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1 /*
2  * Copyright 2023 Advanced Micro Devices, Inc.
3  *
4  * SPDX-License-Identifier: MIT
5  */
6 
7 #include "ac_nir.h"
8 #include "sid.h"
9 #include "nir_builder.h"
10 #include "nir_builtin_builder.h"
11 
12 typedef struct {
13    const ac_nir_lower_ps_options *options;
14 
15    nir_variable *persp_center;
16    nir_variable *persp_centroid;
17    nir_variable *persp_sample;
18    nir_variable *linear_center;
19    nir_variable *linear_centroid;
20    nir_variable *linear_sample;
21    bool lower_load_barycentric;
22 
23    /* Add one for dual source blend second output. */
24    nir_def *outputs[FRAG_RESULT_MAX + 1][4];
25    nir_alu_type output_types[FRAG_RESULT_MAX + 1];
26 
27    /* MAX_DRAW_BUFFERS for MRT export, 1 for MRTZ export */
28    nir_intrinsic_instr *exp[MAX_DRAW_BUFFERS + 1];
29    unsigned exp_num;
30 
31    unsigned compacted_mrt_index;
32 } lower_ps_state;
33 
34 #define DUAL_SRC_BLEND_SLOT FRAG_RESULT_MAX
35 
36 static void
create_interp_param(nir_builder * b,lower_ps_state * s)37 create_interp_param(nir_builder *b, lower_ps_state *s)
38 {
39    if (s->options->force_persp_sample_interp) {
40       s->persp_center =
41          nir_local_variable_create(b->impl, glsl_vec_type(2), "persp_center");
42    }
43 
44    if (s->options->bc_optimize_for_persp ||
45        s->options->force_persp_sample_interp ||
46        s->options->force_persp_center_interp) {
47       s->persp_centroid =
48          nir_local_variable_create(b->impl, glsl_vec_type(2), "persp_centroid");
49    }
50 
51    if (s->options->force_persp_center_interp) {
52       s->persp_sample =
53          nir_local_variable_create(b->impl, glsl_vec_type(2), "persp_sample");
54    }
55 
56    if (s->options->force_linear_sample_interp) {
57       s->linear_center =
58          nir_local_variable_create(b->impl, glsl_vec_type(2), "linear_center");
59    }
60 
61    if (s->options->bc_optimize_for_linear ||
62        s->options->force_linear_sample_interp ||
63        s->options->force_linear_center_interp) {
64       s->linear_centroid =
65          nir_local_variable_create(b->impl, glsl_vec_type(2), "linear_centroid");
66    }
67 
68    if (s->options->force_linear_center_interp) {
69       s->linear_sample =
70          nir_local_variable_create(b->impl, glsl_vec_type(2), "linear_sample");
71    }
72 
73    s->lower_load_barycentric =
74       s->persp_center || s->persp_centroid || s->persp_sample ||
75       s->linear_center || s->linear_centroid || s->linear_sample;
76 }
77 
78 static void
init_interp_param(nir_builder * b,lower_ps_state * s)79 init_interp_param(nir_builder *b, lower_ps_state *s)
80 {
81    b->cursor = nir_before_cf_list(&b->impl->body);
82 
83    /* The shader should do: if (PRIM_MASK[31]) CENTROID = CENTER;
84     * The hw doesn't compute CENTROID if the whole wave only
85     * contains fully-covered quads.
86     */
87    if (s->options->bc_optimize_for_persp || s->options->bc_optimize_for_linear) {
88       nir_def *bc_optimize = nir_load_barycentric_optimize_amd(b);
89 
90       if (s->options->bc_optimize_for_persp) {
91          nir_def *center =
92             nir_load_barycentric_pixel(b, 32, .interp_mode = INTERP_MODE_SMOOTH);
93          nir_def *centroid =
94             nir_load_barycentric_centroid(b, 32, .interp_mode = INTERP_MODE_SMOOTH);
95 
96          nir_def *value = nir_bcsel(b, bc_optimize, center, centroid);
97          nir_store_var(b, s->persp_centroid, value, 0x3);
98       }
99 
100       if (s->options->bc_optimize_for_linear) {
101          nir_def *center =
102             nir_load_barycentric_pixel(b, 32, .interp_mode = INTERP_MODE_NOPERSPECTIVE);
103          nir_def *centroid =
104             nir_load_barycentric_centroid(b, 32, .interp_mode = INTERP_MODE_NOPERSPECTIVE);
105 
106          nir_def *value = nir_bcsel(b, bc_optimize, center, centroid);
107          nir_store_var(b, s->linear_centroid, value, 0x3);
108       }
109    }
110 
111    if (s->options->force_persp_sample_interp) {
112       nir_def *sample =
113          nir_load_barycentric_sample(b, 32, .interp_mode = INTERP_MODE_SMOOTH);
114       nir_store_var(b, s->persp_center, sample, 0x3);
115       nir_store_var(b, s->persp_centroid, sample, 0x3);
116    }
117 
118    if (s->options->force_linear_sample_interp) {
119       nir_def *sample =
120          nir_load_barycentric_sample(b, 32, .interp_mode = INTERP_MODE_NOPERSPECTIVE);
121       nir_store_var(b, s->linear_center, sample, 0x3);
122       nir_store_var(b, s->linear_centroid, sample, 0x3);
123    }
124 
125    if (s->options->force_persp_center_interp) {
126       nir_def *center =
127          nir_load_barycentric_pixel(b, 32, .interp_mode = INTERP_MODE_SMOOTH);
128       nir_store_var(b, s->persp_sample, center, 0x3);
129       nir_store_var(b, s->persp_centroid, center, 0x3);
130    }
131 
132    if (s->options->force_linear_center_interp) {
133       nir_def *center =
134          nir_load_barycentric_pixel(b, 32, .interp_mode = INTERP_MODE_NOPERSPECTIVE);
135       nir_store_var(b, s->linear_sample, center, 0x3);
136       nir_store_var(b, s->linear_centroid, center, 0x3);
137    }
138 }
139 
140 static bool
lower_ps_load_barycentric(nir_builder * b,nir_intrinsic_instr * intrin,lower_ps_state * s)141 lower_ps_load_barycentric(nir_builder *b, nir_intrinsic_instr *intrin, lower_ps_state *s)
142 {
143    enum glsl_interp_mode mode = nir_intrinsic_interp_mode(intrin);
144    nir_variable *var = NULL;
145 
146    switch (mode) {
147    case INTERP_MODE_NONE:
148    case INTERP_MODE_SMOOTH:
149       switch (intrin->intrinsic) {
150       case nir_intrinsic_load_barycentric_pixel:
151          var = s->persp_center;
152          break;
153       case nir_intrinsic_load_barycentric_centroid:
154          var = s->persp_centroid;
155          break;
156       case nir_intrinsic_load_barycentric_sample:
157          var = s->persp_sample;
158          break;
159       default:
160          break;
161       }
162       break;
163 
164    case INTERP_MODE_NOPERSPECTIVE:
165       switch (intrin->intrinsic) {
166       case nir_intrinsic_load_barycentric_pixel:
167          var = s->linear_center;
168          break;
169       case nir_intrinsic_load_barycentric_centroid:
170          var = s->linear_centroid;
171          break;
172       case nir_intrinsic_load_barycentric_sample:
173          var = s->linear_sample;
174          break;
175       default:
176          break;
177       }
178       break;
179 
180    default:
181       break;
182    }
183 
184    if (!var)
185       return false;
186 
187    b->cursor = nir_before_instr(&intrin->instr);
188 
189    nir_def *replacement = nir_load_var(b, var);
190    nir_def_rewrite_uses(&intrin->def, replacement);
191 
192    nir_instr_remove(&intrin->instr);
193    return true;
194 }
195 
196 static bool
gather_ps_store_output(nir_builder * b,nir_intrinsic_instr * intrin,lower_ps_state * s)197 gather_ps_store_output(nir_builder *b, nir_intrinsic_instr *intrin, lower_ps_state *s)
198 {
199    nir_io_semantics sem = nir_intrinsic_io_semantics(intrin);
200    unsigned write_mask = nir_intrinsic_write_mask(intrin);
201    unsigned component = nir_intrinsic_component(intrin);
202    nir_alu_type type = nir_intrinsic_src_type(intrin);
203    nir_def *store_val = intrin->src[0].ssa;
204 
205    b->cursor = nir_before_instr(&intrin->instr);
206 
207    unsigned slot = sem.dual_source_blend_index ?
208       DUAL_SRC_BLEND_SLOT : sem.location;
209 
210    u_foreach_bit (i, write_mask) {
211       unsigned comp = component + i;
212       s->outputs[slot][comp] = nir_channel(b, store_val, i);
213    }
214 
215    /* Same slot should have same type for all components. */
216    assert(s->output_types[slot] == nir_type_invalid || s->output_types[slot] == type);
217 
218    s->output_types[slot] = type;
219 
220    /* Keep output instruction if not exported in nir. */
221    if (!s->options->no_color_export && !s->options->no_depth_export) {
222       nir_instr_remove(&intrin->instr);
223    } else {
224       if (slot >= FRAG_RESULT_DATA0 && !s->options->no_color_export) {
225          nir_instr_remove(&intrin->instr);
226       } else if ((slot == FRAG_RESULT_DEPTH || slot == FRAG_RESULT_STENCIL ||
227                   slot == FRAG_RESULT_SAMPLE_MASK) && !s->options->no_depth_export) {
228          nir_instr_remove(&intrin->instr);
229       }
230    }
231 
232    return true;
233 }
234 
235 static bool
lower_ps_load_sample_mask_in(nir_builder * b,nir_intrinsic_instr * intrin,lower_ps_state * s)236 lower_ps_load_sample_mask_in(nir_builder *b, nir_intrinsic_instr *intrin, lower_ps_state *s)
237 {
238    /* Section 15.2.2 (Shader Inputs) of the OpenGL 4.5 (Core Profile) spec
239     * says:
240     *
241     *    "When per-sample shading is active due to the use of a fragment
242     *     input qualified by sample or due to the use of the gl_SampleID
243     *     or gl_SamplePosition variables, only the bit for the current
244     *     sample is set in gl_SampleMaskIn. When state specifies multiple
245     *     fragment shader invocations for a given fragment, the sample
246     *     mask for any single fragment shader invocation may specify a
247     *     subset of the covered samples for the fragment. In this case,
248     *     the bit corresponding to each covered sample will be set in
249     *     exactly one fragment shader invocation."
250     *
251     * The samplemask loaded by hardware is always the coverage of the
252     * entire pixel/fragment, so mask bits out based on the sample ID.
253     */
254 
255    b->cursor = nir_before_instr(&intrin->instr);
256 
257    uint32_t ps_iter_mask = ac_get_ps_iter_mask(s->options->ps_iter_samples);
258    nir_def *sampleid = nir_load_sample_id(b);
259    nir_def *submask = nir_ishl(b, nir_imm_int(b, ps_iter_mask), sampleid);
260 
261    nir_def *sample_mask = nir_load_sample_mask_in(b);
262    nir_def *replacement = nir_iand(b, sample_mask, submask);
263 
264    nir_def_rewrite_uses(&intrin->def, replacement);
265 
266    nir_instr_remove(&intrin->instr);
267    return true;
268 }
269 
270 static bool
lower_ps_intrinsic(nir_builder * b,nir_instr * instr,void * state)271 lower_ps_intrinsic(nir_builder *b, nir_instr *instr, void *state)
272 {
273    lower_ps_state *s = (lower_ps_state *)state;
274 
275    if (instr->type != nir_instr_type_intrinsic)
276       return false;
277 
278    nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
279 
280    switch (intrin->intrinsic) {
281    case nir_intrinsic_store_output:
282       return gather_ps_store_output(b, intrin, s);
283    case nir_intrinsic_load_barycentric_pixel:
284    case nir_intrinsic_load_barycentric_centroid:
285    case nir_intrinsic_load_barycentric_sample:
286       if (s->lower_load_barycentric)
287          return lower_ps_load_barycentric(b, intrin, s);
288       break;
289    case nir_intrinsic_load_sample_mask_in:
290       if (s->options->ps_iter_samples > 1)
291          return lower_ps_load_sample_mask_in(b, intrin, s);
292       break;
293    default:
294       break;
295    }
296 
297    return false;
298 }
299 
300 static void
emit_ps_color_clamp_and_alpha_test(nir_builder * b,lower_ps_state * s)301 emit_ps_color_clamp_and_alpha_test(nir_builder *b, lower_ps_state *s)
302 {
303    uint32_t color_mask =
304       BITFIELD_BIT(FRAG_RESULT_COLOR) |
305       BITFIELD_RANGE(FRAG_RESULT_DATA0, MAX_DRAW_BUFFERS);
306    uint32_t color_outputs =
307       (b->shader->info.outputs_written & color_mask) |
308       /* both dual source blend outputs use FRAG_RESULT_DATA0 slot in nir,
309        * but we use an extra slot number in lower_ps_state for the second
310        * output
311        */
312       BITFIELD_BIT(DUAL_SRC_BLEND_SLOT);
313 
314    u_foreach_bit (slot, color_outputs) {
315       if (s->options->clamp_color) {
316          for (int i = 0; i < 4; i++) {
317             if (s->outputs[slot][i])
318                s->outputs[slot][i] = nir_fsat(b, s->outputs[slot][i]);
319          }
320       }
321 
322       if (s->options->alpha_to_one) {
323          /* any one has written to this slot */
324          if (s->output_types[slot] != nir_type_invalid) {
325             unsigned bit_size = nir_alu_type_get_type_size(s->output_types[slot]);
326             s->outputs[slot][3] = nir_imm_floatN_t(b, 1, bit_size);
327          }
328       }
329 
330       if (slot == FRAG_RESULT_COLOR || slot == FRAG_RESULT_DATA0) {
331          if (s->options->alpha_func == COMPARE_FUNC_ALWAYS) {
332             /* always pass, do nothing */
333          } else if (s->options->alpha_func == COMPARE_FUNC_NEVER) {
334             nir_discard(b);
335          } else if (s->outputs[slot][3]) {
336             nir_def *ref = nir_load_alpha_reference_amd(b);
337             nir_def *cond =
338                nir_compare_func(b, s->options->alpha_func, s->outputs[slot][3], ref);
339             nir_discard_if(b, nir_inot(b, cond));
340          }
341       }
342    }
343 }
344 
345 static void
emit_ps_mrtz_export(nir_builder * b,lower_ps_state * s)346 emit_ps_mrtz_export(nir_builder *b, lower_ps_state *s)
347 {
348    uint64_t outputs_written = b->shader->info.outputs_written;
349 
350    nir_def *mrtz_alpha = NULL;
351    if (s->options->alpha_to_coverage_via_mrtz) {
352       mrtz_alpha = s->outputs[FRAG_RESULT_COLOR][3] ?
353          s->outputs[FRAG_RESULT_COLOR][3] :
354          s->outputs[FRAG_RESULT_DATA0][3];
355    }
356 
357    nir_def *depth = s->outputs[FRAG_RESULT_DEPTH][0];
358    nir_def *stencil = s->outputs[FRAG_RESULT_STENCIL][0];
359    nir_def *sample_mask = s->outputs[FRAG_RESULT_SAMPLE_MASK][0];
360 
361    if (s->options->kill_samplemask) {
362       sample_mask = NULL;
363       outputs_written &= ~BITFIELD64_BIT(FRAG_RESULT_SAMPLE_MASK);
364    }
365 
366    /* skip mrtz export if no one has written to any of them */
367    if (!depth && !stencil && !sample_mask && !mrtz_alpha)
368       return;
369 
370    /* use outputs_written to determine export format as we use it to set
371     * R_028710_SPI_SHADER_Z_FORMAT instead of relying on the real store output,
372     * because store output may be optimized out.
373     */
374    unsigned format =
375       ac_get_spi_shader_z_format(outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH),
376                                  outputs_written & BITFIELD64_BIT(FRAG_RESULT_STENCIL),
377                                  outputs_written & BITFIELD64_BIT(FRAG_RESULT_SAMPLE_MASK),
378                                  s->options->alpha_to_coverage_via_mrtz);
379 
380    nir_def *undef = nir_undef(b, 1, 32);
381    nir_def *outputs[4] = {undef, undef, undef, undef};
382    unsigned write_mask = 0;
383    unsigned flags = 0;
384 
385    if (format == V_028710_SPI_SHADER_UINT16_ABGR) {
386       assert(!depth && !mrtz_alpha);
387 
388       if (s->options->gfx_level < GFX11)
389          flags |= AC_EXP_FLAG_COMPRESSED;
390 
391       if (stencil) {
392          outputs[0] = nir_ishl_imm(b, stencil, 16);
393          write_mask |= s->options->gfx_level >= GFX11 ? 0x1 : 0x3;
394       }
395 
396       if (sample_mask) {
397          outputs[1] = sample_mask;
398          write_mask |= s->options->gfx_level >= GFX11 ? 0x2 : 0xc;
399       }
400    } else {
401       if (depth) {
402          outputs[0] = depth;
403          write_mask |= 0x1;
404       }
405 
406       if (stencil) {
407          outputs[1] = stencil;
408          write_mask |= 0x2;
409       }
410 
411       if (sample_mask) {
412          outputs[2] = sample_mask;
413          write_mask |= 0x4;
414       }
415 
416       if (mrtz_alpha) {
417          outputs[3] = mrtz_alpha;
418          write_mask |= 0x8;
419       }
420    }
421 
422    /* GFX6 (except OLAND and HAINAN) has a bug that it only looks at the
423     * X writemask component.
424     */
425    if (s->options->gfx_level == GFX6 &&
426        s->options->family != CHIP_OLAND &&
427        s->options->family != CHIP_HAINAN) {
428       write_mask |= 0x1;
429    }
430 
431    s->exp[s->exp_num++] = nir_export_amd(b, nir_vec(b, outputs, 4),
432                                          .base = V_008DFC_SQ_EXP_MRTZ,
433                                          .write_mask = write_mask,
434                                          .flags = flags);
435 }
436 
437 static unsigned
get_ps_color_export_target(lower_ps_state * s)438 get_ps_color_export_target(lower_ps_state *s)
439 {
440    unsigned target = V_008DFC_SQ_EXP_MRT + s->compacted_mrt_index;
441 
442    if (s->options->dual_src_blend_swizzle && s->compacted_mrt_index < 2)
443       target += 21;
444 
445    s->compacted_mrt_index++;
446 
447    return target;
448 }
449 
450 static bool
emit_ps_color_export(nir_builder * b,lower_ps_state * s,gl_frag_result slot,unsigned cbuf)451 emit_ps_color_export(nir_builder *b, lower_ps_state *s, gl_frag_result slot, unsigned cbuf)
452 {
453    assert(cbuf < 8);
454 
455    unsigned spi_shader_col_format = (s->options->spi_shader_col_format >> (cbuf * 4)) & 0xf;
456    if (spi_shader_col_format == V_028714_SPI_SHADER_ZERO)
457       return false;
458 
459    /* get target after checking spi_shader_col_format as we need to increase
460     * compacted_mrt_index anyway regardless of whether the export is built
461     */
462    unsigned target = get_ps_color_export_target(s);
463 
464    nir_alu_type type = s->output_types[slot];
465    /* no one has written to this slot */
466    if (type == nir_type_invalid)
467       return false;
468 
469    bool is_int8 = s->options->color_is_int8 & BITFIELD_BIT(cbuf);
470    bool is_int10 = s->options->color_is_int10 & BITFIELD_BIT(cbuf);
471    bool enable_mrt_output_nan_fixup =
472       s->options->enable_mrt_output_nan_fixup & BITFIELD_BIT(cbuf);
473 
474    nir_def *undef = nir_undef(b, 1, 32);
475    nir_def *outputs[4] = {undef, undef, undef, undef};
476    unsigned write_mask = 0;
477    unsigned flags = 0;
478 
479    nir_alu_type base_type = nir_alu_type_get_base_type(type);
480    unsigned type_size = nir_alu_type_get_type_size(type);
481 
482    nir_def *data[4];
483    memcpy(data, s->outputs[slot], sizeof(data));
484 
485    /* Replace NaN by zero (for 32-bit float formats) to fix game bugs if requested. */
486    if (enable_mrt_output_nan_fixup && type == nir_type_float32) {
487       for (int i = 0; i < 4; i++) {
488          if (data[i]) {
489             nir_def *isnan = nir_fisnan(b, data[i]);
490             data[i] = nir_bcsel(b, isnan, nir_imm_float(b, 0), data[i]);
491          }
492       }
493    }
494 
495    switch (spi_shader_col_format) {
496    case V_028714_SPI_SHADER_32_R:
497       if (!data[0])
498          return false;
499 
500       outputs[0] = nir_convert_to_bit_size(b, data[0], base_type, 32);
501       write_mask = 0x1;
502       break;
503 
504    case V_028714_SPI_SHADER_32_GR:
505       if (!data[0] && !data[1])
506          return false;
507 
508       if (data[0]) {
509          outputs[0] = nir_convert_to_bit_size(b, data[0], base_type, 32);
510          write_mask |= 0x1;
511       }
512 
513       if (data[1]) {
514          outputs[1] = nir_convert_to_bit_size(b, data[1], base_type, 32);
515          write_mask |= 0x2;
516       }
517       break;
518 
519    case V_028714_SPI_SHADER_32_AR:
520       if (!data[0] && !data[3])
521          return false;
522 
523       if (data[0]) {
524          outputs[0] = nir_convert_to_bit_size(b, data[0], base_type, 32);
525          write_mask |= 0x1;
526       }
527 
528       if (data[3]) {
529          unsigned index = s->options->gfx_level >= GFX10 ? 1 : 3;
530          outputs[index] = nir_convert_to_bit_size(b, data[3], base_type, 32);
531          write_mask |= BITFIELD_BIT(index);
532       }
533       break;
534 
535    case V_028714_SPI_SHADER_32_ABGR:
536       for (int i = 0; i < 4; i++) {
537          if (data[i]) {
538             outputs[i] = nir_convert_to_bit_size(b, data[i], base_type, 32);
539             write_mask |= BITFIELD_BIT(i);
540          }
541       }
542       break;
543 
544    default: {
545       nir_op pack_op = nir_op_pack_32_2x16;
546 
547       switch (spi_shader_col_format) {
548       case V_028714_SPI_SHADER_FP16_ABGR:
549          if (type_size == 32)
550             pack_op = nir_op_pack_half_2x16;
551          break;
552       case V_028714_SPI_SHADER_UINT16_ABGR:
553          if (type_size == 32) {
554             pack_op = nir_op_pack_uint_2x16;
555             if (is_int8 || is_int10) {
556                /* clamp 32bit output for 8/10 bit color component */
557                uint32_t max_rgb = is_int8 ? 255 : 1023;
558 
559                for (int i = 0; i < 4; i++) {
560                   if (!data[i])
561                      continue;
562 
563                   uint32_t max_value = i == 3 && is_int10 ? 3 : max_rgb;
564                   data[i] = nir_umin(b, data[i], nir_imm_int(b, max_value));
565                }
566             }
567          }
568          break;
569       case V_028714_SPI_SHADER_SINT16_ABGR:
570          if (type_size == 32) {
571             pack_op = nir_op_pack_sint_2x16;
572             if (is_int8 || is_int10) {
573                /* clamp 32bit output for 8/10 bit color component */
574                uint32_t max_rgb = is_int8 ? 127 : 511;
575                uint32_t min_rgb = is_int8 ? -128 : -512;
576 
577                for (int i = 0; i < 4; i++) {
578                   if (!data[i])
579                      continue;
580 
581                   uint32_t max_value = i == 3 && is_int10 ? 1 : max_rgb;
582                   uint32_t min_value = i == 3 && is_int10 ? -2u : min_rgb;
583 
584                   data[i] = nir_imin(b, data[i], nir_imm_int(b, max_value));
585                   data[i] = nir_imax(b, data[i], nir_imm_int(b, min_value));
586                }
587             }
588          }
589          break;
590       case V_028714_SPI_SHADER_UNORM16_ABGR:
591          pack_op = nir_op_pack_unorm_2x16;
592          break;
593       case V_028714_SPI_SHADER_SNORM16_ABGR:
594          pack_op = nir_op_pack_snorm_2x16;
595          break;
596       default:
597          unreachable("unsupported color export format");
598          break;
599       }
600 
601       for (int i = 0; i < 2; i++) {
602          nir_def *lo = data[i * 2];
603          nir_def *hi = data[i * 2 + 1];
604          if (!lo && !hi)
605             continue;
606 
607          lo = lo ? lo : nir_undef(b, 1, type_size);
608          hi = hi ? hi : nir_undef(b, 1, type_size);
609          nir_def *vec = nir_vec2(b, lo, hi);
610 
611          outputs[i] = nir_build_alu1(b, pack_op, vec);
612 
613          if (s->options->gfx_level >= GFX11)
614             write_mask |= BITFIELD_BIT(i);
615          else
616             write_mask |= 0x3 << (i * 2);
617       }
618 
619       if (s->options->gfx_level < GFX11)
620          flags |= AC_EXP_FLAG_COMPRESSED;
621    }
622    }
623 
624    s->exp[s->exp_num++] = nir_export_amd(b, nir_vec(b, outputs, 4),
625                                          .base = target,
626                                          .write_mask = write_mask,
627                                          .flags = flags);
628    return true;
629 }
630 
631 static void
emit_ps_dual_src_blend_swizzle(nir_builder * b,lower_ps_state * s,unsigned first_color_export)632 emit_ps_dual_src_blend_swizzle(nir_builder *b, lower_ps_state *s, unsigned first_color_export)
633 {
634    assert(s->exp_num > first_color_export + 1);
635 
636    nir_intrinsic_instr *mrt0_exp = s->exp[first_color_export];
637    nir_intrinsic_instr *mrt1_exp = s->exp[first_color_export + 1];
638 
639    /* There are some instructions which operate mrt1_exp's argument
640     * between mrt0_exp and mrt1_exp. Move mrt0_exp next to mrt1_exp,
641     * so that we can swizzle their arguments.
642     */
643    unsigned target0 = nir_intrinsic_base(mrt0_exp);
644    unsigned target1 = nir_intrinsic_base(mrt1_exp);
645    if (target0 > target1) {
646       /* mrt0 export is after mrt1 export, this happens when src0 is missing,
647        * so we emit mrt1 first then emit an empty mrt0.
648        *
649        * swap the pointer
650        */
651       nir_intrinsic_instr *tmp = mrt0_exp;
652       mrt0_exp = mrt1_exp;
653       mrt1_exp = tmp;
654 
655       /* move mrt1_exp down to after mrt0_exp */
656       nir_instr_move(nir_after_instr(&mrt0_exp->instr), &mrt1_exp->instr);
657    } else {
658       /* move mrt0_exp down to before mrt1_exp */
659       nir_instr_move(nir_before_instr(&mrt1_exp->instr), &mrt0_exp->instr);
660    }
661 
662    uint32_t mrt0_write_mask = nir_intrinsic_write_mask(mrt0_exp);
663    uint32_t mrt1_write_mask = nir_intrinsic_write_mask(mrt1_exp);
664    uint32_t write_mask = mrt0_write_mask | mrt1_write_mask;
665 
666    nir_def *mrt0_arg = mrt0_exp->src[0].ssa;
667    nir_def *mrt1_arg = mrt1_exp->src[0].ssa;
668 
669    /* Swizzle code is right before mrt0_exp. */
670    b->cursor = nir_before_instr(&mrt0_exp->instr);
671 
672    /* ACO need to emit the swizzle code by a pseudo instruction. */
673    if (s->options->use_aco) {
674       nir_export_dual_src_blend_amd(b, mrt0_arg, mrt1_arg, .write_mask = write_mask);
675       nir_instr_remove(&mrt0_exp->instr);
676       nir_instr_remove(&mrt1_exp->instr);
677       return;
678    }
679 
680    nir_def *undef = nir_undef(b, 1, 32);
681    nir_def *arg0_vec[4] = {undef, undef, undef, undef};
682    nir_def *arg1_vec[4] = {undef, undef, undef, undef};
683 
684    /* For illustration, originally
685     *   lane0 export arg00 and arg01
686     *   lane1 export arg10 and arg11.
687     *
688     * After the following operation
689     *   lane0 export arg00 and arg10
690     *   lane1 export arg01 and arg11.
691     */
692    u_foreach_bit (i, write_mask) {
693       nir_def *arg0 = nir_channel(b, mrt0_arg, i);
694       nir_def *arg1 = nir_channel(b, mrt1_arg, i);
695 
696       /* swap odd,even lanes of arg0 */
697       arg0 = nir_quad_swizzle_amd(b, arg0, .swizzle_mask = 0b10110001, .fetch_inactive = true);
698 
699       /* swap even lanes between arg0 and arg1 */
700       nir_def *tid = nir_load_subgroup_invocation(b);
701       nir_def *is_even = nir_ieq_imm(b, nir_iand_imm(b, tid, 1), 0);
702 
703       nir_def *tmp = arg0;
704       arg0 = nir_bcsel(b, is_even, arg1, arg0);
705       arg1 = nir_bcsel(b, is_even, tmp, arg1);
706 
707       /* swap odd,even lanes again for arg0 */
708       arg0 = nir_quad_swizzle_amd(b, arg0, .swizzle_mask = 0b10110001, .fetch_inactive = true);
709 
710       arg0_vec[i] = arg0;
711       arg1_vec[i] = arg1;
712    }
713 
714    nir_src_rewrite(&mrt0_exp->src[0], nir_vec(b, arg0_vec, 4));
715    nir_src_rewrite(&mrt1_exp->src[0], nir_vec(b, arg1_vec, 4));
716 
717    nir_intrinsic_set_write_mask(mrt0_exp, write_mask);
718    nir_intrinsic_set_write_mask(mrt1_exp, write_mask);
719 }
720 
721 static void
emit_ps_null_export(nir_builder * b,lower_ps_state * s)722 emit_ps_null_export(nir_builder *b, lower_ps_state *s)
723 {
724    const bool pops = b->shader->info.fs.sample_interlock_ordered ||
725                      b->shader->info.fs.sample_interlock_unordered ||
726                      b->shader->info.fs.pixel_interlock_ordered ||
727                      b->shader->info.fs.pixel_interlock_unordered;
728 
729    /* Gfx10+ doesn't need to export anything if we don't need to export the EXEC mask
730     * for discard.
731     * In Primitive Ordered Pixel Shading, however, GFX11+ explicitly uses the `done` export to exit
732     * the ordered section, and before GFX11, shaders with POPS also need an export.
733     */
734    if (s->options->gfx_level >= GFX10 && !s->options->uses_discard && !pops)
735       return;
736 
737    /* The `done` export exits the POPS ordered section on GFX11+, make sure UniformMemory and
738     * ImageMemory (in SPIR-V terms) accesses from the ordered section may not be reordered below it.
739     */
740    if (s->options->gfx_level >= GFX11 && pops)
741       nir_scoped_memory_barrier(b, SCOPE_QUEUE_FAMILY, NIR_MEMORY_RELEASE,
742                                 nir_var_image | nir_var_mem_ubo | nir_var_mem_ssbo |
743                                 nir_var_mem_global);
744 
745    /* Gfx11 doesn't support null exports, and mrt0 should be exported instead. */
746    unsigned target = s->options->gfx_level >= GFX11 ?
747       V_008DFC_SQ_EXP_MRT : V_008DFC_SQ_EXP_NULL;
748 
749    nir_intrinsic_instr *intrin =
750       nir_export_amd(b, nir_undef(b, 4, 32),
751                      .base = target,
752                      .flags = AC_EXP_FLAG_VALID_MASK | AC_EXP_FLAG_DONE);
753    /* To avoid builder set write mask to 0xf. */
754    nir_intrinsic_set_write_mask(intrin, 0);
755 }
756 
757 static void
export_ps_outputs(nir_builder * b,lower_ps_state * s)758 export_ps_outputs(nir_builder *b, lower_ps_state *s)
759 {
760    b->cursor = nir_after_impl(b->impl);
761 
762    emit_ps_color_clamp_and_alpha_test(b, s);
763 
764    if (!s->options->no_depth_export)
765       emit_ps_mrtz_export(b, s);
766 
767    /* When non-monolithic shader, RADV export mrtz in main part (except on
768     * RDNA3 for alpha to coverage) and export color in epilog.
769     */
770    if (s->options->no_color_export)
771       return;
772 
773    unsigned first_color_export = s->exp_num;
774 
775    /* When dual src blend is enabled and we need both src0 and src1
776     * export present, try to export both src, and add an empty export
777     * for either src missing.
778     */
779    if (s->output_types[DUAL_SRC_BLEND_SLOT] != nir_type_invalid ||
780        s->options->dual_src_blend_swizzle) {
781       unsigned slot;
782       if (s->output_types[FRAG_RESULT_COLOR] != nir_type_invalid) {
783          /* when dual source blending, there must be only one color buffer */
784          assert(s->options->broadcast_last_cbuf == 0);
785          slot = FRAG_RESULT_COLOR;
786       } else {
787          slot = FRAG_RESULT_DATA0;
788       }
789 
790       bool src0_exported = emit_ps_color_export(b, s, slot, 0);
791       /* src1 use cubf1 info, when dual src blend is enabled it's
792        * same as cbuf0, but when dual src blend is disabled it's used
793        * to disable src1 export.
794        */
795       bool src1_exported = emit_ps_color_export(b, s, DUAL_SRC_BLEND_SLOT, 1);
796 
797       bool need_empty_export =
798          /* miss src1, need to add src1 only when swizzle case */
799          (src0_exported && !src1_exported && s->options->dual_src_blend_swizzle) ||
800          /* miss src0, always need to add src0 */
801          (!src0_exported && src1_exported);
802 
803       if (need_empty_export) {
804          /* set to expected value */
805          s->compacted_mrt_index = src0_exported ? 1 : 0;
806 
807          unsigned target = get_ps_color_export_target(s);
808 
809          s->exp[s->exp_num++] =
810             nir_export_amd(b, nir_undef(b, 4, 32), .base = target);
811       }
812    } else {
813       if (s->output_types[FRAG_RESULT_COLOR] != nir_type_invalid) {
814          /* write to all color buffers */
815          for (int cbuf = 0; cbuf <= s->options->broadcast_last_cbuf; cbuf++)
816             emit_ps_color_export(b, s, FRAG_RESULT_COLOR, cbuf);
817       } else {
818          for (int cbuf = 0; cbuf < MAX_DRAW_BUFFERS; cbuf++) {
819             unsigned slot = FRAG_RESULT_DATA0 + cbuf;
820             emit_ps_color_export(b, s, slot, cbuf);
821          }
822       }
823    }
824 
825    if (s->exp_num) {
826       if (s->options->dual_src_blend_swizzle) {
827          emit_ps_dual_src_blend_swizzle(b, s, first_color_export);
828          /* Skip last export flag setting because they have been replaced by
829           * a pseudo instruction.
830           */
831          if (s->options->use_aco)
832             return;
833       }
834 
835       /* Specify that this is the last export */
836       nir_intrinsic_instr *final_exp = s->exp[s->exp_num - 1];
837       unsigned final_exp_flags = nir_intrinsic_flags(final_exp);
838       final_exp_flags |= AC_EXP_FLAG_DONE | AC_EXP_FLAG_VALID_MASK;
839       nir_intrinsic_set_flags(final_exp, final_exp_flags);
840 
841       /* The `done` export exits the POPS ordered section on GFX11+, make sure UniformMemory and
842        * ImageMemory (in SPIR-V terms) accesses from the ordered section may not be reordered below
843        * it.
844        */
845       if (s->options->gfx_level >= GFX11 &&
846           (b->shader->info.fs.sample_interlock_ordered ||
847            b->shader->info.fs.sample_interlock_unordered ||
848            b->shader->info.fs.pixel_interlock_ordered ||
849            b->shader->info.fs.pixel_interlock_unordered)) {
850          b->cursor = nir_before_instr(&final_exp->instr);
851          nir_scoped_memory_barrier(b, SCOPE_QUEUE_FAMILY, NIR_MEMORY_RELEASE,
852                                    nir_var_image | nir_var_mem_ubo | nir_var_mem_ssbo |
853                                    nir_var_mem_global);
854       }
855    } else {
856       emit_ps_null_export(b, s);
857    }
858 }
859 
860 void
ac_nir_lower_ps(nir_shader * nir,const ac_nir_lower_ps_options * options)861 ac_nir_lower_ps(nir_shader *nir, const ac_nir_lower_ps_options *options)
862 {
863    nir_function_impl *impl = nir_shader_get_entrypoint(nir);
864 
865    nir_builder builder = nir_builder_create(impl);
866    nir_builder *b = &builder;
867 
868    lower_ps_state state = {
869       .options = options,
870    };
871 
872    create_interp_param(b, &state);
873 
874    nir_shader_instructions_pass(nir, lower_ps_intrinsic,
875                                 nir_metadata_block_index | nir_metadata_dominance,
876                                 &state);
877 
878    /* Must be after lower_ps_intrinsic() to prevent it lower added intrinsic here. */
879    init_interp_param(b, &state);
880 
881    export_ps_outputs(b, &state);
882 
883    /* Cleanup nir variable, as RADV won't do this. */
884    if (state.lower_load_barycentric)
885       nir_lower_vars_to_ssa(nir);
886 }
887