1 /* libs/pixelflinger/codeflinger/blending.cpp
2 **
3 ** Copyright 2006, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 **     http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17 
18 #define LOG_TAG "pixelflinger-code"
19 
20 #include <assert.h>
21 #include <stdint.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <sys/types.h>
25 
26 #include <log/log.h>
27 
28 #include "GGLAssembler.h"
29 
30 namespace android {
31 
build_fog(component_t & temp,int component,Scratch & regs)32 void GGLAssembler::build_fog(
33                         component_t& temp,      // incomming fragment / output
34                         int component,
35                         Scratch& regs)
36 {
37    if (mInfo[component].fog) {
38         Scratch scratches(registerFile());
39         comment("fog");
40 
41         integer_t fragment(temp.reg, temp.h, temp.flags);
42         if (!(temp.flags & CORRUPTIBLE)) {
43             temp.reg = regs.obtain();
44             temp.flags |= CORRUPTIBLE;
45         }
46 
47         integer_t fogColor(scratches.obtain(), 8, CORRUPTIBLE);
48         LDRB(AL, fogColor.reg, mBuilderContext.Rctx,
49                 immed12_pre(GGL_OFFSETOF(state.fog.color[component])));
50 
51         integer_t factor(scratches.obtain(), 16, CORRUPTIBLE);
52         CONTEXT_LOAD(factor.reg, generated_vars.f);
53 
54         // clamp fog factor (TODO: see if there is a way to guarantee
55         // we won't overflow, when setting the iterators)
56         BIC(AL, 0, factor.reg, factor.reg, reg_imm(factor.reg, ASR, 31));
57         CMP(AL, factor.reg, imm( 0x10000 ));
58         MOV(HS, 0, factor.reg, imm( 0x10000 ));
59 
60         build_blendFOneMinusF(temp, factor, fragment, fogColor);
61     }
62 }
63 
build_blending(component_t & temp,const pixel_t & pixel,int component,Scratch & regs)64 void GGLAssembler::build_blending(
65                         component_t& temp,      // incomming fragment / output
66                         const pixel_t& pixel,   // framebuffer
67                         int component,
68                         Scratch& regs)
69 {
70    if (!mInfo[component].blend)
71         return;
72 
73     int fs = component==GGLFormat::ALPHA ? mBlendSrcA : mBlendSrc;
74     int fd = component==GGLFormat::ALPHA ? mBlendDstA : mBlendDst;
75     if (fs==GGL_SRC_ALPHA_SATURATE && component==GGLFormat::ALPHA)
76         fs = GGL_ONE;
77     const int blending = blending_codes(fs, fd);
78     if (!temp.size()) {
79         // here, blending will produce something which doesn't depend on
80         // that component (eg: GL_ZERO:GL_*), so the register has not been
81         // allocated yet. Will never be used as a source.
82         temp = component_t(regs.obtain(), CORRUPTIBLE);
83     }
84 
85     // we are doing real blending...
86     // fb:          extracted dst
87     // fragment:    extracted src
88     // temp:        component_t(fragment) and result
89 
90     // scoped register allocator
91     Scratch scratches(registerFile());
92     comment("blending");
93 
94     // we can optimize these cases a bit...
95     // (1) saturation is not needed
96     // (2) we can use only one multiply instead of 2
97     // (3) we can reduce the register pressure
98     //      R = S*f + D*(1-f) = (S-D)*f + D
99     //      R = S*(1-f) + D*f = (D-S)*f + S
100 
101     const bool same_factor_opt1 =
102         (fs==GGL_DST_COLOR && fd==GGL_ONE_MINUS_DST_COLOR) ||
103         (fs==GGL_SRC_COLOR && fd==GGL_ONE_MINUS_SRC_COLOR) ||
104         (fs==GGL_DST_ALPHA && fd==GGL_ONE_MINUS_DST_ALPHA) ||
105         (fs==GGL_SRC_ALPHA && fd==GGL_ONE_MINUS_SRC_ALPHA);
106 
107     const bool same_factor_opt2 =
108         (fs==GGL_ONE_MINUS_DST_COLOR && fd==GGL_DST_COLOR) ||
109         (fs==GGL_ONE_MINUS_SRC_COLOR && fd==GGL_SRC_COLOR) ||
110         (fs==GGL_ONE_MINUS_DST_ALPHA && fd==GGL_DST_ALPHA) ||
111         (fs==GGL_ONE_MINUS_SRC_ALPHA && fd==GGL_SRC_ALPHA);
112 
113 
114     // XXX: we could also optimize these cases:
115     // R = S*f + D*f = (S+D)*f
116     // R = S*(1-f) + D*(1-f) = (S+D)*(1-f)
117     // R = S*D + D*S = 2*S*D
118 
119 
120     // see if we need to extract 'component' from the destination (fb)
121     integer_t fb;
122     if (blending & (BLEND_DST|FACTOR_DST)) {
123         fb.setTo(scratches.obtain(), 32);
124         extract(fb, pixel, component);
125         if (mDithering) {
126             // XXX: maybe what we should do instead, is simply
127             // expand fb -or- fragment to the larger of the two
128             if (fb.size() < temp.size()) {
129                 // for now we expand 'fb' to min(fragment, 8)
130                 int new_size = temp.size() < 8 ? temp.size() : 8;
131                 expand(fb, fb, new_size);
132             }
133         }
134     }
135 
136 
137     // convert input fragment to integer_t
138     if (temp.l && (temp.flags & CORRUPTIBLE)) {
139         MOV(AL, 0, temp.reg, reg_imm(temp.reg, LSR, temp.l));
140         temp.h -= temp.l;
141         temp.l = 0;
142     }
143     integer_t fragment(temp.reg, temp.size(), temp.flags);
144 
145     // if not done yet, convert input fragment to integer_t
146     if (temp.l) {
147         // here we know temp is not CORRUPTIBLE
148         fragment.reg = scratches.obtain();
149         MOV(AL, 0, fragment.reg, reg_imm(temp.reg, LSR, temp.l));
150         fragment.flags |= CORRUPTIBLE;
151     }
152 
153     if (!(temp.flags & CORRUPTIBLE)) {
154         // temp is not corruptible, but since it's the destination it
155         // will be modified, so we need to allocate a new register.
156         temp.reg = regs.obtain();
157         temp.flags &= ~CORRUPTIBLE;
158         fragment.flags &= ~CORRUPTIBLE;
159     }
160 
161     if ((blending & BLEND_SRC) && !same_factor_opt1) {
162         // source (fragment) is needed for the blending stage
163         // so it's not CORRUPTIBLE (unless we're doing same_factor_opt1)
164         fragment.flags &= ~CORRUPTIBLE;
165     }
166 
167 
168     if (same_factor_opt1) {
169         //  R = S*f + D*(1-f) = (S-D)*f + D
170         integer_t factor;
171         build_blend_factor(factor, fs,
172                 component, pixel, fragment, fb, scratches);
173         // fb is always corruptible from this point
174         fb.flags |= CORRUPTIBLE;
175         build_blendFOneMinusF(temp, factor, fragment, fb);
176     } else if (same_factor_opt2) {
177         //  R = S*(1-f) + D*f = (D-S)*f + S
178         integer_t factor;
179         // fb is always corrruptible here
180         fb.flags |= CORRUPTIBLE;
181         build_blend_factor(factor, fd,
182                 component, pixel, fragment, fb, scratches);
183         build_blendOneMinusFF(temp, factor, fragment, fb);
184     } else {
185         integer_t src_factor;
186         integer_t dst_factor;
187 
188         // if destination (fb) is not needed for the blending stage,
189         // then it can be marked as CORRUPTIBLE
190         if (!(blending & BLEND_DST)) {
191             fb.flags |= CORRUPTIBLE;
192         }
193 
194         // XXX: try to mark some registers as CORRUPTIBLE
195         // in most case we could make those corruptible
196         // when we're processing the last component
197         // but not always, for instance
198         //    when fragment is constant and not reloaded
199         //    when fb is needed for logic-ops or masking
200         //    when a register is aliased (for instance with mAlphaSource)
201 
202         // blend away...
203         if (fs==GGL_ZERO) {
204             if (fd==GGL_ZERO) {         // R = 0
205                 // already taken care of
206             } else if (fd==GGL_ONE) {   // R = D
207                 // already taken care of
208             } else {                    // R = D*fd
209                 // compute fd
210                 build_blend_factor(dst_factor, fd,
211                         component, pixel, fragment, fb, scratches);
212                 mul_factor(temp, fb, dst_factor);
213             }
214         } else if (fs==GGL_ONE) {
215             if (fd==GGL_ZERO) {         // R = S
216                 // NOP, taken care of
217             } else if (fd==GGL_ONE) {   // R = S + D
218                 component_add(temp, fb, fragment); // args order matters
219                 component_sat(temp);
220             } else {                    // R = S + D*fd
221                 // compute fd
222                 build_blend_factor(dst_factor, fd,
223                         component, pixel, fragment, fb, scratches);
224                 mul_factor_add(temp, fb, dst_factor, component_t(fragment));
225                 component_sat(temp);
226             }
227         } else {
228             // compute fs
229             build_blend_factor(src_factor, fs,
230                     component, pixel, fragment, fb, scratches);
231             if (fd==GGL_ZERO) {         // R = S*fs
232                 mul_factor(temp, fragment, src_factor);
233             } else if (fd==GGL_ONE) {   // R = S*fs + D
234                 mul_factor_add(temp, fragment, src_factor, component_t(fb));
235                 component_sat(temp);
236             } else {                    // R = S*fs + D*fd
237                 mul_factor(temp, fragment, src_factor);
238                 if (scratches.isUsed(src_factor.reg))
239                     scratches.recycle(src_factor.reg);
240                 // compute fd
241                 build_blend_factor(dst_factor, fd,
242                         component, pixel, fragment, fb, scratches);
243                 mul_factor_add(temp, fb, dst_factor, temp);
244                 if (!same_factor_opt1 && !same_factor_opt2) {
245                     component_sat(temp);
246                 }
247             }
248         }
249     }
250 
251     // now we can be corrupted (it's the dest)
252     temp.flags |= CORRUPTIBLE;
253 }
254 
build_blend_factor(integer_t & factor,int f,int component,const pixel_t & dst_pixel,integer_t & fragment,integer_t & fb,Scratch & scratches)255 void GGLAssembler::build_blend_factor(
256         integer_t& factor, int f, int component,
257         const pixel_t& dst_pixel,
258         integer_t& fragment,
259         integer_t& fb,
260         Scratch& scratches)
261 {
262     integer_t src_alpha(fragment);
263 
264     // src_factor/dst_factor won't be used after blending,
265     // so it's fine to mark them as CORRUPTIBLE (if not aliased)
266     factor.flags |= CORRUPTIBLE;
267 
268     switch(f) {
269     case GGL_ONE_MINUS_SRC_ALPHA:
270     case GGL_SRC_ALPHA:
271         if (component==GGLFormat::ALPHA && !isAlphaSourceNeeded()) {
272             // we're processing alpha, so we already have
273             // src-alpha in fragment, and we need src-alpha just this time.
274         } else {
275            // alpha-src will be needed for other components
276             if (!mBlendFactorCached || mBlendFactorCached==f) {
277                 src_alpha = mAlphaSource;
278                 factor = mAlphaSource;
279                 factor.flags &= ~CORRUPTIBLE;
280                 // we already computed the blend factor before, nothing to do.
281                 if (mBlendFactorCached)
282                     return;
283                 // this is the first time, make sure to compute the blend
284                 // factor properly.
285                 mBlendFactorCached = f;
286                 break;
287             } else {
288                 // we have a cached alpha blend factor, but we want another one,
289                 // this should really not happen because by construction,
290                 // we cannot have BOTH source and destination
291                 // blend factors use ALPHA *and* ONE_MINUS_ALPHA (because
292                 // the blending stage uses the f/(1-f) optimization
293 
294                 // for completeness, we handle this case though. Since there
295                 // are only 2 choices, this meens we want "the other one"
296                 // (1-factor)
297                 factor = mAlphaSource;
298                 factor.flags &= ~CORRUPTIBLE;
299                 RSB(AL, 0, factor.reg, factor.reg, imm((1<<factor.s)));
300                 mBlendFactorCached = f;
301                 return;
302             }
303         }
304         // fall-through...
305     case GGL_ONE_MINUS_DST_COLOR:
306     case GGL_DST_COLOR:
307     case GGL_ONE_MINUS_SRC_COLOR:
308     case GGL_SRC_COLOR:
309     case GGL_ONE_MINUS_DST_ALPHA:
310     case GGL_DST_ALPHA:
311     case GGL_SRC_ALPHA_SATURATE:
312         // help us find out what register we can use for the blend-factor
313         // CORRUPTIBLE registers are chosen first, or a new one is allocated.
314         if (fragment.flags & CORRUPTIBLE) {
315             factor.setTo(fragment.reg, 32, CORRUPTIBLE);
316             fragment.flags &= ~CORRUPTIBLE;
317         } else if (fb.flags & CORRUPTIBLE) {
318             factor.setTo(fb.reg, 32, CORRUPTIBLE);
319             fb.flags &= ~CORRUPTIBLE;
320         } else {
321             factor.setTo(scratches.obtain(), 32, CORRUPTIBLE);
322         }
323         break;
324     }
325 
326     // XXX: doesn't work if size==1
327 
328     switch(f) {
329     case GGL_ONE_MINUS_DST_COLOR:
330     case GGL_DST_COLOR:
331         factor.s = fb.s;
332         ADD(AL, 0, factor.reg, fb.reg, reg_imm(fb.reg, LSR, fb.s-1));
333         break;
334     case GGL_ONE_MINUS_SRC_COLOR:
335     case GGL_SRC_COLOR:
336         factor.s = fragment.s;
337         ADD(AL, 0, factor.reg, fragment.reg,
338             reg_imm(fragment.reg, LSR, fragment.s-1));
339         break;
340     case GGL_ONE_MINUS_SRC_ALPHA:
341     case GGL_SRC_ALPHA:
342         factor.s = src_alpha.s;
343         ADD(AL, 0, factor.reg, src_alpha.reg,
344                 reg_imm(src_alpha.reg, LSR, src_alpha.s-1));
345         break;
346     case GGL_ONE_MINUS_DST_ALPHA:
347     case GGL_DST_ALPHA:
348         // XXX: should be precomputed
349         extract(factor, dst_pixel, GGLFormat::ALPHA);
350         ADD(AL, 0, factor.reg, factor.reg,
351                 reg_imm(factor.reg, LSR, factor.s-1));
352         break;
353     case GGL_SRC_ALPHA_SATURATE:
354         // XXX: should be precomputed
355         // XXX: f = min(As, 1-Ad)
356         // btw, we're guaranteed that Ad's size is <= 8, because
357         // it's extracted from the framebuffer
358         break;
359     }
360 
361     switch(f) {
362     case GGL_ONE_MINUS_DST_COLOR:
363     case GGL_ONE_MINUS_SRC_COLOR:
364     case GGL_ONE_MINUS_DST_ALPHA:
365     case GGL_ONE_MINUS_SRC_ALPHA:
366         RSB(AL, 0, factor.reg, factor.reg, imm((1<<factor.s)));
367     }
368 
369     // don't need more than 8-bits for the blend factor
370     // and this will prevent overflows in the multiplies later
371     if (factor.s > 8) {
372         MOV(AL, 0, factor.reg, reg_imm(factor.reg, LSR, factor.s-8));
373         factor.s = 8;
374     }
375 }
376 
blending_codes(int fs,int fd)377 int GGLAssembler::blending_codes(int fs, int fd)
378 {
379     int blending = 0;
380     switch(fs) {
381     case GGL_ONE:
382         blending |= BLEND_SRC;
383         break;
384 
385     case GGL_ONE_MINUS_DST_COLOR:
386     case GGL_DST_COLOR:
387         blending |= FACTOR_DST|BLEND_SRC;
388         break;
389     case GGL_ONE_MINUS_DST_ALPHA:
390     case GGL_DST_ALPHA:
391         // no need to extract 'component' from the destination
392         // for the blend factor, because we need ALPHA only.
393         blending |= BLEND_SRC;
394         break;
395 
396     case GGL_ONE_MINUS_SRC_COLOR:
397     case GGL_SRC_COLOR:
398         blending |= FACTOR_SRC|BLEND_SRC;
399         break;
400     case GGL_ONE_MINUS_SRC_ALPHA:
401     case GGL_SRC_ALPHA:
402     case GGL_SRC_ALPHA_SATURATE:
403         blending |= FACTOR_SRC|BLEND_SRC;
404         break;
405     }
406     switch(fd) {
407     case GGL_ONE:
408         blending |= BLEND_DST;
409         break;
410 
411     case GGL_ONE_MINUS_DST_COLOR:
412     case GGL_DST_COLOR:
413         blending |= FACTOR_DST|BLEND_DST;
414         break;
415     case GGL_ONE_MINUS_DST_ALPHA:
416     case GGL_DST_ALPHA:
417         blending |= FACTOR_DST|BLEND_DST;
418         break;
419 
420     case GGL_ONE_MINUS_SRC_COLOR:
421     case GGL_SRC_COLOR:
422         blending |= FACTOR_SRC|BLEND_DST;
423         break;
424     case GGL_ONE_MINUS_SRC_ALPHA:
425     case GGL_SRC_ALPHA:
426         // no need to extract 'component' from the source
427         // for the blend factor, because we need ALPHA only.
428         blending |= BLEND_DST;
429         break;
430     }
431     return blending;
432 }
433 
434 // ---------------------------------------------------------------------------
435 
build_blendFOneMinusF(component_t & temp,const integer_t & factor,const integer_t & fragment,const integer_t & fb)436 void GGLAssembler::build_blendFOneMinusF(
437         component_t& temp,
438         const integer_t& factor,
439         const integer_t& fragment,
440         const integer_t& fb)
441 {
442     //  R = S*f + D*(1-f) = (S-D)*f + D
443     Scratch scratches(registerFile());
444     // compute S-D
445     integer_t diff(fragment.flags & CORRUPTIBLE ?
446             fragment.reg : scratches.obtain(), fb.size(), CORRUPTIBLE);
447     const int shift = fragment.size() - fb.size();
448     if (shift>0)        RSB(AL, 0, diff.reg, fb.reg, reg_imm(fragment.reg, LSR, shift));
449     else if (shift<0)   RSB(AL, 0, diff.reg, fb.reg, reg_imm(fragment.reg, LSL,-shift));
450     else                RSB(AL, 0, diff.reg, fb.reg, fragment.reg);
451     mul_factor_add(temp, diff, factor, component_t(fb));
452 }
453 
build_blendOneMinusFF(component_t & temp,const integer_t & factor,const integer_t & fragment,const integer_t & fb)454 void GGLAssembler::build_blendOneMinusFF(
455         component_t& temp,
456         const integer_t& factor,
457         const integer_t& fragment,
458         const integer_t& fb)
459 {
460     //  R = S*f + D*(1-f) = (S-D)*f + D
461     Scratch scratches(registerFile());
462     // compute D-S
463     integer_t diff(fb.flags & CORRUPTIBLE ?
464             fb.reg : scratches.obtain(), fb.size(), CORRUPTIBLE);
465     const int shift = fragment.size() - fb.size();
466     if (shift>0)        SUB(AL, 0, diff.reg, fb.reg, reg_imm(fragment.reg, LSR, shift));
467     else if (shift<0)   SUB(AL, 0, diff.reg, fb.reg, reg_imm(fragment.reg, LSL,-shift));
468     else                SUB(AL, 0, diff.reg, fb.reg, fragment.reg);
469     mul_factor_add(temp, diff, factor, component_t(fragment));
470 }
471 
472 // ---------------------------------------------------------------------------
473 
mul_factor(component_t & d,const integer_t & v,const integer_t & f)474 void GGLAssembler::mul_factor(  component_t& d,
475                                 const integer_t& v,
476                                 const integer_t& f)
477 {
478     int vs = v.size();
479     int fs = f.size();
480     int ms = vs+fs;
481 
482     // XXX: we could have special cases for 1 bit mul
483 
484     // all this code below to use the best multiply instruction
485     // wrt the parameters size. We take advantage of the fact
486     // that the 16-bits multiplies allow a 16-bit shift
487     // The trick is that we just make sure that we have at least 8-bits
488     // per component (which is enough for a 8 bits display).
489 
490     int xy;
491     int vshift = 0;
492     int fshift = 0;
493     int smulw = 0;
494 
495     if (vs<16) {
496         if (fs<16) {
497             xy = xyBB;
498         } else if (GGL_BETWEEN(fs, 24, 31)) {
499             ms -= 16;
500             xy = xyTB;
501         } else {
502             // eg: 15 * 18  ->  15 * 15
503             fshift = fs - 15;
504             ms -= fshift;
505             xy = xyBB;
506         }
507     } else if (GGL_BETWEEN(vs, 24, 31)) {
508         if (fs<16) {
509             ms -= 16;
510             xy = xyTB;
511         } else if (GGL_BETWEEN(fs, 24, 31)) {
512             ms -= 32;
513             xy = xyTT;
514         } else {
515             // eg: 24 * 18  ->  8 * 18
516             fshift = fs - 15;
517             ms -= 16 + fshift;
518             xy = xyTB;
519         }
520     } else {
521         if (fs<16) {
522             // eg: 18 * 15  ->  15 * 15
523             vshift = vs - 15;
524             ms -= vshift;
525             xy = xyBB;
526         } else if (GGL_BETWEEN(fs, 24, 31)) {
527             // eg: 18 * 24  ->  15 * 8
528             vshift = vs - 15;
529             ms -= 16 + vshift;
530             xy = xyBT;
531         } else {
532             // eg: 18 * 18  ->  (15 * 18)>>16
533             fshift = fs - 15;
534             ms -= 16 + fshift;
535             xy = yB;    //XXX SMULWB
536             smulw = 1;
537         }
538     }
539 
540     ALOGE_IF(ms>=32, "mul_factor overflow vs=%d, fs=%d", vs, fs);
541 
542     int vreg = v.reg;
543     int freg = f.reg;
544     if (vshift) {
545         MOV(AL, 0, d.reg, reg_imm(vreg, LSR, vshift));
546         vreg = d.reg;
547     }
548     if (fshift) {
549         MOV(AL, 0, d.reg, reg_imm(vreg, LSR, fshift));
550         freg = d.reg;
551     }
552     if (smulw)  SMULW(AL, xy, d.reg, vreg, freg);
553     else        SMUL(AL, xy, d.reg, vreg, freg);
554 
555 
556     d.h = ms;
557     if (mDithering) {
558         d.l = 0;
559     } else {
560         d.l = fs;
561         d.flags |= CLEAR_LO;
562     }
563 }
564 
mul_factor_add(component_t & d,const integer_t & v,const integer_t & f,const component_t & a)565 void GGLAssembler::mul_factor_add(  component_t& d,
566                                     const integer_t& v,
567                                     const integer_t& f,
568                                     const component_t& a)
569 {
570     // XXX: we could have special cases for 1 bit mul
571     Scratch scratches(registerFile());
572 
573     int vs = v.size();
574     int fs = f.size();
575     int as = a.h;
576     int ms = vs+fs;
577 
578     ALOGE_IF(ms>=32, "mul_factor_add overflow vs=%d, fs=%d, as=%d", vs, fs, as);
579 
580     integer_t add(a.reg, a.h, a.flags);
581 
582     // 'a' is a component_t but it is guaranteed to have
583     // its high bits set to 0. However in the dithering case,
584     // we can't get away with truncating the potentially bad bits
585     // so extraction is needed.
586 
587    if ((mDithering) && (a.size() < ms)) {
588         // we need to expand a
589         if (!(a.flags & CORRUPTIBLE)) {
590             // ... but it's not corruptible, so we need to pick a
591             // temporary register.
592             // Try to uses the destination register first (it's likely
593             // to be usable, unless it aliases an input).
594             if (d.reg!=a.reg && d.reg!=v.reg && d.reg!=f.reg) {
595                 add.reg = d.reg;
596             } else {
597                 add.reg = scratches.obtain();
598             }
599         }
600         expand(add, a, ms); // extracts and expands
601         as = ms;
602     }
603 
604     if (ms == as) {
605         if (vs<16 && fs<16) SMLABB(AL, d.reg, v.reg, f.reg, add.reg);
606         else                MLA(AL, 0, d.reg, v.reg, f.reg, add.reg);
607     } else {
608         int temp = d.reg;
609         if (temp == add.reg) {
610             // the mul will modify add.reg, we need an intermediary reg
611             if (v.flags & CORRUPTIBLE)      temp = v.reg;
612             else if (f.flags & CORRUPTIBLE) temp = f.reg;
613             else                            temp = scratches.obtain();
614         }
615 
616         if (vs<16 && fs<16) SMULBB(AL, temp, v.reg, f.reg);
617         else                MUL(AL, 0, temp, v.reg, f.reg);
618 
619         if (ms>as) {
620             ADD(AL, 0, d.reg, temp, reg_imm(add.reg, LSL, ms-as));
621         } else if (ms<as) {
622             // not sure if we should expand the mul instead?
623             ADD(AL, 0, d.reg, temp, reg_imm(add.reg, LSR, as-ms));
624         }
625     }
626 
627     d.h = ms;
628     if (mDithering) {
629         d.l = a.l;
630     } else {
631         d.l = fs>a.l ? fs : a.l;
632         d.flags |= CLEAR_LO;
633     }
634 }
635 
component_add(component_t & d,const integer_t & dst,const integer_t & src)636 void GGLAssembler::component_add(component_t& d,
637         const integer_t& dst, const integer_t& src)
638 {
639     // here we're guaranteed that fragment.size() >= fb.size()
640     const int shift = src.size() - dst.size();
641     if (!shift) {
642         ADD(AL, 0, d.reg, src.reg, dst.reg);
643     } else {
644         ADD(AL, 0, d.reg, src.reg, reg_imm(dst.reg, LSL, shift));
645     }
646 
647     d.h = src.size();
648     if (mDithering) {
649         d.l = 0;
650     } else {
651         d.l = shift;
652         d.flags |= CLEAR_LO;
653     }
654 }
655 
component_sat(const component_t & v)656 void GGLAssembler::component_sat(const component_t& v)
657 {
658     const int one = ((1<<v.size())-1)<<v.l;
659     CMP(AL, v.reg, imm( 1<<v.h ));
660     if (isValidImmediate(one)) {
661         MOV(HS, 0, v.reg, imm( one ));
662     } else if (isValidImmediate(~one)) {
663         MVN(HS, 0, v.reg, imm( ~one ));
664     } else {
665         MOV(HS, 0, v.reg, imm( 1<<v.h ));
666         SUB(HS, 0, v.reg, v.reg, imm( 1<<v.l ));
667     }
668 }
669 
670 // ----------------------------------------------------------------------------
671 
672 }; // namespace android
673 
674