1/**************************************************************************
2 *
3 * Copyright 2009 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29/**
30 * @file
31 * Helper functions for packing/unpacking.
32 *
33 * Pack/unpacking is necessary for conversion between types of different
34 * bit width.
35 *
36 * They are also commonly used when an computation needs higher
37 * precision for the intermediate values. For example, if one needs the
38 * function:
39 *
40 *   c = compute(a, b);
41 *
42 * to use more precision for intermediate results then one should implement it
43 * as:
44 *
45 *   LLVMValueRef
46 *   compute(LLVMBuilderRef builder struct lp_type type, LLVMValueRef a, LLVMValueRef b)
47 *   {
48 *      struct lp_type wide_type = lp_wider_type(type);
49 *      LLVMValueRef al, ah, bl, bh, cl, ch, c;
50 *
51 *      lp_build_unpack2(builder, type, wide_type, a, &al, &ah);
52 *      lp_build_unpack2(builder, type, wide_type, b, &bl, &bh);
53 *
54 *      cl = compute_half(al, bl);
55 *      ch = compute_half(ah, bh);
56 *
57 *      c = lp_build_pack2(bld->builder, wide_type, type, cl, ch);
58 *
59 *      return c;
60 *   }
61 *
62 * where compute_half() would do the computation for half the elements with
63 * twice the precision.
64 *
65 * @author Jose Fonseca <jfonseca@vmware.com>
66 */
67
68
69#include "util/u_debug.h"
70#include "util/u_math.h"
71#include "util/u_cpu_detect.h"
72#include "util/u_memory.h"
73
74#include "lp_bld_type.h"
75#include "lp_bld_const.h"
76#include "lp_bld_init.h"
77#include "lp_bld_intr.h"
78#include "lp_bld_arit.h"
79#include "lp_bld_pack.h"
80#include "lp_bld_swizzle.h"
81
82
83/**
84 * Build shuffle vectors that match PUNPCKLxx and PUNPCKHxx instructions.
85 */
86static LLVMValueRef
87lp_build_const_unpack_shuffle(struct gallivm_state *gallivm,
88                              unsigned n, unsigned lo_hi)
89{
90   LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
91   unsigned i, j;
92
93   assert(n <= LP_MAX_VECTOR_LENGTH);
94   assert(lo_hi < 2);
95
96   /* TODO: cache results in a static table */
97
98   for(i = 0, j = lo_hi*n/2; i < n; i += 2, ++j) {
99      elems[i + 0] = lp_build_const_int32(gallivm, 0 + j);
100      elems[i + 1] = lp_build_const_int32(gallivm, n + j);
101   }
102
103   return LLVMConstVector(elems, n);
104}
105
106/**
107 * Similar to lp_build_const_unpack_shuffle but for special AVX 256bit unpack.
108 * See comment above lp_build_interleave2_half for more details.
109 */
110static LLVMValueRef
111lp_build_const_unpack_shuffle_half(struct gallivm_state *gallivm,
112                                   unsigned n, unsigned lo_hi)
113{
114   LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
115   unsigned i, j;
116
117   assert(n <= LP_MAX_VECTOR_LENGTH);
118   assert(lo_hi < 2);
119
120   for (i = 0, j = lo_hi*(n/4); i < n; i += 2, ++j) {
121      if (i == (n / 2))
122         j += n / 4;
123
124      elems[i + 0] = lp_build_const_int32(gallivm, 0 + j);
125      elems[i + 1] = lp_build_const_int32(gallivm, n + j);
126   }
127
128   return LLVMConstVector(elems, n);
129}
130
131/**
132 * Similar to lp_build_const_unpack_shuffle_half, but for AVX512
133 * See comment above lp_build_interleave2_half for more details.
134 */
135static LLVMValueRef
136lp_build_const_unpack_shuffle_16wide(struct gallivm_state *gallivm,
137                                     unsigned lo_hi)
138{
139   LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
140   unsigned i, j;
141
142   assert(lo_hi < 2);
143
144   // for the following lo_hi setting, convert 0 -> f to:
145   // 0: 0 16 4 20  8 24 12 28 1 17 5 21  9 25 13 29
146   // 1: 2 18 6 22 10 26 14 30 3 19 7 23 11 27 15 31
147   for (i = 0; i < 16; i++) {
148      j = ((i&0x06)<<1) + ((i&1)<<4) + (i>>3) + (lo_hi<<1);
149
150      elems[i] = lp_build_const_int32(gallivm, j);
151   }
152
153   return LLVMConstVector(elems, 16);
154}
155
156/**
157 * Build shuffle vectors that match PACKxx (SSE) instructions or
158 * VPERM (Altivec).
159 */
160static LLVMValueRef
161lp_build_const_pack_shuffle(struct gallivm_state *gallivm, unsigned n)
162{
163   LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
164   unsigned i;
165
166   assert(n <= LP_MAX_VECTOR_LENGTH);
167
168   for(i = 0; i < n; ++i)
169#if UTIL_ARCH_LITTLE_ENDIAN
170      elems[i] = lp_build_const_int32(gallivm, 2*i);
171#else
172      elems[i] = lp_build_const_int32(gallivm, 2*i+1);
173#endif
174
175   return LLVMConstVector(elems, n);
176}
177
178/**
179 * Return a vector with elements src[start:start+size]
180 * Most useful for getting half the values out of a 256bit sized vector,
181 * otherwise may cause data rearrangement to happen.
182 */
183LLVMValueRef
184lp_build_extract_range(struct gallivm_state *gallivm,
185                       LLVMValueRef src,
186                       unsigned start,
187                       unsigned size)
188{
189   LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
190   unsigned i;
191
192   assert(size <= ARRAY_SIZE(elems));
193
194   for (i = 0; i < size; ++i)
195      elems[i] = lp_build_const_int32(gallivm, i + start);
196
197   if (size == 1) {
198      return LLVMBuildExtractElement(gallivm->builder, src, elems[0], "");
199   }
200   else {
201      return LLVMBuildShuffleVector(gallivm->builder, src, src,
202                                    LLVMConstVector(elems, size), "");
203   }
204}
205
206/**
207 * Concatenates several (must be a power of 2) vectors (of same type)
208 * into a larger one.
209 * Most useful for building up a 256bit sized vector out of two 128bit ones.
210 */
211LLVMValueRef
212lp_build_concat(struct gallivm_state *gallivm,
213                LLVMValueRef src[],
214                struct lp_type src_type,
215                unsigned num_vectors)
216{
217   unsigned new_length, i;
218   LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH/2];
219   LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH];
220
221   assert(src_type.length * num_vectors <= ARRAY_SIZE(shuffles));
222   assert(util_is_power_of_two_or_zero(num_vectors));
223
224   new_length = src_type.length;
225
226   for (i = 0; i < num_vectors; i++)
227      tmp[i] = src[i];
228
229   while (num_vectors > 1) {
230      num_vectors >>= 1;
231      new_length <<= 1;
232      for (i = 0; i < new_length; i++) {
233         shuffles[i] = lp_build_const_int32(gallivm, i);
234      }
235      for (i = 0; i < num_vectors; i++) {
236         tmp[i] = LLVMBuildShuffleVector(gallivm->builder, tmp[i*2], tmp[i*2 + 1],
237                                         LLVMConstVector(shuffles, new_length), "");
238      }
239   }
240
241   return tmp[0];
242}
243
244
245/**
246 * Combines vectors to reduce from num_srcs to num_dsts.
247 * Returns the number of src vectors concatenated in a single dst.
248 *
249 * num_srcs must be exactly divisible by num_dsts.
250 *
251 * e.g. For num_srcs = 4 and src = [x, y, z, w]
252 *          num_dsts = 1  dst = [xyzw]    return = 4
253 *          num_dsts = 2  dst = [xy, zw]  return = 2
254 */
255int
256lp_build_concat_n(struct gallivm_state *gallivm,
257                  struct lp_type src_type,
258                  LLVMValueRef *src,
259                  unsigned num_srcs,
260                  LLVMValueRef *dst,
261                  unsigned num_dsts)
262{
263   int size = num_srcs / num_dsts;
264   unsigned i;
265
266   assert(num_srcs >= num_dsts);
267   assert((num_srcs % size) == 0);
268
269   if (num_srcs == num_dsts) {
270      for (i = 0; i < num_dsts; ++i) {
271         dst[i] = src[i];
272      }
273      return 1;
274   }
275
276   for (i = 0; i < num_dsts; ++i) {
277      dst[i] = lp_build_concat(gallivm, &src[i * size], src_type, size);
278   }
279
280   return size;
281}
282
283
284/**
285 * Un-interleave vector.
286 * This will return a vector consisting of every second element
287 * (depending on lo_hi, beginning at 0 or 1).
288 * The returned vector size (elems and width) will only be half
289 * that of the source vector.
290 */
291LLVMValueRef
292lp_build_uninterleave1(struct gallivm_state *gallivm,
293                       unsigned num_elems,
294                       LLVMValueRef a,
295                       unsigned lo_hi)
296{
297   LLVMValueRef shuffle, elems[LP_MAX_VECTOR_LENGTH];
298   unsigned i;
299   assert(num_elems <= LP_MAX_VECTOR_LENGTH);
300
301   for (i = 0; i < num_elems / 2; ++i)
302      elems[i] = lp_build_const_int32(gallivm, 2*i + lo_hi);
303
304   shuffle = LLVMConstVector(elems, num_elems / 2);
305
306   return LLVMBuildShuffleVector(gallivm->builder, a, a, shuffle, "");
307}
308
309
310/**
311 * Interleave vector elements.
312 *
313 * Matches the PUNPCKLxx and PUNPCKHxx SSE instructions
314 * (but not for 256bit AVX vectors).
315 */
316LLVMValueRef
317lp_build_interleave2(struct gallivm_state *gallivm,
318                     struct lp_type type,
319                     LLVMValueRef a,
320                     LLVMValueRef b,
321                     unsigned lo_hi)
322{
323   LLVMValueRef shuffle;
324
325   if (type.length == 2 && type.width == 128 && util_get_cpu_caps()->has_avx) {
326      /*
327       * XXX: This is a workaround for llvm code generation deficiency. Strangely
328       * enough, while this needs vinsertf128/vextractf128 instructions (hence
329       * a natural match when using 2x128bit vectors) the "normal" unpack shuffle
330       * generates code ranging from atrocious (llvm 3.1) to terrible (llvm 3.2, 3.3).
331       * So use some different shuffles instead (the exact shuffles don't seem to
332       * matter, as long as not using 128bit wide vectors, works with 8x32 or 4x64).
333       */
334      struct lp_type tmp_type = type;
335      LLVMValueRef srchalf[2], tmpdst;
336      tmp_type.length = 4;
337      tmp_type.width = 64;
338      a = LLVMBuildBitCast(gallivm->builder, a, lp_build_vec_type(gallivm, tmp_type), "");
339      b = LLVMBuildBitCast(gallivm->builder, b, lp_build_vec_type(gallivm, tmp_type), "");
340      srchalf[0] = lp_build_extract_range(gallivm, a, lo_hi * 2, 2);
341      srchalf[1] = lp_build_extract_range(gallivm, b, lo_hi * 2, 2);
342      tmp_type.length = 2;
343      tmpdst = lp_build_concat(gallivm, srchalf, tmp_type, 2);
344      return LLVMBuildBitCast(gallivm->builder, tmpdst, lp_build_vec_type(gallivm, type), "");
345   }
346
347   shuffle = lp_build_const_unpack_shuffle(gallivm, type.length, lo_hi);
348
349   return LLVMBuildShuffleVector(gallivm->builder, a, b, shuffle, "");
350}
351
352/**
353 * Interleave vector elements but with 256 (or 512) bit,
354 * treats it as interleave with 2 concatenated 128 (or 256) bit vectors.
355 *
356 * This differs to lp_build_interleave2 as that function would do the following (for lo):
357 * a0 b0 a1 b1 a2 b2 a3 b3, and this does not compile into an AVX unpack instruction.
358 *
359 *
360 * An example interleave 8x float with 8x float on AVX 256bit unpack:
361 *   a0 a1 a2 a3 a4 a5 a6 a7 <-> b0 b1 b2 b3 b4 b5 b6 b7
362 *
363 * Equivalent to interleaving 2x 128 bit vectors
364 *   a0 a1 a2 a3 <-> b0 b1 b2 b3 concatenated with a4 a5 a6 a7 <-> b4 b5 b6 b7
365 *
366 * So interleave-lo would result in:
367 *   a0 b0 a1 b1 a4 b4 a5 b5
368 *
369 * And interleave-hi would result in:
370 *   a2 b2 a3 b3 a6 b6 a7 b7
371 *
372 * For 512 bits, the following are true:
373 *
374 * Interleave-lo would result in (capital letters denote hex indices):
375 *   a0 b0 a1 b1 a4 b4 a5 b5 a8 b8 a9 b9 aC bC aD bD
376 *
377 * Interleave-hi would result in:
378 *   a2 b2 a3 b3 a6 b6 a7 b7 aA bA aB bB aE bE aF bF
379 */
380LLVMValueRef
381lp_build_interleave2_half(struct gallivm_state *gallivm,
382                          struct lp_type type,
383                          LLVMValueRef a,
384                          LLVMValueRef b,
385                          unsigned lo_hi)
386{
387   if (type.length * type.width == 256) {
388      LLVMValueRef shuffle = lp_build_const_unpack_shuffle_half(gallivm, type.length, lo_hi);
389      return LLVMBuildShuffleVector(gallivm->builder, a, b, shuffle, "");
390   } else if ((type.length == 16) && (type.width == 32)) {
391      LLVMValueRef shuffle = lp_build_const_unpack_shuffle_16wide(gallivm, lo_hi);
392      return LLVMBuildShuffleVector(gallivm->builder, a, b, shuffle, "");
393   } else {
394      return lp_build_interleave2(gallivm, type, a, b, lo_hi);
395   }
396}
397
398
399/**
400 * Double the bit width.
401 *
402 * This will only change the number of bits the values are represented, not the
403 * values themselves.
404 *
405 */
406void
407lp_build_unpack2(struct gallivm_state *gallivm,
408                 struct lp_type src_type,
409                 struct lp_type dst_type,
410                 LLVMValueRef src,
411                 LLVMValueRef *dst_lo,
412                 LLVMValueRef *dst_hi)
413{
414   LLVMBuilderRef builder = gallivm->builder;
415   LLVMValueRef msb;
416   LLVMTypeRef dst_vec_type;
417
418   assert(!src_type.floating);
419   assert(!dst_type.floating);
420   assert(dst_type.width == src_type.width * 2);
421   assert(dst_type.length * 2 == src_type.length);
422
423   if(dst_type.sign && src_type.sign) {
424      /* Replicate the sign bit in the most significant bits */
425      msb = LLVMBuildAShr(builder, src, lp_build_const_int_vec(gallivm, src_type, src_type.width - 1), "");
426   }
427   else
428      /* Most significant bits always zero */
429      msb = lp_build_zero(gallivm, src_type);
430
431   /* Interleave bits */
432#if UTIL_ARCH_LITTLE_ENDIAN
433   *dst_lo = lp_build_interleave2(gallivm, src_type, src, msb, 0);
434   *dst_hi = lp_build_interleave2(gallivm, src_type, src, msb, 1);
435
436#else
437   *dst_lo = lp_build_interleave2(gallivm, src_type, msb, src, 0);
438   *dst_hi = lp_build_interleave2(gallivm, src_type, msb, src, 1);
439#endif
440
441   /* Cast the result into the new type (twice as wide) */
442
443   dst_vec_type = lp_build_vec_type(gallivm, dst_type);
444
445   *dst_lo = LLVMBuildBitCast(builder, *dst_lo, dst_vec_type, "");
446   *dst_hi = LLVMBuildBitCast(builder, *dst_hi, dst_vec_type, "");
447}
448
449
450/**
451 * Double the bit width, with an order which fits the cpu nicely.
452 *
453 * This will only change the number of bits the values are represented, not the
454 * values themselves.
455 *
456 * The order of the results is not guaranteed, other than it will match
457 * the corresponding lp_build_pack2_native call.
458 */
459void
460lp_build_unpack2_native(struct gallivm_state *gallivm,
461                        struct lp_type src_type,
462                        struct lp_type dst_type,
463                        LLVMValueRef src,
464                        LLVMValueRef *dst_lo,
465                        LLVMValueRef *dst_hi)
466{
467   LLVMBuilderRef builder = gallivm->builder;
468   LLVMValueRef msb;
469   LLVMTypeRef dst_vec_type;
470
471   assert(!src_type.floating);
472   assert(!dst_type.floating);
473   assert(dst_type.width == src_type.width * 2);
474   assert(dst_type.length * 2 == src_type.length);
475
476   if(dst_type.sign && src_type.sign) {
477      /* Replicate the sign bit in the most significant bits */
478      msb = LLVMBuildAShr(builder, src,
479               lp_build_const_int_vec(gallivm, src_type, src_type.width - 1), "");
480   }
481   else
482      /* Most significant bits always zero */
483      msb = lp_build_zero(gallivm, src_type);
484
485   /* Interleave bits */
486#if UTIL_ARCH_LITTLE_ENDIAN
487   if (src_type.length * src_type.width == 256 && util_get_cpu_caps()->has_avx2) {
488      *dst_lo = lp_build_interleave2_half(gallivm, src_type, src, msb, 0);
489      *dst_hi = lp_build_interleave2_half(gallivm, src_type, src, msb, 1);
490   } else {
491      *dst_lo = lp_build_interleave2(gallivm, src_type, src, msb, 0);
492      *dst_hi = lp_build_interleave2(gallivm, src_type, src, msb, 1);
493   }
494#else
495   *dst_lo = lp_build_interleave2(gallivm, src_type, msb, src, 0);
496   *dst_hi = lp_build_interleave2(gallivm, src_type, msb, src, 1);
497#endif
498
499   /* Cast the result into the new type (twice as wide) */
500
501   dst_vec_type = lp_build_vec_type(gallivm, dst_type);
502
503   *dst_lo = LLVMBuildBitCast(builder, *dst_lo, dst_vec_type, "");
504   *dst_hi = LLVMBuildBitCast(builder, *dst_hi, dst_vec_type, "");
505}
506
507
508/**
509 * Expand the bit width.
510 *
511 * This will only change the number of bits the values are represented, not the
512 * values themselves.
513 */
514void
515lp_build_unpack(struct gallivm_state *gallivm,
516                struct lp_type src_type,
517                struct lp_type dst_type,
518                LLVMValueRef src,
519                LLVMValueRef *dst, unsigned num_dsts)
520{
521   unsigned num_tmps;
522   unsigned i;
523
524   /* Register width must remain constant */
525   assert(src_type.width * src_type.length == dst_type.width * dst_type.length);
526
527   /* We must not loose or gain channels. Only precision */
528   assert(src_type.length == dst_type.length * num_dsts);
529
530   num_tmps = 1;
531   dst[0] = src;
532
533   while(src_type.width < dst_type.width) {
534      struct lp_type tmp_type = src_type;
535
536      tmp_type.width *= 2;
537      tmp_type.length /= 2;
538
539      for(i = num_tmps; i--; ) {
540         lp_build_unpack2(gallivm, src_type, tmp_type, dst[i], &dst[2*i + 0],
541                          &dst[2*i + 1]);
542      }
543
544      src_type = tmp_type;
545
546      num_tmps *= 2;
547   }
548
549   assert(num_tmps == num_dsts);
550}
551
552
553/**
554 * Non-interleaved pack.
555 *
556 * This will move values as
557 *         (LSB)                     (MSB)
558 *   lo =   l0 __ l1 __ l2 __..  __ ln __
559 *   hi =   h0 __ h1 __ h2 __..  __ hn __
560 *   res =  l0 l1 l2 .. ln h0 h1 h2 .. hn
561 *
562 * This will only change the number of bits the values are represented, not the
563 * values themselves.
564 *
565 * It is assumed the values are already clamped into the destination type range.
566 * Values outside that range will produce undefined results. Use
567 * lp_build_packs2 instead.
568 */
569LLVMValueRef
570lp_build_pack2(struct gallivm_state *gallivm,
571               struct lp_type src_type,
572               struct lp_type dst_type,
573               LLVMValueRef lo,
574               LLVMValueRef hi)
575{
576   LLVMBuilderRef builder = gallivm->builder;
577   LLVMTypeRef dst_vec_type = lp_build_vec_type(gallivm, dst_type);
578   LLVMValueRef shuffle;
579   LLVMValueRef res = NULL;
580   struct lp_type intr_type = dst_type;
581
582   assert(!src_type.floating);
583   assert(!dst_type.floating);
584   assert(src_type.width == dst_type.width * 2);
585   assert(src_type.length * 2 == dst_type.length);
586
587   /* Check for special cases first */
588   if ((util_get_cpu_caps()->has_sse2 || util_get_cpu_caps()->has_altivec) &&
589        src_type.width * src_type.length >= 128) {
590      const char *intrinsic = NULL;
591      boolean swap_intrinsic_operands = FALSE;
592
593      switch(src_type.width) {
594      case 32:
595         if (util_get_cpu_caps()->has_sse2) {
596           if (dst_type.sign) {
597              intrinsic = "llvm.x86.sse2.packssdw.128";
598           } else {
599              if (util_get_cpu_caps()->has_sse4_1) {
600                 intrinsic = "llvm.x86.sse41.packusdw";
601              }
602           }
603         } else if (util_get_cpu_caps()->has_altivec) {
604            if (dst_type.sign) {
605               intrinsic = "llvm.ppc.altivec.vpkswss";
606            } else {
607               intrinsic = "llvm.ppc.altivec.vpkuwus";
608            }
609#if UTIL_ARCH_LITTLE_ENDIAN
610            swap_intrinsic_operands = TRUE;
611#endif
612         }
613         break;
614      case 16:
615         if (dst_type.sign) {
616            if (util_get_cpu_caps()->has_sse2) {
617               intrinsic = "llvm.x86.sse2.packsswb.128";
618            } else if (util_get_cpu_caps()->has_altivec) {
619               intrinsic = "llvm.ppc.altivec.vpkshss";
620#if UTIL_ARCH_LITTLE_ENDIAN
621               swap_intrinsic_operands = TRUE;
622#endif
623            }
624         } else {
625            if (util_get_cpu_caps()->has_sse2) {
626               intrinsic = "llvm.x86.sse2.packuswb.128";
627            } else if (util_get_cpu_caps()->has_altivec) {
628               intrinsic = "llvm.ppc.altivec.vpkshus";
629#if UTIL_ARCH_LITTLE_ENDIAN
630               swap_intrinsic_operands = TRUE;
631#endif
632            }
633         }
634         break;
635      /* default uses generic shuffle below */
636      }
637      if (intrinsic) {
638         if (src_type.width * src_type.length == 128) {
639            LLVMTypeRef intr_vec_type = lp_build_vec_type(gallivm, intr_type);
640            if (swap_intrinsic_operands) {
641               res = lp_build_intrinsic_binary(builder, intrinsic, intr_vec_type, hi, lo);
642            } else {
643               res = lp_build_intrinsic_binary(builder, intrinsic, intr_vec_type, lo, hi);
644            }
645            if (dst_vec_type != intr_vec_type) {
646               res = LLVMBuildBitCast(builder, res, dst_vec_type, "");
647            }
648         }
649         else {
650            int num_split = src_type.width * src_type.length / 128;
651            int i;
652            int nlen = 128 / src_type.width;
653            int lo_off = swap_intrinsic_operands ? nlen : 0;
654            int hi_off = swap_intrinsic_operands ? 0 : nlen;
655            struct lp_type ndst_type = lp_type_unorm(dst_type.width, 128);
656            struct lp_type nintr_type = lp_type_unorm(intr_type.width, 128);
657            LLVMValueRef tmpres[LP_MAX_VECTOR_WIDTH / 128];
658            LLVMValueRef tmplo, tmphi;
659            LLVMTypeRef ndst_vec_type = lp_build_vec_type(gallivm, ndst_type);
660            LLVMTypeRef nintr_vec_type = lp_build_vec_type(gallivm, nintr_type);
661
662            assert(num_split <= LP_MAX_VECTOR_WIDTH / 128);
663
664            for (i = 0; i < num_split / 2; i++) {
665               tmplo = lp_build_extract_range(gallivm,
666                                              lo, i*nlen*2 + lo_off, nlen);
667               tmphi = lp_build_extract_range(gallivm,
668                                              lo, i*nlen*2 + hi_off, nlen);
669               tmpres[i] = lp_build_intrinsic_binary(builder, intrinsic,
670                                                     nintr_vec_type, tmplo, tmphi);
671               if (ndst_vec_type != nintr_vec_type) {
672                  tmpres[i] = LLVMBuildBitCast(builder, tmpres[i], ndst_vec_type, "");
673               }
674            }
675            for (i = 0; i < num_split / 2; i++) {
676               tmplo = lp_build_extract_range(gallivm,
677                                              hi, i*nlen*2 + lo_off, nlen);
678               tmphi = lp_build_extract_range(gallivm,
679                                              hi, i*nlen*2 + hi_off, nlen);
680               tmpres[i+num_split/2] = lp_build_intrinsic_binary(builder, intrinsic,
681                                                                 nintr_vec_type,
682                                                                 tmplo, tmphi);
683               if (ndst_vec_type != nintr_vec_type) {
684                  tmpres[i+num_split/2] = LLVMBuildBitCast(builder, tmpres[i+num_split/2],
685                                                           ndst_vec_type, "");
686               }
687            }
688            res = lp_build_concat(gallivm, tmpres, ndst_type, num_split);
689         }
690         return res;
691      }
692   }
693
694   /* generic shuffle */
695   lo = LLVMBuildBitCast(builder, lo, dst_vec_type, "");
696   hi = LLVMBuildBitCast(builder, hi, dst_vec_type, "");
697
698   shuffle = lp_build_const_pack_shuffle(gallivm, dst_type.length);
699
700   res = LLVMBuildShuffleVector(builder, lo, hi, shuffle, "");
701
702   return res;
703}
704
705
706/**
707 * Non-interleaved native pack.
708 *
709 * Similar to lp_build_pack2, but the ordering of values is not
710 * guaranteed, other than it will match lp_build_unpack2_native.
711 *
712 * In particular, with avx2, the lower and upper 128bits of the vectors will
713 * be packed independently, so that (with 32bit->16bit values)
714 *         (LSB)                                       (MSB)
715 *   lo =   l0 __ l1 __ l2 __ l3 __ l4 __ l5 __ l6 __ l7 __
716 *   hi =   h0 __ h1 __ h2 __ h3 __ h4 __ h5 __ h6 __ h7 __
717 *   res =  l0 l1 l2 l3 h0 h1 h2 h3 l4 l5 l6 l7 h4 h5 h6 h7
718 *
719 * This will only change the number of bits the values are represented, not the
720 * values themselves.
721 *
722 * It is assumed the values are already clamped into the destination type range.
723 * Values outside that range will produce undefined results.
724 */
725LLVMValueRef
726lp_build_pack2_native(struct gallivm_state *gallivm,
727                      struct lp_type src_type,
728                      struct lp_type dst_type,
729                      LLVMValueRef lo,
730                      LLVMValueRef hi)
731{
732   LLVMBuilderRef builder = gallivm->builder;
733   struct lp_type intr_type = dst_type;
734   const char *intrinsic = NULL;
735
736   assert(!src_type.floating);
737   assert(!dst_type.floating);
738   assert(src_type.width == dst_type.width * 2);
739   assert(src_type.length * 2 == dst_type.length);
740
741   /* At this point only have special case for avx2 */
742   if (src_type.length * src_type.width == 256 &&
743       util_get_cpu_caps()->has_avx2) {
744      switch(src_type.width) {
745      case 32:
746         if (dst_type.sign) {
747            intrinsic = "llvm.x86.avx2.packssdw";
748         } else {
749            intrinsic = "llvm.x86.avx2.packusdw";
750         }
751         break;
752      case 16:
753         if (dst_type.sign) {
754            intrinsic = "llvm.x86.avx2.packsswb";
755         } else {
756            intrinsic = "llvm.x86.avx2.packuswb";
757         }
758         break;
759      }
760   }
761   if (intrinsic) {
762      LLVMTypeRef intr_vec_type = lp_build_vec_type(gallivm, intr_type);
763      return lp_build_intrinsic_binary(builder, intrinsic, intr_vec_type,
764                                       lo, hi);
765   }
766   else {
767      return lp_build_pack2(gallivm, src_type, dst_type, lo, hi);
768   }
769}
770
771/**
772 * Non-interleaved pack and saturate.
773 *
774 * Same as lp_build_pack2 but will saturate values so that they fit into the
775 * destination type.
776 */
777LLVMValueRef
778lp_build_packs2(struct gallivm_state *gallivm,
779                struct lp_type src_type,
780                struct lp_type dst_type,
781                LLVMValueRef lo,
782                LLVMValueRef hi)
783{
784   boolean clamp;
785
786   assert(!src_type.floating);
787   assert(!dst_type.floating);
788   assert(src_type.sign == dst_type.sign);
789   assert(src_type.width == dst_type.width * 2);
790   assert(src_type.length * 2 == dst_type.length);
791
792   clamp = TRUE;
793
794   /* All X86 SSE non-interleaved pack instructions take signed inputs and
795    * saturate them, so no need to clamp for those cases. */
796   if(util_get_cpu_caps()->has_sse2 &&
797      src_type.width * src_type.length >= 128 &&
798      src_type.sign &&
799      (src_type.width == 32 || src_type.width == 16))
800      clamp = FALSE;
801
802   if(clamp) {
803      struct lp_build_context bld;
804      unsigned dst_bits = dst_type.sign ? dst_type.width - 1 : dst_type.width;
805      LLVMValueRef dst_max = lp_build_const_int_vec(gallivm, src_type,
806                                ((unsigned long long)1 << dst_bits) - 1);
807      lp_build_context_init(&bld, gallivm, src_type);
808      lo = lp_build_min(&bld, lo, dst_max);
809      hi = lp_build_min(&bld, hi, dst_max);
810      /* FIXME: What about lower bound? */
811   }
812
813   return lp_build_pack2(gallivm, src_type, dst_type, lo, hi);
814}
815
816
817/**
818 * Truncate the bit width.
819 *
820 * TODO: Handle saturation consistently.
821 */
822LLVMValueRef
823lp_build_pack(struct gallivm_state *gallivm,
824              struct lp_type src_type,
825              struct lp_type dst_type,
826              boolean clamped,
827              const LLVMValueRef *src, unsigned num_srcs)
828{
829   LLVMValueRef (*pack2)(struct gallivm_state *gallivm,
830                         struct lp_type src_type,
831                         struct lp_type dst_type,
832                         LLVMValueRef lo,
833                         LLVMValueRef hi);
834   LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
835   unsigned i;
836
837   /* Register width must remain constant */
838   assert(src_type.width * src_type.length == dst_type.width * dst_type.length);
839
840   /* We must not loose or gain channels. Only precision */
841   assert(src_type.length * num_srcs == dst_type.length);
842
843   if(clamped)
844      pack2 = &lp_build_pack2;
845   else
846      pack2 = &lp_build_packs2;
847
848   for(i = 0; i < num_srcs; ++i)
849      tmp[i] = src[i];
850
851   while(src_type.width > dst_type.width) {
852      struct lp_type tmp_type = src_type;
853
854      tmp_type.width /= 2;
855      tmp_type.length *= 2;
856
857      /* Take in consideration the sign changes only in the last step */
858      if(tmp_type.width == dst_type.width)
859         tmp_type.sign = dst_type.sign;
860
861      num_srcs /= 2;
862
863      for(i = 0; i < num_srcs; ++i)
864         tmp[i] = pack2(gallivm, src_type, tmp_type,
865                        tmp[2*i + 0], tmp[2*i + 1]);
866
867      src_type = tmp_type;
868   }
869
870   assert(num_srcs == 1);
871
872   return tmp[0];
873}
874
875
876/**
877 * Truncate or expand the bitwidth.
878 *
879 * NOTE: Getting the right sign flags is crucial here, as we employ some
880 * intrinsics that do saturation.
881 */
882void
883lp_build_resize(struct gallivm_state *gallivm,
884                struct lp_type src_type,
885                struct lp_type dst_type,
886                const LLVMValueRef *src, unsigned num_srcs,
887                LLVMValueRef *dst, unsigned num_dsts)
888{
889   LLVMBuilderRef builder = gallivm->builder;
890   LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
891   unsigned i;
892
893   /*
894    * We don't support float <-> int conversion here. That must be done
895    * before/after calling this function.
896    */
897   assert(src_type.floating == dst_type.floating);
898
899   /*
900    * We don't support double <-> float conversion yet, although it could be
901    * added with little effort.
902    */
903   assert((!src_type.floating && !dst_type.floating) ||
904          src_type.width == dst_type.width);
905
906   /* We must not loose or gain channels. Only precision */
907   assert(src_type.length * num_srcs == dst_type.length * num_dsts);
908
909   assert(src_type.length <= LP_MAX_VECTOR_LENGTH);
910   assert(dst_type.length <= LP_MAX_VECTOR_LENGTH);
911   assert(num_srcs <= LP_MAX_VECTOR_LENGTH);
912   assert(num_dsts <= LP_MAX_VECTOR_LENGTH);
913
914   if (src_type.width > dst_type.width) {
915      /*
916       * Truncate bit width.
917       */
918
919      /* Conversion must be M:1 */
920      assert(num_dsts == 1);
921
922      if (src_type.width * src_type.length == dst_type.width * dst_type.length) {
923        /*
924         * Register width remains constant -- use vector packing intrinsics
925         */
926         tmp[0] = lp_build_pack(gallivm, src_type, dst_type, TRUE, src, num_srcs);
927      }
928      else {
929         if (src_type.width / dst_type.width > num_srcs) {
930            /*
931            * First change src vectors size (with shuffle) so they have the
932            * same size as the destination vector, then pack normally.
933            * Note: cannot use cast/extract because llvm generates atrocious code.
934            */
935            unsigned size_ratio = (src_type.width * src_type.length) /
936                                  (dst_type.length * dst_type.width);
937            unsigned new_length = src_type.length / size_ratio;
938
939            for (i = 0; i < size_ratio * num_srcs; i++) {
940               unsigned start_index = (i % size_ratio) * new_length;
941               tmp[i] = lp_build_extract_range(gallivm, src[i / size_ratio],
942                                               start_index, new_length);
943            }
944            num_srcs *= size_ratio;
945            src_type.length = new_length;
946            tmp[0] = lp_build_pack(gallivm, src_type, dst_type, TRUE, tmp, num_srcs);
947         }
948         else {
949            /*
950             * Truncate bit width but expand vector size - first pack
951             * then expand simply because this should be more AVX-friendly
952             * for the cases we probably hit.
953             */
954            unsigned size_ratio = (dst_type.width * dst_type.length) /
955                                  (src_type.length * src_type.width);
956            unsigned num_pack_srcs = num_srcs / size_ratio;
957            dst_type.length = dst_type.length / size_ratio;
958
959            for (i = 0; i < size_ratio; i++) {
960               tmp[i] = lp_build_pack(gallivm, src_type, dst_type, TRUE,
961                                      &src[i*num_pack_srcs], num_pack_srcs);
962            }
963            tmp[0] = lp_build_concat(gallivm, tmp, dst_type, size_ratio);
964         }
965      }
966   }
967   else if (src_type.width < dst_type.width) {
968      /*
969       * Expand bit width.
970       */
971
972      /* Conversion must be 1:N */
973      assert(num_srcs == 1);
974
975      if (src_type.width * src_type.length == dst_type.width * dst_type.length) {
976         /*
977          * Register width remains constant -- use vector unpack intrinsics
978          */
979         lp_build_unpack(gallivm, src_type, dst_type, src[0], tmp, num_dsts);
980      }
981      else {
982         /*
983          * Do it element-wise.
984          */
985         assert(src_type.length * num_srcs == dst_type.length * num_dsts);
986
987         for (i = 0; i < num_dsts; i++) {
988            tmp[i] = lp_build_undef(gallivm, dst_type);
989         }
990
991         for (i = 0; i < src_type.length; ++i) {
992            unsigned j = i / dst_type.length;
993            LLVMValueRef srcindex = lp_build_const_int32(gallivm, i);
994            LLVMValueRef dstindex = lp_build_const_int32(gallivm, i % dst_type.length);
995            LLVMValueRef val = LLVMBuildExtractElement(builder, src[0], srcindex, "");
996
997            if (src_type.sign && dst_type.sign) {
998               val = LLVMBuildSExt(builder, val, lp_build_elem_type(gallivm, dst_type), "");
999            } else {
1000               val = LLVMBuildZExt(builder, val, lp_build_elem_type(gallivm, dst_type), "");
1001            }
1002            tmp[j] = LLVMBuildInsertElement(builder, tmp[j], val, dstindex, "");
1003         }
1004      }
1005   }
1006   else {
1007      /*
1008       * No-op
1009       */
1010
1011      /* "Conversion" must be N:N */
1012      assert(num_srcs == num_dsts);
1013
1014      for(i = 0; i < num_dsts; ++i)
1015         tmp[i] = src[i];
1016   }
1017
1018   for(i = 0; i < num_dsts; ++i)
1019      dst[i] = tmp[i];
1020}
1021
1022
1023/**
1024 * Expands src vector from src.length to dst_length
1025 */
1026LLVMValueRef
1027lp_build_pad_vector(struct gallivm_state *gallivm,
1028                    LLVMValueRef src,
1029                    unsigned dst_length)
1030{
1031   LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
1032   LLVMValueRef undef;
1033   LLVMTypeRef type;
1034   unsigned i, src_length;
1035
1036   type = LLVMTypeOf(src);
1037
1038   if (LLVMGetTypeKind(type) != LLVMVectorTypeKind) {
1039      /* Can't use ShuffleVector on non-vector type */
1040      undef = LLVMGetUndef(LLVMVectorType(type, dst_length));
1041      return LLVMBuildInsertElement(gallivm->builder, undef, src, lp_build_const_int32(gallivm, 0), "");
1042   }
1043
1044   undef      = LLVMGetUndef(type);
1045   src_length = LLVMGetVectorSize(type);
1046
1047   assert(dst_length <= ARRAY_SIZE(elems));
1048   assert(dst_length >= src_length);
1049
1050   if (src_length == dst_length)
1051      return src;
1052
1053   /* All elements from src vector */
1054   for (i = 0; i < src_length; ++i)
1055      elems[i] = lp_build_const_int32(gallivm, i);
1056
1057   /* Undef fill remaining space */
1058   for (i = src_length; i < dst_length; ++i)
1059      elems[i] = lp_build_const_int32(gallivm, src_length);
1060
1061   /* Combine the two vectors */
1062   return LLVMBuildShuffleVector(gallivm->builder, src, undef, LLVMConstVector(elems, dst_length), "");
1063}
1064