• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright © 2015 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  */
27 
28 #include <math.h>
29 
30 #include "nir/nir_builtin_builder.h"
31 
32 #include "vtn_private.h"
33 #include "GLSL.std.450.h"
34 
35 #define M_PIf   ((float) M_PI)
36 #define M_PI_2f ((float) M_PI_2)
37 #define M_PI_4f ((float) M_PI_4)
38 
39 static nir_ssa_def *
build_mat2_det(nir_builder * b,nir_ssa_def * col[2])40 build_mat2_det(nir_builder *b, nir_ssa_def *col[2])
41 {
42    unsigned swiz[2] = {1, 0 };
43    nir_ssa_def *p = nir_fmul(b, col[0], nir_swizzle(b, col[1], swiz, 2));
44    return nir_fsub(b, nir_channel(b, p, 0), nir_channel(b, p, 1));
45 }
46 
47 static nir_ssa_def *
build_mat3_det(nir_builder * b,nir_ssa_def * col[3])48 build_mat3_det(nir_builder *b, nir_ssa_def *col[3])
49 {
50    unsigned yzx[3] = {1, 2, 0 };
51    unsigned zxy[3] = {2, 0, 1 };
52 
53    nir_ssa_def *prod0 =
54       nir_fmul(b, col[0],
55                nir_fmul(b, nir_swizzle(b, col[1], yzx, 3),
56                            nir_swizzle(b, col[2], zxy, 3)));
57    nir_ssa_def *prod1 =
58       nir_fmul(b, col[0],
59                nir_fmul(b, nir_swizzle(b, col[1], zxy, 3),
60                            nir_swizzle(b, col[2], yzx, 3)));
61 
62    nir_ssa_def *diff = nir_fsub(b, prod0, prod1);
63 
64    return nir_fadd(b, nir_channel(b, diff, 0),
65                       nir_fadd(b, nir_channel(b, diff, 1),
66                                   nir_channel(b, diff, 2)));
67 }
68 
69 static nir_ssa_def *
build_mat4_det(nir_builder * b,nir_ssa_def ** col)70 build_mat4_det(nir_builder *b, nir_ssa_def **col)
71 {
72    nir_ssa_def *subdet[4];
73    for (unsigned i = 0; i < 4; i++) {
74       unsigned swiz[3];
75       for (unsigned j = 0; j < 3; j++)
76          swiz[j] = j + (j >= i);
77 
78       nir_ssa_def *subcol[3];
79       subcol[0] = nir_swizzle(b, col[1], swiz, 3);
80       subcol[1] = nir_swizzle(b, col[2], swiz, 3);
81       subcol[2] = nir_swizzle(b, col[3], swiz, 3);
82 
83       subdet[i] = build_mat3_det(b, subcol);
84    }
85 
86    nir_ssa_def *prod = nir_fmul(b, col[0], nir_vec(b, subdet, 4));
87 
88    return nir_fadd(b, nir_fsub(b, nir_channel(b, prod, 0),
89                                   nir_channel(b, prod, 1)),
90                       nir_fsub(b, nir_channel(b, prod, 2),
91                                   nir_channel(b, prod, 3)));
92 }
93 
94 static nir_ssa_def *
build_mat_det(struct vtn_builder * b,struct vtn_ssa_value * src)95 build_mat_det(struct vtn_builder *b, struct vtn_ssa_value *src)
96 {
97    unsigned size = glsl_get_vector_elements(src->type);
98 
99    nir_ssa_def *cols[4];
100    for (unsigned i = 0; i < size; i++)
101       cols[i] = src->elems[i]->def;
102 
103    switch(size) {
104    case 2: return build_mat2_det(&b->nb, cols);
105    case 3: return build_mat3_det(&b->nb, cols);
106    case 4: return build_mat4_det(&b->nb, cols);
107    default:
108       vtn_fail("Invalid matrix size");
109    }
110 }
111 
112 /* Computes the determinate of the submatrix given by taking src and
113  * removing the specified row and column.
114  */
115 static nir_ssa_def *
build_mat_subdet(struct nir_builder * b,struct vtn_ssa_value * src,unsigned size,unsigned row,unsigned col)116 build_mat_subdet(struct nir_builder *b, struct vtn_ssa_value *src,
117                  unsigned size, unsigned row, unsigned col)
118 {
119    assert(row < size && col < size);
120    if (size == 2) {
121       return nir_channel(b, src->elems[1 - col]->def, 1 - row);
122    } else {
123       /* Swizzle to get all but the specified row */
124       unsigned swiz[NIR_MAX_VEC_COMPONENTS] = {0};
125       for (unsigned j = 0; j < 3; j++)
126          swiz[j] = j + (j >= row);
127 
128       /* Grab all but the specified column */
129       nir_ssa_def *subcol[3];
130       for (unsigned j = 0; j < size; j++) {
131          if (j != col) {
132             subcol[j - (j > col)] = nir_swizzle(b, src->elems[j]->def,
133                                                 swiz, size - 1);
134          }
135       }
136 
137       if (size == 3) {
138          return build_mat2_det(b, subcol);
139       } else {
140          assert(size == 4);
141          return build_mat3_det(b, subcol);
142       }
143    }
144 }
145 
146 static struct vtn_ssa_value *
matrix_inverse(struct vtn_builder * b,struct vtn_ssa_value * src)147 matrix_inverse(struct vtn_builder *b, struct vtn_ssa_value *src)
148 {
149    nir_ssa_def *adj_col[4];
150    unsigned size = glsl_get_vector_elements(src->type);
151 
152    /* Build up an adjugate matrix */
153    for (unsigned c = 0; c < size; c++) {
154       nir_ssa_def *elem[4];
155       for (unsigned r = 0; r < size; r++) {
156          elem[r] = build_mat_subdet(&b->nb, src, size, c, r);
157 
158          if ((r + c) % 2)
159             elem[r] = nir_fneg(&b->nb, elem[r]);
160       }
161 
162       adj_col[c] = nir_vec(&b->nb, elem, size);
163    }
164 
165    nir_ssa_def *det_inv = nir_frcp(&b->nb, build_mat_det(b, src));
166 
167    struct vtn_ssa_value *val = vtn_create_ssa_value(b, src->type);
168    for (unsigned i = 0; i < size; i++)
169       val->elems[i]->def = nir_fmul(&b->nb, adj_col[i], det_inv);
170 
171    return val;
172 }
173 
174 /**
175  * Approximate asin(x) by the piecewise formula:
176  * for |x| < 0.5, asin~(x) = x * (1 + x²(pS0 + x²(pS1 + x²*pS2)) / (1 + x²*qS1))
177  * for |x| ≥ 0.5, asin~(x) = sign(x) * (π/2 - sqrt(1 - |x|) * (π/2 + |x|(π/4 - 1 + |x|(p0 + |x|p1))))
178  *
179  * The latter is correct to first order at x=0 and x=±1 regardless of the p
180  * coefficients but can be made second-order correct at both ends by selecting
181  * the fit coefficients appropriately.  Different p coefficients can be used
182  * in the asin and acos implementation to minimize some relative error metric
183  * in each case.
184  */
185 static nir_ssa_def *
build_asin(nir_builder * b,nir_ssa_def * x,float p0,float p1,bool piecewise)186 build_asin(nir_builder *b, nir_ssa_def *x, float p0, float p1, bool piecewise)
187 {
188    if (x->bit_size == 16) {
189       /* The polynomial approximation isn't precise enough to meet half-float
190        * precision requirements. Alternatively, we could implement this using
191        * the formula:
192        *
193        * asin(x) = atan2(x, sqrt(1 - x*x))
194        *
195        * But that is very expensive, so instead we just do the polynomial
196        * approximation in 32-bit math and then we convert the result back to
197        * 16-bit.
198        */
199       return nir_f2f16(b, build_asin(b, nir_f2f32(b, x), p0, p1, piecewise));
200    }
201    nir_ssa_def *one = nir_imm_floatN_t(b, 1.0f, x->bit_size);
202    nir_ssa_def *half = nir_imm_floatN_t(b, 0.5f, x->bit_size);
203    nir_ssa_def *abs_x = nir_fabs(b, x);
204 
205    nir_ssa_def *p0_plus_xp1 = nir_ffma_imm12(b, abs_x, p1, p0);
206 
207    nir_ssa_def *expr_tail =
208       nir_ffma_imm2(b, abs_x,
209                        nir_ffma_imm2(b, abs_x, p0_plus_xp1, M_PI_4f - 1.0f),
210                        M_PI_2f);
211 
212    nir_ssa_def *result0 = nir_fmul(b, nir_fsign(b, x),
213                       nir_a_minus_bc(b, nir_imm_floatN_t(b, M_PI_2f, x->bit_size),
214                                         nir_fsqrt(b, nir_fsub(b, one, abs_x)),
215                                         expr_tail));
216    if (piecewise) {
217       /* approximation for |x| < 0.5 */
218       const float pS0 =  1.6666586697e-01f;
219       const float pS1 = -4.2743422091e-02f;
220       const float pS2 = -8.6563630030e-03f;
221       const float qS1 = -7.0662963390e-01f;
222 
223       nir_ssa_def *x2 = nir_fmul(b, x, x);
224       nir_ssa_def *p = nir_fmul(b,
225                                 x2,
226                                 nir_ffma_imm2(b, x2,
227                                                  nir_ffma_imm12(b, x2, pS2, pS1),
228                                                  pS0));
229 
230       nir_ssa_def *q = nir_ffma_imm1(b, x2, qS1, one);
231       nir_ssa_def *result1 = nir_ffma(b, x, nir_fdiv(b, p, q), x);
232       return nir_bcsel(b, nir_flt(b, abs_x, half), result1, result0);
233    } else {
234       return result0;
235    }
236 }
237 
238 static nir_op
vtn_nir_alu_op_for_spirv_glsl_opcode(struct vtn_builder * b,enum GLSLstd450 opcode,unsigned execution_mode,bool * exact)239 vtn_nir_alu_op_for_spirv_glsl_opcode(struct vtn_builder *b,
240                                      enum GLSLstd450 opcode,
241                                      unsigned execution_mode,
242                                      bool *exact)
243 {
244    *exact = false;
245    switch (opcode) {
246    case GLSLstd450Round:         return nir_op_fround_even;
247    case GLSLstd450RoundEven:     return nir_op_fround_even;
248    case GLSLstd450Trunc:         return nir_op_ftrunc;
249    case GLSLstd450FAbs:          return nir_op_fabs;
250    case GLSLstd450SAbs:          return nir_op_iabs;
251    case GLSLstd450FSign:         return nir_op_fsign;
252    case GLSLstd450SSign:         return nir_op_isign;
253    case GLSLstd450Floor:         return nir_op_ffloor;
254    case GLSLstd450Ceil:          return nir_op_fceil;
255    case GLSLstd450Fract:         return nir_op_ffract;
256    case GLSLstd450Sin:           return nir_op_fsin;
257    case GLSLstd450Cos:           return nir_op_fcos;
258    case GLSLstd450Pow:           return nir_op_fpow;
259    case GLSLstd450Exp2:          return nir_op_fexp2;
260    case GLSLstd450Log2:          return nir_op_flog2;
261    case GLSLstd450Sqrt:          return nir_op_fsqrt;
262    case GLSLstd450InverseSqrt:   return nir_op_frsq;
263    case GLSLstd450NMin:          *exact = true; return nir_op_fmin;
264    case GLSLstd450FMin:          return nir_op_fmin;
265    case GLSLstd450UMin:          return nir_op_umin;
266    case GLSLstd450SMin:          return nir_op_imin;
267    case GLSLstd450NMax:          *exact = true; return nir_op_fmax;
268    case GLSLstd450FMax:          return nir_op_fmax;
269    case GLSLstd450UMax:          return nir_op_umax;
270    case GLSLstd450SMax:          return nir_op_imax;
271    case GLSLstd450FMix:          return nir_op_flrp;
272    case GLSLstd450Fma:           return nir_op_ffma;
273    case GLSLstd450Ldexp:         return nir_op_ldexp;
274    case GLSLstd450FindILsb:      return nir_op_find_lsb;
275    case GLSLstd450FindSMsb:      return nir_op_ifind_msb;
276    case GLSLstd450FindUMsb:      return nir_op_ufind_msb;
277 
278    /* Packing/Unpacking functions */
279    case GLSLstd450PackSnorm4x8:     return nir_op_pack_snorm_4x8;
280    case GLSLstd450PackUnorm4x8:     return nir_op_pack_unorm_4x8;
281    case GLSLstd450PackSnorm2x16:    return nir_op_pack_snorm_2x16;
282    case GLSLstd450PackUnorm2x16:    return nir_op_pack_unorm_2x16;
283    case GLSLstd450PackHalf2x16:     return nir_op_pack_half_2x16;
284    case GLSLstd450PackDouble2x32:   return nir_op_pack_64_2x32;
285    case GLSLstd450UnpackSnorm4x8:   return nir_op_unpack_snorm_4x8;
286    case GLSLstd450UnpackUnorm4x8:   return nir_op_unpack_unorm_4x8;
287    case GLSLstd450UnpackSnorm2x16:  return nir_op_unpack_snorm_2x16;
288    case GLSLstd450UnpackUnorm2x16:  return nir_op_unpack_unorm_2x16;
289    case GLSLstd450UnpackHalf2x16:
290       if (execution_mode & FLOAT_CONTROLS_DENORM_FLUSH_TO_ZERO_FP16)
291          return nir_op_unpack_half_2x16_flush_to_zero;
292       else
293          return nir_op_unpack_half_2x16;
294    case GLSLstd450UnpackDouble2x32: return nir_op_unpack_64_2x32;
295 
296    default:
297       vtn_fail("No NIR equivalent");
298    }
299 }
300 
301 #define NIR_IMM_FP(n, v) (nir_imm_floatN_t(n, v, src[0]->bit_size))
302 
303 static void
handle_glsl450_alu(struct vtn_builder * b,enum GLSLstd450 entrypoint,const uint32_t * w,unsigned count)304 handle_glsl450_alu(struct vtn_builder *b, enum GLSLstd450 entrypoint,
305                    const uint32_t *w, unsigned count)
306 {
307    struct nir_builder *nb = &b->nb;
308    const struct glsl_type *dest_type = vtn_get_type(b, w[1])->type;
309 
310    /* Collect the various SSA sources */
311    unsigned num_inputs = count - 5;
312    nir_ssa_def *src[3] = { NULL, };
313    for (unsigned i = 0; i < num_inputs; i++) {
314       /* These are handled specially below */
315       if (vtn_untyped_value(b, w[i + 5])->value_type == vtn_value_type_pointer)
316          continue;
317 
318       src[i] = vtn_get_nir_ssa(b, w[i + 5]);
319    }
320 
321    struct vtn_ssa_value *dest = vtn_create_ssa_value(b, dest_type);
322    vtn_handle_no_contraction(b, vtn_untyped_value(b, w[2]));
323    switch (entrypoint) {
324    case GLSLstd450Radians:
325       dest->def = nir_radians(nb, src[0]);
326       break;
327    case GLSLstd450Degrees:
328       dest->def = nir_degrees(nb, src[0]);
329       break;
330    case GLSLstd450Tan:
331       dest->def = nir_ftan(nb, src[0]);
332       break;
333 
334    case GLSLstd450Modf: {
335       nir_ssa_def *sign = nir_fsign(nb, src[0]);
336       nir_ssa_def *abs = nir_fabs(nb, src[0]);
337       dest->def = nir_fmul(nb, sign, nir_ffract(nb, abs));
338 
339       struct vtn_pointer *i_ptr = vtn_value(b, w[6], vtn_value_type_pointer)->pointer;
340       struct vtn_ssa_value *whole = vtn_create_ssa_value(b, i_ptr->type->type);
341       whole->def = nir_fmul(nb, sign, nir_ffloor(nb, abs));
342       vtn_variable_store(b, whole, i_ptr, 0);
343       break;
344    }
345 
346    case GLSLstd450ModfStruct: {
347       nir_ssa_def *sign = nir_fsign(nb, src[0]);
348       nir_ssa_def *abs = nir_fabs(nb, src[0]);
349       vtn_assert(glsl_type_is_struct_or_ifc(dest_type));
350       dest->elems[0]->def = nir_fmul(nb, sign, nir_ffract(nb, abs));
351       dest->elems[1]->def = nir_fmul(nb, sign, nir_ffloor(nb, abs));
352       break;
353    }
354 
355    case GLSLstd450Step:
356       dest->def = nir_sge(nb, src[1], src[0]);
357       break;
358 
359    case GLSLstd450Length:
360       dest->def = nir_fast_length(nb, src[0]);
361       break;
362    case GLSLstd450Distance:
363       dest->def = nir_fast_distance(nb, src[0], src[1]);
364       break;
365    case GLSLstd450Normalize:
366       dest->def = nir_fast_normalize(nb, src[0]);
367       break;
368 
369    case GLSLstd450Exp:
370       dest->def = nir_fexp(nb, src[0]);
371       break;
372 
373    case GLSLstd450Log:
374       dest->def = nir_flog(nb, src[0]);
375       break;
376 
377    case GLSLstd450FClamp:
378       dest->def = nir_fclamp(nb, src[0], src[1], src[2]);
379       break;
380    case GLSLstd450NClamp:
381       nb->exact = true;
382       dest->def = nir_fclamp(nb, src[0], src[1], src[2]);
383       nb->exact = false;
384       break;
385    case GLSLstd450UClamp:
386       dest->def = nir_uclamp(nb, src[0], src[1], src[2]);
387       break;
388    case GLSLstd450SClamp:
389       dest->def = nir_iclamp(nb, src[0], src[1], src[2]);
390       break;
391 
392    case GLSLstd450Cross: {
393       dest->def = nir_cross3(nb, src[0], src[1]);
394       break;
395    }
396 
397    case GLSLstd450SmoothStep: {
398       dest->def = nir_smoothstep(nb, src[0], src[1], src[2]);
399       break;
400    }
401 
402    case GLSLstd450FaceForward:
403       dest->def =
404          nir_bcsel(nb, nir_flt(nb, nir_fdot(nb, src[2], src[1]),
405                                    NIR_IMM_FP(nb, 0.0)),
406                        src[0], nir_fneg(nb, src[0]));
407       break;
408 
409    case GLSLstd450Reflect:
410       /* I - 2 * dot(N, I) * N */
411       dest->def =
412          nir_a_minus_bc(nb, src[0],
413                             src[1],
414                             nir_fmul(nb, nir_fdot(nb, src[0], src[1]),
415                                          NIR_IMM_FP(nb, 2.0)));
416       break;
417 
418    case GLSLstd450Refract: {
419       nir_ssa_def *I = src[0];
420       nir_ssa_def *N = src[1];
421       nir_ssa_def *eta = src[2];
422       nir_ssa_def *n_dot_i = nir_fdot(nb, N, I);
423       nir_ssa_def *one = NIR_IMM_FP(nb, 1.0);
424       nir_ssa_def *zero = NIR_IMM_FP(nb, 0.0);
425       /* According to the SPIR-V and GLSL specs, eta is always a float
426        * regardless of the type of the other operands. However in practice it
427        * seems that if you try to pass it a float then glslang will just
428        * promote it to a double and generate invalid SPIR-V. In order to
429        * support a hypothetical fixed version of glslang we’ll promote eta to
430        * double if the other operands are double also.
431        */
432       if (I->bit_size != eta->bit_size) {
433          nir_op conversion_op =
434             nir_type_conversion_op(nir_type_float | eta->bit_size,
435                                    nir_type_float | I->bit_size,
436                                    nir_rounding_mode_undef);
437          eta = nir_build_alu(nb, conversion_op, eta, NULL, NULL, NULL);
438       }
439       /* k = 1.0 - eta * eta * (1.0 - dot(N, I) * dot(N, I)) */
440       nir_ssa_def *k =
441          nir_a_minus_bc(nb, one, eta,
442                             nir_fmul(nb, eta, nir_a_minus_bc(nb, one, n_dot_i, n_dot_i)));
443       nir_ssa_def *result =
444          nir_a_minus_bc(nb, nir_fmul(nb, eta, I),
445                             nir_ffma(nb, eta, n_dot_i, nir_fsqrt(nb, k)),
446                             N);
447       /* XXX: bcsel, or if statement? */
448       dest->def = nir_bcsel(nb, nir_flt(nb, k, zero), zero, result);
449       break;
450    }
451 
452    case GLSLstd450Sinh:
453       /* 0.5 * (e^x - e^(-x)) */
454       dest->def =
455          nir_fmul_imm(nb, nir_fsub(nb, nir_fexp(nb, src[0]),
456                                        nir_fexp(nb, nir_fneg(nb, src[0]))),
457                           0.5f);
458       break;
459 
460    case GLSLstd450Cosh:
461       /* 0.5 * (e^x + e^(-x)) */
462       dest->def =
463          nir_fmul_imm(nb, nir_fadd(nb, nir_fexp(nb, src[0]),
464                                        nir_fexp(nb, nir_fneg(nb, src[0]))),
465                           0.5f);
466       break;
467 
468    case GLSLstd450Tanh: {
469       /* tanh(x) := (e^x - e^(-x)) / (e^x + e^(-x))
470        *
471        * We clamp x to [-10, +10] to avoid precision problems.  When x > 10,
472        * e^x dominates the sum, e^(-x) is lost and tanh(x) is 1.0 for 32 bit
473        * floating point.
474        *
475        * For 16-bit precision this we clamp x to [-4.2, +4.2].
476        */
477       const uint32_t bit_size = src[0]->bit_size;
478       const double clamped_x = bit_size > 16 ? 10.0 : 4.2;
479       nir_ssa_def *x = nir_fclamp(nb, src[0],
480                                   nir_imm_floatN_t(nb, -clamped_x, bit_size),
481                                   nir_imm_floatN_t(nb, clamped_x, bit_size));
482       dest->def =
483          nir_fdiv(nb, nir_fsub(nb, nir_fexp(nb, x),
484                                nir_fexp(nb, nir_fneg(nb, x))),
485                   nir_fadd(nb, nir_fexp(nb, x),
486                            nir_fexp(nb, nir_fneg(nb, x))));
487       break;
488    }
489 
490    case GLSLstd450Asinh:
491       dest->def = nir_fmul(nb, nir_fsign(nb, src[0]),
492          nir_flog(nb, nir_fadd(nb, nir_fabs(nb, src[0]),
493                       nir_fsqrt(nb, nir_ffma_imm2(nb, src[0], src[0], 1.0f)))));
494       break;
495    case GLSLstd450Acosh:
496       dest->def = nir_flog(nb, nir_fadd(nb, src[0],
497          nir_fsqrt(nb, nir_ffma_imm2(nb, src[0], src[0], -1.0f))));
498       break;
499    case GLSLstd450Atanh: {
500       nir_ssa_def *one = nir_imm_floatN_t(nb, 1.0, src[0]->bit_size);
501       dest->def =
502          nir_fmul_imm(nb, nir_flog(nb, nir_fdiv(nb, nir_fadd(nb, src[0], one),
503                                        nir_fsub(nb, one, src[0]))),
504                           0.5f);
505       break;
506    }
507 
508    case GLSLstd450Asin:
509       dest->def = build_asin(nb, src[0], 0.086566724, -0.03102955, true);
510       break;
511 
512    case GLSLstd450Acos:
513       dest->def =
514          nir_fsub(nb, nir_imm_floatN_t(nb, M_PI_2f, src[0]->bit_size),
515                       build_asin(nb, src[0], 0.08132463, -0.02363318, false));
516       break;
517 
518    case GLSLstd450Atan:
519       dest->def = nir_atan(nb, src[0]);
520       break;
521 
522    case GLSLstd450Atan2:
523       dest->def = nir_atan2(nb, src[0], src[1]);
524       break;
525 
526    case GLSLstd450Frexp: {
527       dest->def = nir_frexp_sig(nb, src[0]);
528 
529       struct vtn_pointer *i_ptr = vtn_value(b, w[6], vtn_value_type_pointer)->pointer;
530       struct vtn_ssa_value *exp = vtn_create_ssa_value(b, i_ptr->type->type);
531       exp->def = nir_frexp_exp(nb, src[0]);
532       vtn_variable_store(b, exp, i_ptr, 0);
533       break;
534    }
535 
536    case GLSLstd450FrexpStruct: {
537       vtn_assert(glsl_type_is_struct_or_ifc(dest_type));
538       dest->elems[0]->def = nir_frexp_sig(nb, src[0]);
539       dest->elems[1]->def = nir_frexp_exp(nb, src[0]);
540       break;
541    }
542 
543    default: {
544       unsigned execution_mode =
545          b->shader->info.float_controls_execution_mode;
546       bool exact;
547       nir_op op = vtn_nir_alu_op_for_spirv_glsl_opcode(b, entrypoint, execution_mode, &exact);
548       /* don't override explicit decoration */
549       b->nb.exact |= exact;
550       dest->def = nir_build_alu(&b->nb, op, src[0], src[1], src[2], NULL);
551       break;
552    }
553    }
554    b->nb.exact = false;
555 
556    vtn_push_ssa_value(b, w[2], dest);
557 }
558 
559 static void
handle_glsl450_interpolation(struct vtn_builder * b,enum GLSLstd450 opcode,const uint32_t * w,unsigned count)560 handle_glsl450_interpolation(struct vtn_builder *b, enum GLSLstd450 opcode,
561                              const uint32_t *w, unsigned count)
562 {
563    nir_intrinsic_op op;
564    switch (opcode) {
565    case GLSLstd450InterpolateAtCentroid:
566       op = nir_intrinsic_interp_deref_at_centroid;
567       break;
568    case GLSLstd450InterpolateAtSample:
569       op = nir_intrinsic_interp_deref_at_sample;
570       break;
571    case GLSLstd450InterpolateAtOffset:
572       op = nir_intrinsic_interp_deref_at_offset;
573       break;
574    default:
575       vtn_fail("Invalid opcode");
576    }
577 
578    nir_intrinsic_instr *intrin = nir_intrinsic_instr_create(b->nb.shader, op);
579 
580    struct vtn_pointer *ptr =
581       vtn_value(b, w[5], vtn_value_type_pointer)->pointer;
582    nir_deref_instr *deref = vtn_pointer_to_deref(b, ptr);
583 
584    /* If the value we are interpolating has an index into a vector then
585     * interpolate the vector and index the result of that instead. This is
586     * necessary because the index will get generated as a series of nir_bcsel
587     * instructions so it would no longer be an input variable.
588     */
589    const bool vec_array_deref = deref->deref_type == nir_deref_type_array &&
590       glsl_type_is_vector(nir_deref_instr_parent(deref)->type);
591 
592    nir_deref_instr *vec_deref = NULL;
593    if (vec_array_deref) {
594       vec_deref = deref;
595       deref = nir_deref_instr_parent(deref);
596    }
597    intrin->src[0] = nir_src_for_ssa(&deref->dest.ssa);
598 
599    switch (opcode) {
600    case GLSLstd450InterpolateAtCentroid:
601       break;
602    case GLSLstd450InterpolateAtSample:
603    case GLSLstd450InterpolateAtOffset:
604       intrin->src[1] = nir_src_for_ssa(vtn_get_nir_ssa(b, w[6]));
605       break;
606    default:
607       vtn_fail("Invalid opcode");
608    }
609 
610    intrin->num_components = glsl_get_vector_elements(deref->type);
611    nir_ssa_dest_init(&intrin->instr, &intrin->dest,
612                      glsl_get_vector_elements(deref->type),
613                      glsl_get_bit_size(deref->type), NULL);
614 
615    nir_builder_instr_insert(&b->nb, &intrin->instr);
616 
617    nir_ssa_def *def = &intrin->dest.ssa;
618    if (vec_array_deref)
619       def = nir_vector_extract(&b->nb, def, vec_deref->arr.index.ssa);
620 
621    vtn_push_nir_ssa(b, w[2], def);
622 }
623 
624 bool
vtn_handle_glsl450_instruction(struct vtn_builder * b,SpvOp ext_opcode,const uint32_t * w,unsigned count)625 vtn_handle_glsl450_instruction(struct vtn_builder *b, SpvOp ext_opcode,
626                                const uint32_t *w, unsigned count)
627 {
628    switch ((enum GLSLstd450)ext_opcode) {
629    case GLSLstd450Determinant: {
630       vtn_push_nir_ssa(b, w[2], build_mat_det(b, vtn_ssa_value(b, w[5])));
631       break;
632    }
633 
634    case GLSLstd450MatrixInverse: {
635       vtn_push_ssa_value(b, w[2], matrix_inverse(b, vtn_ssa_value(b, w[5])));
636       break;
637    }
638 
639    case GLSLstd450InterpolateAtCentroid:
640    case GLSLstd450InterpolateAtSample:
641    case GLSLstd450InterpolateAtOffset:
642       handle_glsl450_interpolation(b, (enum GLSLstd450)ext_opcode, w, count);
643       break;
644 
645    default:
646       handle_glsl450_alu(b, (enum GLSLstd450)ext_opcode, w, count);
647    }
648 
649    return true;
650 }
651