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 (at] jlekstrand.net) 25 26 import nir_algebraic 27 28 # Convenience variables 29 a = 'a' 30 b = 'b' 31 c = 'c' 32 d = 'd' 33 34 # Written in the form (<search>, <replace>) where <search> is an expression 35 # and <replace> is either an expression or a value. An expression is 36 # defined as a tuple of the form ([~]<op>, <src0>, <src1>, <src2>, <src3>) 37 # where each source is either an expression or a value. A value can be 38 # either a numeric constant or a string representing a variable name. 39 # 40 # If the opcode in a search expression is prefixed by a '~' character, this 41 # indicates that the operation is inexact. Such operations will only get 42 # applied to SSA values that do not have the exact bit set. This should be 43 # used by by any optimizations that are not bit-for-bit exact. It should not, 44 # however, be used for backend-requested lowering operations as those need to 45 # happen regardless of precision. 46 # 47 # Variable names are specified as "[#]name[@type][(cond)]" where "#" inicates 48 # that the given variable will only match constants and the type indicates that 49 # the given variable will only match values from ALU instructions with the 50 # given output type, and (cond) specifies an additional condition function 51 # (see nir_search_helpers.h). 52 # 53 # For constants, you have to be careful to make sure that it is the right 54 # type because python is unaware of the source and destination types of the 55 # opcodes. 56 # 57 # All expression types can have a bit-size specified. For opcodes, this 58 # looks like "op@32", for variables it is "a@32" or "a@uint32" to specify a 59 # type and size, and for literals, you can write "2.0@32". In the search half 60 # of the expression this indicates that it should only match that particular 61 # bit-size. In the replace half of the expression this indicates that the 62 # constructed value should have that bit-size. 63 64 optimizations = [ 65 66 (('imul', a, '#b@32(is_pos_power_of_two)'), ('ishl', a, ('find_lsb', b))), 67 (('imul', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('ishl', a, ('find_lsb', ('iabs', b))))), 68 (('udiv', a, 1), a), 69 (('idiv', a, 1), a), 70 (('umod', a, 1), 0), 71 (('imod', a, 1), 0), 72 (('udiv', a, '#b@32(is_pos_power_of_two)'), ('ushr', a, ('find_lsb', b))), 73 (('idiv', a, '#b@32(is_pos_power_of_two)'), ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', b))), 'options->lower_idiv'), 74 (('idiv', a, '#b@32(is_neg_power_of_two)'), ('ineg', ('imul', ('isign', a), ('ushr', ('iabs', a), ('find_lsb', ('iabs', b))))), 'options->lower_idiv'), 75 (('umod', a, '#b(is_pos_power_of_two)'), ('iand', a, ('isub', b, 1))), 76 77 (('fneg', ('fneg', a)), a), 78 (('ineg', ('ineg', a)), a), 79 (('fabs', ('fabs', a)), ('fabs', a)), 80 (('fabs', ('fneg', a)), ('fabs', a)), 81 (('fabs', ('u2f32', a)), ('u2f32', a)), 82 (('iabs', ('iabs', a)), ('iabs', a)), 83 (('iabs', ('ineg', a)), ('iabs', a)), 84 (('~fadd', a, 0.0), a), 85 (('iadd', a, 0), a), 86 (('usadd_4x8', a, 0), a), 87 (('usadd_4x8', a, ~0), ~0), 88 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))), 89 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))), 90 (('~fadd', ('fneg', a), a), 0.0), 91 (('iadd', ('ineg', a), a), 0), 92 (('iadd', ('ineg', a), ('iadd', a, b)), b), 93 (('iadd', a, ('iadd', ('ineg', a), b)), b), 94 (('~fadd', ('fneg', a), ('fadd', a, b)), b), 95 (('~fadd', a, ('fadd', ('fneg', a), b)), b), 96 (('~fmul', a, 0.0), 0.0), 97 (('imul', a, 0), 0), 98 (('umul_unorm_4x8', a, 0), 0), 99 (('umul_unorm_4x8', a, ~0), a), 100 (('fmul', a, 1.0), a), 101 (('imul', a, 1), a), 102 (('fmul', a, -1.0), ('fneg', a)), 103 (('imul', a, -1), ('ineg', a)), 104 (('~ffma', 0.0, a, b), b), 105 (('~ffma', a, 0.0, b), b), 106 (('~ffma', a, b, 0.0), ('fmul', a, b)), 107 (('ffma', a, 1.0, b), ('fadd', a, b)), 108 (('ffma', 1.0, a, b), ('fadd', a, b)), 109 (('~flrp', a, b, 0.0), a), 110 (('~flrp', a, b, 1.0), b), 111 (('~flrp', a, a, b), a), 112 (('~flrp', 0.0, a, b), ('fmul', a, b)), 113 (('~flrp', a, b, ('b2f', c)), ('bcsel', c, b, a), 'options->lower_flrp32'), 114 (('~flrp', a, 0.0, c), ('fadd', ('fmul', ('fneg', a), c), a)), 115 (('flrp@32', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp32'), 116 (('flrp@64', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp64'), 117 (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'), 118 (('~fadd', ('fmul', a, ('fadd', 1.0, ('fneg', ('b2f', c)))), ('fmul', b, ('b2f', c))), ('bcsel', c, b, a), 'options->lower_flrp32'), 119 (('~fadd@32', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp32'), 120 (('~fadd@64', ('fmul', a, ('fadd', 1.0, ('fneg', c ))), ('fmul', b, c )), ('flrp', a, b, c), '!options->lower_flrp64'), 121 (('~fadd', a, ('fmul', ('b2f', c), ('fadd', b, ('fneg', a)))), ('bcsel', c, b, a), 'options->lower_flrp32'), 122 (('~fadd@32', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp32'), 123 (('~fadd@64', a, ('fmul', c , ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp64'), 124 (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'), 125 (('~fadd', ('fmul', a, b), c), ('ffma', a, b, c), 'options->fuse_ffma'), 126 127 # (a * #b + #c) << #d 128 # ((a * #b) << #d) + (#c << #d) 129 # (a * (#b << #d)) + (#c << #d) 130 (('ishl', ('iadd', ('imul', a, '#b'), '#c'), '#d'), 131 ('iadd', ('imul', a, ('ishl', b, d)), ('ishl', c, d))), 132 133 # (a * #b) << #c 134 # a * (#b << #c) 135 (('ishl', ('imul', a, '#b'), '#c'), ('imul', a, ('ishl', b, c))), 136 137 # Comparison simplifications 138 (('~inot', ('flt', a, b)), ('fge', a, b)), 139 (('~inot', ('fge', a, b)), ('flt', a, b)), 140 (('~inot', ('feq', a, b)), ('fne', a, b)), 141 (('~inot', ('fne', a, b)), ('feq', a, b)), 142 (('inot', ('ilt', a, b)), ('ige', a, b)), 143 (('inot', ('ige', a, b)), ('ilt', a, b)), 144 (('inot', ('ieq', a, b)), ('ine', a, b)), 145 (('inot', ('ine', a, b)), ('ieq', a, b)), 146 147 # 0.0 >= b2f(a) 148 # b2f(a) <= 0.0 149 # b2f(a) == 0.0 because b2f(a) can only be 0 or 1 150 # inot(a) 151 (('fge', 0.0, ('b2f', a)), ('inot', a)), 152 153 (('fge', ('fneg', ('b2f', a)), 0.0), ('inot', a)), 154 155 # 0.0 < fabs(a) 156 # fabs(a) > 0.0 157 # fabs(a) != 0.0 because fabs(a) must be >= 0 158 # a != 0.0 159 (('flt', 0.0, ('fabs', a)), ('fne', a, 0.0)), 160 161 # ignore this opt when the result is used by a bcsel or if so we can make 162 # use of conditional modifiers on supported hardware. 163 (('flt(is_not_used_by_conditional)', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)), 164 165 (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)), 166 (('bcsel', ('flt', b, a), b, a), ('fmin', a, b)), 167 (('bcsel', ('flt', a, b), b, a), ('fmax', a, b)), 168 (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)), 169 (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)), 170 (('bcsel', a, True, 'b@bool'), ('ior', a, b)), 171 (('fmin', a, a), a), 172 (('fmax', a, a), a), 173 (('imin', a, a), a), 174 (('imax', a, a), a), 175 (('umin', a, a), a), 176 (('umax', a, a), a), 177 (('fmin', a, ('fneg', a)), ('fneg', ('fabs', a))), 178 (('imin', a, ('ineg', a)), ('ineg', ('iabs', a))), 179 (('fmin', a, ('fneg', ('fabs', a))), ('fneg', ('fabs', a))), 180 (('imin', a, ('ineg', ('iabs', a))), ('ineg', ('iabs', a))), 181 (('fmin', a, ('fabs', a)), a), 182 (('imin', a, ('iabs', a)), a), 183 (('fmax', a, ('fneg', ('fabs', a))), a), 184 (('imax', a, ('ineg', ('iabs', a))), a), 185 (('fmax', a, ('fabs', a)), ('fabs', a)), 186 (('imax', a, ('iabs', a)), ('iabs', a)), 187 (('fmax', a, ('fneg', a)), ('fabs', a)), 188 (('imax', a, ('ineg', a)), ('iabs', a)), 189 (('~fmin', ('fmax', a, 0.0), 1.0), ('fsat', a), '!options->lower_fsat'), 190 (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'), 191 (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'), 192 (('fsat', ('fsat', a)), ('fsat', a)), 193 (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)), 194 (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)), 195 (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)), 196 (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))), 197 (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))), 198 (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)), 199 (('~ior', ('flt', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))), 200 (('~ior', ('flt', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)), 201 (('~ior', ('fge', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))), 202 (('~ior', ('fge', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)), 203 (('fabs', ('slt', a, b)), ('slt', a, b)), 204 (('fabs', ('sge', a, b)), ('sge', a, b)), 205 (('fabs', ('seq', a, b)), ('seq', a, b)), 206 (('fabs', ('sne', a, b)), ('sne', a, b)), 207 (('slt', a, b), ('b2f', ('flt', a, b)), 'options->lower_scmp'), 208 (('sge', a, b), ('b2f', ('fge', a, b)), 'options->lower_scmp'), 209 (('seq', a, b), ('b2f', ('feq', a, b)), 'options->lower_scmp'), 210 (('sne', a, b), ('b2f', ('fne', a, b)), 'options->lower_scmp'), 211 (('fne', ('fneg', a), a), ('fne', a, 0.0)), 212 (('feq', ('fneg', a), a), ('feq', a, 0.0)), 213 # Emulating booleans 214 (('imul', ('b2i', a), ('b2i', b)), ('b2i', ('iand', a, b))), 215 (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))), 216 (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))), 217 (('iand', 'a@bool', 1.0), ('b2f', a)), 218 # True/False are ~0 and 0 in NIR. b2i of True is 1, and -1 is ~0 (True). 219 (('ineg', ('b2i@32', a)), a), 220 (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF. 221 (('flt', ('fsub', 0.0, ('b2f', a)), 0), a), # Generated by TGSI KILL_IF. 222 # Comparison with the same args. Note that these are not done for 223 # the float versions because NaN always returns false on float 224 # inequalities. 225 (('ilt', a, a), False), 226 (('ige', a, a), True), 227 (('ieq', a, a), True), 228 (('ine', a, a), False), 229 (('ult', a, a), False), 230 (('uge', a, a), True), 231 # Logical and bit operations 232 (('fand', a, 0.0), 0.0), 233 (('iand', a, a), a), 234 (('iand', a, ~0), a), 235 (('iand', a, 0), 0), 236 (('ior', a, a), a), 237 (('ior', a, 0), a), 238 (('ior', a, True), True), 239 (('fxor', a, a), 0.0), 240 (('ixor', a, a), 0), 241 (('ixor', a, 0), a), 242 (('inot', ('inot', a)), a), 243 # DeMorgan's Laws 244 (('iand', ('inot', a), ('inot', b)), ('inot', ('ior', a, b))), 245 (('ior', ('inot', a), ('inot', b)), ('inot', ('iand', a, b))), 246 # Shift optimizations 247 (('ishl', 0, a), 0), 248 (('ishl', a, 0), a), 249 (('ishr', 0, a), 0), 250 (('ishr', a, 0), a), 251 (('ushr', 0, a), 0), 252 (('ushr', a, 0), a), 253 (('iand', 0xff, ('ushr@32', a, 24)), ('ushr', a, 24)), 254 (('iand', 0xffff, ('ushr@32', a, 16)), ('ushr', a, 16)), 255 # Exponential/logarithmic identities 256 (('~fexp2', ('flog2', a)), a), # 2^lg2(a) = a 257 (('~flog2', ('fexp2', a)), a), # lg2(2^a) = a 258 (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # a^b = 2^(lg2(a)*b) 259 (('~fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b 260 (('~fexp2', ('fadd', ('fmul', ('flog2', a), b), ('fmul', ('flog2', c), d))), 261 ('~fmul', ('fpow', a, b), ('fpow', c, d)), '!options->lower_fpow'), # 2^(lg2(a) * b + lg2(c) + d) = a^b * c^d 262 (('~fpow', a, 1.0), a), 263 (('~fpow', a, 2.0), ('fmul', a, a)), 264 (('~fpow', a, 4.0), ('fmul', ('fmul', a, a), ('fmul', a, a))), 265 (('~fpow', 2.0, a), ('fexp2', a)), 266 (('~fpow', ('fpow', a, 2.2), 0.454545), a), 267 (('~fpow', ('fabs', ('fpow', a, 2.2)), 0.454545), ('fabs', a)), 268 (('~fsqrt', ('fexp2', a)), ('fexp2', ('fmul', 0.5, a))), 269 (('~frcp', ('fexp2', a)), ('fexp2', ('fneg', a))), 270 (('~frsq', ('fexp2', a)), ('fexp2', ('fmul', -0.5, a))), 271 (('~flog2', ('fsqrt', a)), ('fmul', 0.5, ('flog2', a))), 272 (('~flog2', ('frcp', a)), ('fneg', ('flog2', a))), 273 (('~flog2', ('frsq', a)), ('fmul', -0.5, ('flog2', a))), 274 (('~flog2', ('fpow', a, b)), ('fmul', b, ('flog2', a))), 275 (('~fmul', ('fexp2', a), ('fexp2', b)), ('fexp2', ('fadd', a, b))), 276 # Division and reciprocal 277 (('~fdiv', 1.0, a), ('frcp', a)), 278 (('fdiv', a, b), ('fmul', a, ('frcp', b)), 'options->lower_fdiv'), 279 (('~frcp', ('frcp', a)), a), 280 (('~frcp', ('fsqrt', a)), ('frsq', a)), 281 (('fsqrt', a), ('frcp', ('frsq', a)), 'options->lower_fsqrt'), 282 (('~frcp', ('frsq', a)), ('fsqrt', a), '!options->lower_fsqrt'), 283 # Boolean simplifications 284 (('ieq', 'a@bool', True), a), 285 (('ine(is_not_used_by_if)', 'a@bool', True), ('inot', a)), 286 (('ine', 'a@bool', False), a), 287 (('ieq(is_not_used_by_if)', 'a@bool', False), ('inot', 'a')), 288 (('bcsel', a, True, False), a), 289 (('bcsel', a, False, True), ('inot', a)), 290 (('bcsel@32', a, 1.0, 0.0), ('b2f', a)), 291 (('bcsel@32', a, 0.0, 1.0), ('b2f', ('inot', a))), 292 (('bcsel@32', a, -1.0, -0.0), ('fneg', ('b2f', a))), 293 (('bcsel@32', a, -0.0, -1.0), ('fneg', ('b2f', ('inot', a)))), 294 (('bcsel', True, b, c), b), 295 (('bcsel', False, b, c), c), 296 # The result of this should be hit by constant propagation and, in the 297 # next round of opt_algebraic, get picked up by one of the above two. 298 (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)), 299 300 (('bcsel', a, b, b), b), 301 (('fcsel', a, b, b), b), 302 303 # Conversions 304 (('i2b', ('b2i', a)), a), 305 (('f2i32', ('ftrunc', a)), ('f2i32', a)), 306 (('f2u32', ('ftrunc', a)), ('f2u32', a)), 307 (('i2b', ('ineg', a)), ('i2b', a)), 308 (('i2b', ('iabs', a)), ('i2b', a)), 309 (('fabs', ('b2f', a)), ('b2f', a)), 310 (('iabs', ('b2i', a)), ('b2i', a)), 311 312 # Packing and then unpacking does nothing 313 (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a), 314 (('unpack_64_2x32_split_y', ('pack_64_2x32_split', a, b)), b), 315 (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a), 316 ('unpack_64_2x32_split_y', a)), a), 317 318 # Byte extraction 319 (('ushr', a, 24), ('extract_u8', a, 3), '!options->lower_extract_byte'), 320 (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'), 321 (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'), 322 (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'), 323 324 # Word extraction 325 (('ushr', a, 16), ('extract_u16', a, 1), '!options->lower_extract_word'), 326 (('iand', 0xffff, a), ('extract_u16', a, 0), '!options->lower_extract_word'), 327 328 # Subtracts 329 (('~fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)), 330 (('isub', a, ('isub', 0, b)), ('iadd', a, b)), 331 (('ussub_4x8', a, 0), a), 332 (('ussub_4x8', a, ~0), 0), 333 (('fsub', a, b), ('fadd', a, ('fneg', b)), 'options->lower_sub'), 334 (('isub', a, b), ('iadd', a, ('ineg', b)), 'options->lower_sub'), 335 (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'), 336 (('ineg', a), ('isub', 0, a), 'options->lower_negate'), 337 (('~fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)), 338 (('iadd', a, ('isub', 0, b)), ('isub', a, b)), 339 (('fabs', ('fsub', 0.0, a)), ('fabs', a)), 340 (('iabs', ('isub', 0, a)), ('iabs', a)), 341 342 # Propagate negation up multiplication chains 343 (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))), 344 (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))), 345 346 # Propagate constants up multiplication chains 347 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fmul', ('fmul', a, c), b)), 348 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('imul', ('imul', a, c), b)), 349 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('fadd', ('fadd', a, c), b)), 350 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', 'b(is_not_const)'), '#c'), ('iadd', ('iadd', a, c), b)), 351 352 # Reassociate constants in add/mul chains so they can be folded together. 353 # For now, we mostly only handle cases where the constants are separated by 354 # a single non-constant. We could do better eventually. 355 (('~fmul', '#a', ('fmul', b, '#c')), ('fmul', ('fmul', a, c), b)), 356 (('imul', '#a', ('imul', b, '#c')), ('imul', ('imul', a, c), b)), 357 (('~fadd', '#a', ('fadd', b, '#c')), ('fadd', ('fadd', a, c), b)), 358 (('iadd', '#a', ('iadd', b, '#c')), ('iadd', ('iadd', a, c), b)), 359 360 # By definition... 361 (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)), 362 (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)), 363 (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)), 364 365 (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)), 366 (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)), 367 (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)), 368 369 (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)), 370 371 # Misc. lowering 372 (('fmod@32', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod32'), 373 (('fmod@64', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod64'), 374 (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod32'), 375 (('uadd_carry@32', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'), 376 (('usub_borrow@32', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'), 377 378 (('bitfield_insert', 'base', 'insert', 'offset', 'bits'), 379 ('bcsel', ('ilt', 31, 'bits'), 'insert', 380 ('bfi', ('bfm', 'bits', 'offset'), 'insert', 'base')), 381 'options->lower_bitfield_insert'), 382 383 (('ibitfield_extract', 'value', 'offset', 'bits'), 384 ('bcsel', ('ilt', 31, 'bits'), 'value', 385 ('ibfe', 'value', 'offset', 'bits')), 386 'options->lower_bitfield_extract'), 387 388 (('ubitfield_extract', 'value', 'offset', 'bits'), 389 ('bcsel', ('ult', 31, 'bits'), 'value', 390 ('ubfe', 'value', 'offset', 'bits')), 391 'options->lower_bitfield_extract'), 392 393 (('extract_i8', a, 'b@32'), 394 ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24), 395 'options->lower_extract_byte'), 396 397 (('extract_u8', a, 'b@32'), 398 ('iand', ('ushr', a, ('imul', b, 8)), 0xff), 399 'options->lower_extract_byte'), 400 401 (('extract_i16', a, 'b@32'), 402 ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16), 403 'options->lower_extract_word'), 404 405 (('extract_u16', a, 'b@32'), 406 ('iand', ('ushr', a, ('imul', b, 16)), 0xffff), 407 'options->lower_extract_word'), 408 409 (('pack_unorm_2x16', 'v'), 410 ('pack_uvec2_to_uint', 411 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 65535.0)))), 412 'options->lower_pack_unorm_2x16'), 413 414 (('pack_unorm_4x8', 'v'), 415 ('pack_uvec4_to_uint', 416 ('f2u32', ('fround_even', ('fmul', ('fsat', 'v'), 255.0)))), 417 'options->lower_pack_unorm_4x8'), 418 419 (('pack_snorm_2x16', 'v'), 420 ('pack_uvec2_to_uint', 421 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 32767.0)))), 422 'options->lower_pack_snorm_2x16'), 423 424 (('pack_snorm_4x8', 'v'), 425 ('pack_uvec4_to_uint', 426 ('f2i32', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))), 427 'options->lower_pack_snorm_4x8'), 428 429 (('unpack_unorm_2x16', 'v'), 430 ('fdiv', ('u2f32', ('vec2', ('extract_u16', 'v', 0), 431 ('extract_u16', 'v', 1))), 432 65535.0), 433 'options->lower_unpack_unorm_2x16'), 434 435 (('unpack_unorm_4x8', 'v'), 436 ('fdiv', ('u2f32', ('vec4', ('extract_u8', 'v', 0), 437 ('extract_u8', 'v', 1), 438 ('extract_u8', 'v', 2), 439 ('extract_u8', 'v', 3))), 440 255.0), 441 'options->lower_unpack_unorm_4x8'), 442 443 (('unpack_snorm_2x16', 'v'), 444 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f32', ('vec2', ('extract_i16', 'v', 0), 445 ('extract_i16', 'v', 1))), 446 32767.0))), 447 'options->lower_unpack_snorm_2x16'), 448 449 (('unpack_snorm_4x8', 'v'), 450 ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f32', ('vec4', ('extract_i8', 'v', 0), 451 ('extract_i8', 'v', 1), 452 ('extract_i8', 'v', 2), 453 ('extract_i8', 'v', 3))), 454 127.0))), 455 'options->lower_unpack_snorm_4x8'), 456 ] 457 458 def fexp2i(exp, bits): 459 # We assume that exp is already in the right range. 460 if bits == 32: 461 return ('ishl', ('iadd', exp, 127), 23) 462 elif bits == 64: 463 return ('pack_64_2x32_split', 0, ('ishl', ('iadd', exp, 1023), 20)) 464 else: 465 assert False 466 467 def ldexp(f, exp, bits): 468 # First, we clamp exp to a reasonable range. The maximum possible range 469 # for a normal exponent is [-126, 127] and, throwing in denormals, you get 470 # a maximum range of [-149, 127]. This means that we can potentially have 471 # a swing of +-276. If you start with FLT_MAX, you actually have to do 472 # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL 473 # spec, on the other hand, only requires that we handle an exponent value 474 # in the range [-126, 128]. This implementation is *mostly* correct; it 475 # handles a range on exp of [-252, 254] which allows you to create any 476 # value (including denorms if the hardware supports it) and to adjust the 477 # exponent of any normal value to anything you want. 478 if bits == 32: 479 exp = ('imin', ('imax', exp, -252), 254) 480 elif bits == 64: 481 exp = ('imin', ('imax', exp, -2044), 2046) 482 else: 483 assert False 484 485 # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2. 486 # (We use ishr which isn't the same for -1, but the -1 case still works 487 # since we use exp-exp/2 as the second exponent.) While the spec 488 # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't 489 # work with denormals and doesn't allow for the full swing in exponents 490 # that you can get with normalized values. Instead, we create two powers 491 # of two and multiply by them each in turn. That way the effective range 492 # of our exponent is doubled. 493 pow2_1 = fexp2i(('ishr', exp, 1), bits) 494 pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1)), bits) 495 return ('fmul', ('fmul', f, pow2_1), pow2_2) 496 497 optimizations += [ 498 (('ldexp@32', 'x', 'exp'), ldexp('x', 'exp', 32)), 499 (('ldexp@64', 'x', 'exp'), ldexp('x', 'exp', 64)), 500 ] 501 502 # Unreal Engine 4 demo applications open-codes bitfieldReverse() 503 def bitfield_reverse(u): 504 step1 = ('ior', ('ishl', u, 16), ('ushr', u, 16)) 505 step2 = ('ior', ('ishl', ('iand', step1, 0x00ff00ff), 8), ('ushr', ('iand', step1, 0xff00ff00), 8)) 506 step3 = ('ior', ('ishl', ('iand', step2, 0x0f0f0f0f), 4), ('ushr', ('iand', step2, 0xf0f0f0f0), 4)) 507 step4 = ('ior', ('ishl', ('iand', step3, 0x33333333), 2), ('ushr', ('iand', step3, 0xcccccccc), 2)) 508 step5 = ('ior', ('ishl', ('iand', step4, 0x55555555), 1), ('ushr', ('iand', step4, 0xaaaaaaaa), 1)) 509 510 return step5 511 512 optimizations += [(bitfield_reverse('x@32'), ('bitfield_reverse', 'x'))] 513 514 # For any float comparison operation, "cmp", if you have "a == a && a cmp b" 515 # then the "a == a" is redundant because it's equivalent to "a is not NaN" 516 # and, if a is a NaN then the second comparison will fail anyway. 517 for op in ['flt', 'fge', 'feq']: 518 optimizations += [ 519 (('iand', ('feq', a, a), (op, a, b)), (op, a, b)), 520 (('iand', ('feq', a, a), (op, b, a)), (op, b, a)), 521 ] 522 523 # Add optimizations to handle the case where the result of a ternary is 524 # compared to a constant. This way we can take things like 525 # 526 # (a ? 0 : 1) > 0 527 # 528 # and turn it into 529 # 530 # a ? (0 > 0) : (1 > 0) 531 # 532 # which constant folding will eat for lunch. The resulting ternary will 533 # further get cleaned up by the boolean reductions above and we will be 534 # left with just the original variable "a". 535 for op in ['flt', 'fge', 'feq', 'fne', 536 'ilt', 'ige', 'ieq', 'ine', 'ult', 'uge']: 537 optimizations += [ 538 ((op, ('bcsel', 'a', '#b', '#c'), '#d'), 539 ('bcsel', 'a', (op, 'b', 'd'), (op, 'c', 'd'))), 540 ((op, '#d', ('bcsel', a, '#b', '#c')), 541 ('bcsel', 'a', (op, 'd', 'b'), (op, 'd', 'c'))), 542 ] 543 544 # This section contains "late" optimizations that should be run before 545 # creating ffmas and calling regular optimizations for the final time. 546 # Optimizations should go here if they help code generation and conflict 547 # with the regular optimizations. 548 before_ffma_optimizations = [ 549 # Propagate constants down multiplication chains 550 (('~fmul(is_used_once)', ('fmul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fmul', ('fmul', a, c), b)), 551 (('imul(is_used_once)', ('imul(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('imul', ('imul', a, c), b)), 552 (('~fadd(is_used_once)', ('fadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('fadd', ('fadd', a, c), b)), 553 (('iadd(is_used_once)', ('iadd(is_used_once)', 'a(is_not_const)', '#b'), 'c(is_not_const)'), ('iadd', ('iadd', a, c), b)), 554 555 (('~fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))), 556 (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))), 557 (('~fadd', ('fneg', a), a), 0.0), 558 (('iadd', ('ineg', a), a), 0), 559 (('iadd', ('ineg', a), ('iadd', a, b)), b), 560 (('iadd', a, ('iadd', ('ineg', a), b)), b), 561 (('~fadd', ('fneg', a), ('fadd', a, b)), b), 562 (('~fadd', a, ('fadd', ('fneg', a), b)), b), 563 ] 564 565 # This section contains "late" optimizations that should be run after the 566 # regular optimizations have finished. Optimizations should go here if 567 # they help code generation but do not necessarily produce code that is 568 # more easily optimizable. 569 late_optimizations = [ 570 # Most of these optimizations aren't quite safe when you get infinity or 571 # Nan involved but the first one should be fine. 572 (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))), 573 (('~fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))), 574 (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))), 575 (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))), 576 577 (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'), 578 (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'), 579 (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'), 580 (('fdph', a, b), ('fdph_replicated', a, b), 'options->fdot_replicates'), 581 582 (('b2f(is_used_more_than_once)', ('inot', a)), ('bcsel', a, 0.0, 1.0)), 583 (('fneg(is_used_more_than_once)', ('b2f', ('inot', a))), ('bcsel', a, -0.0, -1.0)), 584 585 # we do these late so that we don't get in the way of creating ffmas 586 (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))), 587 (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))), 588 ] 589 590 print nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render() 591 print nir_algebraic.AlgebraicPass("nir_opt_algebraic_before_ffma", 592 before_ffma_optimizations).render() 593 print nir_algebraic.AlgebraicPass("nir_opt_algebraic_late", 594 late_optimizations).render() 595
