src/compiler/nir/nir_range_analysis.c

   1 /*
   2  * Copyright © 2018 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 #include <math.h>
  24 #include <float.h>
  25 #include "nir.h"
  26 #include "nir_range_analysis.h"
  27 #include "util/hash_table.h"
  28
  29 /**
  30  * Analyzes a sequence of operations to determine some aspects of the range of
  31  * the result.
  32  */
  33
  34 static bool
  35 is_not_zero(enum ssa_ranges r)
  36 {
  37    return r == gt_zero || r == lt_zero || r == ne_zero;
  38 }
  39
  40 static void *
  41 pack_data(const struct ssa_result_range r)
  42 {
  43    return (void *)(uintptr_t)(r.range | r.is_integral << 8);
  44 }
  45
  46 static struct ssa_result_range
  47 unpack_data(const void *p)
  48 {
  49    const uintptr_t v = (uintptr_t) p;
  50
  51    return (struct ssa_result_range){v & 0xff, (v & 0x0ff00) != 0};
  52 }
  53
  54 static struct ssa_result_range
  55 analyze_constant(const struct nir_alu_instr *instr, unsigned src)
  56 {
  57    uint8_t swizzle[4] = { 0, 1, 2, 3 };
  58
  59    /* If the source is an explicitly sized source, then we need to reset
  60     * both the number of components and the swizzle.
  61     */
  62    const unsigned num_components = nir_ssa_alu_instr_src_components(instr, src);
  63
  64    for (unsigned i = 0; i < num_components; ++i)
  65       swizzle[i] = instr->src[src].swizzle[i];
  66
  67    const nir_load_const_instr *const load =
  68       nir_instr_as_load_const(instr->src[src].src.ssa->parent_instr);
  69
  70    struct ssa_result_range r = { unknown, false };
  71
  72    switch (nir_op_infos[instr->op].input_types[src]) {
  73    case nir_type_float: {
  74       double min_value = DBL_MAX;
  75       double max_value = -DBL_MAX;
  76       bool any_zero = false;
  77       bool all_zero = true;
  78
  79       r.is_integral = true;
  80
  81       for (unsigned i = 0; i < num_components; ++i) {
  82          const double v = nir_const_value_as_float(load->value[swizzle[i]],
  83                                                    load->def.bit_size);
  84
  85          if (floor(v) != v)
  86             r.is_integral = false;
  87
  88          any_zero = any_zero || (v == 0.0);
  89          all_zero = all_zero && (v == 0.0);
  90          min_value = MIN2(min_value, v);
  91          max_value = MAX2(max_value, v);
  92       }
  93
  94       assert(any_zero >= all_zero);
  95       assert(isnan(max_value) || max_value >= min_value);
  96
  97       if (all_zero)
  98          r.range = eq_zero;
  99       else if (min_value > 0.0)
 100          r.range = gt_zero;
 101       else if (min_value == 0.0)
 102          r.range = ge_zero;
 103       else if (max_value < 0.0)
 104          r.range = lt_zero;
 105       else if (max_value == 0.0)
 106          r.range = le_zero;
 107       else if (!any_zero)
 108          r.range = ne_zero;
 109       else
 110          r.range = unknown;
 111
 112       return r;
 113    }
 114
 115    case nir_type_int:
 116    case nir_type_bool: {
 117       int64_t min_value = INT_MAX;
 118       int64_t max_value = INT_MIN;
 119       bool any_zero = false;
 120       bool all_zero = true;
 121
 122       for (unsigned i = 0; i < num_components; ++i) {
 123          const int64_t v = nir_const_value_as_int(load->value[swizzle[i]],
 124                                                   load->def.bit_size);
 125
 126          any_zero = any_zero || (v == 0);
 127          all_zero = all_zero && (v == 0);
 128          min_value = MIN2(min_value, v);
 129          max_value = MAX2(max_value, v);
 130       }
 131
 132       assert(any_zero >= all_zero);
 133       assert(max_value >= min_value);
 134
 135       if (all_zero)
 136          r.range = eq_zero;
 137       else if (min_value > 0)
 138          r.range = gt_zero;
 139       else if (min_value == 0)
 140          r.range = ge_zero;
 141       else if (max_value < 0)
 142          r.range = lt_zero;
 143       else if (max_value == 0)
 144          r.range = le_zero;
 145       else if (!any_zero)
 146          r.range = ne_zero;
 147       else
 148          r.range = unknown;
 149
 150       return r;
 151    }
 152
 153    case nir_type_uint: {
 154       bool any_zero = false;
 155       bool all_zero = true;
 156
 157       for (unsigned i = 0; i < num_components; ++i) {
 158          const uint64_t v = nir_const_value_as_uint(load->value[swizzle[i]],
 159                                                     load->def.bit_size);
 160
 161          any_zero = any_zero || (v == 0);
 162          all_zero = all_zero && (v == 0);
 163       }
 164
 165       assert(any_zero >= all_zero);
 166
 167       if (all_zero)
 168          r.range = eq_zero;
 169       else if (any_zero)
 170          r.range = ge_zero;
 171       else
 172          r.range = gt_zero;
 173
 174       return r;
 175    }
 176
 177    default:
 178       unreachable("Invalid alu source type");
 179    }
 180 }
 181
 182 #ifndef NDEBUG
 183 #define ASSERT_TABLE_IS_COMMUTATIVE(t)                        \
 184    do {                                                       \
 185       for (unsigned r = 0; r < ARRAY_SIZE(t); r++) {          \
 186          for (unsigned c = 0; c < ARRAY_SIZE(t[0]); c++)      \
 187             assert(t[r][c] == t[c][r]);                       \
 188       }                                                       \
 189    } while (false)
 190
 191 #define ASSERT_TABLE_IS_DIAGONAL(t)                           \
 192    do {                                                       \
 193       for (unsigned r = 0; r < ARRAY_SIZE(t); r++)            \
 194          assert(t[r][r] == r);                                \
 195    } while (false)
 196 #else
 197 #define ASSERT_TABLE_IS_COMMUTATIVE(t)
 198 #define ASSERT_TABLE_IS_DIAGONAL(t)
 199 #endif
 200
 201 /**
 202  * Short-hand name for use in the tables in analyze_expression.  If this name
 203  * becomes a problem on some compiler, we can change it to _.
 204  */
 205 #define _______ unknown
 206
 207 /**
 208  * Analyze an expression to determine the range of its result
 209  *
 210  * The end result of this analysis is a token that communicates something
 211  * about the range of values.  There's an implicit grammar that produces
 212  * tokens from sequences of literal values, other tokens, and operations.
 213  * This function implements this grammar as a recursive-descent parser.  Some
 214  * (but not all) of the grammar is listed in-line in the function.
 215  */
 216 static struct ssa_result_range
 217 analyze_expression(const nir_alu_instr *instr, unsigned src,
 218                    struct hash_table *ht)
 219 {
 220    if (nir_src_is_const(instr->src[src].src))
 221       return analyze_constant(instr, src);
 222
 223    if (instr->src[src].src.ssa->parent_instr->type != nir_instr_type_alu)
 224       return (struct ssa_result_range){unknown, false};
 225
 226    const struct nir_alu_instr *const alu =
 227        nir_instr_as_alu(instr->src[src].src.ssa->parent_instr);
 228
 229    struct hash_entry *he = _mesa_hash_table_search(ht, alu);
 230    if (he != NULL)
 231       return unpack_data(he->data);
 232
 233    struct ssa_result_range r = {unknown, false};
 234
 235    switch (alu->op) {
 236    case nir_op_b2f32:
 237    case nir_op_b2i32:
 238       r = (struct ssa_result_range){ge_zero, alu->op == nir_op_b2f32};
 239       break;
 240
 241    case nir_op_i2f32:
 242    case nir_op_u2f32:
 243       r = analyze_expression(alu, 0, ht);
 244
 245       r.is_integral = true;
 246
 247       if (r.range == unknown && alu->op == nir_op_u2f32)
 248          r.range = ge_zero;
 249
 250       break;
 251
 252    case nir_op_fabs:
 253       r = analyze_expression(alu, 0, ht);
 254
 255       switch (r.range) {
 256       case unknown:
 257       case le_zero:
 258       case ge_zero:
 259          r.range = ge_zero;
 260          break;
 261
 262       case lt_zero:
 263       case gt_zero:
 264       case ne_zero:
 265          r.range = gt_zero;
 266          break;
 267
 268       case eq_zero:
 269          break;
 270       }
 271
 272       break;
 273
 274    case nir_op_fadd: {
 275       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 276       const struct ssa_result_range right = analyze_expression(alu, 1, ht);
 277
 278       r.is_integral = left.is_integral && right.is_integral;
 279
 280       /* ge_zero: ge_zero + ge_zero
 281        *
 282        * gt_zero: gt_zero + eq_zero
 283        *        | gt_zero + ge_zero
 284        *        | eq_zero + gt_zero   # Addition is commutative
 285        *        | ge_zero + gt_zero   # Addition is commutative
 286        *        | gt_zero + gt_zero
 287        *        ;
 288        *
 289        * le_zero: le_zero + le_zero
 290        *
 291        * lt_zero: lt_zero + eq_zero
 292        *        | lt_zero + le_zero
 293        *        | eq_zero + lt_zero   # Addition is commutative
 294        *        | le_zero + lt_zero   # Addition is commutative
 295        *        | lt_zero + lt_zero
 296        *        ;
 297        *
 298        * eq_zero: eq_zero + eq_zero
 299        *
 300        * All other cases are 'unknown'.
 301        */
 302       static const enum ssa_ranges table[last_range + 1][last_range + 1] = {
 303          /* left\right   unknown  lt_zero  le_zero  gt_zero  ge_zero  ne_zero  eq_zero */
 304          /* unknown */ { _______, _______, _______, _______, _______, _______, _______ },
 305          /* lt_zero */ { _______, lt_zero, lt_zero, _______, _______, _______, lt_zero },
 306          /* le_zero */ { _______, lt_zero, le_zero, _______, _______, _______, le_zero },
 307          /* gt_zero */ { _______, _______, _______, gt_zero, gt_zero, _______, gt_zero },
 308          /* ge_zero */ { _______, _______, _______, gt_zero, ge_zero, _______, ge_zero },
 309          /* ne_zero */ { _______, _______, _______, _______, _______, ne_zero, ne_zero },
 310          /* eq_zero */ { _______, lt_zero, le_zero, gt_zero, ge_zero, ne_zero, eq_zero },
 311       };
 312
 313       ASSERT_TABLE_IS_COMMUTATIVE(table);
 314       ASSERT_TABLE_IS_DIAGONAL(table);
 315
 316       r.range = table[left.range][right.range];
 317       break;
 318    }
 319
 320    case nir_op_fexp2:
 321       r = (struct ssa_result_range){gt_zero, analyze_expression(alu, 0, ht).is_integral};
 322       break;
 323
 324    case nir_op_fmax: {
 325       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 326       const struct ssa_result_range right = analyze_expression(alu, 1, ht);
 327
 328       r.is_integral = left.is_integral && right.is_integral;
 329
 330       /* gt_zero: fmax(gt_zero, *)
 331        *        | fmax(*, gt_zero)        # Treat fmax as commutative
 332        *        ;
 333        *
 334        * ge_zero: fmax(ge_zero, ne_zero)
 335        *        | fmax(ge_zero, lt_zero)
 336        *        | fmax(ge_zero, le_zero)
 337        *        | fmax(ge_zero, eq_zero)
 338        *        | fmax(ne_zero, ge_zero)  # Treat fmax as commutative
 339        *        | fmax(lt_zero, ge_zero)  # Treat fmax as commutative
 340        *        | fmax(le_zero, ge_zero)  # Treat fmax as commutative
 341        *        | fmax(eq_zero, ge_zero)  # Treat fmax as commutative
 342        *        | fmax(ge_zero, ge_zero)
 343        *        ;
 344        *
 345        * le_zero: fmax(le_zero, lt_zero)
 346        *        | fmax(lt_zero, le_zero)  # Treat fmax as commutative
 347        *        | fmax(le_zero, le_zero)
 348        *        ;
 349        *
 350        * lt_zero: fmax(lt_zero, lt_zero)
 351        *        ;
 352        *
 353        * ne_zero: fmax(ne_zero, lt_zero)
 354        *        | fmax(lt_zero, ne_zero)  # Treat fmax as commutative
 355        *        | fmax(ne_zero, ne_zero)
 356        *        ;
 357        *
 358        * eq_zero: fmax(eq_zero, le_zero)
 359        *        | fmax(eq_zero, lt_zero)
 360        *        | fmax(le_zero, eq_zero)  # Treat fmax as commutative
 361        *        | fmax(lt_zero, eq_zero)  # Treat fmax as commutative
 362        *        | fmax(eq_zero, eq_zero)
 363        *        ;
 364        *
 365        * All other cases are 'unknown'.
 366        */
 367       static const enum ssa_ranges table[last_range + 1][last_range + 1] = {
 368          /* left\right   unknown  lt_zero  le_zero  gt_zero  ge_zero  ne_zero  eq_zero */
 369          /* unknown */ { _______, _______, _______, gt_zero, ge_zero, _______, _______ },
 370          /* lt_zero */ { _______, lt_zero, le_zero, gt_zero, ge_zero, ne_zero, eq_zero },
 371          /* le_zero */ { _______, le_zero, le_zero, gt_zero, ge_zero, _______, eq_zero },
 372          /* gt_zero */ { gt_zero, gt_zero, gt_zero, gt_zero, gt_zero, gt_zero, gt_zero },
 373          /* ge_zero */ { ge_zero, ge_zero, ge_zero, gt_zero, ge_zero, ge_zero, ge_zero },
 374          /* ne_zero */ { _______, ne_zero, _______, gt_zero, ge_zero, ne_zero, _______ },
 375          /* eq_zero */ { _______, eq_zero, eq_zero, gt_zero, ge_zero, _______, eq_zero }
 376       };
 377
 378       /* Treat fmax as commutative. */
 379       ASSERT_TABLE_IS_COMMUTATIVE(table);
 380       ASSERT_TABLE_IS_DIAGONAL(table);
 381
 382       r.range = table[left.range][right.range];
 383       break;
 384    }
 385
 386    case nir_op_fmin: {
 387       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 388       const struct ssa_result_range right = analyze_expression(alu, 1, ht);
 389
 390       r.is_integral = left.is_integral && right.is_integral;
 391
 392       /* lt_zero: fmin(lt_zero, *)
 393        *        | fmin(*, lt_zero)        # Treat fmin as commutative
 394        *        ;
 395        *
 396        * le_zero: fmin(le_zero, ne_zero)
 397        *        | fmin(le_zero, gt_zero)
 398        *        | fmin(le_zero, ge_zero)
 399        *        | fmin(le_zero, eq_zero)
 400        *        | fmin(ne_zero, le_zero)  # Treat fmin as commutative
 401        *        | fmin(gt_zero, le_zero)  # Treat fmin as commutative
 402        *        | fmin(ge_zero, le_zero)  # Treat fmin as commutative
 403        *        | fmin(eq_zero, le_zero)  # Treat fmin as commutative
 404        *        | fmin(le_zero, le_zero)
 405        *        ;
 406        *
 407        * ge_zero: fmin(ge_zero, gt_zero)
 408        *        | fmin(gt_zero, ge_zero)  # Treat fmin as commutative
 409        *        | fmin(ge_zero, ge_zero)
 410        *        ;
 411        *
 412        * gt_zero: fmin(gt_zero, gt_zero)
 413        *        ;
 414        *
 415        * ne_zero: fmin(ne_zero, gt_zero)
 416        *        | fmin(gt_zero, ne_zero)  # Treat fmin as commutative
 417        *        | fmin(ne_zero, ne_zero)
 418        *        ;
 419        *
 420        * eq_zero: fmin(eq_zero, ge_zero)
 421        *        | fmin(eq_zero, gt_zero)
 422        *        | fmin(ge_zero, eq_zero)  # Treat fmin as commutative
 423        *        | fmin(gt_zero, eq_zero)  # Treat fmin as commutative
 424        *        | fmin(eq_zero, eq_zero)
 425        *        ;
 426        *
 427        * All other cases are 'unknown'.
 428        */
 429       static const enum ssa_ranges table[last_range + 1][last_range + 1] = {
 430          /* left\right   unknown  lt_zero  le_zero  gt_zero  ge_zero  ne_zero  eq_zero */
 431          /* unknown */ { _______, lt_zero, le_zero, _______, _______, _______, _______ },
 432          /* lt_zero */ { lt_zero, lt_zero, lt_zero, lt_zero, lt_zero, lt_zero, lt_zero },
 433          /* le_zero */ { le_zero, lt_zero, le_zero, le_zero, le_zero, le_zero, le_zero },
 434          /* gt_zero */ { _______, lt_zero, le_zero, gt_zero, ge_zero, ne_zero, eq_zero },
 435          /* ge_zero */ { _______, lt_zero, le_zero, ge_zero, ge_zero, _______, eq_zero },
 436          /* ne_zero */ { _______, lt_zero, le_zero, ne_zero, _______, ne_zero, _______ },
 437          /* eq_zero */ { _______, lt_zero, le_zero, eq_zero, eq_zero, _______, eq_zero }
 438       };
 439
 440       /* Treat fmin as commutative. */
 441       ASSERT_TABLE_IS_COMMUTATIVE(table);
 442       ASSERT_TABLE_IS_DIAGONAL(table);
 443
 444       r.range = table[left.range][right.range];
 445       break;
 446    }
 447
 448    case nir_op_fmul: {
 449       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 450       const struct ssa_result_range right = analyze_expression(alu, 1, ht);
 451
 452       r.is_integral = left.is_integral && right.is_integral;
 453
 454       /* ge_zero: ge_zero * ge_zero
 455        *        | ge_zero * gt_zero
 456        *        | ge_zero * eq_zero
 457        *        | le_zero * lt_zero
 458        *        | lt_zero * le_zero  # Multiplication is commutative
 459        *        | le_zero * le_zero
 460        *        | gt_zero * ge_zero  # Multiplication is commutative
 461        *        | eq_zero * ge_zero  # Multiplication is commutative
 462        *        | a * a              # Left source == right source
 463        *        ;
 464        *
 465        * gt_zero: gt_zero * gt_zero
 466        *        | lt_zero * lt_zero
 467        *        ;
 468        *
 469        * le_zero: ge_zero * le_zero
 470        *        | ge_zero * lt_zero
 471        *        | lt_zero * ge_zero  # Multiplication is commutative
 472        *        | le_zero * ge_zero  # Multiplication is commutative
 473        *        | le_zero * gt_zero
 474        *        ;
 475        *
 476        * lt_zero: lt_zero * gt_zero
 477        *        | gt_zero * lt_zero  # Multiplication is commutative
 478        *        ;
 479        *
 480        * ne_zero: ne_zero * gt_zero
 481        *        | ne_zero * lt_zero
 482        *        | gt_zero * ne_zero  # Multiplication is commutative
 483        *        | lt_zero * ne_zero  # Multiplication is commutative
 484        *        | ne_zero * ne_zero
 485        *        ;
 486        *
 487        * eq_zero: eq_zero * <any>
 488        *          <any> * eq_zero    # Multiplication is commutative
 489        *
 490        * All other cases are 'unknown'.
 491        */
 492       static const enum ssa_ranges table[last_range + 1][last_range + 1] = {
 493          /* left\right   unknown  lt_zero  le_zero  gt_zero  ge_zero  ne_zero  eq_zero */
 494          /* unknown */ { _______, _______, _______, _______, _______, _______, eq_zero },
 495          /* lt_zero */ { _______, gt_zero, ge_zero, lt_zero, le_zero, ne_zero, eq_zero },
 496          /* le_zero */ { _______, ge_zero, ge_zero, le_zero, le_zero, _______, eq_zero },
 497          /* gt_zero */ { _______, lt_zero, le_zero, gt_zero, ge_zero, ne_zero, eq_zero },
 498          /* ge_zero */ { _______, le_zero, le_zero, ge_zero, ge_zero, _______, eq_zero },
 499          /* ne_zero */ { _______, ne_zero, _______, ne_zero, _______, ne_zero, eq_zero },
 500          /* eq_zero */ { eq_zero, eq_zero, eq_zero, eq_zero, eq_zero, eq_zero, eq_zero }
 501       };
 502
 503       ASSERT_TABLE_IS_COMMUTATIVE(table);
 504
 505       /* x * x => ge_zero */
 506       if (left.range != eq_zero && nir_alu_srcs_equal(alu, alu, 0, 1)) {
 507          /* x * x => ge_zero or gt_zero depending on the range of x. */
 508          r.range = is_not_zero(left.range) ? gt_zero : ge_zero;
 509       } else if (left.range != eq_zero && nir_alu_srcs_negative_equal(alu, alu, 0, 1)) {
 510          /* -x * x => le_zero or lt_zero depending on the range of x. */
 511          r.range = is_not_zero(left.range) ? lt_zero : le_zero;
 512       } else
 513          r.range = table[left.range][right.range];
 514
 515       break;
 516    }
 517
 518    case nir_op_frcp:
 519       r = (struct ssa_result_range){analyze_expression(alu, 0, ht).range, false};
 520       break;
 521
 522    case nir_op_mov:
 523       r = analyze_expression(alu, 0, ht);
 524       break;
 525
 526    case nir_op_fneg:
 527       r = analyze_expression(alu, 0, ht);
 528
 529       switch (r.range) {
 530       case le_zero:
 531          r.range = ge_zero;
 532          break;
 533
 534       case ge_zero:
 535          r.range = le_zero;
 536          break;
 537
 538       case lt_zero:
 539          r.range = gt_zero;
 540          break;
 541
 542       case gt_zero:
 543          r.range = lt_zero;
 544          break;
 545
 546       case ne_zero:
 547       case eq_zero:
 548       case unknown:
 549          /* Negation doesn't change anything about these ranges. */
 550          break;
 551       }
 552
 553       break;
 554
 555    case nir_op_fsat:
 556       r = (struct ssa_result_range){ge_zero, analyze_expression(alu, 0, ht).is_integral};
 557       break;
 558
 559    case nir_op_fsign:
 560       r = (struct ssa_result_range){analyze_expression(alu, 0, ht).range, true};
 561       break;
 562
 563    case nir_op_fsqrt:
 564    case nir_op_frsq:
 565       r = (struct ssa_result_range){ge_zero, false};
 566       break;
 567
 568    case nir_op_ffloor: {
 569       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 570
 571       r.is_integral = true;
 572
 573       if (left.is_integral || left.range == le_zero || left.range == lt_zero)
 574          r.range = left.range;
 575       else if (left.range == ge_zero || left.range == gt_zero)
 576          r.range = ge_zero;
 577       else if (left.range == ne_zero)
 578          r.range = unknown;
 579
 580       break;
 581    }
 582
 583    case nir_op_fceil: {
 584       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 585
 586       r.is_integral = true;
 587
 588       if (left.is_integral || left.range == ge_zero || left.range == gt_zero)
 589          r.range = left.range;
 590       else if (left.range == le_zero || left.range == lt_zero)
 591          r.range = le_zero;
 592       else if (left.range == ne_zero)
 593          r.range = unknown;
 594
 595       break;
 596    }
 597
 598    case nir_op_ftrunc: {
 599       const struct ssa_result_range left = analyze_expression(alu, 0, ht);
 600
 601       r.is_integral = true;
 602
 603       if (left.is_integral)
 604          r.range = left.range;
 605       else if (left.range == ge_zero || left.range == gt_zero)
 606          r.range = ge_zero;
 607       else if (left.range == le_zero || left.range == lt_zero)
 608          r.range = le_zero;
 609       else if (left.range == ne_zero)
 610          r.range = unknown;
 611
 612       break;
 613    }
 614
 615    case nir_op_flt:
 616    case nir_op_fge:
 617    case nir_op_feq:
 618    case nir_op_fne:
 619    case nir_op_ilt:
 620    case nir_op_ige:
 621    case nir_op_ieq:
 622    case nir_op_ine:
 623    case nir_op_ult:
 624    case nir_op_uge:
 625       /* Boolean results are 0 or -1. */
 626       r = (struct ssa_result_range){le_zero, false};
 627       break;
 628
 629    default:
 630       r = (struct ssa_result_range){unknown, false};
 631       break;
 632    }
 633
 634    if (r.range == eq_zero)
 635       r.is_integral = true;
 636
 637    _mesa_hash_table_insert(ht, alu, pack_data(r));
 638    return r;
 639 }
 640
 641 #undef _______
 642
 643 struct ssa_result_range
 644 nir_analyze_range(const nir_alu_instr *instr, unsigned src)
 645 {
 646    struct hash_table *ht = _mesa_pointer_hash_table_create(NULL);
 647
 648    const struct ssa_result_range r = analyze_expression(instr, src, ht);
 649
 650    _mesa_hash_table_destroy(ht, NULL);
 651
 652    return r;
 653 }