nir: recombine nir_op_*sub when lower_sub = false
[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_fsat'),
495 (('~fmax', ('fmin', a, 0.0), -1.0), ('fneg', ('fsat', ('fneg', a))), '!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_fsat'),
501 (('fsat', ('fneg(is_used_once)', ('fmul(is_used_once)', a, b))), ('fsat', ('fmul', ('fneg', a), b)), '!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 (('iand', ('ineg', ('b2i', a)), 1), ('b2i', a)),
786
787 # SM5 32-bit shifts are defined to use the 5 least significant bits
788 (('ishl', 'a@32', ('iand', 31, b)), ('ishl', a, b)),
789 (('ishr', 'a@32', ('iand', 31, b)), ('ishr', a, b)),
790 (('ushr', 'a@32', ('iand', 31, b)), ('ushr', a, b)),
791
792 # Conversions
793 (('i2b32', ('b2i', 'a@32')), a),
794 (('f2i', ('ftrunc', a)), ('f2i', a)),
795 (('f2u', ('ftrunc', a)), ('f2u', a)),
796 (('i2b', ('ineg', a)), ('i2b', a)),
797 (('i2b', ('iabs', a)), ('i2b', a)),
798 (('inot', ('f2b1', a)), ('feq', a, 0.0)),
799
800 # Ironically, mark these as imprecise because removing the conversions may
801 # preserve more precision than doing the conversions (e.g.,
802 # uint(float(0x81818181u)) == 0x81818200).
803 (('~f2i32', ('i2f', 'a@32')), a),
804 (('~f2i32', ('u2f', 'a@32')), a),
805 (('~f2u32', ('i2f', 'a@32')), a),
806 (('~f2u32', ('u2f', 'a@32')), a),
807
808 (('ffloor', 'a(is_integral)'), a),
809 (('fceil', 'a(is_integral)'), a),
810 (('ftrunc', 'a(is_integral)'), a),
811 # fract(x) = x - floor(x), so fract(NaN) = NaN
812 (('~ffract', 'a(is_integral)'), 0.0),
813 (('fabs', 'a(is_not_negative)'), a),
814 (('iabs', 'a(is_not_negative)'), a),
815 (('fsat', 'a(is_not_positive)'), 0.0),
816
817 # Section 5.4.1 (Conversion and Scalar Constructors) of the GLSL 4.60 spec
818 # says:
819 #
820 # It is undefined to convert a negative floating-point value to an
821 # uint.
822 #
823 # Assuming that (uint)some_float behaves like (uint)(int)some_float allows
824 # some optimizations in the i965 backend to proceed.
825 (('ige', ('f2u', a), b), ('ige', ('f2i', a), b)),
826 (('ige', b, ('f2u', a)), ('ige', b, ('f2i', a))),
827 (('ilt', ('f2u', a), b), ('ilt', ('f2i', a), b)),
828 (('ilt', b, ('f2u', a)), ('ilt', b, ('f2i', a))),
829
830 (('~fmin', 'a(is_not_negative)', 1.0), ('fsat', a), '!options->lower_fsat'),
831
832 # The result of the multiply must be in [-1, 0], so the result of the ffma
833 # must be in [0, 1].
834 (('flt', ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0), 0.0), False),
835 (('flt', ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0), 0.0), False),
836 (('fmax', ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0), 0.0), ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0)),
837 (('fmax', ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0), 0.0), ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0)),
838
839 (('fne', 'a(is_not_zero)', 0.0), True),
840 (('feq', 'a(is_not_zero)', 0.0), False),
841
842 # In this chart, + means value > 0 and - means value < 0.
843 #
844 # + >= + -> unknown 0 >= + -> false - >= + -> false
845 # + >= 0 -> true 0 >= 0 -> true - >= 0 -> false
846 # + >= - -> true 0 >= - -> true - >= - -> unknown
847 #
848 # Using grouping conceptually similar to a Karnaugh map...
849 #
850 # (+ >= 0, + >= -, 0 >= 0, 0 >= -) == (is_not_negative >= is_not_positive) -> true
851 # (0 >= +, - >= +) == (is_not_positive >= gt_zero) -> false
852 # (- >= +, - >= 0) == (lt_zero >= is_not_negative) -> false
853 #
854 # The flt / ilt cases just invert the expected result.
855 #
856 # The results expecting true, must be marked imprecise. The results
857 # expecting false are fine because NaN compared >= or < anything is false.
858
859 (('~fge', 'a(is_not_negative)', 'b(is_not_positive)'), True),
860 (('fge', 'a(is_not_positive)', 'b(is_gt_zero)'), False),
861 (('fge', 'a(is_lt_zero)', 'b(is_not_negative)'), False),
862
863 (('flt', 'a(is_not_negative)', 'b(is_not_positive)'), False),
864 (('~flt', 'a(is_not_positive)', 'b(is_gt_zero)'), True),
865 (('~flt', 'a(is_lt_zero)', 'b(is_not_negative)'), True),
866
867 (('ine', 'a(is_not_zero)', 0), True),
868 (('ieq', 'a(is_not_zero)', 0), False),
869
870 (('ige', 'a(is_not_negative)', 'b(is_not_positive)'), True),
871 (('ige', 'a(is_not_positive)', 'b(is_gt_zero)'), False),
872 (('ige', 'a(is_lt_zero)', 'b(is_not_negative)'), False),
873
874 (('ilt', 'a(is_not_negative)', 'b(is_not_positive)'), False),
875 (('ilt', 'a(is_not_positive)', 'b(is_gt_zero)'), True),
876 (('ilt', 'a(is_lt_zero)', 'b(is_not_negative)'), True),
877
878 (('ult', 0, 'a(is_gt_zero)'), True),
879
880 # Packing and then unpacking does nothing
881 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),
882 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b),
883 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a),
884 ('unpack_64_2x32_split_y', a)), a),
885
886 # Comparing two halves of an unpack separately. While this optimization
887 # should be correct for non-constant values, it's less obvious that it's
888 # useful in that case. For constant values, the pack will fold and we're
889 # guaranteed to reduce the whole tree to one instruction.
890 (('iand', ('ieq', ('unpack_32_2x16_split_x', a), '#b'),
891 ('ieq', ('unpack_32_2x16_split_y', a), '#c')),
892 ('ieq', a, ('pack_32_2x16_split', b, c))),
893
894 # Byte extraction
895 (('ushr', 'a@16', 8), ('extract_u8', a, 1), '!options->lower_extract_byte'),
896 (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'),
897 (('ushr', 'a@64', 56), ('extract_u8', a, 7), '!options->lower_extract_byte'),
898 (('ishr', 'a@16', 8), ('extract_i8', a, 1), '!options->lower_extract_byte'),
899 (('ishr', 'a@32', 24), ('extract_i8', a, 3), '!options->lower_extract_byte'),
900 (('ishr', 'a@64', 56), ('extract_i8', a, 7), '!options->lower_extract_byte'),
901 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'),
902
903 # Useless masking before unpacking
904 (('unpack_half_2x16_split_x', ('iand', a, 0xffff)), ('unpack_half_2x16_split_x', a)),
905 (('unpack_32_2x16_split_x', ('iand', a, 0xffff)), ('unpack_32_2x16_split_x', a)),
906 (('unpack_64_2x32_split_x', ('iand', a, 0xffffffff)), ('unpack_64_2x32_split_x', a)),
907 (('unpack_half_2x16_split_y', ('iand', a, 0xffff0000)), ('unpack_half_2x16_split_y', a)),
908 (('unpack_32_2x16_split_y', ('iand', a, 0xffff0000)), ('unpack_32_2x16_split_y', a)),
909 (('unpack_64_2x32_split_y', ('iand', a, 0xffffffff00000000)), ('unpack_64_2x32_split_y', a)),
910 ])
911
912 # After the ('extract_u8', a, 0) pattern, above, triggers, there will be
913 # patterns like those below.
914 for op in ('ushr', 'ishr'):
915 optimizations.extend([(('extract_u8', (op, 'a@16', 8), 0), ('extract_u8', a, 1))])
916 optimizations.extend([(('extract_u8', (op, 'a@32', 8 * i), 0), ('extract_u8', a, i)) for i in range(1, 4)])
917 optimizations.extend([(('extract_u8', (op, 'a@64', 8 * i), 0), ('extract_u8', a, i)) for i in range(1, 8)])
918
919 optimizations.extend([(('extract_u8', ('extract_u16', a, 1), 0), ('extract_u8', a, 2))])
920
921 # After the ('extract_[iu]8', a, 3) patterns, above, trigger, there will be
922 # patterns like those below.
923 for op in ('extract_u8', 'extract_i8'):
924 optimizations.extend([((op, ('ishl', 'a@16', 8), 1), (op, a, 0))])
925 optimizations.extend([((op, ('ishl', 'a@32', 24 - 8 * i), 3), (op, a, i)) for i in range(2, -1, -1)])
926 optimizations.extend([((op, ('ishl', 'a@64', 56 - 8 * i), 7), (op, a, i)) for i in range(6, -1, -1)])
927
928 optimizations.extend([
929 # Word extraction
930 (('ushr', ('ishl', 'a@32', 16), 16), ('extract_u16', a, 0), '!options->lower_extract_word'),
931 (('ushr', 'a@32', 16), ('extract_u16', a, 1), '!options->lower_extract_word'),
932 (('ishr', ('ishl', 'a@32', 16), 16), ('extract_i16', a, 0), '!options->lower_extract_word'),
933 (('ishr', 'a@32', 16), ('extract_i16', a, 1), '!options->lower_extract_word'),
934 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'),
935
936 # Subtracts
937 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)),
938 (('isub', a, ('isub', 0, b)), ('iadd', a, b)),
939 (('isub', ('iadd', a, b), b), a),
940 (('~fsub', ('fadd', a, b), b), a),
941 (('ussub_4x8', a, 0), a),
942 (('ussub_4x8', a, ~0), 0),
943 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)),
944 (('iadd', a, ('isub', 0, b)), ('isub', a, b)),
945 (('fabs', ('fsub', 0.0, a)), ('fabs', a)),
946 (('iabs', ('isub', 0, a)), ('iabs', a)),
947 # Lower all Subtractions first - they can get recombined later
948 (('fsub', a, b), ('fadd', a, ('fneg', b))),
949 (('isub', a, b), ('iadd', a, ('ineg', b))),
950
951 # Propagate negation up multiplication chains
952 (('fmul(is_used_by_non_fsat)', ('fneg', a), b), ('fneg', ('fmul', a, b))),
953 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))),
954
955 # Propagate constants up multiplication chains
956 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)),
957 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)),
958 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)),
959 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)),
960
961 # Reassociate constants in add/mul chains so they can be folded together.
962 # For now, we mostly only handle cases where the constants are separated by
963 # a single non-constant. We could do better eventually.
964 (('~fmul', '#a', ('fmul', 'b(is_not_const)', '#c')), ('fmul', ('fmul', a, c), b)),
965 (('imul', '#a', ('imul', 'b(is_not_const)', '#c')), ('imul', ('imul', a, c), b)),
966 (('~fadd', '#a', ('fadd', 'b(is_not_const)', '#c')), ('fadd', ('fadd', a, c), b)),
967 (('~fadd', '#a', ('fneg', ('fadd', 'b(is_not_const)', '#c'))), ('fadd', ('fadd', a, ('fneg', c)), ('fneg', b))),
968 (('iadd', '#a', ('iadd', 'b(is_not_const)', '#c')), ('iadd', ('iadd', a, c), b)),
969
970 # Drop mul-div by the same value when there's no wrapping.
971 (('idiv', ('imul(no_signed_wrap)', a, b), b), a),
972
973 # By definition...
974 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
975 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
976 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
977
978 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
979 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
980 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
981
982 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
983
984 # Misc. lowering
985 (('fmod@16', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'),
986 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'),
987 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod'),
988 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'),
989 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'),
990
991 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
992 ('bcsel', ('ult', 31, 'bits'), 'insert',
993 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')),
994 'options->lower_bitfield_insert'),
995 (('ihadd', a, b), ('iadd', ('iand', a, b), ('ishr', ('ixor', a, b), 1)), 'options->lower_hadd'),
996 (('uhadd', a, b), ('iadd', ('iand', a, b), ('ushr', ('ixor', a, b), 1)), 'options->lower_hadd'),
997 (('irhadd', a, b), ('isub', ('ior', a, b), ('ishr', ('ixor', a, b), 1)), 'options->lower_hadd'),
998 (('urhadd', a, b), ('isub', ('ior', a, b), ('ushr', ('ixor', a, b), 1)), 'options->lower_hadd'),
999 (('uadd_sat', a, b), ('bcsel', ('ult', ('iadd', a, b), a), -1, ('iadd', a, b)), 'options->lower_add_sat'),
1000 (('usub_sat', a, b), ('bcsel', ('ult', a, b), 0, ('isub', a, b)), 'options->lower_add_sat'),
1001
1002 # Alternative lowering that doesn't rely on bfi.
1003 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
1004 ('bcsel', ('ult', 31, 'bits'),
1005 'insert',
1006 (('ior',
1007 ('iand', 'base', ('inot', ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'))),
1008 ('iand', ('ishl', 'insert', 'offset'), ('ishl', ('isub', ('ishl', 1, 'bits'), 1), 'offset'))))),
1009 'options->lower_bitfield_insert_to_shifts'),
1010
1011 # Alternative lowering that uses bitfield_select.
1012 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'),
1013 ('bcsel', ('ult', 31, 'bits'), 'insert',
1014 ('bitfield_select', ('bfm', 'bits', 'offset'), ('ishl', 'insert', 'offset'), 'base')),
1015 'options->lower_bitfield_insert_to_bitfield_select'),
1016
1017 (('ibitfield_extract', 'value', 'offset', 'bits'),
1018 ('bcsel', ('ult', 31, 'bits'), 'value',
1019 ('ibfe', 'value', 'offset', 'bits')),
1020 'options->lower_bitfield_extract'),
1021
1022 (('ubitfield_extract', 'value', 'offset', 'bits'),
1023 ('bcsel', ('ult', 31, 'bits'), 'value',
1024 ('ubfe', 'value', 'offset', 'bits')),
1025 'options->lower_bitfield_extract'),
1026
1027 # Note that these opcodes are defined to only use the five least significant bits of 'offset' and 'bits'
1028 (('ubfe', 'value', 'offset', ('iand', 31, 'bits')), ('ubfe', 'value', 'offset', 'bits')),
1029 (('ubfe', 'value', ('iand', 31, 'offset'), 'bits'), ('ubfe', 'value', 'offset', 'bits')),
1030 (('ibfe', 'value', 'offset', ('iand', 31, 'bits')), ('ibfe', 'value', 'offset', 'bits')),
1031 (('ibfe', 'value', ('iand', 31, 'offset'), 'bits'), ('ibfe', 'value', 'offset', 'bits')),
1032 (('bfm', 'bits', ('iand', 31, 'offset')), ('bfm', 'bits', 'offset')),
1033 (('bfm', ('iand', 31, 'bits'), 'offset'), ('bfm', 'bits', 'offset')),
1034
1035 (('ibitfield_extract', 'value', 'offset', 'bits'),
1036 ('bcsel', ('ieq', 0, 'bits'),
1037 0,
1038 ('ishr',
1039 ('ishl', 'value', ('isub', ('isub', 32, 'bits'), 'offset')),
1040 ('isub', 32, 'bits'))),
1041 'options->lower_bitfield_extract_to_shifts'),
1042
1043 (('ubitfield_extract', 'value', 'offset', 'bits'),
1044 ('iand',
1045 ('ushr', 'value', 'offset'),
1046 ('bcsel', ('ieq', 'bits', 32),
1047 0xffffffff,
1048 ('isub', ('ishl', 1, 'bits'), 1))),
1049 'options->lower_bitfield_extract_to_shifts'),
1050
1051 (('ifind_msb', 'value'),
1052 ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')),
1053 'options->lower_ifind_msb'),
1054
1055 (('find_lsb', 'value'),
1056 ('ufind_msb', ('iand', 'value', ('ineg', 'value'))),
1057 'options->lower_find_lsb'),
1058
1059 (('extract_i8', a, 'b@32'),
1060 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
1061 'options->lower_extract_byte'),
1062
1063 (('extract_u8', a, 'b@32'),
1064 ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
1065 'options->lower_extract_byte'),
1066
1067 (('extract_i16', a, 'b@32'),
1068 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
1069 'options->lower_extract_word'),
1070
1071 (('extract_u16', a, 'b@32'),
1072 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
1073 'options->lower_extract_word'),
1074
1075 (('pack_unorm_2x16', 'v'),
1076 ('pack_uvec2_to_uint',
1077 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))),
1078 'options->lower_pack_unorm_2x16'),
1079
1080 (('pack_unorm_4x8', 'v'),
1081 ('pack_uvec4_to_uint',
1082 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))),
1083 'options->lower_pack_unorm_4x8'),
1084
1085 (('pack_snorm_2x16', 'v'),
1086 ('pack_uvec2_to_uint',
1087 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))),
1088 'options->lower_pack_snorm_2x16'),
1089
1090 (('pack_snorm_4x8', 'v'),
1091 ('pack_uvec4_to_uint',
1092 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
1093 'options->lower_pack_snorm_4x8'),
1094
1095 (('unpack_unorm_2x16', 'v'),
1096 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0),
1097 ('extract_u16', 'v', 1))),
1098 65535.0),
1099 'options->lower_unpack_unorm_2x16'),
1100
1101 (('unpack_unorm_4x8', 'v'),
1102 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0),
1103 ('extract_u8', 'v', 1),
1104 ('extract_u8', 'v', 2),
1105 ('extract_u8', 'v', 3))),
1106 255.0),
1107 'options->lower_unpack_unorm_4x8'),
1108
1109 (('unpack_snorm_2x16', 'v'),
1110 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec2', ('extract_i16', 'v', 0),
1111 ('extract_i16', 'v', 1))),
1112 32767.0))),
1113 'options->lower_unpack_snorm_2x16'),
1114
1115 (('unpack_snorm_4x8', 'v'),
1116 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_i8', 'v', 0),
1117 ('extract_i8', 'v', 1),
1118 ('extract_i8', 'v', 2),
1119 ('extract_i8', 'v', 3))),
1120 127.0))),
1121 'options->lower_unpack_snorm_4x8'),
1122
1123 (('isign', a), ('imin', ('imax', a, -1), 1), 'options->lower_isign'),
1124 (('fsign', a), ('fsub', ('b2f', ('flt', 0.0, a)), ('b2f', ('flt', a, 0.0))), 'options->lower_fsign'),
1125 ])
1126
1127 # bit_size dependent lowerings
1128 for bit_size in [8, 16, 32, 64]:
1129 # convenience constants
1130 intmax = (1 << (bit_size - 1)) - 1
1131 intmin = 1 << (bit_size - 1)
1132
1133 optimizations += [
1134 (('iadd_sat@' + str(bit_size), a, b),
1135 ('bcsel', ('ige', b, 1), ('bcsel', ('ilt', ('iadd', a, b), a), intmax, ('iadd', a, b)),
1136 ('bcsel', ('ilt', a, ('iadd', a, b)), intmin, ('iadd', a, b))), 'options->lower_add_sat'),
1137 (('isub_sat@' + str(bit_size), a, b),
1138 ('bcsel', ('ilt', b, 0), ('bcsel', ('ilt', ('isub', a, b), a), intmax, ('isub', a, b)),
1139 ('bcsel', ('ilt', a, ('isub', a, b)), intmin, ('isub', a, b))), 'options->lower_add_sat'),
1140 ]
1141
1142 invert = OrderedDict([('feq', 'fne'), ('fne', 'feq'), ('fge', 'flt'), ('flt', 'fge')])
1143
1144 for left, right in itertools.combinations_with_replacement(invert.keys(), 2):
1145 optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))),
1146 ('iand', (invert[left], a, b), (invert[right], c, d))))
1147 optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))),
1148 ('ior', (invert[left], a, b), (invert[right], c, d))))
1149
1150 # Optimize x2bN(b2x(x)) -> x
1151 for size in type_sizes('bool'):
1152 aN = 'a@' + str(size)
1153 f2bN = 'f2b' + str(size)
1154 i2bN = 'i2b' + str(size)
1155 optimizations.append(((f2bN, ('b2f', aN)), a))
1156 optimizations.append(((i2bN, ('b2i', aN)), a))
1157
1158 # Optimize x2yN(b2x(x)) -> b2y
1159 for x, y in itertools.product(['f', 'u', 'i'], ['f', 'u', 'i']):
1160 if x != 'f' and y != 'f' and x != y:
1161 continue
1162
1163 b2x = 'b2f' if x == 'f' else 'b2i'
1164 b2y = 'b2f' if y == 'f' else 'b2i'
1165 x2yN = '{}2{}'.format(x, y)
1166 optimizations.append(((x2yN, (b2x, a)), (b2y, a)))
1167
1168 # Optimize away x2xN(a@N)
1169 for t in ['int', 'uint', 'float']:
1170 for N in type_sizes(t):
1171 x2xN = '{0}2{0}{1}'.format(t[0], N)
1172 aN = 'a@{0}'.format(N)
1173 optimizations.append(((x2xN, aN), a))
1174
1175 # Optimize x2xN(y2yM(a@P)) -> y2yN(a) for integers
1176 # In particular, we can optimize away everything except upcast of downcast and
1177 # upcasts where the type differs from the other cast
1178 for N, M in itertools.product(type_sizes('uint'), type_sizes('uint')):
1179 if N < M:
1180 # The outer cast is a down-cast. It doesn't matter what the size of the
1181 # argument of the inner cast is because we'll never been in the upcast
1182 # of downcast case. Regardless of types, we'll always end up with y2yN
1183 # in the end.
1184 for x, y in itertools.product(['i', 'u'], ['i', 'u']):
1185 x2xN = '{0}2{0}{1}'.format(x, N)
1186 y2yM = '{0}2{0}{1}'.format(y, M)
1187 y2yN = '{0}2{0}{1}'.format(y, N)
1188 optimizations.append(((x2xN, (y2yM, a)), (y2yN, a)))
1189 elif N > M:
1190 # If the outer cast is an up-cast, we have to be more careful about the
1191 # size of the argument of the inner cast and with types. In this case,
1192 # the type is always the type of type up-cast which is given by the
1193 # outer cast.
1194 for P in type_sizes('uint'):
1195 # We can't optimize away up-cast of down-cast.
1196 if M < P:
1197 continue
1198
1199 # Because we're doing down-cast of down-cast, the types always have
1200 # to match between the two casts
1201 for x in ['i', 'u']:
1202 x2xN = '{0}2{0}{1}'.format(x, N)
1203 x2xM = '{0}2{0}{1}'.format(x, M)
1204 aP = 'a@{0}'.format(P)
1205 optimizations.append(((x2xN, (x2xM, aP)), (x2xN, a)))
1206 else:
1207 # The N == M case is handled by other optimizations
1208 pass
1209
1210 # Optimize comparisons with up-casts
1211 for t in ['int', 'uint', 'float']:
1212 for N, M in itertools.product(type_sizes(t), repeat=2):
1213 if N == 1 or N >= M:
1214 continue
1215
1216 x2xM = '{0}2{0}{1}'.format(t[0], M)
1217 x2xN = '{0}2{0}{1}'.format(t[0], N)
1218 aN = 'a@' + str(N)
1219 bN = 'b@' + str(N)
1220 xeq = 'feq' if t == 'float' else 'ieq'
1221 xne = 'fne' if t == 'float' else 'ine'
1222 xge = '{0}ge'.format(t[0])
1223 xlt = '{0}lt'.format(t[0])
1224
1225 # Up-casts are lossless so for correctly signed comparisons of
1226 # up-casted values we can do the comparison at the largest of the two
1227 # original sizes and drop one or both of the casts. (We have
1228 # optimizations to drop the no-op casts which this may generate.)
1229 for P in type_sizes(t):
1230 if P == 1 or P > N:
1231 continue
1232
1233 bP = 'b@' + str(P)
1234 optimizations += [
1235 ((xeq, (x2xM, aN), (x2xM, bP)), (xeq, a, (x2xN, b))),
1236 ((xne, (x2xM, aN), (x2xM, bP)), (xne, a, (x2xN, b))),
1237 ((xge, (x2xM, aN), (x2xM, bP)), (xge, a, (x2xN, b))),
1238 ((xlt, (x2xM, aN), (x2xM, bP)), (xlt, a, (x2xN, b))),
1239 ((xge, (x2xM, bP), (x2xM, aN)), (xge, (x2xN, b), a)),
1240 ((xlt, (x2xM, bP), (x2xM, aN)), (xlt, (x2xN, b), a)),
1241 ]
1242
1243 # The next bit doesn't work on floats because the range checks would
1244 # get way too complicated.
1245 if t in ['int', 'uint']:
1246 if t == 'int':
1247 xN_min = -(1 << (N - 1))
1248 xN_max = (1 << (N - 1)) - 1
1249 elif t == 'uint':
1250 xN_min = 0
1251 xN_max = (1 << N) - 1
1252 else:
1253 assert False
1254
1255 # If we're up-casting and comparing to a constant, we can unfold
1256 # the comparison into a comparison with the shrunk down constant
1257 # and a check that the constant fits in the smaller bit size.
1258 optimizations += [
1259 ((xeq, (x2xM, aN), '#b'),
1260 ('iand', (xeq, a, (x2xN, b)), (xeq, (x2xM, (x2xN, b)), b))),
1261 ((xne, (x2xM, aN), '#b'),
1262 ('ior', (xne, a, (x2xN, b)), (xne, (x2xM, (x2xN, b)), b))),
1263 ((xlt, (x2xM, aN), '#b'),
1264 ('iand', (xlt, xN_min, b),
1265 ('ior', (xlt, xN_max, b), (xlt, a, (x2xN, b))))),
1266 ((xlt, '#a', (x2xM, bN)),
1267 ('iand', (xlt, a, xN_max),
1268 ('ior', (xlt, a, xN_min), (xlt, (x2xN, a), b)))),
1269 ((xge, (x2xM, aN), '#b'),
1270 ('iand', (xge, xN_max, b),
1271 ('ior', (xge, xN_min, b), (xge, a, (x2xN, b))))),
1272 ((xge, '#a', (x2xM, bN)),
1273 ('iand', (xge, a, xN_min),
1274 ('ior', (xge, a, xN_max), (xge, (x2xN, a), b)))),
1275 ]
1276
1277 def fexp2i(exp, bits):
1278 # We assume that exp is already in the right range.
1279 if bits == 16:
1280 return ('i2i16', ('ishl', ('iadd', exp, 15), 10))
1281 elif bits == 32:
1282 return ('ishl', ('iadd', exp, 127), 23)
1283 elif bits == 64:
1284 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20))
1285 else:
1286 assert False
1287
1288 def ldexp(f, exp, bits):
1289 # First, we clamp exp to a reasonable range. The maximum possible range
1290 # for a normal exponent is [-126, 127] and, throwing in denormals, you get
1291 # a maximum range of [-149, 127]. This means that we can potentially have
1292 # a swing of +-276. If you start with FLT_MAX, you actually have to do
1293 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL
1294 # spec, on the other hand, only requires that we handle an exponent value
1295 # in the range [-126, 128]. This implementation is *mostly* correct; it
1296 # handles a range on exp of [-252, 254] which allows you to create any
1297 # value (including denorms if the hardware supports it) and to adjust the
1298 # exponent of any normal value to anything you want.
1299 if bits == 16:
1300 exp = ('imin', ('imax', exp, -28), 30)
1301 elif bits == 32:
1302 exp = ('imin', ('imax', exp, -252), 254)
1303 elif bits == 64:
1304 exp = ('imin', ('imax', exp, -2044), 2046)
1305 else:
1306 assert False
1307
1308 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2.
1309 # (We use ishr which isn't the same for -1, but the -1 case still works
1310 # since we use exp-exp/2 as the second exponent.) While the spec
1311 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't
1312 # work with denormals and doesn't allow for the full swing in exponents
1313 # that you can get with normalized values. Instead, we create two powers
1314 # of two and multiply by them each in turn. That way the effective range
1315 # of our exponent is doubled.
1316 pow2_1 = fexp2i(('ishr', exp, 1), bits)
1317 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits)
1318 return ('fmul', ('fmul', f, pow2_1), pow2_2)
1319
1320 optimizations += [
1321 (('ldexp@16', 'x', 'exp'), ldexp('x', 'exp', 16), 'options->lower_ldexp'),
1322 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32), 'options->lower_ldexp'),
1323 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64), 'options->lower_ldexp'),
1324 ]
1325
1326 # Unreal Engine 4 demo applications open-codes bitfieldReverse()
1327 def bitfield_reverse(u):
1328 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16))
1329 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8))
1330 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4))
1331 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2))
1332 step5 = ('ior(many-comm-expr)', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1))
1333
1334 return step5
1335
1336 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'), '!options->lower_bitfield_reverse')]
1337
1338 # For any float comparison operation, "cmp", if you have "a == a && a cmp b"
1339 # then the "a == a" is redundant because it's equivalent to "a is not NaN"
1340 # and, if a is a NaN then the second comparison will fail anyway.
1341 for op in ['flt', 'fge', 'feq']:
1342 optimizations += [
1343 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)),
1344 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)),
1345 ]
1346
1347 # Add optimizations to handle the case where the result of a ternary is
1348 # compared to a constant. This way we can take things like
1349 #
1350 # (a ? 0 : 1) > 0
1351 #
1352 # and turn it into
1353 #
1354 # a ? (0 > 0) : (1 > 0)
1355 #
1356 # which constant folding will eat for lunch. The resulting ternary will
1357 # further get cleaned up by the boolean reductions above and we will be
1358 # left with just the original variable "a".
1359 for op in ['flt', 'fge', 'feq', 'fne',
1360 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']:
1361 optimizations += [
1362 ((op, ('bcsel', 'a', '#b', '#c'), '#d'),
1363 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))),
1364 ((op, '#d', ('bcsel', a, '#b', '#c')),
1365 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))),
1366 ]
1367
1368
1369 # For example, this converts things like
1370 #
1371 # 1 + mix(0, a - 1, condition)
1372 #
1373 # into
1374 #
1375 # mix(1, (a-1)+1, condition)
1376 #
1377 # Other optimizations will rearrange the constants.
1378 for op in ['fadd', 'fmul', 'iadd', 'imul']:
1379 optimizations += [
1380 ((op, ('bcsel(is_used_once)', a, '#b', c), '#d'), ('bcsel', a, (op, b, d), (op, c, d)))
1381 ]
1382
1383 # For derivatives in compute shaders, GLSL_NV_compute_shader_derivatives
1384 # states:
1385 #
1386 # If neither layout qualifier is specified, derivatives in compute shaders
1387 # return zero, which is consistent with the handling of built-in texture
1388 # functions like texture() in GLSL 4.50 compute shaders.
1389 for op in ['fddx', 'fddx_fine', 'fddx_coarse',
1390 'fddy', 'fddy_fine', 'fddy_coarse']:
1391 optimizations += [
1392 ((op, 'a'), 0.0, 'info->stage == MESA_SHADER_COMPUTE && info->cs.derivative_group == DERIVATIVE_GROUP_NONE')
1393 ]
1394
1395 # Some optimizations for ir3-specific instructions.
1396 optimizations += [
1397 # 'al * bl': If either 'al' or 'bl' is zero, return zero.
1398 (('umul_low', '#a(is_lower_half_zero)', 'b'), (0)),
1399 # '(ah * bl) << 16 + c': If either 'ah' or 'bl' is zero, return 'c'.
1400 (('imadsh_mix16', '#a@32(is_lower_half_zero)', 'b@32', 'c@32'), ('c')),
1401 (('imadsh_mix16', 'a@32', '#b@32(is_upper_half_zero)', 'c@32'), ('c')),
1402 ]
1403
1404 # This section contains "late" optimizations that should be run before
1405 # creating ffmas and calling regular optimizations for the final time.
1406 # Optimizations should go here if they help code generation and conflict
1407 # with the regular optimizations.
1408 before_ffma_optimizations = [
1409 # Propagate constants down multiplication chains
1410 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)),
1411 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)),
1412 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)),
1413 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)),
1414
1415 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
1416 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
1417 (('~fadd', ('fneg', a), a), 0.0),
1418 (('iadd', ('ineg', a), a), 0),
1419 (('iadd', ('ineg', a), ('iadd', a, b)), b),
1420 (('iadd', a, ('iadd', ('ineg', a), b)), b),
1421 (('~fadd', ('fneg', a), ('fadd', a, b)), b),
1422 (('~fadd', a, ('fadd', ('fneg', a), b)), b),
1423
1424 (('~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)),
1425 (('~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)),
1426 (('~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))),
1427 ]
1428
1429 # This section contains "late" optimizations that should be run after the
1430 # regular optimizations have finished. Optimizations should go here if
1431 # they help code generation but do not necessarily produce code that is
1432 # more easily optimizable.
1433 late_optimizations = [
1434 # Most of these optimizations aren't quite safe when you get infinity or
1435 # Nan involved but the first one should be fine.
1436 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
1437 (('flt', ('fneg', ('fadd', a, b)), 0.0), ('flt', ('fneg', a), b)),
1438 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
1439 (('~fge', ('fneg', ('fadd', a, b)), 0.0), ('fge', ('fneg', a), b)),
1440 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
1441 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
1442
1443 # nir_lower_to_source_mods will collapse this, but its existence during the
1444 # optimization loop can prevent other optimizations.
1445 (('fneg', ('fneg', a)), a),
1446
1447 # Subtractions get lowered during optimization, so we need to recombine them
1448 (('fadd', 'a', ('fneg', 'b')), ('fsub', 'a', 'b'), '!options->lower_sub'),
1449 (('iadd', 'a', ('ineg', 'b')), ('isub', 'a', 'b'), '!options->lower_sub'),
1450 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'),
1451 (('ineg', a), ('isub', 0, a), 'options->lower_negate'),
1452
1453 # These are duplicated from the main optimizations table. The late
1454 # patterns that rearrange expressions like x - .5 < 0 to x < .5 can create
1455 # new patterns like these. The patterns that compare with zero are removed
1456 # because they are unlikely to be created in by anything in
1457 # late_optimizations.
1458 (('flt', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('flt', a, b)),
1459 (('flt', '#b(is_gt_0_and_lt_1)', ('fsat(is_used_once)', a)), ('flt', b, a)),
1460 (('fge', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('fge', a, b)),
1461 (('fge', '#b(is_gt_0_and_lt_1)', ('fsat(is_used_once)', a)), ('fge', b, a)),
1462 (('feq', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('feq', a, b)),
1463 (('fne', ('fsat(is_used_once)', a), '#b(is_gt_0_and_lt_1)'), ('fne', a, b)),
1464
1465 (('fge', ('fsat(is_used_once)', a), 1.0), ('fge', a, 1.0)),
1466 (('flt', ('fsat(is_used_once)', a), 1.0), ('flt', a, 1.0)),
1467
1468 (('~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)))),
1469
1470 (('flt', ('fneg', a), ('fneg', b)), ('flt', b, a)),
1471 (('fge', ('fneg', a), ('fneg', b)), ('fge', b, a)),
1472 (('feq', ('fneg', a), ('fneg', b)), ('feq', b, a)),
1473 (('fne', ('fneg', a), ('fneg', b)), ('fne', b, a)),
1474 (('flt', ('fneg', a), -1.0), ('flt', 1.0, a)),
1475 (('flt', -1.0, ('fneg', a)), ('flt', a, 1.0)),
1476 (('fge', ('fneg', a), -1.0), ('fge', 1.0, a)),
1477 (('fge', -1.0, ('fneg', a)), ('fge', a, 1.0)),
1478 (('fne', ('fneg', a), -1.0), ('fne', 1.0, a)),
1479 (('feq', -1.0, ('fneg', a)), ('feq', a, 1.0)),
1480
1481 (('ior', a, a), a),
1482 (('iand', a, a), a),
1483
1484 (('~fadd', ('fneg(is_used_once)', ('fsat(is_used_once)', 'a(is_not_fmul)')), 1.0), ('fsat', ('fadd', 1.0, ('fneg', a)))),
1485
1486 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
1487 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
1488 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),
1489 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'),
1490
1491 (('~flrp@32', ('fadd(is_used_once)', a, b), ('fadd(is_used_once)', a, c), d), ('fadd', ('flrp', b, c, d), a)),
1492 (('~flrp@64', ('fadd(is_used_once)', a, b), ('fadd(is_used_once)', a, c), d), ('fadd', ('flrp', b, c, d), a)),
1493
1494 (('~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'),
1495 (('~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'),
1496
1497 # A similar operation could apply to any ffma(#a, b, #(-a/2)), but this
1498 # particular operation is common for expanding values stored in a texture
1499 # from [0,1] to [-1,1].
1500 (('~ffma@32', a, 2.0, -1.0), ('flrp', -1.0, 1.0, a ), '!options->lower_flrp32'),
1501 (('~ffma@32', a, -2.0, -1.0), ('flrp', -1.0, 1.0, ('fneg', a)), '!options->lower_flrp32'),
1502 (('~ffma@32', a, -2.0, 1.0), ('flrp', 1.0, -1.0, a ), '!options->lower_flrp32'),
1503 (('~ffma@32', a, 2.0, 1.0), ('flrp', 1.0, -1.0, ('fneg', a)), '!options->lower_flrp32'),
1504 (('~fadd@32', ('fmul(is_used_once)', 2.0, a), -1.0), ('flrp', -1.0, 1.0, a ), '!options->lower_flrp32'),
1505 (('~fadd@32', ('fmul(is_used_once)', -2.0, a), -1.0), ('flrp', -1.0, 1.0, ('fneg', a)), '!options->lower_flrp32'),
1506 (('~fadd@32', ('fmul(is_used_once)', -2.0, a), 1.0), ('flrp', 1.0, -1.0, a ), '!options->lower_flrp32'),
1507 (('~fadd@32', ('fmul(is_used_once)', 2.0, a), 1.0), ('flrp', 1.0, -1.0, ('fneg', a)), '!options->lower_flrp32'),
1508
1509 # flrp(a, b, a)
1510 # a*(1-a) + b*a
1511 # a + -a*a + a*b (1)
1512 # a + a*(b - a)
1513 # Option 1: ffma(a, (b-a), a)
1514 #
1515 # Alternately, after (1):
1516 # a*(1+b) + -a*a
1517 # a*((1+b) + -a)
1518 #
1519 # Let b=1
1520 #
1521 # Option 2: ffma(a, 2, -(a*a))
1522 # Option 3: ffma(a, 2, (-a)*a)
1523 # Option 4: ffma(a, -a, (2*a)
1524 # Option 5: a * (2 - a)
1525 #
1526 # There are a lot of other possible combinations.
1527 (('~ffma@32', ('fadd', b, ('fneg', a)), a, a), ('flrp', a, b, a), '!options->lower_flrp32'),
1528 (('~ffma@32', a, 2.0, ('fneg', ('fmul', a, a))), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1529 (('~ffma@32', a, 2.0, ('fmul', ('fneg', a), a)), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1530 (('~ffma@32', a, ('fneg', a), ('fmul', 2.0, a)), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1531 (('~fmul@32', a, ('fadd', 2.0, ('fneg', a))), ('flrp', a, 1.0, a), '!options->lower_flrp32'),
1532
1533 # we do these late so that we don't get in the way of creating ffmas
1534 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
1535 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),
1536
1537 (('bcsel', a, 0, ('b2f32', ('inot', 'b@bool'))), ('b2f32', ('inot', ('ior', a, b)))),
1538
1539 # Things that look like DPH in the source shader may get expanded to
1540 # something that looks like dot(v1.xyz, v2.xyz) + v1.w by the time it gets
1541 # to NIR. After FFMA is generated, this can look like:
1542 #
1543 # fadd(ffma(v1.z, v2.z, ffma(v1.y, v2.y, fmul(v1.x, v2.x))), v1.w)
1544 #
1545 # Reassociate the last addition into the first multiplication.
1546 #
1547 # Some shaders do not use 'invariant' in vertex and (possibly) geometry
1548 # shader stages on some outputs that are intended to be invariant. For
1549 # various reasons, this optimization may not be fully applied in all
1550 # shaders used for different rendering passes of the same geometry. This
1551 # can result in Z-fighting artifacts (at best). For now, disable this
1552 # optimization in these stages. See bugzilla #111490. In tessellation
1553 # stages applications seem to use 'precise' when necessary, so allow the
1554 # optimization in those stages.
1555 (('~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)'),
1556 ('ffma', a, b, ('ffma', c, d, ('ffma', e, 'f', 'g'))), '(info->stage != MESA_SHADER_VERTEX && info->stage != MESA_SHADER_GEOMETRY) && !options->intel_vec4'),
1557 (('~fadd', ('ffma(is_used_once)', a, b, ('fmul', 'c(is_not_const_and_not_fsign)', 'd(is_not_const_and_not_fsign)') ), 'e(is_not_const)'),
1558 ('ffma', a, b, ('ffma', c, d, e)), '(info->stage != MESA_SHADER_VERTEX && info->stage != MESA_SHADER_GEOMETRY) && !options->intel_vec4'),
1559 ]
1560
1561 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render())
1562 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma",
1563 before_ffma_optimizations).render())
1564 print(nir_algebraic.AlgebraicPass("nir_opt_algebraic_late",
1565 late_optimizations).render())