src/glsl/nir/nir_opcodes.py

   1 #! /usr/bin/env python
   2 #
   3 # Copyright (C) 2014 Connor Abbott
   4 #
   5 # Permission is hereby granted, free of charge, to any person obtaining a
   6 # copy of this software and associated documentation files (the "Software"),
   7 # to deal in the Software without restriction, including without limitation
   8 # the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9 # and/or sell copies of the Software, and to permit persons to whom the
  10 # Software is furnished to do so, subject to the following conditions:
  11 #
  12 # The above copyright notice and this permission notice (including the next
  13 # paragraph) shall be included in all copies or substantial portions of the
  14 # Software.
  15 #
  16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19 # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  22 # IN THE SOFTWARE.
  23 #
  24 # Authors:
  25 #    Connor Abbott (cwabbott0@gmail.com)
  26
  27
  28 # Class that represents all the information we have about the opcode
  29 # NOTE: this must be kept in sync with nir_op_info
  30
  31 class Opcode(object):
  32    """Class that represents all the information we have about the opcode
  33    NOTE: this must be kept in sync with nir_op_info
  34    """
  35    def __init__(self, name, output_size, output_type, input_sizes,
  36                 input_types, algebraic_properties, const_expr):
  37       """Parameters:
  38
  39       - name is the name of the opcode (prepend nir_op_ for the enum name)
  40       - all types are strings that get nir_type_ prepended to them
  41       - input_types is a list of types
  42       - algebraic_properties is a space-seperated string, where nir_op_is_ is
  43         prepended before each entry
  44       - const_expr is an expression or series of statements that computes the
  45         constant value of the opcode given the constant values of its inputs.
  46
  47       Constant expressions are formed from the variables src0, src1, ...,
  48       src(N-1), where N is the number of arguments.  The output of the
  49       expression should be stored in the dst variable.  Per-component input
  50       and output variables will be scalars and non-per-component input and
  51       output variables will be a struct with fields named x, y, z, and w
  52       all of the correct type.  Input and output variables can be assumed
  53       to already be of the correct type and need no conversion.  In
  54       particular, the conversion from the C bool type to/from  NIR_TRUE and
  55       NIR_FALSE happens automatically.
  56
  57       For per-component instructions, the entire expression will be
  58       executed once for each component.  For non-per-component
  59       instructions, the expression is expected to store the correct values
  60       in dst.x, dst.y, etc.  If "dst" does not exist anywhere in the
  61       constant expression, an assignment to dst will happen automatically
  62       and the result will be equivalent to "dst = <expression>" for
  63       per-component instructions and "dst.x = dst.y = ... = <expression>"
  64       for non-per-component instructions.
  65       """
  66       assert isinstance(name, str)
  67       assert isinstance(output_size, int)
  68       assert isinstance(output_type, str)
  69       assert isinstance(input_sizes, list)
  70       assert isinstance(input_sizes[0], int)
  71       assert isinstance(input_types, list)
  72       assert isinstance(input_types[0], str)
  73       assert isinstance(algebraic_properties, str)
  74       assert isinstance(const_expr, str)
  75       assert len(input_sizes) == len(input_types)
  76       assert 0 <= output_size <= 4
  77       for size in input_sizes:
  78          assert 0 <= size <= 4
  79          if output_size != 0:
  80             assert size != 0
  81       self.name = name
  82       self.num_inputs = len(input_sizes)
  83       self.output_size = output_size
  84       self.output_type = output_type
  85       self.input_sizes = input_sizes
  86       self.input_types = input_types
  87       self.algebraic_properties = algebraic_properties
  88       self.const_expr = const_expr
  89
  90 # helper variables for strings
  91 tfloat = "float"
  92 tint = "int"
  93 tbool = "bool"
  94 tunsigned = "unsigned"
  95
  96 commutative = "commutative "
  97 associative = "associative "
  98
  99 # global dictionary of opcodes
 100 opcodes = {}
 101
 102 def opcode(name, output_size, output_type, input_sizes, input_types,
 103            algebraic_properties, const_expr):
 104    assert name not in opcodes
 105    opcodes[name] = Opcode(name, output_size, output_type, input_sizes,
 106                           input_types, algebraic_properties, const_expr)
 107
 108 def unop_convert(name, in_type, out_type, const_expr):
 109    opcode(name, 0, out_type, [0], [in_type], "", const_expr)
 110
 111 def unop(name, ty, const_expr):
 112    opcode(name, 0, ty, [0], [ty], "", const_expr)
 113
 114 def unop_horiz(name, output_size, output_type, input_size, input_type,
 115                const_expr):
 116    opcode(name, output_size, output_type, [input_size], [input_type], "",
 117           const_expr)
 118
 119 def unop_reduce(name, output_size, output_type, input_type, prereduce_expr,
 120                 reduce_expr, final_expr):
 121    def prereduce(src):
 122       return "(" + prereduce_expr.format(src=src) + ")"
 123    def final(src):
 124       return final_expr.format(src="(" + src + ")")
 125    def reduce_(src0, src1):
 126       return reduce_expr.format(src0=src0, src1=src1)
 127    src0 = prereduce("src0.x")
 128    src1 = prereduce("src0.y")
 129    src2 = prereduce("src0.z")
 130    src3 = prereduce("src0.w")
 131    unop_horiz(name + "2", output_size, output_type, 2, input_type,
 132               final(reduce_(src0, src1)))
 133    unop_horiz(name + "3", output_size, output_type, 3, input_type,
 134               final(reduce_(reduce_(src0, src1), src2)))
 135    unop_horiz(name + "4", output_size, output_type, 4, input_type,
 136               final(reduce_(reduce_(src0, src1), reduce_(src2, src3))))
 137
 138
 139 # These two move instructions differ in what modifiers they support and what
 140 # the negate modifier means. Otherwise, they are identical.
 141 unop("fmov", tfloat, "src0")
 142 unop("imov", tint, "src0")
 143
 144 unop("ineg", tint, "-src0")
 145 unop("fneg", tfloat, "-src0")
 146 unop("inot", tint, "~src0") # invert every bit of the integer
 147 unop("fnot", tfloat, "(src0 == 0.0f) ? 1.0f : 0.0f")
 148 unop("fsign", tfloat, "(src0 == 0.0f) ? 0.0f : ((src0 > 0.0f) ? 1.0f : -1.0f)")
 149 unop("isign", tint, "(src0 == 0) ? 0 : ((src0 > 0) ? 1 : -1)")
 150 unop("iabs", tint, "(src0 < 0) ? -src0 : src0")
 151 unop("fabs", tfloat, "fabsf(src0)")
 152 unop("fsat", tfloat, "(src0 > 1.0f) ? 1.0f : ((src0 <= 0.0f) ? 0.0f : src0)")
 153 unop("frcp", tfloat, "1.0f / src0")
 154 unop("frsq", tfloat, "1.0f / sqrtf(src0)")
 155 unop("fsqrt", tfloat, "sqrtf(src0)")
 156 unop("fexp", tfloat, "expf(src0)") # < e^x
 157 unop("flog", tfloat, "logf(src0)") # log base e
 158 unop("fexp2", tfloat, "exp2f(src0)")
 159 unop("flog2", tfloat, "log2f(src0)")
 160 unop_convert("f2i", tfloat, tint, "src0") # Float-to-integer conversion.
 161 unop_convert("f2u", tfloat, tunsigned, "src0") # Float-to-unsigned conversion
 162 unop_convert("i2f", tint, tfloat, "src0") # Integer-to-float conversion.
 163 # Float-to-boolean conversion
 164 unop_convert("f2b", tfloat, tbool, "src0 == 0.0f")
 165 # Boolean-to-float conversion
 166 unop_convert("b2f", tbool, tfloat, "src0 ? 1.0f : 0.0f")
 167 # Int-to-boolean conversion
 168 unop_convert("i2b", tint, tbool, "src0 == 0")
 169 unop_convert("b2i", tbool, tint, "src0 ? 0 : -1") # Boolean-to-int conversion
 170 unop_convert("u2f", tunsigned, tfloat, "src0") #Unsigned-to-float conversion.
 171
 172 unop_reduce("bany", 1, tbool, tbool, "{src}", "{src0} || {src1}", "{src}")
 173 unop_reduce("ball", 1, tbool, tbool, "{src}", "{src0} && {src1}", "{src}")
 174 unop_reduce("fany", 1, tfloat, tfloat, "{src} != 0.0f", "{src0} || {src1}",
 175             "{src} ? 1.0f : 0.0f")
 176 unop_reduce("fall", 1, tfloat, tfloat, "{src} != 0.0f", "{src0} && {src1}",
 177             "{src} ? 1.0f : 0.0f")
 178
 179 # Unary floating-point rounding operations.
 180
 181
 182 unop("ftrunc", tfloat, "truncf(src0)")
 183 unop("fceil", tfloat, "ceilf(src0)")
 184 unop("ffloor", tfloat, "floorf(src0)")
 185 unop("ffract", tfloat, "src0 - floorf(src0)")
 186 unop("fround_even", tfloat, "_mesa_round_to_even(src0)")
 187
 188
 189 # Trigonometric operations.
 190
 191
 192 unop("fsin", tfloat, "sinf(src0)")
 193 unop("fcos", tfloat, "cosf(src0)")
 194 unop("fsin_reduced", tfloat, "sinf(src0)")
 195 unop("fcos_reduced", tfloat, "cosf(src0)")
 196
 197
 198 # Partial derivatives.
 199
 200
 201 unop("fddx", tfloat, "0.0f") # the derivative of a constant is 0.
 202 unop("fddy", tfloat, "0.0f")
 203 unop("fddx_fine", tfloat, "0.0f")
 204 unop("fddy_fine", tfloat, "0.0f")
 205 unop("fddx_coarse", tfloat, "0.0f")
 206 unop("fddy_coarse", tfloat, "0.0f")
 207
 208
 209 # Floating point pack and unpack operations.
 210
 211 def pack_2x16(fmt):
 212    unop_horiz("pack_" + fmt + "_2x16", 1, tunsigned, 2, tfloat, """
 213 dst.x = (uint32_t) pack_fmt_1x16(src0.x);
 214 dst.x |= ((uint32_t) pack_fmt_1x16(src0.y)) << 16;
 215 """.replace("fmt", fmt))
 216
 217 def pack_4x8(fmt):
 218    unop_horiz("pack_" + fmt + "_4x8", 1, tunsigned, 4, tfloat, """
 219 dst.x = (uint32_t) pack_fmt_1x8(src0.x);
 220 dst.x |= ((uint32_t) pack_fmt_1x8(src0.y)) << 8;
 221 dst.x |= ((uint32_t) pack_fmt_1x8(src0.z)) << 16;
 222 dst.x |= ((uint32_t) pack_fmt_1x8(src0.w)) << 24;
 223 """.replace("fmt", fmt))
 224
 225 def unpack_2x16(fmt):
 226    unop_horiz("unpack_" + fmt + "_2x16", 2, tfloat, 1, tunsigned, """
 227 dst.x = unpack_fmt_1x16((uint16_t)(src0.x & 0xffff));
 228 dst.y = unpack_fmt_1x16((uint16_t)(src0.x << 16));
 229 """.replace("fmt", fmt))
 230
 231 def unpack_4x8(fmt):
 232    unop_horiz("unpack_" + fmt + "_4x8", 4, tfloat, 1, tunsigned, """
 233 dst.x = unpack_fmt_1x8((uint8_t)(src0.x & 0xff));
 234 dst.y = unpack_fmt_1x8((uint8_t)((src0.x >> 8) & 0xff));
 235 dst.z = unpack_fmt_1x8((uint8_t)((src0.x >> 16) & 0xff));
 236 dst.w = unpack_fmt_1x8((uint8_t)(src0.x >> 24));
 237 """.replace("fmt", fmt))
 238
 239
 240 pack_2x16("snorm")
 241 pack_4x8("snorm")
 242 pack_2x16("unorm")
 243 pack_4x8("unorm")
 244 pack_2x16("half")
 245 unpack_2x16("snorm")
 246 unpack_4x8("snorm")
 247 unpack_2x16("unorm")
 248 unpack_4x8("unorm")
 249 unpack_2x16("half")
 250
 251
 252 # Lowered floating point unpacking operations.
 253
 254
 255 unop_horiz("unpack_half_2x16_split_x", 1, tfloat, 1, tunsigned,
 256            "unpack_half_1x16((uint16_t)(src0.x & 0xffff))")
 257 unop_horiz("unpack_half_2x16_split_y", 1, tfloat, 1, tunsigned,
 258            "unpack_half_1x16((uint16_t)(src0.x >> 16))")
 259
 260
 261 # Bit operations, part of ARB_gpu_shader5.
 262
 263
 264 unop("bitfield_reverse", tunsigned, """
 265 /* we're not winning any awards for speed here, but that's ok */
 266 dst = 0;
 267 for (unsigned bit = 0; bit < 32; bit++)
 268    dst |= ((src0 >> bit) & 1) << (31 - bit);
 269 """)
 270 unop("bit_count", tunsigned, """
 271 dst = 0;
 272 for (unsigned bit = 0; bit < 32; bit++) {
 273    if ((src0 >> bit) & 1)
 274       dst++;
 275 }
 276 """)
 277
 278 unop_convert("ufind_msb", tunsigned, tint, """
 279 dst = -1;
 280 for (int bit = 31; bit > 0; bit--) {
 281    if ((src0 >> bit) & 1) {
 282       dst = bit;
 283       break;
 284    }
 285 }
 286 """)
 287
 288 unop("ifind_msb", tint, """
 289 dst = -1;
 290 for (int bit = 31; bit >= 0; bit--) {
 291    /* If src0 < 0, we're looking for the first 0 bit.
 292     * if src0 >= 0, we're looking for the first 1 bit.
 293     */
 294    if ((((src0 >> bit) & 1) && (src0 >= 0)) ||
 295       (!((src0 >> bit) & 1) && (src0 < 0))) {
 296       dst = bit;
 297       break;
 298    }
 299 }
 300 """)
 301
 302 unop("find_lsb", tint, """
 303 dst = -1;
 304 for (unsigned bit = 0; bit < 32; bit++) {
 305    if ((src0 >> bit) & 1) {
 306       dst = bit;
 307       break;
 308    }
 309 }
 310 """)
 311
 312
 313 for i in xrange(1, 5):
 314    for j in xrange(1, 5):
 315       unop_horiz("fnoise{0}_{1}".format(i, j), i, tfloat, j, tfloat, "0.0f")
 316
 317 def binop_convert(name, out_type, in_type, alg_props, const_expr):
 318    opcode(name, 0, out_type, [0, 0], [in_type, in_type], alg_props, const_expr)
 319
 320 def binop(name, ty, alg_props, const_expr):
 321    binop_convert(name, ty, ty, alg_props, const_expr)
 322
 323 def binop_compare(name, ty, alg_props, const_expr):
 324    binop_convert(name, tbool, ty, alg_props, const_expr)
 325
 326 def binop_horiz(name, out_size, out_type, src1_size, src1_type, src2_size,
 327                 src2_type, const_expr):
 328    opcode(name, out_size, out_type, [src1_size, src2_size], [src1_type, src2_type],
 329           "", const_expr)
 330
 331 def binop_reduce(name, output_size, output_type, src_type, prereduce_expr,
 332                  reduce_expr, final_expr):
 333    def final(src):
 334       return final_expr.format(src= "(" + src + ")")
 335    def reduce_(src0, src1):
 336       return reduce_expr.format(src0=src0, src1=src1)
 337    def prereduce(src0, src1):
 338       return "(" + prereduce_expr.format(src0=src0, src1=src1) + ")"
 339    src0 = prereduce("src0.x", "src1.x")
 340    src1 = prereduce("src0.y", "src1.y")
 341    src2 = prereduce("src0.z", "src1.z")
 342    src3 = prereduce("src0.w", "src1.w")
 343    opcode(name + "2", output_size, output_type,
 344           [2, 2], [src_type, src_type], commutative,
 345           final(reduce_(src0, src1)))
 346    opcode(name + "3", output_size, output_type,
 347           [3, 3], [src_type, src_type], commutative,
 348           final(reduce_(reduce_(src0, src1), src2)))
 349    opcode(name + "4", output_size, output_type,
 350           [4, 4], [src_type, src_type], commutative,
 351           final(reduce_(reduce_(src0, src1), reduce_(src2, src3))))
 352
 353 binop("fadd", tfloat, commutative + associative, "src0 + src1")
 354 binop("iadd", tint, commutative + associative, "src0 + src1")
 355 binop("fsub", tfloat, "", "src0 - src1")
 356 binop("isub", tint, "", "src0 - src1")
 357
 358 binop("fmul", tfloat, commutative + associative, "src0 * src1")
 359 # low 32-bits of signed/unsigned integer multiply
 360 binop("imul", tint, commutative + associative, "src0 * src1")
 361 # high 32-bits of signed integer multiply
 362 binop("imul_high", tint, commutative,
 363       "(int32_t)(((int64_t) src0 * (int64_t) src1) >> 32)")
 364 # high 32-bits of unsigned integer multiply
 365 binop("umul_high", tunsigned, commutative,
 366       "(uint32_t)(((uint64_t) src0 * (uint64_t) src1) >> 32)")
 367
 368 binop("fdiv", tfloat, "", "src0 / src1")
 369 binop("idiv", tint, "", "src0 / src1")
 370 binop("udiv", tunsigned, "", "src0 / src1")
 371
 372 # returns a boolean representing the carry resulting from the addition of
 373 # the two unsigned arguments.
 374
 375 binop_convert("uadd_carry", tbool, tunsigned, commutative, "src0 + src1 < src0")
 376
 377 # returns a boolean representing the borrow resulting from the subtraction
 378 # of the two unsigned arguments.
 379
 380 binop_convert("usub_borrow", tbool, tunsigned, "", "src1 < src0")
 381
 382 binop("fmod", tfloat, "", "src0 - src1 * floorf(src0 / src1)")
 383 binop("umod", tunsigned, "", "src1 == 0 ? 0 : src0 % src1")
 384
 385 #
 386 # Comparisons
 387 #
 388
 389
 390 # these integer-aware comparisons return a boolean (0 or ~0)
 391
 392 binop_compare("flt", tfloat, "", "src0 < src1")
 393 binop_compare("fge", tfloat, "", "src0 >= src1")
 394 binop_compare("feq", tfloat, commutative, "src0 == src1")
 395 binop_compare("fne", tfloat, commutative, "src0 != src1")
 396 binop_compare("ilt", tint, "", "src0 < src1")
 397 binop_compare("ige", tint, "", "src0 >= src1")
 398 binop_compare("ieq", tint, commutative, "src0 == src1")
 399 binop_compare("ine", tint, commutative, "src0 != src1")
 400 binop_compare("ult", tunsigned, "", "src0 < src1")
 401 binop_compare("uge", tunsigned, "", "src0 >= src1")
 402
 403 # integer-aware GLSL-style comparisons that compare floats and ints
 404
 405 binop_reduce("ball_fequal",  1, tbool, tfloat, "{src0} == {src1}",
 406              "{src0} && {src1}", "{src}")
 407 binop_reduce("bany_fnequal", 1, tbool, tfloat, "{src0} != {src1}",
 408              "{src0} || {src1}", "{src}")
 409 binop_reduce("ball_iequal",  1, tbool, tint, "{src0} == {src1}",
 410              "{src0} && {src1}", "{src}")
 411 binop_reduce("bany_inequal", 1, tbool, tint, "{src0} != {src1}",
 412              "{src0} || {src1}", "{src}")
 413
 414 # non-integer-aware GLSL-style comparisons that return 0.0 or 1.0
 415
 416 binop_reduce("fall_equal",  1, tfloat, tfloat, "{src0} == {src1}",
 417              "{src0} && {src1}", "{src} ? 1.0f : 0.0f")
 418 binop_reduce("fany_nequal", 1, tfloat, tfloat, "{src0} != {src1}",
 419              "{src0} || {src1}", "{src} ? 1.0f : 0.0f")
 420
 421 # These comparisons for integer-less hardware return 1.0 and 0.0 for true
 422 # and false respectively
 423
 424 binop("slt", tfloat, "", "(src0 < src1) ? 1.0f : 0.0f") # Set on Less Than
 425 binop("sge", tfloat, "", "(src0 >= src1) ? 1.0f : 0.0f") # Set on Greater or Equal
 426 binop("seq", tfloat, commutative, "(src0 == src1) ? 1.0f : 0.0f") # Set on Equal
 427 binop("sne", tfloat, commutative, "(src0 != src1) ? 1.0f : 0.0f") # Set on Not Equal
 428
 429
 430 binop("ishl", tint, "", "src0 << src1")
 431 binop("ishr", tint, "", "src0 >> src1")
 432 binop("ushr", tunsigned, "", "src0 >> src1")
 433
 434 # bitwise logic operators
 435 #
 436 # These are also used as boolean and, or, xor for hardware supporting
 437 # integers.
 438
 439
 440 binop("iand", tunsigned, commutative + associative, "src0 & src1")
 441 binop("ior", tunsigned, commutative + associative, "src0 | src1")
 442 binop("ixor", tunsigned, commutative + associative, "src0 ^ src1")
 443
 444
 445 # floating point logic operators
 446 #
 447 # These use (src != 0.0) for testing the truth of the input, and output 1.0
 448 # for true and 0.0 for false
 449
 450 binop("fand", tfloat, commutative,
 451       "((src0 != 0.0f) && (src1 != 0.0f)) ? 1.0f : 0.0f")
 452 binop("for", tfloat, commutative,
 453       "((src0 != 0.0f) || (src1 != 0.0f)) ? 1.0f : 0.0f")
 454 binop("fxor", tfloat, commutative,
 455       "(src0 != 0.0f && src1 == 0.0f) || (src0 == 0.0f && src1 != 0.0f) ? 1.0f : 0.0f")
 456
 457 binop_reduce("fdot", 1, tfloat, tfloat, "{src0} * {src1}", "{src0} + {src1}",
 458              "{src}")
 459
 460 binop("fmin", tfloat, "", "fminf(src0, src1)")
 461 binop("imin", tint, commutative + associative, "src1 > src0 ? src0 : src1")
 462 binop("umin", tunsigned, commutative + associative, "src1 > src0 ? src0 : src1")
 463 binop("fmax", tfloat, "", "fmaxf(src0, src1)")
 464 binop("imax", tint, commutative + associative, "src1 > src0 ? src1 : src0")
 465 binop("umax", tunsigned, commutative + associative, "src1 > src0 ? src1 : src0")
 466
 467 binop("fpow", tfloat, "", "powf(src0, src1)")
 468
 469 binop_horiz("pack_half_2x16_split", 1, tunsigned, 1, tfloat, 1, tfloat,
 470             "pack_half_1x16(src0.x) | (pack_half_1x16(src1.x) << 16)")
 471
 472 binop_convert("bfm", tunsigned, tint, "", """
 473 int offset = src0, bits = src1;
 474 if (offset < 0 || bits < 0 || offset + bits > 32)
 475    dst = 0; /* undefined per the spec */
 476 else
 477    dst = ((1 << bits)- 1) << offset;
 478 """)
 479
 480 opcode("ldexp", 0, tunsigned, [0, 0], [tfloat, tint], "", """
 481 dst = ldexp(src0, src1);
 482 /* flush denormals to zero. */
 483 if (!isnormal(dst))
 484    dst = copysign(0.0f, src0);
 485 """)
 486
 487 # Combines the first component of each input to make a 2-component vector.
 488
 489 binop_horiz("vec2", 2, tunsigned, 1, tunsigned, 1, tunsigned, """
 490 dst.x = src0.x;
 491 dst.y = src1.x;
 492 """)
 493
 494 def triop(name, ty, const_expr):
 495    opcode(name, 0, ty, [0, 0, 0], [ty, ty, ty], "", const_expr)
 496 def triop_horiz(name, output_size, src1_size, src2_size, src3_size, const_expr):
 497    opcode(name, output_size, tunsigned,
 498    [src1_size, src2_size, src3_size],
 499    [tunsigned, tunsigned, tunsigned], "", const_expr)
 500
 501 triop("ffma", tfloat, "src0 * src1 + src2")
 502
 503 triop("flrp", tfloat, "src0 * (1 - src2) + src1 * src2")
 504
 505 # Conditional Select
 506 #
 507 # A vector conditional select instruction (like ?:, but operating per-
 508 # component on vectors). There are two versions, one for floating point
 509 # bools (0.0 vs 1.0) and one for integer bools (0 vs ~0).
 510
 511
 512 triop("fcsel", tfloat, "(src0 != 0.0f) ? src1 : src2")
 513 opcode("bcsel", 0, tunsigned, [0, 0, 0],
 514       [tbool, tunsigned, tunsigned], "", "src0 ? src1 : src2")
 515
 516 triop("bfi", tunsigned, """
 517 unsigned mask = src0, insert = src1 & mask, base = src2;
 518 if (mask == 0) {
 519    dst = base;
 520 } else {
 521    unsigned tmp = mask;
 522    while (!(tmp & 1)) {
 523       tmp >>= 1;
 524       insert <<= 1;
 525    }
 526    dst = (base & ~mask) | insert;
 527 }
 528 """)
 529
 530 opcode("ubitfield_extract", 0, tunsigned,
 531        [0, 1, 1], [tunsigned, tint, tint], "", """
 532 unsigned base = src0;
 533 int offset = src1.x, bits = src2.x;
 534 if (bits == 0) {
 535    dst = 0;
 536 } else if (bits < 0 || offset < 0 || offset + bits > 32) {
 537    dst = 0; /* undefined per the spec */
 538 } else {
 539    dst = (base >> offset) & ((1 << bits) - 1);
 540 }
 541 """)
 542 opcode("ibitfield_extract", 0, tint,
 543        [0, 1, 1], [tint, tint, tint], "", """
 544 int base = src0;
 545 int offset = src1.x, bits = src2.x;
 546 if (bits == 0) {
 547    dst = 0;
 548 } else if (offset < 0 || bits < 0 || offset + bits > 32) {
 549    dst = 0;
 550 } else {
 551    dst = (base << (32 - offset - bits)) >> offset; /* use sign-extending shift */
 552 }
 553 """)
 554
 555 # Combines the first component of each input to make a 3-component vector.
 556
 557 triop_horiz("vec3", 3, 1, 1, 1, """
 558 dst.x = src0.x;
 559 dst.y = src1.x;
 560 dst.z = src2.x;
 561 """)
 562
 563 def quadop_horiz(name, output_size, src1_size, src2_size, src3_size,
 564                  src4_size, const_expr):
 565    opcode(name, output_size, tunsigned,
 566           [src1_size, src2_size, src3_size, src4_size],
 567           [tunsigned, tunsigned, tunsigned, tunsigned],
 568           "", const_expr)
 569
 570 opcode("bitfield_insert", 0, tunsigned, [0, 0, 1, 1],
 571        [tunsigned, tunsigned, tint, tint], "", """
 572 unsigned base = src0, insert = src1;
 573 int offset = src2.x, bits = src3.x;
 574 if (bits == 0) {
 575    dst = 0;
 576 } else if (offset < 0 || bits < 0 || bits + offset > 32) {
 577    dst = 0;
 578 } else {
 579    unsigned mask = ((1 << bits) - 1) << offset;
 580    dst = (base & ~mask) | ((insert << bits) & mask);
 581 }
 582 """)
 583
 584 quadop_horiz("vec4", 4, 1, 1, 1, 1, """
 585 dst.x = src0.x;
 586 dst.y = src1.x;
 587 dst.z = src2.x;
 588 dst.w = src3.x;
 589 """)
 590
 591