat(1 - x) == 1 - fsat(x) trivially
204 # If x < 0: 1 - fsat(x) => 1 - 0 => 1 and fsat(1 - x) => fsat(> 1) => 1
205 # If x > 1: 1 - fsat(x) => 1 - 1 => 0 and fsat(1 - x) => fsat(< 0) => 0
206 (('~fadd', ('fneg(is_used_once)', ('fsat(is_used_once)', 'a(is_not_fmul)')), 1.0), ('fsat', ('fadd', 1.0, ('fneg', a)))),
207 (('~fsub', 1.0, ('fsat', a)), ('fsat', ('fsub', 1.0, a))),
208
209 # 1 - ((1 - a) * (1 - b))
210 # 1 - (1 - a - b + a*b)
211 # 1 - 1 + a + b - a*b
212 # a + b - a*b
213 # a + b*(1 - a)
214 # b*(1 - a) + 1*a
215 # flrp(b, 1, a)
216 (('~fadd@32', 1.0, ('fneg', ('fmul', ('fadd', 1.0, ('fneg', a)), ('fadd', 1.0, ('fneg', b))))),
217 ('flrp', b, 1.0, a), '!options->lower_flrp32'),
218
219 # (a * #b + #c) << #d
220 # ((a * #b) << #d) + (#c << #d)
221 # (a * (#b << #d)) + (#c << #d)
222 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'),
223 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))),
224
225 # (a * #b) << #c
226 # a * (#b << #c)
227 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))),
228 ]
229
230 # Care must be taken here. Shifts in NIR uses only the lower log2(bitsize)
231 # bits of the second source. These replacements must correctly handle the
232 # case where (b % bitsize) + (c % bitsize) >= bitsize.
233 for s in [8, 16, 32, 64]:
234 mask = (1 << s) - 1
235
236 ishl = "ishl@{}".format(s)
237 ishr = "ishr@{}".format(s)
238 ushr = "ushr@{}".format(s)
239
240 in_bounds = ('ult', ('iadd', ('iand', b, mask), ('iand', c, mask)), s)
241
242 optimizations.extend([
243 ((ishl, (ishl, a, '#b'), '#c'), ('bcsel', in_bounds, (ishl, a, ('iadd', b, c)), 0)),
244 ((ushr, (ushr, a, '#b'), '#c'), ('bcsel', in_bounds, (ushr, a, ('iadd', b, c)), 0)),
245
246 # To get get -1 for large shifts of negative values, ishr must instead
247 # clamp the shift count to the maximum value.
248 ((ishr, (ishr, a, '#b'), '#c'),
249 (ishr, a, ('imin', ('iadd', ('iand', b, mask), ('iand', c, mask)), s - 1))),
250 ])
251
252 optimizations.extend([
253 # This is common for address calculations. Reassociating may enable the
254 # 'a<<c' to be CSE'd. It also helps architectures that have an ISHLADD
255 # instruction or a constant offset field for in load / store instructions.
256 (('ishl', ('iadd', a, '#b'), '#c'), ('iadd', ('ishl', a, c), ('ishl', b, c))),
257
258 # Comparison simplifications
259 (('~inot', ('flt', a, b)), ('fge', a, b)),
260 (('~inot', ('fge', a, b)), ('flt', a, b)),
261 (('inot', ('feq', a, b)), ('fne', a, b)),
262 (('inot', ('fne', a, b)), ('feq', a, b)),
263 (('inot', ('ilt', a, b)), ('ige', a, b)),
264 (('inot', ('ult', a, b)), ('uge', a, b)),
265 (('inot', ('ige', a, b)), ('ilt', a, b)),
266 (('inot', ('uge', a, b)), ('ult', a, b)),
267 (('inot', ('ieq', a, b)), ('ine', a, b)),
268 (('inot', ('ine', a, b)), ('ieq', a, b)),
269
270 (('iand', ('feq', a, b), ('fne', a, b)), False),
271 (('iand', ('flt', a, b), ('flt', b, a)), False),
272 (('iand', ('ieq', a, b), ('ine', a, b)), False),
273 (('iand', ('ilt', a, b), ('ilt', b, a)), False),
274 (('iand', ('ult', a, b), ('ult', b, a)), False),
275
276 # This helps some shaders because, after some optimizations, they end up
277 # with patterns like (-a < -b) || (b < a). In an ideal world, this sort of
278 # matching would be handled by CSE.
279 (('flt', ('fneg', a), ('fneg', b)), ('flt', b, a)),
280 (('fge', ('fneg', a), ('fneg', b)), ('fge', b, a)),
281 (('feq', ('fneg', a), ('fneg', b)), ('feq', b, a)),
282 (('fne', ('fneg', a), ('fneg', b)), ('fne', b, a)),
283 (('flt', ('fneg', a), -1.0), ('flt', 1.0, a)),
284 (('flt', -1.0, ('fneg', a)), ('flt', a, 1.0)),
285 (('fge', ('fneg', a), -1.0), ('fge', 1.0, a)),
286 (('fge', -1.0, ('fneg', a)), ('fge', a, 1.0)),
287 (('fne', ('fneg', a), -1.0), ('fne', 1.0, a)),
288 (('feq', -1.0, ('fneg', a)), ('feq', a, 1.0)),
289
290 (('flt', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('flt', a, b)),
291 (('flt', '#b(is_gt_0_and_lt_1)', ('fsat(is_used_once)', a)), ('flt', b, a)),
292 (('fge', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('fge', a, b)),
293 (('fge', '#b(is_gt_0_and_lt_1)', ('fsat(is_used_once)', a)), ('fge', b, a)),
294 (('feq', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('feq', a, b)),
295 (('fne', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('fne', a, b)),
296
297 (('fge', ('fsat(is_used_once)', a), 1.0), ('fge', a, 1.0)),
298 (('flt', ('fsat(is_used_once)', a), 1.0), ('flt', a, 1.0)),
299 (('fge', 0.0, ('fsat(is_used_once)', a)), ('fge', 0.0, a)),
300 (('flt', 0.0, ('fsat(is_used_once)', a)), ('flt', 0.0, a)),
301
302 # 0.0 >= b2f(a)
303 # b2f(a) <= 0.0
304 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1
305 # inot(a)
306 (('fge', 0.0, ('b2f', 'a@1')), ('inot', a)),
307
308 (('fge', ('fneg', ('b2f', 'a@1')), 0.0), ('inot', a)),
309
310 (('fne', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('ior', a, b)),
311 (('fne', ('fmax', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('ior', a, b)),
312 (('fne', ('bcsel', a, 1.0, ('b2f', 'b@1')) , 0.0), ('ior', a, b)),
313 (('fne', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), ('ior', a, b)),
314 (('fne', ('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('iand', a, b)),
315 (('fne', ('fmin', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('iand', a, b)),
316 (('fne', ('bcsel', a, ('b2f', 'b@1'), 0.0) , 0.0), ('iand', a, b)),
317 (('fne', ('fadd', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), 0.0), ('ixor', a, b)),
318 (('fne', ('b2f', 'a@1') , ('b2f', 'b@1') ), ('ixor', a, b)),
319 (('fne', ('fneg', ('b2f', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('ixor', a, b)),
320 (('feq', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('ior', a, b))),
321 (('feq', ('fmax', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('ior', a, b))),
322 (('feq', ('bcsel', a, 1.0, ('b2f', 'b@1')) , 0.0), ('inot', ('ior', a, b))),
323 (('feq', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), ('inot', ('ior', a, b))),
324 (('feq', ('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('iand', a, b))),
325 (('feq', ('fmin', ('b2f', 'a@1'), ('b2f', 'b@1')), 0.0), ('inot', ('iand', a, b))),
326 (('feq', ('bcsel', a, ('b2f', 'b@1'), 0.0) , 0.0), ('inot', ('iand', a, b))),
327 (('feq', ('fadd', ('b2f', 'a@1'), ('fneg', ('b2f', 'b@1'))), 0.0), ('ieq', a, b)),
328 (('feq', ('b2f', 'a@1') , ('b2f', 'b@1') ), ('ieq', a, b)),
329 (('feq', ('fneg', ('b2f', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('ieq', a, b)),
330
331 # -(b2f(a) + b2f(b)) < 0
332 # 0 < b2f(a) + b2f(b)
333 # 0 != b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
334 # a || b
335 (('flt', ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), 0.0), ('ior', a, b)),
336 (('flt', 0.0, ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('ior', a, b)),
337
338 # -(b2f(a) + b2f(b)) >= 0
339 # 0 >= b2f(a) + b2f(b)
340 # 0 == b2f(a) + b2f(b) b2f must be 0 or 1, so the sum is non-negative
341 # !(a || b)
342 (('fge', ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), 0.0), ('inot', ('ior', a, b))),
343 (('fge', 0.0, ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('inot', ('ior', a, b))),
344
345 (('flt', a, ('fneg', a)), ('flt', a, 0.0)),
346 (('fge', a, ('fneg', a)), ('fge', a, 0.0)),
347
348 # Some optimizations (below) convert things like (a < b || c < b) into
349 # (min(a, c) < b). However, this interfers with the previous optimizations
350 # that try to remove comparisons with negated sums of b2f. This just
351 # breaks that apart.
352 (('flt', ('fmin', c, ('fneg', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1')))), 0.0),
353 ('ior', ('flt', c, 0.0), ('ior', a, b))),
354
355 (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)),
356 (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)),
357 (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)),
358 (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)),
359 (('~flt', ('fadd(is_used_once)', a, '#b'), '#c'), ('flt', a, ('fadd', c, ('fneg', b)))),
360 (('~flt', ('fneg(is_used_once)', ('fadd(is_used_once)', a, '#b')), '#c'), ('flt', ('fneg', ('fadd', c, b)), a)),
361 (('~fge', ('fadd(is_used_once)', a, '#b'), '#c'), ('fge', a, ('fadd', c, ('fneg', b)))),
362 (('~fge', ('fneg(is_used_once)', ('fadd(is_used_once)', a, '#b')), '#c'), ('fge', ('fneg', ('fadd', c, b)), a)),
363 (('~feq', ('fadd(is_used_once)', a, '#b'), '#c'), ('feq', a, ('fadd', c, ('fneg', b)))),
364 (('~feq', ('fneg(is_used_once)', ('fadd(is_used_once)', a, '#b')), '#c'), ('feq', ('fneg', ('fadd', c, b)), a)),
365 (('~fne', ('fadd(is_used_once)', a, '#b'), '#c'), ('fne', a, ('fadd', c, ('fneg', b)))),
366 (('~fne', ('fneg(is_used_once)', ('fadd(is_used_once)', a, '#b')), '#c'), ('fne', ('fneg', ('fadd', c, b)), a)),
367
368 # Cannot remove the addition from ilt or ige due to overflow.
369 (('ieq', ('iadd', a, b), a), ('ieq', b, 0)),
370 (('ine', ('iadd', a, b), a), ('ine', b, 0)),
371
372 # fmin(-b2f(a), b) >= 0.0
373 # -b2f(a) >= 0.0 && b >= 0.0
374 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0
375 # b2f(a) == 0.0 && b >= 0.0
376 # a == False && b >= 0.0
377 # !a && b >= 0.0
378 #
379 # The fge in the second replacement is not a typo. I leave the proof that
380 # "fmin(-b2f(a), b) >= 0 <=> fmin(-b2f(a), b) == 0" as an exercise for the
381 # reader.
382 (('fge', ('fmin', ('fneg', ('b2f', 'a@1')), 'b@1'), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
383 (('feq', ('fmin', ('fneg', ('b2f', 'a@1')), 'b@1'), 0.0), ('iand', ('inot', a), ('fge', b, 0.0))),
384
385 (('feq', ('b2f', 'a@1'), 0.0), ('inot', a)),
386 (('fne', ('b2f', 'a@1'), 0.0), a),
387 (('ieq', ('b2i', 'a@1'), 0), ('inot', a)),
388 (('ine', ('b2i', 'a@1'), 0), a),
389
390 (('fne', ('u2f', a), 0.0), ('ine', a, 0)),
391 (('feq', ('u2f', a), 0.0), ('ieq', a, 0)),
392 (('fge', ('u2f', a), 0.0), True),
393 (('fge', 0.0, ('u2f', a)), ('uge', 0, a)), # ieq instead?
394 (('flt', ('u2f', a), 0.0), False),
395 (('flt', 0.0, ('u2f', a)), ('ult', 0, a)), # ine instead?
396 (('fne', ('i2f', a), 0.0), ('ine', a, 0)),
397 (('feq', ('i2f', a), 0.0), ('ieq', a, 0)),
398 (('fge', ('i2f', a), 0.0), ('ige', a, 0)),
399 (('fge', 0.0, ('i2f', a)), ('ige', 0, a)),
400 (('flt', ('i2f', a), 0.0), ('ilt', a, 0)),
401 (('flt', 0.0, ('i2f', a)), ('ilt', 0, a)),
402
403 # 0.0 < fabs(a)
404 # fabs(a) > 0.0
405 # fabs(a) != 0.0 because fabs(a) must be >= 0
406 # a != 0.0
407 (('~flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
408
409 # -fabs(a) < 0.0
410 # fabs(a) > 0.0
411 (('~flt', ('fneg', ('fabs', a)), 0.0), ('fne', a, 0.0)),
412
413 # 0.0 >= fabs(a)
414 # 0.0 == fabs(a) because fabs(a) must be >= 0
415 # 0.0 == a
416 (('fge', 0.0, ('fabs', a)), ('feq', a, 0.0)),
417
418 # -fabs(a) >= 0.0
419 # 0.0 >= fabs(a)
420 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
421
422 # (a >= 0.0) && (a <= 1.0) -> fsat(a) == a
423 (('iand', ('fge', a, 0.0), ('fge', 1.0, a)), ('feq', a, ('fsat', a)), '!options->lower_fsat'),
424
425 # (a < 0.0) || (a > 1.0)
426 # !(!(a < 0.0) && !(a > 1.0))
427 # !((a >= 0.0) && (a <= 1.0))
428 # !(a == fsat(a))
429 # a != fsat(a)
430 (('ior', ('flt', a, 0.0), ('flt', 1.0, a)), ('fne', a, ('fsat', a)), '!options->lower_fsat'),
431
432 (('fmax', ('b2f(is_used_once)', 'a@1'), ('b2f', 'b@1')), ('b2f', ('ior', a, b))),
433 (('fmax', ('fneg(is_used_once)', ('b2f(is_used_once)', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('fneg', ('b2f', ('ior', a, b)))),
434 (('fmin', ('b2f(is_used_once)', 'a@1'), ('b2f', 'b@1')), ('b2f', ('iand', a, b))),
435 (('fmin', ('fneg(is_used_once)', ('b2f(is_used_once)', 'a@1')), ('fneg', ('b2f', 'b@1'))), ('fneg', ('b2f', ('iand', a, b)))),
436
437 # fmin(b2f(a), b)
438 # bcsel(a, fmin(b2f(a), b), fmin(b2f(a), b))
439 # bcsel(a, fmin(b2f(True), b), fmin(b2f(False), b))
440 # bcsel(a, fmin(1.0, b), fmin(0.0, b))
441 #
442 # Since b is a constant, constant folding will eliminate the fmin and the
443 # fmax. If b is > 1.0, the bcsel will be replaced with a b2f.
444 (('fmin', ('b2f', 'a@1'), '#b'), ('bcsel', a, ('fmin', b, 1.0), ('fmin', b, 0.0))),
445
446 (('flt', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
447
448 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
449 (('~bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
450 (('~bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
451 (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)),
452 (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)),
453 (('bcsel', ('i2b', a), b, c), ('bcsel', ('ine', a, 0), b, c)),
454 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)),
455 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)),
456 (('bcsel', a, b, ('bcsel', a, c, d)), ('bcsel', a, b, d)),
457 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
458 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, c, 'e')), ('bcsel', b, c, ('bcsel', a, d, 'e'))),
459 (('bcsel', a, ('bcsel', b, c, d), ('bcsel(is_used_once)', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
460 (('bcsel', a, ('bcsel(is_used_once)', b, c, d), ('bcsel', b, 'e', d)), ('bcsel', b, ('bcsel', a, c, 'e'), d)),
461 (('bcsel', a, True, b), ('ior', a, b)),
462 (('bcsel', a, a, b), ('ior', a, b)),
463 (('bcsel', a, b, False), ('iand', a, b)),
464 (('bcsel', a, b, a), ('iand', a, b)),
465 (('fmin', a, a), a),
466 (('fmax', a, a), a),
467 (('imin', a, a), a),
468 (('imax', a, a), a),
469 (('umin', a, a), a),
470 (('umax', a, a), a),
471 (('fmax', ('fmax', a, b), b), ('fmax', a, b)),
472 (('umax', ('umax', a, b), b), ('umax', a, b)),
473 (('imax', ('imax', a, b), b), ('imax', a, b)),
474 (('fmin', ('fmin', a, b), b), ('fmin', a, b)),
475 (('umin', ('umin', a, b), b), ('umin', a, b)),
476 (('imin', ('imin', a, b), b), ('imin', a, b)),
477 (('fmax', a, ('fneg', a)), ('fabs', a)),
478 (('imax', a, ('ineg', a)), ('iabs', a)),
479 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))),
480 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))),
481 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))),
482 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))),
483 (('fmin', a, ('fabs', a)), a),
484 (('imin', a, ('iabs', a)), a),
485 (('fmax', a, ('fneg', ('fabs', a))), a),
486 (('imax', a, ('ineg', ('iabs', a))), a),
487 (('fmax', a, ('fabs', a)), ('fabs', a)),
488 (('imax', a, ('iabs', a)), ('iabs', a)),
489 (('fmax', a, ('fneg', a)), ('fabs', a)),
490 (('imax', a, ('ineg', a)), ('iabs', a)),
491 (('~fmax', ('fabs', a), 0.0), ('fabs', a)),
492 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'),
493 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'),
494 (('~fmin', ('fmax', a, -1.0), 0.0), ('fneg', ('fsat', ('fneg', a))), '!options->lower_negate && !options->lower_fsat'),
495 (('~fmax', ('fmin', a, 0.0), -1.0), ('fneg', ('fsat', ('fneg', a))), '!options->lower_negate && !options->lower_fsat'),
496 (('fsat', ('fsign', a)), ('b2f', ('flt', 0.0, a))),
497 (('fsat', ('b2f', a)), ('b2f', a)),
498 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'),
499 (('fsat', ('fsat', a)), ('fsat', a)),
500 (('fsat', ('fneg(is_used_once)', ('fadd(is_used_once)', a, b))), ('fsat', ('fadd', ('fneg', a), ('fneg', b))), '!options->lower_negate && !options->lower_fsat'),
501 (('fsat', ('fneg(is_used_once)', ('fmul(is_used_once)', a, b))), ('fsat', ('fmul', ('fneg', a), b)), '!options->lower_negate && !options->lower_fsat'),
502 (('fsat', ('fabs(is_used_once)', ('fmul(is_used_once)', a, b))), ('fsat', ('fmul', ('fabs', a), ('fabs', b))), '!options->lower_fsat'),
503 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)),
504 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)),
505 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)),
506 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))),
507 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))),
508 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
509 (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
510 (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
511 (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
512 (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
513 (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
514 (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
515 (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
516 (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
517 (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
518 (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
519 (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
520 (('~iand', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmin', a, b), c)),
521 (('~iand', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmin', b, c))),
522 (('~iand', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmax', a, b), c)),
523 (('~iand', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmax', b, c))),
524 (('~iand', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmin', a, b), c)),
525
526 (('ior', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imax', b, c))),
527 (('ior', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imin', a, b), c)),
528 (('ior', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imin', b, c))),
529 (('ior', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imax', a, b), c)),
530 (('ior', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umax', b, c))),
531 (('ior', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umin', a, b), c)),
532 (('ior', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umin', b, c))),
533 (('ior', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umax', a, b), c)),
534 (('iand', ('ilt(is_used_once)', a, b), ('ilt', a, c)), ('ilt', a, ('imin', b, c))),
535 (('iand', ('ilt(is_used_once)', a, c), ('ilt', b, c)), ('ilt', ('imax', a, b), c)),
536 (('iand', ('ige(is_used_once)', a, b), ('ige', a, c)), ('ige', a, ('imax', b, c))),
537 (('iand', ('ige(is_used_once)', a, c), ('ige', b, c)), ('ige', ('imin', a, b), c)),
538 (('iand', ('ult(is_used_once)', a, b), ('ult', a, c)), ('ult', a, ('umin', b, c))),
539 (('iand', ('ult(is_used_once)', a, c), ('ult', b, c)), ('ult', ('umax', a, b), c)),
540 (('iand', ('uge(is_used_once)', a, b), ('uge', a, c)), ('uge', a, ('umax', b, c))),
541 (('iand', ('uge(is_used_once)', a, c), ('uge', b, c)), ('uge', ('umin', a, b), c)),
542
543 # These derive from the previous patterns with the application of b < 0 <=>
544 # 0 < -b. The transformation should be applied if either comparison is
545 # used once as this ensures that the number of comparisons will not
546 # increase. The sources to the ior and iand are not symmetric, so the
547 # rules have to be duplicated to get this behavior.
548 (('~ior', ('flt(is_used_once)', 0.0, 'a@32'), ('flt', 'b@32', 0.0)), ('flt', 0.0, ('fmax', a, ('fneg', b)))),
549 (('~ior', ('flt', 0.0, 'a@32'), ('flt(is_used_once)', 'b@32', 0.0)), ('flt', 0.0, ('fmax', a, ('fneg', b)))),
550 (('~ior', ('fge(is_used_once)', 0.0, 'a@32'), ('fge', 'b@32', 0.0)), ('fge', 0.0, ('fmin', a, ('fneg', b)))),
551 (('~ior', ('fge', 0.0, 'a@32'), ('fge(is_used_once)', 'b@32', 0.0)), ('fge', 0.0, ('fmin', a, ('fneg', b)))),
552 (('~iand', ('flt(is_used_once)', 0.0, 'a@32'), ('flt', 'b@32', 0.0)), ('flt', 0.0, ('fmin', a, ('fneg', b)))),
553 (('~iand', ('flt', 0.0, 'a@32'), ('flt(is_used_once)', 'b@32', 0.0)), ('flt', 0.0, ('fmin', a, ('fneg', b)))),
554 (('~iand', ('fge(is_used_once)', 0.0, 'a@32'), ('fge', 'b@32', 0.0)), ('fge', 0.0, ('fmax', a, ('fneg', b)))),
555 (('~iand', ('fge', 0.0, 'a@32'), ('fge(is_used_once)', 'b@32', 0.0)), ('fge', 0.0, ('fmax', a, ('fneg', b)))),
556
557 # Common pattern like 'if (i == 0 || i == 1 || ...)'
558 (('ior', ('ieq', a, 0), ('ieq', a, 1)), ('uge', 1, a)),
559 (('ior', ('uge', 1, a), ('ieq', a, 2)), ('uge', 2, a)),
560 (('ior', ('uge', 2, a), ('ieq', a, 3)), ('uge', 3, a)),
561
562 # The (i2f32, ...) part is an open-coded fsign. When that is combined with
563 # the bcsel, it's basically copysign(1.0, a). There is no copysign in NIR,
564 # so emit an open-coded version of that.
565 (('bcsel@32', ('feq', a, 0.0), 1.0, ('i2f32', ('iadd', ('b2i32', ('flt', 0.0, 'a@32')), ('ineg', ('b2i32', ('flt', 'a@32', 0.0)))))),
566 ('ior', 0x3f800000, ('iand', a, 0x80000000))),
567
568 (('ior', a, ('ieq', a, False)), True),
569 (('ior', a, ('inot', a)), -1),
570
571 (('ine', ('ineg', ('b2i32', 'a@1')), ('ineg', ('b2i32', 'b@1'))), ('ine', a, b)),
572 (('b2i32', ('ine', 'a@1', 'b@1')), ('b2i32', ('ixor', a, b))),
573
574 (('iand', ('ieq', 'a@32', 0), ('ieq', 'b@32', 0)), ('ieq', ('ior', 'a@32', 'b@32'), 0), '!options->lower_bitops'),
575
576 # These patterns can result when (a < b || a < c) => (a < min(b, c))
577 # transformations occur before constant propagation and loop-unrolling.
578 (('~flt', a, ('fmax', b, a)), ('flt', a, b)),
579 (('~flt', ('fmin', a, b), a), ('flt', b, a)),
580 (('~fge', a, ('fmin', b, a)), True),
581 (('~fge', ('fmax', a, b), a), True),
582 (('~flt', a, ('fmin', b, a)), False),
583 (('~flt', ('fmax', a, b), a), False),
584 (('~fge', a, ('fmax', b, a)), ('fge', a, b)),
585 (('~fge', ('fmin', a, b), a), ('fge', b, a)),
586
587 (('ilt', a, ('imax', b, a)), ('ilt', a, b)),
588 (('ilt', ('imin', a, b), a), ('ilt', b, a)),
589 (('ige', a, ('imin', b, a)), True),
590 (('ige', ('imax', a, b), a), True),
591 (('ult', a, ('umax', b, a)), ('ult', a, b)),
592 (('ult', ('umin', a, b), a), ('ult', b, a)),
593 (('uge', a, ('umin', b, a)), True),
594 (('uge', ('umax', a, b), a), True),
595 (('ilt', a, ('imin', b, a)), False),
596 (('ilt', ('imax', a, b), a), False),
597 (('ige', a, ('imax', b, a)), ('ige', a, b)),
598 (('ige', ('imin', a, b), a), ('ige', b, a)),
599 (('ult', a, ('umin', b, a)), False),
600 (('ult', ('umax', a, b), a), False),
601 (('uge', a, ('umax', b, a)), ('uge', a, b)),
602 (('uge', ('umin', a, b), a), ('uge', b, a)),
603 (('ult', a, ('iand', b, a)), False),
604 (('ult', ('ior', a, b), a), False),
605 (('uge', a, ('iand', b, a)), True),
606 (('uge', ('ior', a, b), a), True),
607
608 (('ilt', '#a', ('imax', '#b', c)), ('ior', ('ilt', a, b), ('ilt', a, c))),
609 (('ilt', ('imin', '#a', b), '#c'), ('ior', ('ilt', a, c), ('ilt', b, c))),
610 (('ige', '#a', ('imin', '#b', c)), ('ior', ('ige', a, b), ('ige', a, c))),
611 (('ige', ('imax', '#a', b), '#c'), ('ior', ('ige', a, c), ('ige', b, c))),
612 (('ult', '#a', ('umax', '#b', c)), ('ior', ('ult', a, b), ('ult', a, c))),
613 (('ult', ('umin', '#a', b), '#c'), ('ior', ('ult', a, c), ('ult', b, c))),
614 (('uge', '#a', ('umin', '#b', c)), ('ior', ('uge', a, b), ('uge', a, c))),
615 (('uge', ('umax', '#a', b), '#c'), ('ior', ('uge', a, c), ('uge', b, c))),
616 (('ilt', '#a', ('imin', '#b', c)), ('iand', ('ilt', a, b), ('ilt', a, c))),
617 (('ilt', ('imax', '#a', b), '#c'), ('iand', ('ilt', a, c), ('ilt', b, c))),
618 (('ige', '#a', ('imax', '#b', c)), ('iand', ('ige', a, b), ('ige', a, c))),
619 (('ige', ('imin', '#a', b), '#c'), ('iand', ('ige', a, c), ('ige', b, c))),
620 (('ult', '#a', ('umin', '#b', c)), ('iand', ('ult', a, b), ('ult', a, c))),
621 (('ult', ('umax', '#a', b), '#c'), ('iand', ('ult', a, c), ('ult', b, c))),
622 (('uge', '#a', ('umax', '#b', c)), ('iand', ('uge', a, b), ('uge', a, c))),
623 (('uge', ('umin', '#a', b), '#c'), ('iand', ('uge', a, c), ('uge', b, c))),
624
625 # Thanks to sign extension, the ishr(a, b) is negative if and only if a is
626 # negative.
627 (('bcsel', ('ilt', a, 0), ('ineg', ('ishr', a, b)), ('ishr', a, b)),
628 ('iabs', ('ishr', a, b))),
629 (('iabs', ('ishr', ('iabs', a), b)), ('ishr', ('iabs', a), b)),
630
631 (('fabs', ('slt', a, b)), ('slt', a, b)),
632 (('fabs', ('sge', a, b)), ('sge', a, b)),
633 (('fabs', ('seq', a, b)), ('seq', a, b)),
634 (('fabs', ('sne', a, b)), ('sne', a, b)),
635 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'),
636 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'),
637 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'),
638 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'),
639 (('seq', ('seq', a, b), 1.0), ('seq', a, b)),
640 (('seq', ('sne', a, b), 1.0), ('sne', a, b)),
641 (('seq', ('slt', a, b), 1.0), ('slt', a, b)),
642 (('seq', ('sge', a, b), 1.0), ('sge', a, b)),
643 (('sne', ('seq', a, b), 0.0), ('seq', a, b)),
644 (('sne', ('sne', a, b), 0.0), ('sne', a, b)),
645 (('sne', ('slt', a, b), 0.0), ('slt', a, b)),
646 (('sne', ('sge', a, b), 0.0), ('sge', a, b)),
647 (('seq', ('seq', a, b), 0.0), ('sne', a, b)),
648 (('seq', ('sne', a, b), 0.0), ('seq', a, b)),
649 (('seq', ('slt', a, b), 0.0), ('sge', a, b)),
650 (('seq', ('sge', a, b), 0.0), ('slt', a, b)),
651 (('sne', ('seq', a, b), 1.0), ('sne', a, b)),
652 (('sne', ('sne', a, b), 1.0), ('seq', a, b)),
653 (('sne', ('slt', a, b), 1.0), ('sge', a, b)),
654 (('sne', ('sge', a, b), 1.0), ('slt', a, b)),
655 (('fall_equal2', a, b), ('fmin', ('seq', 'a.x', 'b.x'), ('seq', 'a.y', 'b.y')), 'options->lower_vector_cmp'),
656 (('fall_equal3', a, b), ('seq', ('fany_nequal3', a, b), 0.0), 'options->lower_vector_cmp'),
657 (('fall_equal4', a, b), ('seq', ('fany_nequal4', a, b), 0.0), 'options->lower_vector_cmp'),
658 (('fany_nequal2', a, b), ('fmax', ('sne', 'a.x', 'b.x'), ('sne', 'a.y', 'b.y')), 'options->lower_vector_cmp'),
659 (('fany_nequal3', a, b), ('fsat', ('fdot3', ('sne', a, b), ('sne', a, b))), 'options->lower_vector_cmp'),
660 (('fany_nequal4', a, b), ('fsat', ('fdot4', ('sne', a, b), ('sne', a, b))), 'options->lower_vector_cmp'),
661 (('fne', ('fneg', a), a), ('fne', a, 0.0)),
662 (('feq', ('fneg', a), a), ('feq', a, 0.0)),
663 # Emulating booleans
664 (('imul', ('b2i', 'a@1'), ('b2i', 'b@1')), ('b2i', ('iand', a, b))),
665 (('fmul', ('b2f', 'a@1'), ('b2f', 'b@1')), ('b2f', ('iand', a, b))),
666 (('fsat', ('fadd', ('b2f', 'a@1'), ('b2f', 'b@1'))), ('b2f', ('ior', a, b))),
667 (('iand', 'a@bool32', 1.0), ('b2f', a)),
668 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True).
669 (('ineg', ('b2i32', 'a@32')), a),
670 (('flt', ('fneg', ('b2f', 'a@1')), 0), a), # Generated by TGSI KILL_IF.
671 (('flt', ('fsub', 0.0, ('b2f', 'a@1')), 0), a), # Generated by TGSI KILL_IF.
672 # Comparison with the same args. Note that these are not done for
673 # the float versions because NaN always returns false on float
674 # inequalities.
675 (('ilt', a, a), False),
676 (('ige', a, a), True),
677 (('ieq', a, a), True),
678 (('ine', a, a), False),
679 (('ult', a, a), False),
680 (('uge', a, a), True),
681 # Logical and bit operations
682 (('iand', a, a), a),
683 (('iand', a, ~0), a),
684 (('iand', a, 0), 0),
685 (('ior', a, a), a),
686 (('ior', a, 0), a),
687 (('ior', a, True), True),
688 (('ixor', a, a), 0),
689 (('ixor', a, 0), a),
690 (('inot', ('inot', a)), a),
691 (('ior', ('iand', a, b), b), b),
692 (('ior', ('ior', a, b), b), ('ior', a, b)),
693 (('iand', ('ior', a, b), b), b),
694 (('iand', ('iand', a, b), b), ('iand', a, b)),
695 # DeMorgan's Laws
696 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))),
697 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
698 # Shift optimizations
699 (('ishl', 0, a), 0),
700 (('ishl', a, 0), a),
701 (('ishr', 0, a), 0),
702 (('ishr', a, 0), a),
703 (('ushr', 0, a), 0),
704 (('ushr', a, 0), a),
705 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)),
706 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)),
707 (('ior', ('ishl@16', a, b), ('ushr@16', a, ('iadd', 16, ('ineg', b)))), ('urol', a, b), '!options->lower_rotate'),
708 (('ior', ('ishl@16', a, b), ('ushr@16', a, ('isub', 16, b))), ('urol', a, b), '!options->lower_rotate'),
709 (('ior', ('ishl@32', a, b), ('ushr@32', a, ('iadd', 32, ('ineg', b)))), ('urol', a, b), '!options->lower_rotate'),
710 (('ior', ('ishl@32', a, b), ('ushr@32', a, ('isub', 32, b))), ('urol', a, b), '!options->lower_rotate'),
711 (('ior', ('ushr@16', a, b), ('ishl@16', a, ('iadd', 16, ('ineg', b)))), ('uror', a, b), '!options->lower_rotate'),
712 (('ior', ('ushr@16', a, b), ('ishl@16', a, ('isub', 16, b))), ('uror', a, b), '!options->lower_rotate'),
713 (('ior', ('ushr@32', a, b), ('ishl@32', a, ('iadd', 32, ('ineg', b)))), ('uror', a, b), '!options->lower_rotate'),
714 (('ior', ('ushr@32', a, b), ('ishl@32', a, ('isub', 32, b))), ('uror', a, b), '!options->lower_rotate'),
715 (('urol@16', a, b), ('ior', ('ishl', a, b), ('ushr', a, ('isub', 16, b))), 'options->lower_rotate'),
716 (('urol@32', a, b), ('ior', ('ishl', a, b), ('ushr', a, ('isub', 32, b))), 'options->lower_rotate'),
717 (('uror@16', a, b), ('ior', ('ushr', a, b), ('ishl', a, ('isub', 16, b))), 'options->lower_rotate'),
718 (('uror@32', a, b), ('ior', ('ushr', a, b), ('ishl', a, ('isub', 32, b))), 'options->lower_rotate'),
719 # Exponential/logarithmic identities
720 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a
721 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a
722 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b)
723 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
724 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))),
725 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d
726 (('~fexp2', ('fmul', ('flog2', a), 2.0)), ('fmul', a, a)),
727 (('~fexp2', ('fmul', ('flog2', a), 4.0)), ('fmul', ('fmul', a, a), ('fmul', a, a))),
728 (('~fpow', a, 1.0), a),
729 (('~fpow', a, 2.0), ('fmul', a, a)),
730 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))),
731 (('~fpow', 2.0, a), ('fexp2', a)),
732 (('~fpow', ('fpow', a, 2.2), 0.454545), a),
733 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)),
734 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))),
735 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))),
736 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))),
737 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))),
738 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))),
739 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))),
740 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))),
741 (('~fmul', ('fexp2(is_used_once)', a), ('fexp2(is_used_once)', b)), ('fexp2', ('fadd', a, b))),
742 (('bcsel', ('flt', a, 0.0), 0.0, ('fsqrt', a)), ('fsqrt', ('fmax', a, 0.0))),
743 # Division and reciprocal
744 (('~fdiv', 1.0, a), ('frcp', a)),
745 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'),
746 (('~frcp', ('frcp', a)), a),
747 (('~frcp', ('fsqrt', a)), ('frsq', a)),
748 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'),
749 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'),
750 # Trig
751 (('fsin', a), lowered_sincos(0.5), 'options->lower_sincos'),
752 (('fcos', a), lowered_sincos(0.75), 'options->lower_sincos'),
753 # Boolean simplifications
754 (('i2b32(is_used_by_if)', a), ('ine32', a, 0)),
755 (('i2b1(is_used_by_if)', a), ('ine', a, 0)),
756 (('ieq', a, True), a),
757 (('ine(is_not_used_by_if)', a, True), ('inot', a)),
758 (('ine', a, False), a),
759 (('ieq(is_not_used_by_if)', a, False), ('inot', 'a')),
760 (('bcsel', a, True, False), a),
761 (('bcsel', a, False, True), ('inot', a)),
762 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)),
763 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))),
764 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))),
765 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))),
766 (('bcsel', True, b, c), b),
767 (('bcsel', False, b, c), c),
768 (('bcsel', a, ('b2f(is_used_once)', 'b@32'), ('b2f', 'c@32')), ('b2f', ('bcsel', a, b, c))),
769
770 (('bcsel', a, b, b), b),
771 (('fcsel', a, b, b), b),
772
773 # D3D Boolean emulation
774 (('bcsel', a, -1, 0), ('ineg', ('b2i', 'a@1'))),
775 (('bcsel', a, 0, -1), ('ineg', ('b2i', ('inot', a)))),
776 (('iand', ('ineg', ('b2i', 'a@1')), ('ineg', ('b2i', 'b@1'))),
777 ('ineg', ('b2i', ('iand', a, b)))),
778 (('ior', ('ineg', ('b2i','a@1')), ('ineg', ('b2i', 'b@1'))),
779 ('ineg', ('b2i', ('ior', a, b)))),
780 (('ieq', ('ineg', ('b2i', 'a@1')), 0), ('inot', a)),
781 (('ieq', ('ineg', ('b2i', 'a@1')), -1), a),
782 (('ine', ('ineg', ('b2i', 'a@1')), 0), a),
783 (('ine', ('ineg', ('b2i', 'a@1')), -1), ('inot', a)),
784 (('iand', ('ineg', ('b2i', a)), 1.0), ('b2f', a)),
785
786 # SM5 32-bit shifts are defined to use the 5 least significant bits
787 (('ishl', 'a@32', ('iand', 31, b)), ('ishl', a, b)),
788 (('ishr', 'a@32', ('iand', 31, b)), ('ishr', a, b)),
789 (('ushr', 'a@32', ('iand', 31, b)), ('ushr', a, b)),
790
791 # Conversions
792 (('i2b32', ('b2i', 'a@32')), a),
793 (('f2i', ('ftrunc', a)), ('f2i', a)),
794 (('f2u', ('ftrunc', a)), ('f2u', a)),
795 (('i2b', ('ineg', a)), ('i2b', a)),
796 (('i2b', ('iabs', a)), ('i2b', a)),
797 (('inot', ('f2b1', a)), ('feq', a, 0.0)),
798
799 # Ironically, mark these as imprecise because removing the conversions may
800 # preserve more precision than doing the conversions (e.g.,
801 # uint(float(0x81818181u)) == 0x81818200).
802 (('~f2i32', ('i2f', 'a@32')), a),
803 (('~f2i32', ('u2f', 'a@32')), a),
804 (('~f2u32', ('i2f', 'a@32')), a),
805 (('~f2u32', ('u2f', 'a@32')), a),
806
807 (('ffloor', 'a(is_integral)'), a),
808 (('fceil', 'a(is_integral)'), a),
809 (('ftrunc', 'a(is_integral)'), a),
810 # fract(x) = x - floor(x), so fract(NaN) = NaN
811 (('~ffract', 'a(is_integral)'), 0.0),
812 (('fabs', 'a(is_not_negative)'), a),
813 (('iabs', 'a(is_not_negative)'), a),
814 (('fsat', 'a(is_not_positive)'), 0.0),
815
816 # Section 5.4.1 (Conversion and Scalar Constructors) of the GLSL 4.60 spec
817 # says:
818 #
819 # It is undefined to convert a negative floating-point value to an
820 # uint.
821 #
822 # Assuming that (uint)some_float behaves like (uint)(int)some_float allows
823 # some optimizations in the i965 backend to proceed.
824 (('ige', ('f2u', a), b), ('ige', ('f2i', a), b)),
825 (('ige', b, ('f2u', a)), ('ige', b, ('f2i', a))),
826 (('ilt', ('f2u', a), b), ('ilt', ('f2i', a), b)),
827 (('ilt', b, ('f2u', a)), ('ilt', b, ('f2i', a))),
828
829 (('~fmin', 'a(is_not_negative)', 1.0), ('fsat', a), '!options->lower_fsat'),
830
831 # The result of the multiply must be in [-1, 0], so the result of the ffma
832 # must be in [0, 1].
833 (('flt', ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0), 0.0), False),
834 (('flt', ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0), 0.0), False),
835 (('fmax', ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0), 0.0), ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0)),
836 (('fmax', ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0), 0.0), ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0)),
837
838 (('fne', 'a(is_not_zero)', 0.0), True),
839 (('feq', 'a(is_not_zero)', 0.0), False),
840
841 # The results expecting true, must be marked imprecise. The results
842 # expecting false are fine because NaN compared >= or < anything is false.
843
844 (('~fge', 'a(is_not_negative)', 'b(is_not_positive)'), True),
845 (('fge', 'b(is_not_positive)', 'a(is_gt_zero)'), False),
846 (('fge', 'a(is_lt_zero)', 'b(is_not_negative)'), False),
847 (('~fge', 'b(is_not_negative)', 'a(is_not_positive)'), True),
848
849 (('flt', 'a(is_not_negative)', 'b(is_not_positive)'), False),
850 (('~flt', 'b(is_not_positive)', 'a(is_gt_zero)'), True),
851 (('~flt', 'a(is_lt_zero)', 'b(is_not_negative)'), True),
852 (('flt', 'b(is_not_negative)', 'a(is_not_positive)'), False),
853
854 (('ine', 'a(is_not_zero)', 0), True),
855 (('ieq', 'a(is_not_zero)', 0), False),
856
857 (('ige', 'a(is_not_negative)', 'b(is_not_positive)'), True),
858 (('ige', 'b(is_not_positive)', 'a(is_gt_zero)'), False),
859 (('ige', 'a(is_lt_zero)', 'b(is_not_negative)'), False),
860 (('ige', 'b(is_not_negative)', 'a(is_not_positive)'), True),
861
862 (('ilt', 'a(is_not_negative)', 'b(is_not_positive)'), False),
863 (('ilt', 'b(is_not_positive)', 'a(is_gt_zero)'), True),
864 (('ilt', 'a(is_lt_zero)', 'b(is_not_negative)'), True),
865 (('ilt', 'b(is_not_negative)', 'a(is_not_positive)'), False),
866
867 (('ult', 0, 'a(is_gt_zero)'), True),
868
869 # Packing and then unpacking does nothing
870 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
871 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
872 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
873 ('unpack_64_2x32_split_y', a)), a),
874
875 # Comparing two halves of an unpack separately. While this optimization
876 # should be correct for non-constant values, it's less obvious that it's
877 # useful in that case. For constant values, the pack will fold and we're
878 # guaranteed to reduce the whole tree to one instruction.
879 (('iand', ('ieq', ('unpack_32_2x16_split_x', a), '#b'),
880 ('ieq', ('unpack_32_2x16_split_y', a), '#c')),
881 ('ieq', a, ('pack_32_2x16_split', b, c))),
882
883 # Byte extraction
884 (('ushr', 'a@16', 8), ('extract_u8', a, 1), '!options->lower_extract_byte'),
885 (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
886 (('ushr', 'a@64', 56), ('extract_u8', a, 7), '!options->lower_extract_byte'),
887 (('ishr', 'a@16', 8), ('extract_i8', a, 1), '!options->lower_extract_byte'),
888 (('ishr', 'a@32', 24), ('extract_i8', a, 3), '!options->lower_extract_byte'),
889 (('ishr', 'a@64', 56), ('extract_i8', a, 7), '!options->lower_extract_byte'),
890 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
891
892 # Useless masking before unpacking
893 (('unpack_half_2x16_split_x', ('iand', a, 0xffff)), ('unpack_half_2x16_split_x', a)),
894 (('unpack_32_2x16_split_x', ('iand', a, 0xffff)), ('unpack_32_2x16_split_x', a)),
895 (('unpack_64_2x32_split_x', ('iand', a, 0xffffffff)), ('unpack_64_2x32_split_x', a)),
896 (('unpack_half_2x16_split_y', ('iand', a, 0xffff0000)), ('unpack_half_2x16_split_y', a)),
897 (('unpack_32_2x16_split_y', ('iand', a, 0xffff0000)), ('unpack_32_2x16_split_y', a)),
898 (('unpack_64_2x32_split_y', ('iand', a, 0xffffffff00000000)), ('unpack_64_2x32_split_y', a)),
899 ])
900
901 # After the ('extract_u8', a, 0) pattern, above, triggers, there will be
902 # patterns like those below.
903 for op in ('ushr', 'ishr'):
904 optimizations.extend([(('extract_u8', (op, 'a@16', 8), 0), ('extract_u8', a, 1))])
905 optimizations.extend([(('extract_u8', (op, 'a@32', 8 * i), 0), ('extract_u8', a, i)) for i in range(1, 4)])
906 optimizations.extend([(('extract_u8', (op, 'a@64', 8 * i), 0), ('extract_u8', a, i)) for i in range(1, 8)])
907
908 optimizations.extend([(('extract_u8', ('extract_u16', a, 1), 0), ('extract_u8', a, 2))])
909
910 # After the ('extract_[iu]8', a, 3) patterns, above, trigger, there will be
911 # patterns like those below.
912 for op in ('extract_u8', 'extract_i8'):
913 optimizations.extend([((op, ('ishl', 'a@16', 8), 1), (op, a, 0))])
914 optimizations.extend([((op, ('ishl', 'a@32', 24 - 8 * i), 3), (op, a, i)) for i in range(2, -1, -1)])
915 optimizations.extend([((op, ('ishl', 'a@64', 56 - 8 * i), 7), (op, a, i)) for i in range(6, -1, -1)])
916
917 optimizations.extend([
918 # Word extraction
919 (('ushr', ('ishl', 'a@32', 16), 16), ('extract_u16', a, 0), '!options->lower_extract_word'),
920 (('ushr', 'a@32', 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
921 (('ishr', ('ishl', 'a@32', 16), 16), ('extract_i16', a, 0), '!options->lower_extract_word'),
922 (('ishr', 'a@32', 16), ('extract_i16', a, 1), '!options->lower_extract_word'),
923 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
924
925 # Subtracts
926 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
927 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
928 (('isub', ('iadd', a, b), b), a),
929 (('~fsub', ('fadd', a, b), b), a),
930 (('ussub_4x8', a, 0), a),
931 (('ussub_4x8', a, ~0), 0),
932 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'),
933 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'),
934 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
935 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
936 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
937 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
938 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
939 (('iabs', ('isub', 0, a)), ('iabs', a)),
940
941 # Propagate negation up multiplication chains
942 (('fmul(is_used_by_non_fsat)', ('fneg', a), b), ('fneg', ('fmul', a, b))),
943 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
944
945 # Propagate constants up multiplication chains
946 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
947 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
948 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
949 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
950
951 # Reassociate constants in add/mul chains so they can be folded together.
952 # For now, we mostly only handle cases where the constants are separated by
953 # a single non-constant. We could do better eventually.
954 (('~fmul', '#a', ('fmul', 'b(is_not_const)', '#c')), ('fmul', ('fmul', a, c), b)),
955 (('imul', '#a', ('imul', 'b(is_not_const)', '#c')), ('imul', ('imul', a, c), b)),
956 (('~fadd', '#a', ('fadd', 'b(is_not_const)', '#c')), ('fadd', ('fadd', a, c), b)),
957 (('~fadd', '#a', ('fneg', ('fadd', 'b(is_not_const)', '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
958 (('iadd', '#a', ('iadd', 'b(is_not_const)', '#c')), ('iadd', ('iadd', a, c), b)),
959
960 # Drop mul-div by the same value when there's no wrapping.
961 (('idiv', ('imul(no_signed_wrap)', a, b), b), a),
962
963 # By definition...
964 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
965 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
966 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
967
968 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
969 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
970 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
971
972 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
973
974 # Misc. lowering
975 (('fmod@16', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'),
976 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'),
977 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod'),
978 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
979 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
980
981 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
982 ('bcsel', ('ult', 31, 'bits'), 'insert',
983 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
984 'options->lower_bitfield_insert'),
985 (('ihadd', a, b), ('iadd', ('iand', a, b), ('ishr', ('ixor', a, b), 1)), 'options->lower_hadd'),
986 (('uhadd', a, b), ('iadd', ('iand', a, b), ('ushr', ('ixor', a, b), 1)), 'options->lower_hadd'),
987 (('irhadd', a, b), ('isub', ('ior', a, b), ('ishr', ('ixor', a, b), 1)), 'options->lower_hadd'),
988 (('urhadd', a, b), ('isub', ('ior', a, b), ('ushr', ('ixor', a, b), 1)), 'options->lower_hadd'),
989 (('uadd_sat', a, b), ('bcsel', ('ult', ('iadd', a, b), a), -1, ('iadd', a, b)), 'options->lower_add_sat'),
990 (('usub_sat', a, b), ('bcsel', ('ult', a, b), 0, ('isub', a, b)), 'options->lower_add_sat'),
991
992 # Alternative lowering that doesn't rely on bfi.
993 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
994 ('bcsel', ('ult', 31, 'bits'),
995 'insert',
996 (('ior',
997 ('iand', 'base', ('inot', ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'))),
998 ('iand', ('ishl', 'insert', 'offset'), ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'))))),
999 'options->lower_bitfield_insert_to_shifts'),
1000
1001 # Alternative lowering that uses bitfield_select.
1002 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
1003 ('bcsel', ('ult', 31, 'bits'), 'insert',
1004 ('bitfield_select', ('bfm', 'bits', 'offset'), ('ishl', 'insert', 'offset'), 'base')),
1005 'options->lower_bitfield_insert_to_bitfield_select'),
1006
1007 (('ibitfield_extract', 'value', 'offset', 'bits'),
1008 ('bcsel', ('ult', 31, 'bits'), 'value',
1009 ('ibfe', 'value', 'offset', 'bits')),
1010 'options->lower_bitfield_extract'),
1011
1012 (('ubitfield_extract', 'value', 'offset', 'bits'),
1013 ('bcsel', ('ult', 31, 'bits'), 'value',
1014 ('ubfe', 'value', 'offset', 'bits')),
1015 'options->lower_bitfield_extract'),
1016
1017 # Note that these opcodes are defined to only use the five least significant bits of 'offset' and 'bits'
1018 (('ubfe', 'value', 'offset', ('iand', 31, 'bits')), ('ubfe', 'value', 'offset', 'bits')),
1019 (('ubfe', 'value', ('iand', 31, 'offset'), 'bits'), ('ubfe', 'value', 'offset', 'bits')),
1020 (('ibfe', 'value', 'offset', ('iand', 31, 'bits')), ('ibfe', 'value', 'offset', 'bits')),
1021 (('ibfe', 'value', ('iand', 31, 'offset'), 'bits'), ('ibfe', 'value', 'offset', 'bits')),
1022 (('bfm', 'bits', ('iand', 31, 'offset')), ('bfm', 'bits', 'offset')),
1023 (('bfm', ('iand', 31, 'bits'), 'offset'), ('bfm', 'bits', 'offset')),
1024
1025 (('ibitfield_extract', 'value', 'offset', 'bits'),
1026 ('bcsel', ('ieq', 0, 'bits'),
1027 0,
1028 ('ishr',
1029 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
1030 ('isub', 32, 'bits'))),
1031 'options->lower_bitfield_extract_to_shifts'),
1032
1033 (('ubitfield_extract', 'value', 'offset', 'bits'),
1034 ('iand',
1035 ('ushr', 'value', 'offset'),
1036 ('bcsel', ('ieq', 'bits', 32),
1037 0xffffffff,
1038 ('isub', ('ishl', 1, 'bits'), 1))),
1039 'options->lower_bitfield_extract_to_shifts'),
1040
1041 (('ifind_msb', 'value'),
1042 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
1043 'options->lower_ifind_msb'),
1044
1045 (('find_lsb', 'value'),
1046 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
1047 'options->lower_find_lsb'),
1048
1049 (('extract_i8', a, 'b@32'),
1050 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
1051 'options->lower_extract_byte'),
1052
1053 (('extract_u8', a, 'b@32'),
1054 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
1055 'options->lower_extract_byte'),
1056
1057 (('extract_i16', a, 'b@32'),
1058 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
1059 'options->lower_extract_word'),
1060
1061 (('extract_u16', a, 'b@32'),
1062 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
1063 'options->lower_extract_word'),
1064
1065 (('pack_unorm_2x16', 'v'),
1066 ('pack_uvec2_to_uint',
1067 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
1068 'options->lower_pack_unorm_2x16'),
1069
1070 (('pack_unorm_4x8', 'v'),
1071 ('pack_uvec4_to_uint',
1072 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
1073 'options->lower_pack_unorm_4x8'),
1074
1075 (('pack_snorm_2x16', 'v'),
1076 ('pack_uvec2_to_uint',
1077 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
1078 'options->lower_pack_snorm_2x16'),
1079
1080 (('pack_snorm_4x8', 'v'),
1081 ('pack_uvec4_to_uint',
1082 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
1083 'options->lower_pack_snorm_4x8'),
1084
1085 (('unpack_unorm_2x16', 'v'),
1086 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
1087 ('extract_u16', 'v', 1))),
1088 65535.0),
1089 'options->lower_unpack_unorm_2x16'),
1090
1091 (('unpack_unorm_4x8', 'v'),
1092 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
1093 ('extract_u8', 'v', 1),
1094 ('extract_u8', 'v', 2),
1095 ('extract_u8', 'v', 3))),
1096 255.0),
1097 'options->lower_unpack_unorm_4x8'),
1098
1099 (('unpack_snorm_2x16', 'v'),
1100 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
1101 ('extract_i16', 'v', 1))),
1102 32767.0))),
1103 'options->lower_unpack_snorm_2x16'),
1104
1105 (('unpack_snorm_4x8', 'v'),
1106 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
1107 ('extract_i8', 'v', 1),
1108 ('extract_i8', 'v', 2),
1109 ('extract_i8', 'v', 3))),
1110 127.0))),
1111 'options->lower_unpack_snorm_4x8'),
1112
1113 (('isign', a), ('imin', ('imax', a, -1), 1), 'options->lower_isign'),
1114 (('fsign', a), ('fsub', ('b2f', ('flt', 0.0, a)), ('b2f', ('flt', a, 0.0))), 'options->lower_fsign'),
1115 ])
1116
1117 # bit_size dependent lowerings
1118 for bit_size in [8, 16, 32, 64]:
1119 # convenience constants
1120 intmax = (1 << (bit_size - 1)) - 1
1121 intmin = 1 << (bit_size - 1)
1122
1123 optimizations += [
1124 (('iadd_sat@' + str(bit_size), a, b),
1125 ('bcsel', ('ige', b, 1), ('bcsel', ('ilt', ('iadd', a, b), a), intmax, ('iadd', a, b)),
1126 ('bcsel', ('ilt', a, ('iadd', a, b)), intmin, ('iadd', a, b))), 'options->lower_add_sat'),
1127 (('isub_sat@' + str(bit_size), a, b),
1128 ('bcsel', ('ilt', b, 0), ('bcsel', ('ilt', ('isub', a, b), a), intmax, ('isub', a, b)),
1129 ('bcsel', ('ilt', a, ('isub', a, b)), intmin, ('isub', a, b))), 'options->lower_add_sat'),
1130 ]
1131
1132 invert = OrderedDict([('feq', 'fne'), ('fne', 'feq'), ('fge', 'flt'), ('flt', 'fge')])
1133
1134 for left, right in itertools.combinations_with_replacement(invert.keys(), 2):
1135 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
1136 ('iand', (invert[left], a, b), (invert[right], c, d))))
1137 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
1138 ('ior', (invert[left], a, b), (invert[right], c, d))))
1139
1140 # Optimize x2bN(b2x(x)) -> x
1141 for size in type_sizes('bool'):
1142 aN = 'a@' + str(size)
1143 f2bN = 'f2b' + str(size)
1144 i2bN = 'i2b' + str(size)
1145 optimizations.append(((f2bN, ('b2f', aN)), a))
1146 optimizations.append(((i2bN, ('b2i', aN)), a))
1147
1148 # Optimize x2yN(b2x(x)) -> b2y
1149 for x, y in itertools.product(['f', 'u', 'i'], ['f', 'u', 'i']):
1150 if x != 'f' and y != 'f' and x != y:
1151 continue
1152
1153 b2x = 'b2f' if x == 'f' else 'b2i'
1154 b2y = 'b2f' if y == 'f' else 'b2i'
1155 x2yN = '{}2{}'.format(x, y)
1156 optimizations.append(((x2yN, (b2x, a)), (b2y, a)))
1157
1158 # Optimize away x2xN(a@N)
1159 for t in ['int', 'uint', 'float']:
1160 for N in type_sizes(t):
1161 x2xN = '{0}2{0}{1}'.format(t[0], N)
1162 aN = 'a@{0}'.format(N)
1163 optimizations.append(((x2xN, aN), a))
1164
1165 # Optimize x2xN(y2yM(a@P)) -> y2yN(a) for integers
1166 # In particular, we can optimize away everything except upcast of downcast and
1167 # upcasts where the type differs from the other cast
1168 for N, M in itertools.product(type_sizes('uint'), type_sizes('uint')):
1169 if N < M:
1170 # The outer cast is a down-cast. It doesn't matter what the size of the
1171 # argument of the inner cast is because we'll never been in the upcast
1172 # of downcast case. Regardless of types, we'll always end up with y2yN
1173 # in the end.
1174 for x, y in itertools.product(['i', 'u'], ['i', 'u']):
1175 x2xN = '{0}2{0}{1}'.format(x, N)
1176 y2yM = '{0}2{0}{1}'.format(y, M)
1177 y2yN = '{0}2{0}{1}'.format(y, N)
1178 optimizations.append(((x2xN, (y2yM, a)), (y2yN, a)))
1179 elif N > M:
1180 # If the outer cast is an up-cast, we have to be more careful about the
1181 # size of the argument of the inner cast and with types. In this case,
1182 # the type is always the type of type up-cast which is given by the
1183 # outer cast.
1184 for P in type_sizes('uint'):
1185 # We can't optimize away up-cast of down-cast.
1186 if M < P:
1187 continue
1188
1189 # Because we're doing down-cast of down-cast, the types always have
1190 # to match between the two casts
1191 for x in ['i', 'u']:
1192 x2xN = '{0}2{0}{1}'.format(x, N)
1193 x2xM = '{0}2{0}{1}'.format(x, M)
1194 aP = 'a@{0}'.format(P)
1195 optimizations.append(((x2xN, (x2xM, aP)), (x2xN, a)))
1196 else:
1197 # The N == M case is handled by other optimizations
1198 pass
1199
1200 # Optimize comparisons with up-casts
1201 for t in ['int', 'uint', 'float']:
1202 for N, M in itertools.product(type_sizes(t), repeat=2):
1203 if N == 1 or N >= M:
1204 continue
1205
1206 x2xM = '{0}2{0}{1}'.format(t[0], M)
1207 x2xN = '{0}2{0}{1}'.format(t[0], N)
1208 aN = 'a@' + str(N)
1209 bN = 'b@' + str(N)
1210 xeq = 'feq' if t == 'float' else 'ieq'
1211 xne = 'fne' if t == 'float' else 'ine'
1212 xge = '{0}ge'.format(t[0])
1213 xlt = '{0}lt'.format(t[0])
1214
1215 # Up-casts are lossless so for correctly signed comparisons of
1216 # up-casted values we can do the comparison at the largest of the two
1217 # original sizes and drop one or both of the casts. (We have
1218 # optimizations to drop the no-op casts which this may generate.)
1219 for P in type_sizes(t):
1220 if P == 1 or P > N:
1221 continue
1222
1223 bP = 'b@' + str(P)
1224 optimizations += [
1225 ((xeq, (x2xM, aN), (x2xM, bP)), (xeq, a, (x2xN, b))),
1226 ((xne, (x2xM, aN), (x2xM, bP)), (xne, a, (x2xN, b))),
1227 ((xge, (x2xM, aN), (x2xM, bP)), (xge, a, (x2xN, b))),
1228 ((xlt, (x2xM, aN), (x2xM, bP)), (xlt, a, (x2xN, b))),
1229 ((xge, (x2xM, bP), (x2xM, aN)), (xge, (x2xN, b), a)),
1230 ((xlt, (x2xM, bP), (x2xM, aN)), (xlt, (x2xN, b), a)),
1231 ]
1232
1233 # The next bit doesn't work on floats because the range checks would
1234 # get way too complicated.
1235 if t in ['int', 'uint']:
1236 if t == 'int':
1237 xN_min = -(1 << (N - 1))
1238 xN_max = (1 << (N - 1)) - 1
1239 elif t == 'uint':
1240 xN_min = 0
1241 xN_max = (1 << N) - 1
1242 else:
1243 assert False
1244
1245 # If we're up-casting and comparing to a constant, we can unfold
1246 # the comparison into a comparison with the shrunk down constant
1247 # and a check that the constant fits in the smaller bit size.
1248 optimizations += [
1249 ((xeq, (x2xM, aN), '#b'),
1250 ('iand', (xeq, a, (x2xN, b)), (xeq, (x2xM, (x2xN, b)), b))),
1251 ((xne, (x2xM, aN), '#b'),
1252 ('ior', (xne, a, (x2xN, b)), (xne, (x2xM, (x2xN, b)), b))),
1253 ((xlt, (x2xM, aN), '#b'),
1254 ('iand', (xlt, xN_min, b),
1255 ('ior', (xlt, xN_max, b), (xlt, a, (x2xN, b))))),
1256 ((xlt, '#a', (x2xM, bN)),
1257 ('iand', (xlt, a, xN_max),
1258 ('ior', (xlt, a, xN_min), (xlt, (x2xN, a), b)))),
1259 ((xge, (x2xM, aN), '#b'),
1260 ('iand', (xge, xN_max, b),
1261 ('ior', (xge, xN_min, b), (xge, a, (x2xN, b))))),
1262 ((xge, '#a', (x2xM, bN)),
1263 ('iand', (xge, a, xN_min),
1264 ('ior', (xge, a, xN_max), (xge, (x2xN, a), b)))),
1265 ]
1266
1267 def fexp2i(exp, bits):
1268 # We assume that exp is already in the right range.
1269 if bits == 16:
1270 return ('i2i16', ('ishl', ('iadd', exp, 15), 10))
1271 elif bits == 32:
1272 return ('ishl', ('iadd', exp, 127), 23)
1273 elif bits == 64:
1274 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
1275 else:
1276 assert False
1277
1278 def ldexp(f, exp, bits):
1279 # First, we clamp exp to a reasonable range. The maximum possible range
1280 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
1281 # a maximum range of [-149, 127]. This means that we can potentially have
1282 # a swing of +-276. If you start with FLT_MAX, you actually have to do
1283 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
1284 # spec, on the other hand, only requires that we handle an exponent value
1285 # in the range [-126, 128]. This implementation is *mostly* correct; it
1286 # handles a range on exp of [-252, 254] which allows you to create any
1287 # value (including denorms if the hardware supports it) and to adjust the
1288 # exponent of any normal value to anything you want.
1289 if bits == 16:
1290 exp = ('imin', ('imax', exp, -28), 30)
1291 elif bits == 32:
1292 exp = ('imin', ('imax', exp, -252), 254)
1293 elif bits == 64:
1294 exp = ('imin', ('imax', exp, -2044), 2046)
1295 else:
1296 assert False
1297
1298 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
1299 # (We use ishr which isn't the same for -1, but the -1 case still works
1300 # since we use exp-exp/2 as the second exponent.) While the spec
1301 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
1302 # work with denormals and doesn't allow for the full swing in exponents
1303 # that you can get with normalized values. Instead, we create two powers
1304 # of two and multiply by them each in turn. That way the effective range
1305 # of our exponent is doubled.
1306 pow2_1 = fexp2i(('ishr', exp, 1), bits)
1307 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
1308 return ('fmul', ('fmul', f, pow2_1), pow2_2)
1309
1310 optimizations += [
1311 (('ldexp@16', 'x', 'exp'), ldexp('x', 'exp', 16), 'options->lower_ldexp'),
1312 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
1313 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
1314 ]
1315
1316 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
1317 def bitfield_reverse(u):
1318 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
1319 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
1320 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
1321 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
1322 step5 = ('ior(many-comm-expr)', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
1323
1324 return step5
1325
1326 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'), '!options->lower_bitfield_reverse')]
1327
1328 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
1329 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
1330 # and, if a is a NaN then the second comparison will fail anyway.
1331 for op in ['flt', 'fge', 'feq']:
1332 optimizations += [
1333 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
1334 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
1335 ]
1336
1337 # Add optimizations to handle the case where the result of a ternary is
1338 # compared to a constant. This way we can take things like
1339 #
1340 # (a ? 0 : 1) > 0
1341 #
1342 # and turn it into
1343 #
1344 # a ? (0 > 0) : (1 > 0)
1345 #
1346 # which constant folding will eat for lunch. The resulting ternary will
1347 # further get cleaned up by the boolean reductions above and we will be
1348 # left with just the original variable "a".
1349 for op in ['flt', 'fge', 'feq', 'fne',
1350 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
1351 optimizations += [
1352 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
1353 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
1354 ((op, '#d', ('bcsel', a, '#b', '#c')),
1355 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
1356 ]
1357
1358
1359 # For example, this converts things like
1360 #
1361 # 1 + mix(0, a - 1, condition)
1362 #
1363 # into
1364 #
1365 # mix(1, (a-1)+1, condition)
1366 #
1367 # Other optimizations will rearrange the constants.
1368 for op in ['fadd', 'fmul', 'iadd', 'imul']:
1369 optimizations += [
1370 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
1371 ]
1372
1373 # For derivatives in compute shaders, GLSL_NV_compute_shader_derivatives
1374 # states:
1375 #
1376 # If neither layout qualifier is specified, derivatives in compute shaders
1377 # return zero, which is consistent with the handling of built-in texture
1378 # functions like texture() in GLSL 4.50 compute shaders.
1379 for op in ['fddx', 'fddx_fine', 'fddx_coarse',
1380 'fddy', 'fddy_fine', 'fddy_coarse']:
1381 optimizations += [
1382 ((op, 'a'), 0.0, 'info->stage == MESA_SHADER_COMPUTE && info->cs.derivative_group == DERIVATIVE_GROUP_NONE')
1383 ]
1384
1385 # Some optimizations for ir3-specific instructions.
1386 optimizations += [
1387 # 'al * bl': If either 'al' or 'bl' is zero, return zero.
1388 (('umul_low', '#a(is_lower_half_zero)', 'b'), (0)),
1389 # '(ah * bl) << 16 + c': If either 'ah' or 'bl' is zero, return 'c'.
1390 (('imadsh_mix16', '#a@32(is_lower_half_zero)', 'b@32', 'c@32'), ('c')),
1391 (('imadsh_mix16', 'a@32', '#b@32(is_upper_half_zero)', 'c@32'), ('c')),
1392 ]
1393
1394 # This section contains "late" optimizations that should be run before
1395 # creating ffmas and calling regular optimizations for the final time.
1396 # Optimizations should go here if they help code generation and conflict
1397 # with the regular optimizations.
1398 before_ffma_optimizations = [
1399 # Propagate constants down multiplication chains
1400 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
1401 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
1402 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
1403 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
1404
1405 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
1406 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
1407 (('~fadd', ('fneg', a), a), 0.0),
1408 (('iadd', ('ineg', a), a), 0),
1409 (('iadd', ('ineg', a), ('iadd', a, b)), b),
1410 (('iadd', a, ('iadd', ('ineg', a), b)), b),
1411 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
1412 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
1413
1414 (('~flrp@32', ('fadd(is_used_once)', a, -1.0), ('fadd(is_used_once)', a, 1.0), d), ('fadd', ('flrp', -1.0, 1.0, d), a)),
1415 (('~flrp@32', ('fadd(is_used_once)', a, 1.0), ('fadd(is_used_once)', a, -1.0), d), ('fadd', ('flrp', 1.0, -1.0, d), a)),
1416 (('~flrp@32', ('fadd(is_used_once)', a, '#b'), ('fadd(is_used_once)', a, '#c'), d), ('fadd', ('fmul', d, ('fadd', c, ('fneg', b))), ('fadd', a, b))),
1417 ]
1418
1419 # This section contains "late" optimizations that should be run after the
1420 # regular optimizations have finished. Optimizations should go here if
1421 # they help code generation but do not necessarily produce code that is
1422 # more easily optimizable.
1423 late_optimizations = [
1424 # Most of these optimizations aren't quite safe when you get infinity or
1425 # Nan involved but the first one should be fine.
1426 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
1427 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
1428 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
1429 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
1430 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
1431 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
1432
1433 # nir_lower_to_source_mods will collapse this, but its existence during the
1434 # optimization loop can prevent other optimizations.
1435 (('fneg', ('fneg', a)), a),
1436
1437 # These are duplicated from the main optimizations table. The late
1438 # patterns that rearrange expressions like x - .5 < 0 to x < .5 can create
1439 # new patterns like these. The patterns that compare with zero are removed
1440 # because they are unlikely to be created in by anything in
1441 # late_optimizations.
1442 (('flt', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('flt', a, b)),
1443 (('flt', '#b(is_gt_0_and_lt_1)', ('fsat(is_used_once)', a)), ('flt', b, a)),
1444 (('fge', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('fge', a, b)),
1445 (('fge', '#b(is_gt_0_and_lt_1)', ('fsat(is_used_once)', a)), ('fge', b, a)),
1446 (('feq', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('feq', a, b)),
1447 (('fne', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('fne', a, b)),
1448
1449 (('fge', ('fsat(is_used_once)', a), 1.0), ('fge', a, 1.0)),
1450 (('flt', ('fsat(is_used_once)', a), 1.0), ('flt', a, 1.0)),
1451
1452 (('~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)))),
1453
1454 (('flt', ('fneg', a), ('fneg', b)), ('flt', b, a)),
1455 (('fge', ('fneg', a), ('fneg', b)), ('fge', b, a)),
1456 (('feq', ('fneg', a), ('fneg', b)), ('feq', b, a)),
1457 (('fne', ('fneg', a), ('fneg', b)), ('fne', b, a)),
1458 (('flt', ('fneg', a), -1.0), ('flt', 1.0, a)),
1459 (('flt', -1.0, ('fneg', a)), ('flt', a, 1.0)),
1460 (('fge', ('fneg', a), -1.0), ('fge', 1.0, a)),
1461 (('fge', -1.0, ('fneg', a)), ('fge', a, 1.0)),
1462 (('fne', ('fneg', a), -1.0), ('fne', 1.0, a)),
1463 (('feq', -1.0, ('fneg', a)), ('feq', a, 1.0)),
1464
1465 (('ior', a, a), a),
1466 (('iand', a, a), a),
1467
1468 (('~fadd', ('fneg(is_used_once)', ('fsat(is_used_once)', 'a(is_not_fmul)')), 1.0), ('fsat', ('fadd', 1.0, ('fneg', a)))),
1469
1470 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
1471 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
1472 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
1473 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
1474
1475 (('~flrp@32', ('fadd(is_used_once)', a, b), ('fadd(is_used_once)', a, c), d), ('fadd', ('flrp', b, c, d), a)),
1476 (('~flrp@64', ('fadd(is_used_once)', a, b), ('fadd(is_used_once)', a, c), d), ('fadd', ('flrp', b, c, d), a)),
1477
1478 (('~fadd@32', 1.0, ('fmul(is_used_once)', c , ('fadd', b, -1.0 ))), ('fadd', ('fadd', 1.0, ('fneg', c)), ('fmul', b, c)), 'options->lower_flrp32'),
1479 (('~fadd@64', 1.0, ('fmul(is_used_once)', c , ('fadd', b, -1.0 ))), ('fadd', ('fadd', 1.0, ('fneg', c)), ('fmul', b, c)), 'options->lower_flrp64'),
1480
1481 # A similar operation could apply to any ffma(#a, b, #(-a/2)), but this
1482 # particular operation is common for expanding values stored in a texture
1483 # from [0,1] to [-1,1].
1484 (('~ffma@32', a, 2.0, -1.0), ('flrp', -1.0, 1.0, a ), '!options->lower_flrp32'),
1485 (('~ffma@32', a, -2.0, -1.0), ('flrp', -1.0, 1.0, ('fneg', a)), '!options->lower_flrp32'),
1486 (('~ffma@32', a, -2.0, 1.0), ('flrp', 1.0, -1.0, a ), '!options->lower_flrp32'),
1487 (('~ffma@32', a, 2.0, 1.0), ('flrp', 1.0, -1.0, ('fneg', a)), '!options->lower_flrp32'),
1488 (('~fadd@32', ('fmul(is_used_once)', 2.0, a), -1.0), ('flrp', -1.0, 1.0, a ), '!options->lower_flrp32'),
1489 (('~fadd@32', ('fmul(is_used_once)', -2.0, a), -1.0), ('flrp', -1.0, 1.0, ('fneg', a)), '!options->lower_flrp32'),
1490 (('~fadd@32', ('fmul(is_used_once)', -2.0, a), 1.0), ('flrp', 1.0, -1.0, a ), '!options->lower_flrp32'),
1491 (('~fadd@32', ('fmul(is_used_once)', 2.0, a), 1.0), ('flrp', 1.0, -1.0, ('fneg', a)), '!options->lower_flrp32'),
1492
1493 # flrp(a, b, a)
1494 # a*(1-a) + b*a
1495 # a + -a*a + a*b (1)
1496 # a + a*(b - a)
1497 # Option 1: ffma(a, (b-a), a)
1498 #
1499 # Alternately, after (1):
1500 # a*(1+b) + -a*a
1501 # a*((1+b) + -a)
1502 #
1503 # Let b=1
1504 #
1505 # Option 2: ffma(a, 2, -(a*a))
1506 # Option 3: ffma(a, 2, (-a)*a)
1507 # Option 4: ffma(a, -a, (2*a)
1508 # Option 5: a * (2 - a)
1509 #
1510 # There are a lot of other possible combinations.
1511 (('~ffma@32', ('fadd', b, ('fneg', a)), a, a), ('flrp', a, b, a), '!options->lower_flrp32'),
1512 (('~ffma@32', a, 2.0, ('fneg', ('fmul', a, a))), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1513 (('~ffma@32', a, 2.0, ('fmul', ('fneg', a), a)), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1514 (('~ffma@32', a, ('fneg', a), ('fmul', 2.0, a)), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1515 (('~fmul@32', a, ('fadd', 2.0, ('fneg', a))), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1516
1517 # we do these late so that we don't get in the way of creating ffmas
1518 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
1519 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
1520
1521 (('bcsel', a, 0, ('b2f32', ('inot', 'b@bool'))), ('b2f32', ('inot', ('ior', a, b)))),
1522
1523 # Things that look like DPH in the source shader may get expanded to
1524 # something that looks like dot(v1.xyz, v2.xyz) + v1.w by the time it gets
1525 # to NIR. After FFMA is generated, this can look like:
1526 #
1527 # fadd(ffma(v1.z, v2.z, ffma(v1.y, v2.y, fmul(v1.x, v2.x))), v1.w)
1528 #
1529 # Reassociate the last addition into the first multiplication.
1530 (('~fadd', ('ffma(is_used_once)', a, b, ('ffma', c, d, ('fmul', 'e(is_not_const_and_not_fsign)', 'f(is_not_const_and_not_fsign)'))), 'g(is_not_const)'),
1531 ('ffma', a, b, ('ffma', c, d, ('ffma', e, 'f', 'g'))), '!options->intel_vec4'),
1532 (('~fadd', ('ffma(is_used_once)', a, b, ('fmul', 'e(is_not_const_and_not_fsign)', 'f(is_not_const_and_not_fsign)') ), 'g(is_not_const)'),
1533 ('ffma', a, b, ('ffma', e, 'f', 'g') ), '!options->intel_vec4'),
1534 ]
1535
1536 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render())
1537 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
1538 before_ffma_optimizations).render())
1539 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
1540 late_optimizations).render())