lp_bld_blend_soa.c revision 38f6f23fcf37247fd709d1c612d08bfa9b124e69 
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27
28
29/**
30 * @file
31 * Blend LLVM IR generation -- SoA layout.
32 *
33 * Blending in SoA is much faster than AoS, especially when separate rgb/alpha
34 * factors/functions are used, since no channel masking/shuffling is necessary
35 * and we can achieve the full throughput of the SIMD operations. Furthermore
36 * the fragment shader output is also in SoA, so it fits nicely with the rest of
37 * the fragment pipeline.
38 *
39 * The drawback is that to be displayed the color buffer needs to be in AoS
40 * layout, so we need to tile/untile the color buffer before/after rendering.
41 * A color buffer like
42 *
43 *  R11 G11 B11 A11 R12 G12 B12 A12  R13 G13 B13 A13 R14 G14 B14 A14  ...
44 *  R21 G21 B21 A21 R22 G22 B22 A22  R23 G23 B23 A23 R24 G24 B24 A24  ...
45 *
46 *  R31 G31 B31 A31 R32 G32 B32 A32  R33 G33 B33 A33 R34 G34 B34 A34  ...
47 *  R41 G41 B41 A41 R42 G42 B42 A42  R43 G43 B43 A43 R44 G44 B44 A44  ...
48 *
49 *  ... ... ... ... ... ... ... ...  ... ... ... ... ... ... ... ...  ...
50 *
51 * will actually be stored in memory as
52 *
53 *  R11 R12 R21 R22 R13 R14 R23 R24 ... G11 G12 G21 G22 G13 G14 G23 G24 ... B11 B12 B21 B22 B13 B14 B23 B24 ... A11 A12 A21 A22 A13 A14 A23 A24 ...
54 *  R31 R32 R41 R42 R33 R34 R43 R44 ... G31 G32 G41 G42 G33 G34 G43 G44 ... B31 B32 B41 B42 B33 B34 B43 B44 ... A31 A32 A41 A42 A33 A34 A43 A44 ...
55 *  ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...
56 *
57 * NOTE: Run lp_blend_test after any change to this file.
58 *
59 * You can also run lp_blend_test to obtain AoS vs SoA benchmarks. Invoking it
60 * as:
61 *
62 *  lp_blend_test -o blend.tsv
63 *
64 * will generate a tab-seperated-file with the test results and performance
65 * measurements.
66 *
67 * @author Jose Fonseca <jfonseca@vmware.com>
68 */
69
70
71#include "pipe/p_state.h"
72#include "util/u_debug.h"
73
74#include "lp_bld_type.h"
75#include "lp_bld_arit.h"
76#include "lp_bld_blend.h"
77
78
79/**
80 * We may the same values several times, so we keep them here to avoid
81 * recomputing them. Also reusing the values allows us to do simplifications
82 * that LLVM optimization passes wouldn't normally be able to do.
83 */
84struct lp_build_blend_soa_context
85{
86   struct lp_build_context base;
87
88   LLVMValueRef src[4];
89   LLVMValueRef dst[4];
90   LLVMValueRef con[4];
91
92   LLVMValueRef inv_src[4];
93   LLVMValueRef inv_dst[4];
94   LLVMValueRef inv_con[4];
95
96   LLVMValueRef src_alpha_saturate;
97
98   /**
99    * We store all factors in a table in order to eliminate redundant
100    * multiplications later.
101    */
102   LLVMValueRef factor[2][2][4];
103
104   /**
105    * Table with all terms.
106    */
107   LLVMValueRef term[2][4];
108};
109
110
111static LLVMValueRef
112lp_build_blend_soa_factor(struct lp_build_blend_soa_context *bld,
113                          unsigned factor, unsigned i)
114{
115   /*
116    * Compute src/first term RGB
117    */
118   switch (factor) {
119   case PIPE_BLENDFACTOR_ONE:
120      return bld->base.one;
121   case PIPE_BLENDFACTOR_SRC_COLOR:
122      return bld->src[i];
123   case PIPE_BLENDFACTOR_SRC_ALPHA:
124      return bld->src[3];
125   case PIPE_BLENDFACTOR_DST_COLOR:
126      return bld->dst[i];
127   case PIPE_BLENDFACTOR_DST_ALPHA:
128      return bld->dst[3];
129   case PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE:
130      if(i == 3)
131         return bld->base.one;
132      else {
133         if(!bld->inv_dst[3])
134            bld->inv_dst[3] = lp_build_comp(&bld->base, bld->dst[3]);
135         if(!bld->src_alpha_saturate)
136            bld->src_alpha_saturate = lp_build_min(&bld->base, bld->src[3], bld->inv_dst[3]);
137         return bld->src_alpha_saturate;
138      }
139   case PIPE_BLENDFACTOR_CONST_COLOR:
140      return bld->con[i];
141   case PIPE_BLENDFACTOR_CONST_ALPHA:
142      return bld->con[3];
143   case PIPE_BLENDFACTOR_SRC1_COLOR:
144      /* TODO */
145      assert(0);
146      return bld->base.zero;
147   case PIPE_BLENDFACTOR_SRC1_ALPHA:
148      /* TODO */
149      assert(0);
150      return bld->base.zero;
151   case PIPE_BLENDFACTOR_ZERO:
152      return bld->base.zero;
153   case PIPE_BLENDFACTOR_INV_SRC_COLOR:
154      if(!bld->inv_src[i])
155         bld->inv_src[i] = lp_build_comp(&bld->base, bld->src[i]);
156      return bld->inv_src[i];
157   case PIPE_BLENDFACTOR_INV_SRC_ALPHA:
158      if(!bld->inv_src[3])
159         bld->inv_src[3] = lp_build_comp(&bld->base, bld->src[3]);
160      return bld->inv_src[3];
161   case PIPE_BLENDFACTOR_INV_DST_COLOR:
162      if(!bld->inv_dst[i])
163         bld->inv_dst[i] = lp_build_comp(&bld->base, bld->dst[i]);
164      return bld->inv_dst[i];
165   case PIPE_BLENDFACTOR_INV_DST_ALPHA:
166      if(!bld->inv_dst[3])
167         bld->inv_dst[3] = lp_build_comp(&bld->base, bld->dst[3]);
168      return bld->inv_dst[3];
169   case PIPE_BLENDFACTOR_INV_CONST_COLOR:
170      if(!bld->inv_con[i])
171         bld->inv_con[i] = lp_build_comp(&bld->base, bld->con[i]);
172      return bld->inv_con[i];
173   case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
174      if(!bld->inv_con[3])
175         bld->inv_con[3] = lp_build_comp(&bld->base, bld->con[3]);
176      return bld->inv_con[3];
177   case PIPE_BLENDFACTOR_INV_SRC1_COLOR:
178      /* TODO */
179      assert(0);
180      return bld->base.zero;
181   case PIPE_BLENDFACTOR_INV_SRC1_ALPHA:
182      /* TODO */
183      assert(0);
184      return bld->base.zero;
185   default:
186      assert(0);
187      return bld->base.zero;
188   }
189}
190
191
192/**
193 * Generate blend code in SOA mode.
194 * \param src  src/fragment color
195 * \param dst  dst/framebuffer color
196 * \param con  constant blend color
197 * \param res  the result/output
198 */
199void
200lp_build_blend_soa(LLVMBuilderRef builder,
201                   const struct pipe_blend_state *blend,
202                   struct lp_type type,
203                   LLVMValueRef src[4],
204                   LLVMValueRef dst[4],
205                   LLVMValueRef con[4],
206                   LLVMValueRef res[4])
207{
208   struct lp_build_blend_soa_context bld;
209   unsigned i, j, k;
210
211   /* Setup build context */
212   memset(&bld, 0, sizeof bld);
213   lp_build_context_init(&bld.base, builder, type);
214   for (i = 0; i < 4; ++i) {
215      bld.src[i] = src[i];
216      bld.dst[i] = dst[i];
217      bld.con[i] = con[i];
218   }
219
220   for (i = 0; i < 4; ++i) {
221      if (blend->rt[0].colormask & (1 << i)) {
222         if (blend->logicop_enable) {
223            if(!type.floating) {
224               res[i] = lp_build_logicop(builder, blend->logicop_func, src[i], dst[i]);
225            }
226            else
227               res[i] = dst[i];
228         }
229         else if (blend->rt[0].blend_enable) {
230            unsigned src_factor = i < 3 ? blend->rt[0].rgb_src_factor : blend->rt[0].alpha_src_factor;
231            unsigned dst_factor = i < 3 ? blend->rt[0].rgb_dst_factor : blend->rt[0].alpha_dst_factor;
232            unsigned func = i < 3 ? blend->rt[0].rgb_func : blend->rt[0].alpha_func;
233            boolean func_commutative = lp_build_blend_func_commutative(func);
234
235            /* It makes no sense to blend unless values are normalized */
236            assert(type.norm);
237
238            /*
239             * Compute src/dst factors.
240             */
241
242            bld.factor[0][0][i] = src[i];
243            bld.factor[0][1][i] = lp_build_blend_soa_factor(&bld, src_factor, i);
244            bld.factor[1][0][i] = dst[i];
245            bld.factor[1][1][i] = lp_build_blend_soa_factor(&bld, dst_factor, i);
246
247            /*
248             * Compute src/dst terms
249             */
250
251            for(k = 0; k < 2; ++k) {
252               /* See if this multiplication has been previously computed */
253               for(j = 0; j < i; ++j) {
254                  if((bld.factor[k][0][j] == bld.factor[k][0][i] &&
255                      bld.factor[k][1][j] == bld.factor[k][1][i]) ||
256                     (bld.factor[k][0][j] == bld.factor[k][1][i] &&
257                      bld.factor[k][1][j] == bld.factor[k][0][i]))
258                     break;
259               }
260
261               if(j < i)
262                  bld.term[k][i] = bld.term[k][j];
263               else
264                  bld.term[k][i] = lp_build_mul(&bld.base, bld.factor[k][0][i], bld.factor[k][1][i]);
265            }
266
267            /*
268             * Combine terms
269             */
270
271            /* See if this function has been previously applied */
272            for(j = 0; j < i; ++j) {
273               unsigned prev_func = j < 3 ? blend->rt[0].rgb_func : blend->rt[0].alpha_func;
274               unsigned func_reverse = lp_build_blend_func_reverse(func, prev_func);
275
276               if((!func_reverse &&
277                   bld.term[0][j] == bld.term[0][i] &&
278                   bld.term[1][j] == bld.term[1][i]) ||
279                  ((func_commutative || func_reverse) &&
280                   bld.term[0][j] == bld.term[1][i] &&
281                   bld.term[1][j] == bld.term[0][i]))
282                  break;
283            }
284
285            if(j < i)
286               res[i] = res[j];
287            else
288               res[i] = lp_build_blend_func(&bld.base, func, bld.term[0][i], bld.term[1][i]);
289         }
290         else {
291            res[i] = src[i];
292         }
293      }
294      else {
295         res[i] = dst[i];
296      }
297   }
298}
299