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1 /*
2  * Copyright © 2010 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 
24 /** @file brw_fs_visitor.cpp
25  *
26  * This file supports generating the FS LIR from the GLSL IR.  The LIR
27  * makes it easier to do backend-specific optimizations than doing so
28  * in the GLSL IR or in the native code.
29  */
30 #include "brw_eu.h"
31 #include "brw_fs.h"
32 #include "compiler/glsl_types.h"
33 
34 using namespace brw;
35 
36 /* Sample from the MCS surface attached to this multisample texture. */
37 fs_reg
emit_mcs_fetch(const fs_reg & coordinate,unsigned components,const fs_reg & texture,const fs_reg & texture_handle)38 fs_visitor::emit_mcs_fetch(const fs_reg &coordinate, unsigned components,
39                            const fs_reg &texture,
40                            const fs_reg &texture_handle)
41 {
42    const fs_reg dest = vgrf(glsl_type::uvec4_type);
43 
44    fs_reg srcs[TEX_LOGICAL_NUM_SRCS];
45    srcs[TEX_LOGICAL_SRC_COORDINATE] = coordinate;
46    srcs[TEX_LOGICAL_SRC_SURFACE] = texture;
47    srcs[TEX_LOGICAL_SRC_SAMPLER] = brw_imm_ud(0);
48    srcs[TEX_LOGICAL_SRC_SURFACE_HANDLE] = texture_handle;
49    srcs[TEX_LOGICAL_SRC_COORD_COMPONENTS] = brw_imm_d(components);
50    srcs[TEX_LOGICAL_SRC_GRAD_COMPONENTS] = brw_imm_d(0);
51 
52    fs_inst *inst = bld.emit(SHADER_OPCODE_TXF_MCS_LOGICAL, dest, srcs,
53                             ARRAY_SIZE(srcs));
54 
55    /* We only care about one or two regs of response, but the sampler always
56     * writes 4/8.
57     */
58    inst->size_written = 4 * dest.component_size(inst->exec_size);
59 
60    return dest;
61 }
62 
63 /** Emits a dummy fragment shader consisting of magenta for bringup purposes. */
64 void
emit_dummy_fs()65 fs_visitor::emit_dummy_fs()
66 {
67    int reg_width = dispatch_width / 8;
68 
69    /* Everyone's favorite color. */
70    const float color[4] = { 1.0, 0.0, 1.0, 0.0 };
71    for (int i = 0; i < 4; i++) {
72       bld.MOV(fs_reg(MRF, 2 + i * reg_width, BRW_REGISTER_TYPE_F),
73               brw_imm_f(color[i]));
74    }
75 
76    fs_inst *write;
77    write = bld.emit(FS_OPCODE_FB_WRITE);
78    write->eot = true;
79    write->last_rt = true;
80    if (devinfo->ver >= 6) {
81       write->base_mrf = 2;
82       write->mlen = 4 * reg_width;
83    } else {
84       write->header_size = 2;
85       write->base_mrf = 0;
86       write->mlen = 2 + 4 * reg_width;
87    }
88 
89    /* Tell the SF we don't have any inputs.  Gfx4-5 require at least one
90     * varying to avoid GPU hangs, so set that.
91     */
92    struct brw_wm_prog_data *wm_prog_data = brw_wm_prog_data(this->prog_data);
93    wm_prog_data->num_varying_inputs = devinfo->ver < 6 ? 1 : 0;
94    memset(wm_prog_data->urb_setup, -1,
95           sizeof(wm_prog_data->urb_setup[0]) * VARYING_SLOT_MAX);
96    brw_compute_urb_setup_index(wm_prog_data);
97 
98    /* We don't have any uniforms. */
99    stage_prog_data->nr_params = 0;
100    stage_prog_data->curb_read_length = 0;
101    stage_prog_data->dispatch_grf_start_reg = 2;
102    wm_prog_data->dispatch_grf_start_reg_16 = 2;
103    wm_prog_data->dispatch_grf_start_reg_32 = 2;
104    grf_used = 1; /* Gfx4-5 don't allow zero GRF blocks */
105 
106    calculate_cfg();
107 }
108 
109 /* Input data is organized with first the per-primitive values, followed
110  * by per-vertex values.  The per-vertex will have interpolation information
111  * associated, so use 4 components for each value.
112  */
113 
114 /* The register location here is relative to the start of the URB
115  * data.  It will get adjusted to be a real location before
116  * generate_code() time.
117  */
118 fs_reg
interp_reg(int location,int channel)119 fs_visitor::interp_reg(int location, int channel)
120 {
121    assert(stage == MESA_SHADER_FRAGMENT);
122    assert(BITFIELD64_BIT(location) & ~nir->info.per_primitive_inputs);
123 
124    const struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
125 
126    assert(prog_data->urb_setup[location] >= 0);
127    unsigned nr = prog_data->urb_setup[location];
128 
129    /* Adjust so we start counting from the first per_vertex input. */
130    assert(nr >= prog_data->num_per_primitive_inputs);
131    nr -= prog_data->num_per_primitive_inputs;
132 
133    const unsigned per_vertex_start = prog_data->num_per_primitive_inputs;
134    const unsigned regnr = per_vertex_start + (nr * 4) + channel;
135 
136    return fs_reg(ATTR, regnr, BRW_REGISTER_TYPE_F);
137 }
138 
139 /* The register location here is relative to the start of the URB
140  * data.  It will get adjusted to be a real location before
141  * generate_code() time.
142  */
143 fs_reg
per_primitive_reg(int location)144 fs_visitor::per_primitive_reg(int location)
145 {
146    assert(stage == MESA_SHADER_FRAGMENT);
147    assert(BITFIELD64_BIT(location) & nir->info.per_primitive_inputs);
148 
149    const struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
150 
151    assert(prog_data->urb_setup[location] >= 0);
152 
153    const unsigned regnr = prog_data->urb_setup[location];
154    assert(regnr < prog_data->num_per_primitive_inputs);
155 
156    return fs_reg(ATTR, regnr, BRW_REGISTER_TYPE_F);
157 }
158 
159 /** Emits the interpolation for the varying inputs. */
160 void
emit_interpolation_setup_gfx4()161 fs_visitor::emit_interpolation_setup_gfx4()
162 {
163    struct brw_reg g1_uw = retype(brw_vec1_grf(1, 0), BRW_REGISTER_TYPE_UW);
164 
165    fs_builder abld = bld.annotate("compute pixel centers");
166    this->pixel_x = vgrf(glsl_type::uint_type);
167    this->pixel_y = vgrf(glsl_type::uint_type);
168    this->pixel_x.type = BRW_REGISTER_TYPE_UW;
169    this->pixel_y.type = BRW_REGISTER_TYPE_UW;
170    abld.ADD(this->pixel_x,
171             fs_reg(stride(suboffset(g1_uw, 4), 2, 4, 0)),
172             fs_reg(brw_imm_v(0x10101010)));
173    abld.ADD(this->pixel_y,
174             fs_reg(stride(suboffset(g1_uw, 5), 2, 4, 0)),
175             fs_reg(brw_imm_v(0x11001100)));
176 
177    abld = bld.annotate("compute pixel deltas from v0");
178 
179    this->delta_xy[BRW_BARYCENTRIC_PERSPECTIVE_PIXEL] =
180       vgrf(glsl_type::vec2_type);
181    const fs_reg &delta_xy = this->delta_xy[BRW_BARYCENTRIC_PERSPECTIVE_PIXEL];
182    const fs_reg xstart(negate(brw_vec1_grf(1, 0)));
183    const fs_reg ystart(negate(brw_vec1_grf(1, 1)));
184 
185    if (devinfo->has_pln) {
186       for (unsigned i = 0; i < dispatch_width / 8; i++) {
187          abld.quarter(i).ADD(quarter(offset(delta_xy, abld, 0), i),
188                              quarter(this->pixel_x, i), xstart);
189          abld.quarter(i).ADD(quarter(offset(delta_xy, abld, 1), i),
190                              quarter(this->pixel_y, i), ystart);
191       }
192    } else {
193       abld.ADD(offset(delta_xy, abld, 0), this->pixel_x, xstart);
194       abld.ADD(offset(delta_xy, abld, 1), this->pixel_y, ystart);
195    }
196 
197    this->pixel_z = fetch_payload_reg(bld, payload.source_depth_reg);
198 
199    /* The SF program automatically handles doing the perspective correction or
200     * not based on wm_prog_data::interp_mode[] so we can use the same pixel
201     * offsets for both perspective and non-perspective.
202     */
203    this->delta_xy[BRW_BARYCENTRIC_NONPERSPECTIVE_PIXEL] =
204       this->delta_xy[BRW_BARYCENTRIC_PERSPECTIVE_PIXEL];
205 
206    abld = bld.annotate("compute pos.w and 1/pos.w");
207    /* Compute wpos.w.  It's always in our setup, since it's needed to
208     * interpolate the other attributes.
209     */
210    this->wpos_w = vgrf(glsl_type::float_type);
211    abld.emit(FS_OPCODE_LINTERP, wpos_w, delta_xy,
212              component(interp_reg(VARYING_SLOT_POS, 3), 0));
213    /* Compute the pixel 1/W value from wpos.w. */
214    this->pixel_w = vgrf(glsl_type::float_type);
215    abld.emit(SHADER_OPCODE_RCP, this->pixel_w, wpos_w);
216 }
217 
218 static unsigned
brw_rnd_mode_from_nir(unsigned mode,unsigned * mask)219 brw_rnd_mode_from_nir(unsigned mode, unsigned *mask)
220 {
221    unsigned brw_mode = 0;
222    *mask = 0;
223 
224    if ((FLOAT_CONTROLS_ROUNDING_MODE_RTZ_FP16 |
225         FLOAT_CONTROLS_ROUNDING_MODE_RTZ_FP32 |
226         FLOAT_CONTROLS_ROUNDING_MODE_RTZ_FP64) &
227        mode) {
228       brw_mode |= BRW_RND_MODE_RTZ << BRW_CR0_RND_MODE_SHIFT;
229       *mask |= BRW_CR0_RND_MODE_MASK;
230    }
231    if ((FLOAT_CONTROLS_ROUNDING_MODE_RTE_FP16 |
232         FLOAT_CONTROLS_ROUNDING_MODE_RTE_FP32 |
233         FLOAT_CONTROLS_ROUNDING_MODE_RTE_FP64) &
234        mode) {
235       brw_mode |= BRW_RND_MODE_RTNE << BRW_CR0_RND_MODE_SHIFT;
236       *mask |= BRW_CR0_RND_MODE_MASK;
237    }
238    if (mode & FLOAT_CONTROLS_DENORM_PRESERVE_FP16) {
239       brw_mode |= BRW_CR0_FP16_DENORM_PRESERVE;
240       *mask |= BRW_CR0_FP16_DENORM_PRESERVE;
241    }
242    if (mode & FLOAT_CONTROLS_DENORM_PRESERVE_FP32) {
243       brw_mode |= BRW_CR0_FP32_DENORM_PRESERVE;
244       *mask |= BRW_CR0_FP32_DENORM_PRESERVE;
245    }
246    if (mode & FLOAT_CONTROLS_DENORM_PRESERVE_FP64) {
247       brw_mode |= BRW_CR0_FP64_DENORM_PRESERVE;
248       *mask |= BRW_CR0_FP64_DENORM_PRESERVE;
249    }
250    if (mode & FLOAT_CONTROLS_DENORM_FLUSH_TO_ZERO_FP16)
251       *mask |= BRW_CR0_FP16_DENORM_PRESERVE;
252    if (mode & FLOAT_CONTROLS_DENORM_FLUSH_TO_ZERO_FP32)
253       *mask |= BRW_CR0_FP32_DENORM_PRESERVE;
254    if (mode & FLOAT_CONTROLS_DENORM_FLUSH_TO_ZERO_FP64)
255       *mask |= BRW_CR0_FP64_DENORM_PRESERVE;
256    if (mode == FLOAT_CONTROLS_DEFAULT_FLOAT_CONTROL_MODE)
257       *mask |= BRW_CR0_FP_MODE_MASK;
258 
259    if (*mask != 0)
260       assert((*mask & brw_mode) == brw_mode);
261 
262    return brw_mode;
263 }
264 
265 void
emit_shader_float_controls_execution_mode()266 fs_visitor::emit_shader_float_controls_execution_mode()
267 {
268    unsigned execution_mode = this->nir->info.float_controls_execution_mode;
269    if (execution_mode == FLOAT_CONTROLS_DEFAULT_FLOAT_CONTROL_MODE)
270       return;
271 
272    fs_builder abld = bld.annotate("shader floats control execution mode");
273    unsigned mask, mode = brw_rnd_mode_from_nir(execution_mode, &mask);
274 
275    if (mask == 0)
276       return;
277 
278    abld.emit(SHADER_OPCODE_FLOAT_CONTROL_MODE, bld.null_reg_ud(),
279              brw_imm_d(mode), brw_imm_d(mask));
280 }
281 
282 /** Emits the interpolation for the varying inputs. */
283 void
emit_interpolation_setup_gfx6()284 fs_visitor::emit_interpolation_setup_gfx6()
285 {
286    fs_builder abld = bld.annotate("compute pixel centers");
287 
288    this->pixel_x = vgrf(glsl_type::float_type);
289    this->pixel_y = vgrf(glsl_type::float_type);
290 
291    struct brw_wm_prog_data *wm_prog_data = brw_wm_prog_data(prog_data);
292 
293    fs_reg int_pixel_offset_x, int_pixel_offset_y; /* Used on Gen12HP+ */
294    fs_reg int_pixel_offset_xy; /* Used on Gen8+ */
295    fs_reg half_int_pixel_offset_x, half_int_pixel_offset_y;
296    if (!wm_prog_data->per_coarse_pixel_dispatch) {
297       /* The thread payload only delivers subspan locations (ss0, ss1,
298        * ss2, ...). Since subspans covers 2x2 pixels blocks, we need to
299        * generate 4 pixel coordinates out of each subspan location. We do this
300        * by replicating a subspan coordinate 4 times and adding an offset of 1
301        * in each direction from the initial top left (tl) location to generate
302        * top right (tr = +1 in x), bottom left (bl = +1 in y) and bottom right
303        * (br = +1 in x, +1 in y).
304        *
305        * The locations we build look like this in SIMD8 :
306        *
307        *    ss0.tl ss0.tr ss0.bl ss0.br ss1.tl ss1.tr ss1.bl ss1.br
308        *
309        * The value 0x11001010 is a vector of 8 half byte vector. It adds
310        * following to generate the 4 pixels coordinates out of the subspan0:
311        *
312        *  0x
313        *    1 : ss0.y + 1 -> ss0.br.y
314        *    1 : ss0.y + 1 -> ss0.bl.y
315        *    0 : ss0.y + 0 -> ss0.tr.y
316        *    0 : ss0.y + 0 -> ss0.tl.y
317        *    1 : ss0.x + 1 -> ss0.br.x
318        *    0 : ss0.x + 0 -> ss0.bl.x
319        *    1 : ss0.x + 1 -> ss0.tr.x
320        *    0 : ss0.x + 0 -> ss0.tl.x
321        *
322        * By doing a SIMD16 add in a SIMD8 shader, we can generate the 8 pixels
323        * coordinates out of 2 subspans coordinates in a single ADD instruction
324        * (twice the operation above).
325        */
326       int_pixel_offset_xy = fs_reg(brw_imm_v(0x11001010));
327       half_int_pixel_offset_x = fs_reg(brw_imm_uw(0));
328       half_int_pixel_offset_y = fs_reg(brw_imm_uw(0));
329       /* On Gfx12.5, because of regioning restrictions, the interpolation code
330        * is slightly different and works off X & Y only inputs. The ordering
331        * of the half bytes here is a bit odd, with each subspan replicated
332        * twice and every other element is discarded :
333        *
334        *             ss0.tl ss0.tl ss0.tr ss0.tr ss0.bl ss0.bl ss0.br ss0.br
335        *  X offset:    0      0      1      0      0      0      1      0
336        *  Y offset:    0      0      0      0      1      0      1      0
337        */
338       int_pixel_offset_x = fs_reg(brw_imm_v(0x01000100));
339       int_pixel_offset_y = fs_reg(brw_imm_v(0x01010000));
340    } else {
341       /* In coarse pixel dispatch we have to do the same ADD instruction that
342        * we do in normal per pixel dispatch, except this time we're not adding
343        * 1 in each direction, but instead the coarse pixel size.
344        *
345        * The coarse pixel size is delivered as 2 u8 in r1.0
346        */
347       struct brw_reg r1_0 = retype(brw_vec1_reg(BRW_GENERAL_REGISTER_FILE, 1, 0), BRW_REGISTER_TYPE_UB);
348 
349       const fs_builder dbld =
350          abld.exec_all().group(MIN2(16, dispatch_width) * 2, 0);
351 
352       if (devinfo->verx10 >= 125) {
353          /* To build the array of half bytes we do and AND operation with the
354           * right mask in X.
355           */
356          int_pixel_offset_x = dbld.vgrf(BRW_REGISTER_TYPE_UW);
357          dbld.AND(int_pixel_offset_x, byte_offset(r1_0, 0), brw_imm_v(0x0f000f00));
358 
359          /* And the right mask in Y. */
360          int_pixel_offset_y = dbld.vgrf(BRW_REGISTER_TYPE_UW);
361          dbld.AND(int_pixel_offset_y, byte_offset(r1_0, 1), brw_imm_v(0x0f0f0000));
362       } else {
363          /* To build the array of half bytes we do and AND operation with the
364           * right mask in X.
365           */
366          int_pixel_offset_x = dbld.vgrf(BRW_REGISTER_TYPE_UW);
367          dbld.AND(int_pixel_offset_x, byte_offset(r1_0, 0), brw_imm_v(0x0000f0f0));
368 
369          /* And the right mask in Y. */
370          int_pixel_offset_y = dbld.vgrf(BRW_REGISTER_TYPE_UW);
371          dbld.AND(int_pixel_offset_y, byte_offset(r1_0, 1), brw_imm_v(0xff000000));
372 
373          /* Finally OR the 2 registers. */
374          int_pixel_offset_xy = dbld.vgrf(BRW_REGISTER_TYPE_UW);
375          dbld.OR(int_pixel_offset_xy, int_pixel_offset_x, int_pixel_offset_y);
376       }
377 
378       /* Also compute the half pixel size used to center pixels. */
379       half_int_pixel_offset_x = bld.vgrf(BRW_REGISTER_TYPE_UW);
380       half_int_pixel_offset_y = bld.vgrf(BRW_REGISTER_TYPE_UW);
381 
382       bld.SHR(half_int_pixel_offset_x, suboffset(r1_0, 0), brw_imm_ud(1));
383       bld.SHR(half_int_pixel_offset_y, suboffset(r1_0, 1), brw_imm_ud(1));
384    }
385 
386    for (unsigned i = 0; i < DIV_ROUND_UP(dispatch_width, 16); i++) {
387       const fs_builder hbld = abld.group(MIN2(16, dispatch_width), i);
388       struct brw_reg gi_uw = retype(brw_vec1_grf(1 + i, 0), BRW_REGISTER_TYPE_UW);
389 
390       if (devinfo->verx10 >= 125) {
391          const fs_builder dbld =
392             abld.exec_all().group(hbld.dispatch_width() * 2, 0);
393          const fs_reg int_pixel_x = dbld.vgrf(BRW_REGISTER_TYPE_UW);
394          const fs_reg int_pixel_y = dbld.vgrf(BRW_REGISTER_TYPE_UW);
395 
396          dbld.ADD(int_pixel_x,
397                   fs_reg(stride(suboffset(gi_uw, 4), 2, 8, 0)),
398                   int_pixel_offset_x);
399          dbld.ADD(int_pixel_y,
400                   fs_reg(stride(suboffset(gi_uw, 5), 2, 8, 0)),
401                   int_pixel_offset_y);
402 
403          if (wm_prog_data->per_coarse_pixel_dispatch) {
404             dbld.ADD(int_pixel_x, int_pixel_x,
405                      horiz_stride(half_int_pixel_offset_x, 0));
406             dbld.ADD(int_pixel_y, int_pixel_y,
407                      horiz_stride(half_int_pixel_offset_y, 0));
408          }
409 
410          hbld.MOV(offset(pixel_x, hbld, i), horiz_stride(int_pixel_x, 2));
411          hbld.MOV(offset(pixel_y, hbld, i), horiz_stride(int_pixel_y, 2));
412 
413       } else if (devinfo->ver >= 8 || dispatch_width == 8) {
414          /* The "Register Region Restrictions" page says for BDW (and newer,
415           * presumably):
416           *
417           *     "When destination spans two registers, the source may be one or
418           *      two registers. The destination elements must be evenly split
419           *      between the two registers."
420           *
421           * Thus we can do a single add(16) in SIMD8 or an add(32) in SIMD16
422           * to compute our pixel centers.
423           */
424          const fs_builder dbld =
425             abld.exec_all().group(hbld.dispatch_width() * 2, 0);
426          fs_reg int_pixel_xy = dbld.vgrf(BRW_REGISTER_TYPE_UW);
427 
428          dbld.ADD(int_pixel_xy,
429                   fs_reg(stride(suboffset(gi_uw, 4), 1, 4, 0)),
430                   int_pixel_offset_xy);
431 
432          hbld.emit(FS_OPCODE_PIXEL_X, offset(pixel_x, hbld, i), int_pixel_xy,
433                                       horiz_stride(half_int_pixel_offset_x, 0));
434          hbld.emit(FS_OPCODE_PIXEL_Y, offset(pixel_y, hbld, i), int_pixel_xy,
435                                       horiz_stride(half_int_pixel_offset_y, 0));
436       } else {
437          /* The "Register Region Restrictions" page says for SNB, IVB, HSW:
438           *
439           *     "When destination spans two registers, the source MUST span
440           *      two registers."
441           *
442           * Since the GRF source of the ADD will only read a single register,
443           * we must do two separate ADDs in SIMD16.
444           */
445          const fs_reg int_pixel_x = hbld.vgrf(BRW_REGISTER_TYPE_UW);
446          const fs_reg int_pixel_y = hbld.vgrf(BRW_REGISTER_TYPE_UW);
447 
448          hbld.ADD(int_pixel_x,
449                   fs_reg(stride(suboffset(gi_uw, 4), 2, 4, 0)),
450                   fs_reg(brw_imm_v(0x10101010)));
451          hbld.ADD(int_pixel_y,
452                   fs_reg(stride(suboffset(gi_uw, 5), 2, 4, 0)),
453                   fs_reg(brw_imm_v(0x11001100)));
454 
455          /* As of gfx6, we can no longer mix float and int sources.  We have
456           * to turn the integer pixel centers into floats for their actual
457           * use.
458           */
459          hbld.MOV(offset(pixel_x, hbld, i), int_pixel_x);
460          hbld.MOV(offset(pixel_y, hbld, i), int_pixel_y);
461       }
462    }
463 
464    abld = bld.annotate("compute pos.z");
465    if (wm_prog_data->uses_depth_w_coefficients) {
466       assert(!wm_prog_data->uses_src_depth);
467       /* In coarse pixel mode, the HW doesn't interpolate Z coordinate
468        * properly. In the same way we have to add the coarse pixel size to
469        * pixels locations, here we recompute the Z value with 2 coefficients
470        * in X & Y axis.
471        */
472       fs_reg coef_payload = fetch_payload_reg(abld, payload.depth_w_coef_reg, BRW_REGISTER_TYPE_F);
473       const fs_reg x_start = brw_vec1_grf(coef_payload.nr, 2);
474       const fs_reg y_start = brw_vec1_grf(coef_payload.nr, 6);
475       const fs_reg z_cx    = brw_vec1_grf(coef_payload.nr, 1);
476       const fs_reg z_cy    = brw_vec1_grf(coef_payload.nr, 0);
477       const fs_reg z_c0    = brw_vec1_grf(coef_payload.nr, 3);
478 
479       const fs_reg float_pixel_x = abld.vgrf(BRW_REGISTER_TYPE_F);
480       const fs_reg float_pixel_y = abld.vgrf(BRW_REGISTER_TYPE_F);
481 
482       abld.ADD(float_pixel_x, this->pixel_x, negate(x_start));
483       abld.ADD(float_pixel_y, this->pixel_y, negate(y_start));
484 
485       /* r1.0 - 0:7 ActualCoarsePixelShadingSize.X */
486       const fs_reg u8_cps_width = fs_reg(retype(brw_vec1_grf(1, 0), BRW_REGISTER_TYPE_UB));
487       /* r1.0 - 15:8 ActualCoarsePixelShadingSize.Y */
488       const fs_reg u8_cps_height = byte_offset(u8_cps_width, 1);
489       const fs_reg u32_cps_width = abld.vgrf(BRW_REGISTER_TYPE_UD);
490       const fs_reg u32_cps_height = abld.vgrf(BRW_REGISTER_TYPE_UD);
491       abld.MOV(u32_cps_width, u8_cps_width);
492       abld.MOV(u32_cps_height, u8_cps_height);
493 
494       const fs_reg f_cps_width = abld.vgrf(BRW_REGISTER_TYPE_F);
495       const fs_reg f_cps_height = abld.vgrf(BRW_REGISTER_TYPE_F);
496       abld.MOV(f_cps_width, u32_cps_width);
497       abld.MOV(f_cps_height, u32_cps_height);
498 
499       /* Center in the middle of the coarse pixel. */
500       abld.MAD(float_pixel_x, float_pixel_x, brw_imm_f(0.5f), f_cps_width);
501       abld.MAD(float_pixel_y, float_pixel_y, brw_imm_f(0.5f), f_cps_height);
502 
503       this->pixel_z = abld.vgrf(BRW_REGISTER_TYPE_F);
504       abld.MAD(this->pixel_z, z_c0, z_cx, float_pixel_x);
505       abld.MAD(this->pixel_z, this->pixel_z, z_cy, float_pixel_y);
506    }
507 
508    if (wm_prog_data->uses_src_depth) {
509       assert(!wm_prog_data->uses_depth_w_coefficients);
510       this->pixel_z = fetch_payload_reg(bld, payload.source_depth_reg);
511    }
512 
513    if (wm_prog_data->uses_src_w) {
514       abld = bld.annotate("compute pos.w");
515       this->pixel_w = fetch_payload_reg(abld, payload.source_w_reg);
516       this->wpos_w = vgrf(glsl_type::float_type);
517       abld.emit(SHADER_OPCODE_RCP, this->wpos_w, this->pixel_w);
518    }
519 
520    for (int i = 0; i < BRW_BARYCENTRIC_MODE_COUNT; ++i) {
521       this->delta_xy[i] = fetch_barycentric_reg(
522          bld, payload.barycentric_coord_reg[i]);
523    }
524 
525    uint32_t centroid_modes = wm_prog_data->barycentric_interp_modes &
526       (1 << BRW_BARYCENTRIC_PERSPECTIVE_CENTROID |
527        1 << BRW_BARYCENTRIC_NONPERSPECTIVE_CENTROID);
528 
529    if (devinfo->needs_unlit_centroid_workaround && centroid_modes) {
530       /* Get the pixel/sample mask into f0 so that we know which
531        * pixels are lit.  Then, for each channel that is unlit,
532        * replace the centroid data with non-centroid data.
533        */
534       for (unsigned i = 0; i < DIV_ROUND_UP(dispatch_width, 16); i++) {
535          bld.exec_all().group(1, 0)
536             .MOV(retype(brw_flag_reg(0, i), BRW_REGISTER_TYPE_UW),
537                  retype(brw_vec1_grf(1 + i, 7), BRW_REGISTER_TYPE_UW));
538       }
539 
540       for (int i = 0; i < BRW_BARYCENTRIC_MODE_COUNT; ++i) {
541          if (!(centroid_modes & (1 << i)))
542             continue;
543 
544          const fs_reg centroid_delta_xy = delta_xy[i];
545          const fs_reg &pixel_delta_xy = delta_xy[i - 1];
546 
547          delta_xy[i] = bld.vgrf(BRW_REGISTER_TYPE_F, 2);
548 
549          for (unsigned c = 0; c < 2; c++) {
550             for (unsigned q = 0; q < dispatch_width / 8; q++) {
551                set_predicate(BRW_PREDICATE_NORMAL,
552                   bld.quarter(q).SEL(
553                      quarter(offset(delta_xy[i], bld, c), q),
554                      quarter(offset(centroid_delta_xy, bld, c), q),
555                      quarter(offset(pixel_delta_xy, bld, c), q)));
556             }
557          }
558       }
559    }
560 }
561 
562 static enum brw_conditional_mod
cond_for_alpha_func(enum compare_func func)563 cond_for_alpha_func(enum compare_func func)
564 {
565    switch(func) {
566    case COMPARE_FUNC_GREATER:
567       return BRW_CONDITIONAL_G;
568    case COMPARE_FUNC_GEQUAL:
569       return BRW_CONDITIONAL_GE;
570    case COMPARE_FUNC_LESS:
571       return BRW_CONDITIONAL_L;
572    case COMPARE_FUNC_LEQUAL:
573       return BRW_CONDITIONAL_LE;
574    case COMPARE_FUNC_EQUAL:
575       return BRW_CONDITIONAL_EQ;
576    case COMPARE_FUNC_NOTEQUAL:
577       return BRW_CONDITIONAL_NEQ;
578    default:
579       unreachable("Not reached");
580    }
581 }
582 
583 /**
584  * Alpha test support for when we compile it into the shader instead
585  * of using the normal fixed-function alpha test.
586  */
587 void
emit_alpha_test()588 fs_visitor::emit_alpha_test()
589 {
590    assert(stage == MESA_SHADER_FRAGMENT);
591    brw_wm_prog_key *key = (brw_wm_prog_key*) this->key;
592    const fs_builder abld = bld.annotate("Alpha test");
593 
594    fs_inst *cmp;
595    if (key->alpha_test_func == COMPARE_FUNC_ALWAYS)
596       return;
597 
598    if (key->alpha_test_func == COMPARE_FUNC_NEVER) {
599       /* f0.1 = 0 */
600       fs_reg some_reg = fs_reg(retype(brw_vec8_grf(0, 0),
601                                       BRW_REGISTER_TYPE_UW));
602       cmp = abld.CMP(bld.null_reg_f(), some_reg, some_reg,
603                      BRW_CONDITIONAL_NEQ);
604    } else {
605       /* RT0 alpha */
606       fs_reg color = offset(outputs[0], bld, 3);
607 
608       /* f0.1 &= func(color, ref) */
609       cmp = abld.CMP(bld.null_reg_f(), color, brw_imm_f(key->alpha_test_ref),
610                      cond_for_alpha_func(key->alpha_test_func));
611    }
612    cmp->predicate = BRW_PREDICATE_NORMAL;
613    cmp->flag_subreg = 1;
614 }
615 
616 fs_inst *
emit_single_fb_write(const fs_builder & bld,fs_reg color0,fs_reg color1,fs_reg src0_alpha,unsigned components)617 fs_visitor::emit_single_fb_write(const fs_builder &bld,
618                                  fs_reg color0, fs_reg color1,
619                                  fs_reg src0_alpha, unsigned components)
620 {
621    assert(stage == MESA_SHADER_FRAGMENT);
622    struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
623 
624    /* Hand over gl_FragDepth or the payload depth. */
625    const fs_reg dst_depth = fetch_payload_reg(bld, payload.dest_depth_reg);
626    fs_reg src_depth, src_stencil;
627 
628    if (nir->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
629       src_depth = frag_depth;
630    } else if (source_depth_to_render_target) {
631       /* If we got here, we're in one of those strange Gen4-5 cases where
632        * we're forced to pass the source depth, unmodified, to the FB write.
633        * In this case, we don't want to use pixel_z because we may not have
634        * set up interpolation.  It's also perfectly safe because it only
635        * happens on old hardware (no coarse interpolation) and this is
636        * explicitly the pass-through case.
637        */
638       assert(devinfo->ver <= 5);
639       src_depth = fetch_payload_reg(bld, payload.source_depth_reg);
640    }
641 
642    if (nir->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_STENCIL))
643       src_stencil = frag_stencil;
644 
645    const fs_reg sources[] = {
646       color0, color1, src0_alpha, src_depth, dst_depth, src_stencil,
647       (prog_data->uses_omask ? sample_mask : fs_reg()),
648       brw_imm_ud(components)
649    };
650    assert(ARRAY_SIZE(sources) - 1 == FB_WRITE_LOGICAL_SRC_COMPONENTS);
651    fs_inst *write = bld.emit(FS_OPCODE_FB_WRITE_LOGICAL, fs_reg(),
652                              sources, ARRAY_SIZE(sources));
653 
654    if (prog_data->uses_kill) {
655       write->predicate = BRW_PREDICATE_NORMAL;
656       write->flag_subreg = sample_mask_flag_subreg(this);
657    }
658 
659    return write;
660 }
661 
662 void
emit_fb_writes()663 fs_visitor::emit_fb_writes()
664 {
665    assert(stage == MESA_SHADER_FRAGMENT);
666    struct brw_wm_prog_data *prog_data = brw_wm_prog_data(this->prog_data);
667    brw_wm_prog_key *key = (brw_wm_prog_key*) this->key;
668 
669    fs_inst *inst = NULL;
670 
671    if (source_depth_to_render_target && devinfo->ver == 6) {
672       /* For outputting oDepth on gfx6, SIMD8 writes have to be used.  This
673        * would require SIMD8 moves of each half to message regs, e.g. by using
674        * the SIMD lowering pass.  Unfortunately this is more difficult than it
675        * sounds because the SIMD8 single-source message lacks channel selects
676        * for the second and third subspans.
677        */
678       limit_dispatch_width(8, "Depth writes unsupported in SIMD16+ mode.\n");
679    }
680 
681    if (nir->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_STENCIL)) {
682       /* From the 'Render Target Write message' section of the docs:
683        * "Output Stencil is not supported with SIMD16 Render Target Write
684        * Messages."
685        */
686       limit_dispatch_width(8, "gl_FragStencilRefARB unsupported "
687                            "in SIMD16+ mode.\n");
688    }
689 
690    /* ANV doesn't know about sample mask output during the wm key creation
691     * so we compute if we need replicate alpha and emit alpha to coverage
692     * workaround here.
693     */
694    const bool replicate_alpha = key->alpha_test_replicate_alpha ||
695       (key->nr_color_regions > 1 && key->alpha_to_coverage &&
696        (sample_mask.file == BAD_FILE || devinfo->ver == 6));
697 
698    for (int target = 0; target < key->nr_color_regions; target++) {
699       /* Skip over outputs that weren't written. */
700       if (this->outputs[target].file == BAD_FILE)
701          continue;
702 
703       const fs_builder abld = bld.annotate(
704          ralloc_asprintf(this->mem_ctx, "FB write target %d", target));
705 
706       fs_reg src0_alpha;
707       if (devinfo->ver >= 6 && replicate_alpha && target != 0)
708          src0_alpha = offset(outputs[0], bld, 3);
709 
710       inst = emit_single_fb_write(abld, this->outputs[target],
711                                   this->dual_src_output, src0_alpha, 4);
712       inst->target = target;
713    }
714 
715    prog_data->dual_src_blend = (this->dual_src_output.file != BAD_FILE &&
716                                 this->outputs[0].file != BAD_FILE);
717    assert(!prog_data->dual_src_blend || key->nr_color_regions == 1);
718 
719    if (inst == NULL) {
720       /* Even if there's no color buffers enabled, we still need to send
721        * alpha out the pipeline to our null renderbuffer to support
722        * alpha-testing, alpha-to-coverage, and so on.
723        */
724       /* FINISHME: Factor out this frequently recurring pattern into a
725        * helper function.
726        */
727       const fs_reg srcs[] = { reg_undef, reg_undef,
728                               reg_undef, offset(this->outputs[0], bld, 3) };
729       const fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_UD, 4);
730       bld.LOAD_PAYLOAD(tmp, srcs, 4, 0);
731 
732       inst = emit_single_fb_write(bld, tmp, reg_undef, reg_undef, 4);
733       inst->target = 0;
734    }
735 
736    inst->last_rt = true;
737    inst->eot = true;
738 
739    if (devinfo->ver >= 11 && devinfo->ver <= 12 &&
740        prog_data->dual_src_blend) {
741       /* The dual-source RT write messages fail to release the thread
742        * dependency on ICL and TGL with SIMD32 dispatch, leading to hangs.
743        *
744        * XXX - Emit an extra single-source NULL RT-write marked LastRT in
745        *       order to release the thread dependency without disabling
746        *       SIMD32.
747        *
748        * The dual-source RT write messages may lead to hangs with SIMD16
749        * dispatch on ICL due some unknown reasons, see
750        * https://gitlab.freedesktop.org/mesa/mesa/-/issues/2183
751        */
752       limit_dispatch_width(8, "Dual source blending unsupported "
753                            "in SIMD16 and SIMD32 modes.\n");
754    }
755 }
756 
757 void
emit_urb_writes(const fs_reg & gs_vertex_count)758 fs_visitor::emit_urb_writes(const fs_reg &gs_vertex_count)
759 {
760    int slot, urb_offset, length;
761    int starting_urb_offset = 0;
762    const struct brw_vue_prog_data *vue_prog_data =
763       brw_vue_prog_data(this->prog_data);
764    const struct brw_vs_prog_key *vs_key =
765       (const struct brw_vs_prog_key *) this->key;
766    const GLbitfield64 psiz_mask =
767       VARYING_BIT_LAYER | VARYING_BIT_VIEWPORT | VARYING_BIT_PSIZ | VARYING_BIT_PRIMITIVE_SHADING_RATE;
768    const struct brw_vue_map *vue_map = &vue_prog_data->vue_map;
769    bool flush;
770    fs_reg sources[8];
771    fs_reg urb_handle;
772 
773    if (stage == MESA_SHADER_TESS_EVAL)
774       urb_handle = fs_reg(retype(brw_vec8_grf(4, 0), BRW_REGISTER_TYPE_UD));
775    else
776       urb_handle = fs_reg(retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD));
777 
778    int header_size = 1;
779    fs_reg per_slot_offsets;
780 
781    if (stage == MESA_SHADER_GEOMETRY) {
782       const struct brw_gs_prog_data *gs_prog_data =
783          brw_gs_prog_data(this->prog_data);
784 
785       /* We need to increment the Global Offset to skip over the control data
786        * header and the extra "Vertex Count" field (1 HWord) at the beginning
787        * of the VUE.  We're counting in OWords, so the units are doubled.
788        */
789       starting_urb_offset = 2 * gs_prog_data->control_data_header_size_hwords;
790       if (gs_prog_data->static_vertex_count == -1)
791          starting_urb_offset += 2;
792 
793       /* We also need to use per-slot offsets.  The per-slot offset is the
794        * Vertex Count.  SIMD8 mode processes 8 different primitives at a
795        * time; each may output a different number of vertices.
796        */
797       header_size++;
798 
799       /* The URB offset is in 128-bit units, so we need to multiply by 2 */
800       const int output_vertex_size_owords =
801          gs_prog_data->output_vertex_size_hwords * 2;
802 
803       if (gs_vertex_count.file == IMM) {
804          per_slot_offsets = brw_imm_ud(output_vertex_size_owords *
805                                        gs_vertex_count.ud);
806       } else {
807          per_slot_offsets = vgrf(glsl_type::uint_type);
808          bld.MUL(per_slot_offsets, gs_vertex_count,
809                  brw_imm_ud(output_vertex_size_owords));
810       }
811    }
812 
813    length = 0;
814    urb_offset = starting_urb_offset;
815    flush = false;
816 
817    /* SSO shaders can have VUE slots allocated which are never actually
818     * written to, so ignore them when looking for the last (written) slot.
819     */
820    int last_slot = vue_map->num_slots - 1;
821    while (last_slot > 0 &&
822           (vue_map->slot_to_varying[last_slot] == BRW_VARYING_SLOT_PAD ||
823            outputs[vue_map->slot_to_varying[last_slot]].file == BAD_FILE)) {
824       last_slot--;
825    }
826 
827    bool urb_written = false;
828    for (slot = 0; slot < vue_map->num_slots; slot++) {
829       int varying = vue_map->slot_to_varying[slot];
830       switch (varying) {
831       case VARYING_SLOT_PSIZ: {
832          /* The point size varying slot is the vue header and is always in the
833           * vue map.  But often none of the special varyings that live there
834           * are written and in that case we can skip writing to the vue
835           * header, provided the corresponding state properly clamps the
836           * values further down the pipeline. */
837          if ((vue_map->slots_valid & psiz_mask) == 0) {
838             assert(length == 0);
839             urb_offset++;
840             break;
841          }
842 
843          fs_reg zero(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
844          bld.MOV(zero, brw_imm_ud(0u));
845 
846          if (vue_map->slots_valid & VARYING_BIT_PRIMITIVE_SHADING_RATE &&
847              this->outputs[VARYING_SLOT_PRIMITIVE_SHADING_RATE].file != BAD_FILE) {
848             sources[length++] = this->outputs[VARYING_SLOT_PRIMITIVE_SHADING_RATE];
849          } else if (devinfo->has_coarse_pixel_primitive_and_cb) {
850             uint32_t one_fp16 = 0x3C00;
851             fs_reg one_by_one_fp16(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
852             bld.MOV(one_by_one_fp16, brw_imm_ud((one_fp16 << 16) | one_fp16));
853             sources[length++] = one_by_one_fp16;
854          } else {
855             sources[length++] = zero;
856          }
857 
858          if (vue_map->slots_valid & VARYING_BIT_LAYER)
859             sources[length++] = this->outputs[VARYING_SLOT_LAYER];
860          else
861             sources[length++] = zero;
862 
863          if (vue_map->slots_valid & VARYING_BIT_VIEWPORT)
864             sources[length++] = this->outputs[VARYING_SLOT_VIEWPORT];
865          else
866             sources[length++] = zero;
867 
868          if (vue_map->slots_valid & VARYING_BIT_PSIZ)
869             sources[length++] = this->outputs[VARYING_SLOT_PSIZ];
870          else
871             sources[length++] = zero;
872          break;
873       }
874       case BRW_VARYING_SLOT_NDC:
875       case VARYING_SLOT_EDGE:
876          unreachable("unexpected scalar vs output");
877          break;
878 
879       default:
880          /* gl_Position is always in the vue map, but isn't always written by
881           * the shader.  Other varyings (clip distances) get added to the vue
882           * map but don't always get written.  In those cases, the
883           * corresponding this->output[] slot will be invalid we and can skip
884           * the urb write for the varying.  If we've already queued up a vue
885           * slot for writing we flush a mlen 5 urb write, otherwise we just
886           * advance the urb_offset.
887           */
888          if (varying == BRW_VARYING_SLOT_PAD ||
889              this->outputs[varying].file == BAD_FILE) {
890             if (length > 0)
891                flush = true;
892             else
893                urb_offset++;
894             break;
895          }
896 
897          if (stage == MESA_SHADER_VERTEX && vs_key->clamp_vertex_color &&
898              (varying == VARYING_SLOT_COL0 ||
899               varying == VARYING_SLOT_COL1 ||
900               varying == VARYING_SLOT_BFC0 ||
901               varying == VARYING_SLOT_BFC1)) {
902             /* We need to clamp these guys, so do a saturating MOV into a
903              * temp register and use that for the payload.
904              */
905             for (int i = 0; i < 4; i++) {
906                fs_reg reg = fs_reg(VGRF, alloc.allocate(1), outputs[varying].type);
907                fs_reg src = offset(this->outputs[varying], bld, i);
908                set_saturate(true, bld.MOV(reg, src));
909                sources[length++] = reg;
910             }
911          } else {
912             int slot_offset = 0;
913 
914             /* When using Primitive Replication, there may be multiple slots
915              * assigned to POS.
916              */
917             if (varying == VARYING_SLOT_POS)
918                slot_offset = slot - vue_map->varying_to_slot[VARYING_SLOT_POS];
919 
920             for (unsigned i = 0; i < 4; i++) {
921                sources[length++] = offset(this->outputs[varying], bld,
922                                           i + (slot_offset * 4));
923             }
924          }
925          break;
926       }
927 
928       const fs_builder abld = bld.annotate("URB write");
929 
930       /* If we've queued up 8 registers of payload (2 VUE slots), if this is
931        * the last slot or if we need to flush (see BAD_FILE varying case
932        * above), emit a URB write send now to flush out the data.
933        */
934       if (length == 8 || (length > 0 && slot == last_slot))
935          flush = true;
936       if (flush) {
937          fs_reg srcs[URB_LOGICAL_NUM_SRCS];
938 
939          srcs[URB_LOGICAL_SRC_HANDLE] = urb_handle;
940          srcs[URB_LOGICAL_SRC_PER_SLOT_OFFSETS] = per_slot_offsets;
941          srcs[URB_LOGICAL_SRC_DATA] = fs_reg(VGRF, alloc.allocate(length),
942                                              BRW_REGISTER_TYPE_F);
943          abld.LOAD_PAYLOAD(srcs[URB_LOGICAL_SRC_DATA], sources, length, 0);
944 
945          fs_inst *inst = abld.emit(SHADER_OPCODE_URB_WRITE_LOGICAL, reg_undef,
946                                    srcs, ARRAY_SIZE(srcs));
947 
948          /* For ICL Wa_1805992985 one needs additional write in the end. */
949          if (devinfo->ver == 11 && stage == MESA_SHADER_TESS_EVAL)
950             inst->eot = false;
951          else
952             inst->eot = slot == last_slot && stage != MESA_SHADER_GEOMETRY;
953 
954          inst->mlen = length + header_size;
955          inst->offset = urb_offset;
956          urb_offset = starting_urb_offset + slot + 1;
957          length = 0;
958          flush = false;
959          urb_written = true;
960       }
961    }
962 
963    /* If we don't have any valid slots to write, just do a minimal urb write
964     * send to terminate the shader.  This includes 1 slot of undefined data,
965     * because it's invalid to write 0 data:
966     *
967     * From the Broadwell PRM, Volume 7: 3D Media GPGPU, Shared Functions -
968     * Unified Return Buffer (URB) > URB_SIMD8_Write and URB_SIMD8_Read >
969     * Write Data Payload:
970     *
971     *    "The write data payload can be between 1 and 8 message phases long."
972     */
973    if (!urb_written) {
974       /* For GS, just turn EmitVertex() into a no-op.  We don't want it to
975        * end the thread, and emit_gs_thread_end() already emits a SEND with
976        * EOT at the end of the program for us.
977        */
978       if (stage == MESA_SHADER_GEOMETRY)
979          return;
980 
981       fs_reg uniform_urb_handle = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
982       fs_reg payload = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
983 
984       bld.exec_all().MOV(uniform_urb_handle, urb_handle);
985 
986       fs_reg srcs[URB_LOGICAL_NUM_SRCS];
987       srcs[URB_LOGICAL_SRC_HANDLE] = uniform_urb_handle;
988       srcs[URB_LOGICAL_SRC_DATA] = payload;
989 
990       fs_inst *inst = bld.emit(SHADER_OPCODE_URB_WRITE_LOGICAL, reg_undef,
991                                srcs, ARRAY_SIZE(srcs));
992       inst->eot = true;
993       inst->mlen = 2;
994       inst->offset = 1;
995       return;
996    }
997 
998    /* ICL Wa_1805992985:
999     *
1000     * ICLLP GPU hangs on one of tessellation vkcts tests with DS not done. The
1001     * send cycle, which is a urb write with an eot must be 4 phases long and
1002     * all 8 lanes must valid.
1003     */
1004    if (devinfo->ver == 11 && stage == MESA_SHADER_TESS_EVAL) {
1005       fs_reg uniform_urb_handle = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
1006       fs_reg uniform_mask = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
1007       fs_reg payload = fs_reg(VGRF, alloc.allocate(4), BRW_REGISTER_TYPE_UD);
1008 
1009       /* Workaround requires all 8 channels (lanes) to be valid. This is
1010        * understood to mean they all need to be alive. First trick is to find
1011        * a live channel and copy its urb handle for all the other channels to
1012        * make sure all handles are valid.
1013        */
1014       bld.exec_all().MOV(uniform_urb_handle, bld.emit_uniformize(urb_handle));
1015 
1016       /* Second trick is to use masked URB write where one can tell the HW to
1017        * actually write data only for selected channels even though all are
1018        * active.
1019        * Third trick is to take advantage of the must-be-zero (MBZ) area in
1020        * the very beginning of the URB.
1021        *
1022        * One masks data to be written only for the first channel and uses
1023        * offset zero explicitly to land data to the MBZ area avoiding trashing
1024        * any other part of the URB.
1025        *
1026        * Since the WA says that the write needs to be 4 phases long one uses
1027        * 4 slots data. All are explicitly zeros in order to to keep the MBZ
1028        * area written as zeros.
1029        */
1030       bld.exec_all().MOV(uniform_mask, brw_imm_ud(0x10000u));
1031       bld.exec_all().MOV(offset(payload, bld, 0), brw_imm_ud(0u));
1032       bld.exec_all().MOV(offset(payload, bld, 1), brw_imm_ud(0u));
1033       bld.exec_all().MOV(offset(payload, bld, 2), brw_imm_ud(0u));
1034       bld.exec_all().MOV(offset(payload, bld, 3), brw_imm_ud(0u));
1035 
1036       fs_reg srcs[URB_LOGICAL_NUM_SRCS];
1037       srcs[URB_LOGICAL_SRC_HANDLE] = uniform_urb_handle;
1038       srcs[URB_LOGICAL_SRC_CHANNEL_MASK] = uniform_mask;
1039       srcs[URB_LOGICAL_SRC_DATA] = payload;
1040 
1041       fs_inst *inst = bld.exec_all().emit(SHADER_OPCODE_URB_WRITE_LOGICAL,
1042                                           reg_undef, srcs, ARRAY_SIZE(srcs));
1043       inst->eot = true;
1044       inst->mlen = 6;
1045       inst->offset = 0;
1046    }
1047 }
1048 
1049 void
emit_urb_fence()1050 fs_visitor::emit_urb_fence()
1051 {
1052    fs_reg dst = bld.vgrf(BRW_REGISTER_TYPE_UD);
1053    fs_inst *fence = bld.emit(SHADER_OPCODE_MEMORY_FENCE, dst,
1054                              brw_vec8_grf(0, 0),
1055                              brw_imm_ud(true),
1056                              brw_imm_ud(0));
1057    fence->sfid = BRW_SFID_URB;
1058    fence->desc = lsc_fence_msg_desc(devinfo, LSC_FENCE_LOCAL,
1059                                     LSC_FLUSH_TYPE_NONE, true);
1060 
1061    bld.exec_all().group(1, 0).emit(FS_OPCODE_SCHEDULING_FENCE,
1062                                    bld.null_reg_ud(),
1063                                    &dst,
1064                                    1);
1065 }
1066 
1067 void
emit_cs_terminate()1068 fs_visitor::emit_cs_terminate()
1069 {
1070    assert(devinfo->ver >= 7);
1071 
1072    /* We can't directly send from g0, since sends with EOT have to use
1073     * g112-127. So, copy it to a virtual register, The register allocator will
1074     * make sure it uses the appropriate register range.
1075     */
1076    struct brw_reg g0 = retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD);
1077    fs_reg payload = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
1078    bld.group(8, 0).exec_all().MOV(payload, g0);
1079 
1080    /* Send a message to the thread spawner to terminate the thread. */
1081    fs_inst *inst = bld.exec_all()
1082                       .emit(CS_OPCODE_CS_TERMINATE, reg_undef, payload);
1083    inst->eot = true;
1084 }
1085 
1086 void
emit_barrier()1087 fs_visitor::emit_barrier()
1088 {
1089    /* We are getting the barrier ID from the compute shader header */
1090    assert(gl_shader_stage_uses_workgroup(stage));
1091 
1092    fs_reg payload = fs_reg(VGRF, alloc.allocate(1), BRW_REGISTER_TYPE_UD);
1093 
1094    /* Clear the message payload */
1095    bld.exec_all().group(8, 0).MOV(payload, brw_imm_ud(0u));
1096 
1097    if (devinfo->verx10 >= 125) {
1098       /* mov r0.2[31:24] into m0.2[31:24] and m0.2[23:16] */
1099       fs_reg m0_10ub = component(retype(payload, BRW_REGISTER_TYPE_UB), 10);
1100       fs_reg r0_11ub =
1101          stride(suboffset(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UB), 11),
1102                 0, 1, 0);
1103       bld.exec_all().group(2, 0).MOV(m0_10ub, r0_11ub);
1104    } else {
1105       assert(gl_shader_stage_is_compute(stage));
1106 
1107       uint32_t barrier_id_mask;
1108       switch (devinfo->ver) {
1109       case 7:
1110       case 8:
1111          barrier_id_mask = 0x0f000000u; break;
1112       case 9:
1113          barrier_id_mask = 0x8f000000u; break;
1114       case 11:
1115       case 12:
1116          barrier_id_mask = 0x7f000000u; break;
1117       default:
1118          unreachable("barrier is only available on gen >= 7");
1119       }
1120 
1121       /* Copy the barrier id from r0.2 to the message payload reg.2 */
1122       fs_reg r0_2 = fs_reg(retype(brw_vec1_grf(0, 2), BRW_REGISTER_TYPE_UD));
1123       bld.exec_all().group(1, 0).AND(component(payload, 2), r0_2,
1124                                      brw_imm_ud(barrier_id_mask));
1125    }
1126 
1127    /* Emit a gateway "barrier" message using the payload we set up, followed
1128     * by a wait instruction.
1129     */
1130    bld.exec_all().emit(SHADER_OPCODE_BARRIER, reg_undef, payload);
1131 }
1132 
fs_visitor(const struct brw_compiler * compiler,void * log_data,void * mem_ctx,const brw_base_prog_key * key,struct brw_stage_prog_data * prog_data,const nir_shader * shader,unsigned dispatch_width,bool debug_enabled)1133 fs_visitor::fs_visitor(const struct brw_compiler *compiler, void *log_data,
1134                        void *mem_ctx,
1135                        const brw_base_prog_key *key,
1136                        struct brw_stage_prog_data *prog_data,
1137                        const nir_shader *shader,
1138                        unsigned dispatch_width,
1139                        bool debug_enabled)
1140    : backend_shader(compiler, log_data, mem_ctx, shader, prog_data,
1141                     debug_enabled),
1142      key(key), gs_compile(NULL), prog_data(prog_data),
1143      live_analysis(this), regpressure_analysis(this),
1144      performance_analysis(this),
1145      dispatch_width(dispatch_width),
1146      bld(fs_builder(this, dispatch_width).at_end())
1147 {
1148    init();
1149 }
1150 
fs_visitor(const struct brw_compiler * compiler,void * log_data,void * mem_ctx,struct brw_gs_compile * c,struct brw_gs_prog_data * prog_data,const nir_shader * shader,bool debug_enabled)1151 fs_visitor::fs_visitor(const struct brw_compiler *compiler, void *log_data,
1152                        void *mem_ctx,
1153                        struct brw_gs_compile *c,
1154                        struct brw_gs_prog_data *prog_data,
1155                        const nir_shader *shader,
1156                        bool debug_enabled)
1157    : backend_shader(compiler, log_data, mem_ctx, shader,
1158                     &prog_data->base.base, debug_enabled),
1159      key(&c->key.base), gs_compile(c),
1160      prog_data(&prog_data->base.base),
1161      live_analysis(this), regpressure_analysis(this),
1162      performance_analysis(this),
1163      dispatch_width(8),
1164      bld(fs_builder(this, dispatch_width).at_end())
1165 {
1166    init();
1167 }
1168 
1169 
1170 void
init()1171 fs_visitor::init()
1172 {
1173    if (key)
1174       this->key_tex = &key->tex;
1175    else
1176       this->key_tex = NULL;
1177 
1178    this->max_dispatch_width = 32;
1179    this->prog_data = this->stage_prog_data;
1180 
1181    this->failed = false;
1182    this->fail_msg = NULL;
1183 
1184    this->nir_locals = NULL;
1185    this->nir_ssa_values = NULL;
1186    this->nir_system_values = NULL;
1187 
1188    memset(&this->payload, 0, sizeof(this->payload));
1189    this->source_depth_to_render_target = false;
1190    this->runtime_check_aads_emit = false;
1191    this->first_non_payload_grf = 0;
1192    this->max_grf = devinfo->ver >= 7 ? GFX7_MRF_HACK_START : BRW_MAX_GRF;
1193 
1194    this->uniforms = 0;
1195    this->last_scratch = 0;
1196    this->push_constant_loc = NULL;
1197 
1198    this->shader_stats.scheduler_mode = NULL;
1199    this->shader_stats.promoted_constants = 0,
1200    this->shader_stats.spill_count = 0,
1201    this->shader_stats.fill_count = 0,
1202 
1203    this->grf_used = 0;
1204    this->spilled_any_registers = false;
1205 }
1206 
~fs_visitor()1207 fs_visitor::~fs_visitor()
1208 {
1209 }
1210