1 /**************************************************************************
2 *
3 * Copyright 2009 VMware, Inc.
4 * Copyright 2007-2008 Tungsten Graphics, Inc., Cedar Park, Texas.
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
22 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
23 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
24 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
25 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28
29 /**
30 * @file
31 * Position and shader input interpolation.
32 *
33 * @author Jose Fonseca <jfonseca@vmware.com>
34 */
35
36 #include "pipe/p_shader_tokens.h"
37 #include "util/u_debug.h"
38 #include "util/u_memory.h"
39 #include "util/u_math.h"
40 #include "tgsi/tgsi_scan.h"
41 #include "gallivm/lp_bld_debug.h"
42 #include "gallivm/lp_bld_const.h"
43 #include "gallivm/lp_bld_arit.h"
44 #include "gallivm/lp_bld_swizzle.h"
45 #include "gallivm/lp_bld_flow.h"
46 #include "lp_bld_interp.h"
47
48
49 /*
50 * The shader JIT function operates on blocks of quads.
51 * Each block has 2x2 quads and each quad has 2x2 pixels.
52 *
53 * We iterate over the quads in order 0, 1, 2, 3:
54 *
55 * #################
56 * # | # | #
57 * #---0---#---1---#
58 * # | # | #
59 * #################
60 * # | # | #
61 * #---2---#---3---#
62 * # | # | #
63 * #################
64 *
65 * If we iterate over multiple quads at once, quads 01 and 23 are processed
66 * together.
67 *
68 * Within each quad, we have four pixels which are represented in SOA
69 * order:
70 *
71 * #########
72 * # 0 | 1 #
73 * #---+---#
74 * # 2 | 3 #
75 * #########
76 *
77 * So the green channel (for example) of the four pixels is stored in
78 * a single vector register: {g0, g1, g2, g3}.
79 * The order stays the same even with multiple quads:
80 * 0 1 4 5
81 * 2 3 6 7
82 * is stored as g0..g7
83 */
84
85
86 /**
87 * Do one perspective divide per quad.
88 *
89 * For perspective interpolation, the final attribute value is given
90 *
91 * a' = a/w = a * oow
92 *
93 * where
94 *
95 * a = a0 + dadx*x + dady*y
96 * w = w0 + dwdx*x + dwdy*y
97 * oow = 1/w = 1/(w0 + dwdx*x + dwdy*y)
98 *
99 * Instead of computing the division per pixel, with this macro we compute the
100 * division on the upper left pixel of each quad, and use a linear
101 * approximation in the remaining pixels, given by:
102 *
103 * da'dx = (dadx - dwdx*a)*oow
104 * da'dy = (dady - dwdy*a)*oow
105 *
106 * Ironically, this actually makes things slower -- probably because the
107 * divide hardware unit is rarely used, whereas the multiply unit is typically
108 * already saturated.
109 */
110 #define PERSPECTIVE_DIVIDE_PER_QUAD 0
111
112
113 static const unsigned char quad_offset_x[16] = {0, 1, 0, 1, 2, 3, 2, 3, 0, 1, 0, 1, 2, 3, 2, 3};
114 static const unsigned char quad_offset_y[16] = {0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 3, 3, 2, 2, 3, 3};
115
116
117 static void
attrib_name(LLVMValueRef val,unsigned attrib,unsigned chan,const char * suffix)118 attrib_name(LLVMValueRef val, unsigned attrib, unsigned chan, const char *suffix)
119 {
120 if(attrib == 0)
121 lp_build_name(val, "pos.%c%s", "xyzw"[chan], suffix);
122 else
123 lp_build_name(val, "input%u.%c%s", attrib - 1, "xyzw"[chan], suffix);
124 }
125
126 static void
calc_offsets(struct lp_build_context * coeff_bld,unsigned quad_start_index,LLVMValueRef * pixoffx,LLVMValueRef * pixoffy)127 calc_offsets(struct lp_build_context *coeff_bld,
128 unsigned quad_start_index,
129 LLVMValueRef *pixoffx,
130 LLVMValueRef *pixoffy)
131 {
132 unsigned i;
133 unsigned num_pix = coeff_bld->type.length;
134 struct gallivm_state *gallivm = coeff_bld->gallivm;
135 LLVMBuilderRef builder = coeff_bld->gallivm->builder;
136 LLVMValueRef nr, pixxf, pixyf;
137
138 *pixoffx = coeff_bld->undef;
139 *pixoffy = coeff_bld->undef;
140
141 for (i = 0; i < num_pix; i++) {
142 nr = lp_build_const_int32(gallivm, i);
143 pixxf = lp_build_const_float(gallivm, quad_offset_x[i % num_pix] +
144 (quad_start_index & 1) * 2);
145 pixyf = lp_build_const_float(gallivm, quad_offset_y[i % num_pix] +
146 (quad_start_index & 2));
147 *pixoffx = LLVMBuildInsertElement(builder, *pixoffx, pixxf, nr, "");
148 *pixoffy = LLVMBuildInsertElement(builder, *pixoffy, pixyf, nr, "");
149 }
150 }
151
152
153 /* Much easier, and significantly less instructions in the per-stamp
154 * part (less than half) but overall more instructions so a loss if
155 * most quads are active. Might be a win though with larger vectors.
156 * No ability to do per-quad divide (doable but not implemented)
157 * Could be made to work with passed in pixel offsets (i.e. active quad merging).
158 */
159 static void
coeffs_init_simple(struct lp_build_interp_soa_context * bld,LLVMValueRef a0_ptr,LLVMValueRef dadx_ptr,LLVMValueRef dady_ptr)160 coeffs_init_simple(struct lp_build_interp_soa_context *bld,
161 LLVMValueRef a0_ptr,
162 LLVMValueRef dadx_ptr,
163 LLVMValueRef dady_ptr)
164 {
165 struct lp_build_context *coeff_bld = &bld->coeff_bld;
166 struct lp_build_context *setup_bld = &bld->setup_bld;
167 struct gallivm_state *gallivm = coeff_bld->gallivm;
168 LLVMBuilderRef builder = gallivm->builder;
169 unsigned attrib;
170
171 for (attrib = 0; attrib < bld->num_attribs; ++attrib) {
172 /*
173 * always fetch all 4 values for performance/simplicity
174 * Note: we do that here because it seems to generate better
175 * code. It generates a lot of moves initially but less
176 * moves later. As far as I can tell this looks like a
177 * llvm issue, instead of simply reloading the values from
178 * the passed in pointers it if it runs out of registers
179 * it spills/reloads them. Maybe some optimization passes
180 * would help.
181 * Might want to investigate this again later.
182 */
183 const unsigned interp = bld->interp[attrib];
184 LLVMValueRef index = lp_build_const_int32(gallivm,
185 attrib * TGSI_NUM_CHANNELS);
186 LLVMValueRef ptr;
187 LLVMValueRef dadxaos = setup_bld->zero;
188 LLVMValueRef dadyaos = setup_bld->zero;
189 LLVMValueRef a0aos = setup_bld->zero;
190
191 switch (interp) {
192 case LP_INTERP_PERSPECTIVE:
193 /* fall-through */
194
195 case LP_INTERP_LINEAR:
196 ptr = LLVMBuildGEP(builder, dadx_ptr, &index, 1, "");
197 ptr = LLVMBuildBitCast(builder, ptr,
198 LLVMPointerType(setup_bld->vec_type, 0), "");
199 dadxaos = LLVMBuildLoad(builder, ptr, "");
200
201 ptr = LLVMBuildGEP(builder, dady_ptr, &index, 1, "");
202 ptr = LLVMBuildBitCast(builder, ptr,
203 LLVMPointerType(setup_bld->vec_type, 0), "");
204 dadyaos = LLVMBuildLoad(builder, ptr, "");
205
206 attrib_name(dadxaos, attrib, 0, ".dadxaos");
207 attrib_name(dadyaos, attrib, 0, ".dadyaos");
208 /* fall-through */
209
210 case LP_INTERP_CONSTANT:
211 case LP_INTERP_FACING:
212 ptr = LLVMBuildGEP(builder, a0_ptr, &index, 1, "");
213 ptr = LLVMBuildBitCast(builder, ptr,
214 LLVMPointerType(setup_bld->vec_type, 0), "");
215 a0aos = LLVMBuildLoad(builder, ptr, "");
216 attrib_name(a0aos, attrib, 0, ".a0aos");
217 break;
218
219 case LP_INTERP_POSITION:
220 /* Nothing to do as the position coeffs are already setup in slot 0 */
221 continue;
222
223 default:
224 assert(0);
225 break;
226 }
227 bld->a0aos[attrib] = a0aos;
228 bld->dadxaos[attrib] = dadxaos;
229 bld->dadyaos[attrib] = dadyaos;
230 }
231 }
232
233 /**
234 * Interpolate the shader input attribute values.
235 * This is called for each (group of) quad(s).
236 */
237 static void
attribs_update_simple(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,int quad_start_index,LLVMValueRef loop_iter,int start,int end)238 attribs_update_simple(struct lp_build_interp_soa_context *bld,
239 struct gallivm_state *gallivm,
240 int quad_start_index,
241 LLVMValueRef loop_iter,
242 int start,
243 int end)
244 {
245 LLVMBuilderRef builder = gallivm->builder;
246 struct lp_build_context *coeff_bld = &bld->coeff_bld;
247 struct lp_build_context *setup_bld = &bld->setup_bld;
248 LLVMValueRef oow = NULL;
249 unsigned attrib;
250 LLVMValueRef pixoffx;
251 LLVMValueRef pixoffy;
252
253 /* could do this with code-generated passed in pixel offsets too */
254 if (bld->dynamic_offsets) {
255 LLVMValueRef ptr;
256
257 assert(loop_iter);
258 ptr = LLVMBuildGEP(builder, bld->xoffset_store, &loop_iter, 1, "");
259 pixoffx = LLVMBuildLoad(builder, ptr, "");
260 ptr = LLVMBuildGEP(builder, bld->yoffset_store, &loop_iter, 1, "");
261 pixoffy = LLVMBuildLoad(builder, ptr, "");
262 }
263 else {
264 calc_offsets(coeff_bld, quad_start_index, &pixoffx, &pixoffy);
265 }
266
267 pixoffx = LLVMBuildFAdd(builder, pixoffx,
268 lp_build_broadcast_scalar(coeff_bld, bld->x), "");
269 pixoffy = LLVMBuildFAdd(builder, pixoffy,
270 lp_build_broadcast_scalar(coeff_bld, bld->y), "");
271
272 for (attrib = start; attrib < end; attrib++) {
273 const unsigned mask = bld->mask[attrib];
274 const unsigned interp = bld->interp[attrib];
275 unsigned chan;
276
277 for (chan = 0; chan < TGSI_NUM_CHANNELS; chan++) {
278 if (mask & (1 << chan)) {
279 LLVMValueRef index;
280 LLVMValueRef dadx = coeff_bld->zero;
281 LLVMValueRef dady = coeff_bld->zero;
282 LLVMValueRef a = coeff_bld->zero;
283
284 index = lp_build_const_int32(gallivm, chan);
285 switch (interp) {
286 case LP_INTERP_PERSPECTIVE:
287 /* fall-through */
288
289 case LP_INTERP_LINEAR:
290 if (attrib == 0 && chan == 0) {
291 dadx = coeff_bld->one;
292 }
293 else if (attrib == 0 && chan == 1) {
294 dady = coeff_bld->one;
295 }
296 else {
297 dadx = lp_build_extract_broadcast(gallivm, setup_bld->type,
298 coeff_bld->type, bld->dadxaos[attrib],
299 index);
300 dady = lp_build_extract_broadcast(gallivm, setup_bld->type,
301 coeff_bld->type, bld->dadyaos[attrib],
302 index);
303 a = lp_build_extract_broadcast(gallivm, setup_bld->type,
304 coeff_bld->type, bld->a0aos[attrib],
305 index);
306 }
307 /*
308 * a = a0 + (x * dadx + y * dady)
309 */
310 dadx = LLVMBuildFMul(builder, dadx, pixoffx, "");
311 dady = LLVMBuildFMul(builder, dady, pixoffy, "");
312 a = LLVMBuildFAdd(builder, a, dadx, "");
313 a = LLVMBuildFAdd(builder, a, dady, "");
314
315 if (interp == LP_INTERP_PERSPECTIVE) {
316 if (oow == NULL) {
317 LLVMValueRef w = bld->attribs[0][3];
318 assert(attrib != 0);
319 assert(bld->mask[0] & TGSI_WRITEMASK_W);
320 oow = lp_build_rcp(coeff_bld, w);
321 }
322 a = lp_build_mul(coeff_bld, a, oow);
323 }
324 break;
325
326 case LP_INTERP_CONSTANT:
327 case LP_INTERP_FACING:
328 a = lp_build_extract_broadcast(gallivm, setup_bld->type,
329 coeff_bld->type, bld->a0aos[attrib],
330 index);
331 break;
332
333 case LP_INTERP_POSITION:
334 assert(attrib > 0);
335 a = bld->attribs[0][chan];
336 break;
337
338 default:
339 assert(0);
340 break;
341 }
342
343 if ((attrib == 0) && (chan == 2)){
344 /* FIXME: Depth values can exceed 1.0, due to the fact that
345 * setup interpolation coefficients refer to (0,0) which causes
346 * precision loss. So we must clamp to 1.0 here to avoid artifacts
347 */
348 a = lp_build_min(coeff_bld, a, coeff_bld->one);
349 }
350 bld->attribs[attrib][chan] = a;
351 }
352 }
353 }
354 }
355
356 /**
357 * Initialize the bld->a, dadq fields. This involves fetching
358 * those values from the arrays which are passed into the JIT function.
359 */
360 static void
coeffs_init(struct lp_build_interp_soa_context * bld,LLVMValueRef a0_ptr,LLVMValueRef dadx_ptr,LLVMValueRef dady_ptr)361 coeffs_init(struct lp_build_interp_soa_context *bld,
362 LLVMValueRef a0_ptr,
363 LLVMValueRef dadx_ptr,
364 LLVMValueRef dady_ptr)
365 {
366 struct lp_build_context *coeff_bld = &bld->coeff_bld;
367 struct lp_build_context *setup_bld = &bld->setup_bld;
368 struct gallivm_state *gallivm = coeff_bld->gallivm;
369 LLVMBuilderRef builder = gallivm->builder;
370 LLVMValueRef pixoffx, pixoffy;
371 unsigned attrib;
372 unsigned chan;
373 unsigned i;
374
375 pixoffx = coeff_bld->undef;
376 pixoffy = coeff_bld->undef;
377 for (i = 0; i < coeff_bld->type.length; i++) {
378 LLVMValueRef nr = lp_build_const_int32(gallivm, i);
379 LLVMValueRef pixxf = lp_build_const_float(gallivm, quad_offset_x[i]);
380 LLVMValueRef pixyf = lp_build_const_float(gallivm, quad_offset_y[i]);
381 pixoffx = LLVMBuildInsertElement(builder, pixoffx, pixxf, nr, "");
382 pixoffy = LLVMBuildInsertElement(builder, pixoffy, pixyf, nr, "");
383 }
384
385
386 for (attrib = 0; attrib < bld->num_attribs; ++attrib) {
387 const unsigned mask = bld->mask[attrib];
388 const unsigned interp = bld->interp[attrib];
389 LLVMValueRef index = lp_build_const_int32(gallivm,
390 attrib * TGSI_NUM_CHANNELS);
391 LLVMValueRef ptr;
392 LLVMValueRef dadxaos = setup_bld->zero;
393 LLVMValueRef dadyaos = setup_bld->zero;
394 LLVMValueRef a0aos = setup_bld->zero;
395
396 /* always fetch all 4 values for performance/simplicity */
397 switch (interp) {
398 case LP_INTERP_PERSPECTIVE:
399 /* fall-through */
400
401 case LP_INTERP_LINEAR:
402 ptr = LLVMBuildGEP(builder, dadx_ptr, &index, 1, "");
403 ptr = LLVMBuildBitCast(builder, ptr,
404 LLVMPointerType(setup_bld->vec_type, 0), "");
405 dadxaos = LLVMBuildLoad(builder, ptr, "");
406
407 ptr = LLVMBuildGEP(builder, dady_ptr, &index, 1, "");
408 ptr = LLVMBuildBitCast(builder, ptr,
409 LLVMPointerType(setup_bld->vec_type, 0), "");
410 dadyaos = LLVMBuildLoad(builder, ptr, "");
411
412 attrib_name(dadxaos, attrib, 0, ".dadxaos");
413 attrib_name(dadyaos, attrib, 0, ".dadyaos");
414 /* fall-through */
415
416 case LP_INTERP_CONSTANT:
417 case LP_INTERP_FACING:
418 ptr = LLVMBuildGEP(builder, a0_ptr, &index, 1, "");
419 ptr = LLVMBuildBitCast(builder, ptr,
420 LLVMPointerType(setup_bld->vec_type, 0), "");
421 a0aos = LLVMBuildLoad(builder, ptr, "");
422 attrib_name(a0aos, attrib, 0, ".a0aos");
423 break;
424
425 case LP_INTERP_POSITION:
426 /* Nothing to do as the position coeffs are already setup in slot 0 */
427 continue;
428
429 default:
430 assert(0);
431 break;
432 }
433
434 /*
435 * a = a0 + (x * dadx + y * dady)
436 * a0aos is the attrib value at top left corner of stamp
437 */
438 if (interp != LP_INTERP_CONSTANT &&
439 interp != LP_INTERP_FACING) {
440 LLVMValueRef axaos, ayaos;
441 axaos = LLVMBuildFMul(builder, lp_build_broadcast_scalar(setup_bld, bld->x),
442 dadxaos, "");
443 ayaos = LLVMBuildFMul(builder, lp_build_broadcast_scalar(setup_bld, bld->y),
444 dadyaos, "");
445 a0aos = LLVMBuildFAdd(builder, a0aos, ayaos, "");
446 a0aos = LLVMBuildFAdd(builder, a0aos, axaos, "");
447 }
448
449 /*
450 * dadq = {0, dadx, dady, dadx + dady}
451 * for two quads (side by side) this is:
452 * {0, dadx, dady, dadx+dady, 2*dadx, 2*dadx+dady, 3*dadx+dady}
453 */
454 for (chan = 0; chan < TGSI_NUM_CHANNELS; ++chan) {
455 /* this generates a CRAPLOAD of shuffles... */
456 if (mask & (1 << chan)) {
457 LLVMValueRef dadx, dady;
458 LLVMValueRef dadq, dadq2;
459 LLVMValueRef a;
460 LLVMValueRef chan_index = lp_build_const_int32(gallivm, chan);
461
462 if (attrib == 0 && chan == 0) {
463 a = lp_build_broadcast_scalar(coeff_bld, bld->x);
464 dadx = coeff_bld->one;
465 dady = coeff_bld->zero;
466 }
467 else if (attrib == 0 && chan == 1) {
468 a = lp_build_broadcast_scalar(coeff_bld, bld->y);
469 dady = coeff_bld->one;
470 dadx = coeff_bld->zero;
471 }
472 else {
473 dadx = lp_build_extract_broadcast(gallivm, setup_bld->type,
474 coeff_bld->type, dadxaos, chan_index);
475 dady = lp_build_extract_broadcast(gallivm, setup_bld->type,
476 coeff_bld->type, dadyaos, chan_index);
477
478 /*
479 * a = {a, a, a, a}
480 */
481 a = lp_build_extract_broadcast(gallivm, setup_bld->type,
482 coeff_bld->type, a0aos, chan_index);
483 }
484
485 dadx = LLVMBuildFMul(builder, dadx, pixoffx, "");
486 dady = LLVMBuildFMul(builder, dady, pixoffy, "");
487 dadq = LLVMBuildFAdd(builder, dadx, dady, "");
488
489 /*
490 * Compute the attrib values on the upper-left corner of each
491 * group of quads.
492 * Note that if we process 2 quads at once this doesn't
493 * really exactly to what we want.
494 * We need to access elem 0 and 2 respectively later if we process
495 * 2 quads at once.
496 */
497
498 if (interp != LP_INTERP_CONSTANT &&
499 interp != LP_INTERP_FACING) {
500 dadq2 = LLVMBuildFAdd(builder, dadq, dadq, "");
501 a = LLVMBuildFAdd(builder, a, dadq2, "");
502 }
503
504 #if PERSPECTIVE_DIVIDE_PER_QUAD
505 /*
506 * a *= 1 / w
507 */
508
509 /*
510 * XXX since we're only going to access elements 0,2 out of 8
511 * if we have 8-wide vectors we should do the division only 4-wide.
512 * a is really a 2-elements in a 4-wide vector disguised as 8-wide
513 * in this case.
514 */
515 if (interp == LP_INTERP_PERSPECTIVE) {
516 LLVMValueRef w = bld->a[0][3];
517 assert(attrib != 0);
518 assert(bld->mask[0] & TGSI_WRITEMASK_W);
519 if (!bld->oow) {
520 bld->oow = lp_build_rcp(coeff_bld, w);
521 lp_build_name(bld->oow, "oow");
522 }
523 a = lp_build_mul(coeff_bld, a, bld->oow);
524 }
525 #endif
526
527 attrib_name(a, attrib, chan, ".a");
528 attrib_name(dadq, attrib, chan, ".dadq");
529
530 if (bld->dynamic_offsets) {
531 bld->a[attrib][chan] = lp_build_alloca(gallivm,
532 LLVMTypeOf(a), "");
533 LLVMBuildStore(builder, a, bld->a[attrib][chan]);
534 }
535 else {
536 bld->a[attrib][chan] = a;
537 }
538 bld->dadq[attrib][chan] = dadq;
539 }
540 }
541 }
542 }
543
544
545 /**
546 * Increment the shader input attribute values.
547 * This is called when we move from one quad to the next.
548 */
549 static void
attribs_update(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,int quad_start_index,LLVMValueRef loop_iter,int start,int end)550 attribs_update(struct lp_build_interp_soa_context *bld,
551 struct gallivm_state *gallivm,
552 int quad_start_index,
553 LLVMValueRef loop_iter,
554 int start,
555 int end)
556 {
557 LLVMBuilderRef builder = gallivm->builder;
558 struct lp_build_context *coeff_bld = &bld->coeff_bld;
559 LLVMValueRef shuffle = lp_build_const_int_vec(gallivm, coeff_bld->type, quad_start_index);
560 LLVMValueRef oow = NULL;
561 unsigned attrib;
562 unsigned chan;
563
564 assert(quad_start_index < 4);
565
566 for(attrib = start; attrib < end; ++attrib) {
567 const unsigned mask = bld->mask[attrib];
568 const unsigned interp = bld->interp[attrib];
569 for(chan = 0; chan < TGSI_NUM_CHANNELS; ++chan) {
570 if(mask & (1 << chan)) {
571 LLVMValueRef a;
572 if (interp == LP_INTERP_CONSTANT ||
573 interp == LP_INTERP_FACING) {
574 a = bld->a[attrib][chan];
575 if (bld->dynamic_offsets) {
576 a = LLVMBuildLoad(builder, a, "");
577 }
578 }
579 else if (interp == LP_INTERP_POSITION) {
580 assert(attrib > 0);
581 a = bld->attribs[0][chan];
582 }
583 else {
584 LLVMValueRef dadq;
585
586 a = bld->a[attrib][chan];
587
588 /*
589 * Broadcast the attribute value for this quad into all elements
590 */
591
592 if (bld->dynamic_offsets) {
593 /* stored as vector load as float */
594 LLVMTypeRef ptr_type = LLVMPointerType(LLVMFloatTypeInContext(
595 gallivm->context), 0);
596 LLVMValueRef ptr;
597 a = LLVMBuildBitCast(builder, a, ptr_type, "");
598 ptr = LLVMBuildGEP(builder, a, &loop_iter, 1, "");
599 a = LLVMBuildLoad(builder, ptr, "");
600 a = lp_build_broadcast_scalar(&bld->coeff_bld, a);
601 }
602 else {
603 a = LLVMBuildShuffleVector(builder,
604 a, coeff_bld->undef, shuffle, "");
605 }
606
607 /*
608 * Get the derivatives.
609 */
610
611 dadq = bld->dadq[attrib][chan];
612
613 #if PERSPECTIVE_DIVIDE_PER_QUAD
614 if (interp == LP_INTERP_PERSPECTIVE) {
615 LLVMValueRef dwdq = bld->dadq[0][3];
616
617 if (oow == NULL) {
618 assert(bld->oow);
619 oow = LLVMBuildShuffleVector(coeff_bld->builder,
620 bld->oow, coeff_bld->undef,
621 shuffle, "");
622 }
623
624 dadq = lp_build_sub(coeff_bld,
625 dadq,
626 lp_build_mul(coeff_bld, a, dwdq));
627 dadq = lp_build_mul(coeff_bld, dadq, oow);
628 }
629 #endif
630
631 /*
632 * Add the derivatives
633 */
634
635 a = lp_build_add(coeff_bld, a, dadq);
636
637 #if !PERSPECTIVE_DIVIDE_PER_QUAD
638 if (interp == LP_INTERP_PERSPECTIVE) {
639 if (oow == NULL) {
640 LLVMValueRef w = bld->attribs[0][3];
641 assert(attrib != 0);
642 assert(bld->mask[0] & TGSI_WRITEMASK_W);
643 oow = lp_build_rcp(coeff_bld, w);
644 }
645 a = lp_build_mul(coeff_bld, a, oow);
646 }
647 #endif
648
649 if (attrib == 0 && chan == 2) {
650 /* FIXME: Depth values can exceed 1.0, due to the fact that
651 * setup interpolation coefficients refer to (0,0) which causes
652 * precision loss. So we must clamp to 1.0 here to avoid artifacts
653 */
654 a = lp_build_min(coeff_bld, a, coeff_bld->one);
655 }
656
657 attrib_name(a, attrib, chan, "");
658 }
659 bld->attribs[attrib][chan] = a;
660 }
661 }
662 }
663 }
664
665
666 /**
667 * Generate the position vectors.
668 *
669 * Parameter x0, y0 are the integer values with upper left coordinates.
670 */
671 static void
pos_init(struct lp_build_interp_soa_context * bld,LLVMValueRef x0,LLVMValueRef y0)672 pos_init(struct lp_build_interp_soa_context *bld,
673 LLVMValueRef x0,
674 LLVMValueRef y0)
675 {
676 LLVMBuilderRef builder = bld->coeff_bld.gallivm->builder;
677 struct lp_build_context *coeff_bld = &bld->coeff_bld;
678
679 bld->x = LLVMBuildSIToFP(builder, x0, coeff_bld->elem_type, "");
680 bld->y = LLVMBuildSIToFP(builder, y0, coeff_bld->elem_type, "");
681 }
682
683
684 /**
685 * Initialize fragment shader input attribute info.
686 */
687 void
lp_build_interp_soa_init(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,unsigned num_inputs,const struct lp_shader_input * inputs,LLVMBuilderRef builder,struct lp_type type,boolean dynamic_offsets,LLVMValueRef a0_ptr,LLVMValueRef dadx_ptr,LLVMValueRef dady_ptr,LLVMValueRef x0,LLVMValueRef y0)688 lp_build_interp_soa_init(struct lp_build_interp_soa_context *bld,
689 struct gallivm_state *gallivm,
690 unsigned num_inputs,
691 const struct lp_shader_input *inputs,
692 LLVMBuilderRef builder,
693 struct lp_type type,
694 boolean dynamic_offsets,
695 LLVMValueRef a0_ptr,
696 LLVMValueRef dadx_ptr,
697 LLVMValueRef dady_ptr,
698 LLVMValueRef x0,
699 LLVMValueRef y0)
700 {
701 struct lp_type coeff_type;
702 struct lp_type setup_type;
703 unsigned attrib;
704 unsigned chan;
705
706 memset(bld, 0, sizeof *bld);
707
708 memset(&coeff_type, 0, sizeof coeff_type);
709 coeff_type.floating = TRUE;
710 coeff_type.sign = TRUE;
711 coeff_type.width = 32;
712 coeff_type.length = type.length;
713
714 memset(&setup_type, 0, sizeof setup_type);
715 setup_type.floating = TRUE;
716 setup_type.sign = TRUE;
717 setup_type.width = 32;
718 setup_type.length = TGSI_NUM_CHANNELS;
719
720
721 /* XXX: we don't support interpolating into any other types */
722 assert(memcmp(&coeff_type, &type, sizeof coeff_type) == 0);
723
724 lp_build_context_init(&bld->coeff_bld, gallivm, coeff_type);
725 lp_build_context_init(&bld->setup_bld, gallivm, setup_type);
726
727 /* For convenience */
728 bld->pos = bld->attribs[0];
729 bld->inputs = (const LLVMValueRef (*)[TGSI_NUM_CHANNELS]) bld->attribs[1];
730
731 /* Position */
732 bld->mask[0] = TGSI_WRITEMASK_XYZW;
733 bld->interp[0] = LP_INTERP_LINEAR;
734
735 /* Inputs */
736 for (attrib = 0; attrib < num_inputs; ++attrib) {
737 bld->mask[1 + attrib] = inputs[attrib].usage_mask;
738 bld->interp[1 + attrib] = inputs[attrib].interp;
739 }
740 bld->num_attribs = 1 + num_inputs;
741
742 /* Ensure all masked out input channels have a valid value */
743 for (attrib = 0; attrib < bld->num_attribs; ++attrib) {
744 for (chan = 0; chan < TGSI_NUM_CHANNELS; ++chan) {
745 bld->attribs[attrib][chan] = bld->coeff_bld.undef;
746 }
747 }
748
749 pos_init(bld, x0, y0);
750
751 if (coeff_type.length > 4) {
752 bld->simple_interp = TRUE;
753 if (dynamic_offsets) {
754 /* XXX this should use a global static table */
755 unsigned i;
756 unsigned num_loops = 16 / type.length;
757 LLVMValueRef pixoffx, pixoffy, index;
758 LLVMValueRef ptr;
759
760 bld->dynamic_offsets = TRUE;
761 bld->xoffset_store = lp_build_array_alloca(gallivm,
762 lp_build_vec_type(gallivm, type),
763 lp_build_const_int32(gallivm, num_loops),
764 "");
765 bld->yoffset_store = lp_build_array_alloca(gallivm,
766 lp_build_vec_type(gallivm, type),
767 lp_build_const_int32(gallivm, num_loops),
768 "");
769 for (i = 0; i < num_loops; i++) {
770 index = lp_build_const_int32(gallivm, i);
771 calc_offsets(&bld->coeff_bld, i*type.length/4, &pixoffx, &pixoffy);
772 ptr = LLVMBuildGEP(builder, bld->xoffset_store, &index, 1, "");
773 LLVMBuildStore(builder, pixoffx, ptr);
774 ptr = LLVMBuildGEP(builder, bld->yoffset_store, &index, 1, "");
775 LLVMBuildStore(builder, pixoffy, ptr);
776 }
777 }
778 coeffs_init_simple(bld, a0_ptr, dadx_ptr, dady_ptr);
779 }
780 else {
781 bld->simple_interp = FALSE;
782 if (dynamic_offsets) {
783 bld->dynamic_offsets = TRUE;
784 }
785 coeffs_init(bld, a0_ptr, dadx_ptr, dady_ptr);
786 }
787
788 }
789
790
791 /**
792 * Advance the position and inputs to the given quad within the block.
793 */
794 void
lp_build_interp_soa_update_inputs(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,int quad_start_index)795 lp_build_interp_soa_update_inputs(struct lp_build_interp_soa_context *bld,
796 struct gallivm_state *gallivm,
797 int quad_start_index)
798 {
799 assert(quad_start_index < 4);
800
801 if (bld->simple_interp) {
802 attribs_update_simple(bld, gallivm, quad_start_index, NULL, 1, bld->num_attribs);
803 }
804 else {
805 attribs_update(bld, gallivm, quad_start_index, NULL, 1, bld->num_attribs);
806 }
807 }
808
809 void
lp_build_interp_soa_update_pos(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,int quad_start_index)810 lp_build_interp_soa_update_pos(struct lp_build_interp_soa_context *bld,
811 struct gallivm_state *gallivm,
812 int quad_start_index)
813 {
814 assert(quad_start_index < 4);
815
816 if (bld->simple_interp) {
817 attribs_update_simple(bld, gallivm, quad_start_index, NULL, 0, 1);
818 }
819 else {
820 attribs_update(bld, gallivm, quad_start_index, NULL, 0, 1);
821 }
822 }
823
824 void
lp_build_interp_soa_update_inputs_dyn(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,LLVMValueRef quad_start_index)825 lp_build_interp_soa_update_inputs_dyn(struct lp_build_interp_soa_context *bld,
826 struct gallivm_state *gallivm,
827 LLVMValueRef quad_start_index)
828 {
829 if (bld->simple_interp) {
830 attribs_update_simple(bld, gallivm, 0, quad_start_index, 1, bld->num_attribs);
831 }
832 else {
833 attribs_update(bld, gallivm, 0, quad_start_index, 1, bld->num_attribs);
834 }
835 }
836
837 void
lp_build_interp_soa_update_pos_dyn(struct lp_build_interp_soa_context * bld,struct gallivm_state * gallivm,LLVMValueRef quad_start_index)838 lp_build_interp_soa_update_pos_dyn(struct lp_build_interp_soa_context *bld,
839 struct gallivm_state *gallivm,
840 LLVMValueRef quad_start_index)
841 {
842 if (bld->simple_interp) {
843 attribs_update_simple(bld, gallivm, 0, quad_start_index, 0, 1);
844 }
845 else {
846 attribs_update(bld, gallivm, 0, quad_start_index, 0, 1);
847 }
848 }
849
850