Gitiles
Code Review Sign In
gerrit.aospa.co / AOSPA / android_system_core / 5299857825f10bbc724e1598cc348a5ceafd444b / . / include / private / pixelflinger / ggl_fixed.h
blob: 217ec04b294e2ed79efc4254af9428bb4780832c [file] [log] [blame]
The Android Open Source Projectdd7bc332009-03-03 19:32:55 -0800[diff] [blame]1/*
2 * Copyright (C) 2005 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_GGL_FIXED_H
18#define ANDROID_GGL_FIXED_H
19
20#include <math.h>
21#include <pixelflinger/pixelflinger.h>
22
23// ----------------------------------------------------------------------------
24
25#define CONST __attribute__((const))
26#define ALWAYS_INLINE __attribute__((always_inline))
27
28const GGLfixed FIXED_BITS = 16;
29const GGLfixed FIXED_EPSILON = 1;
30const GGLfixed FIXED_ONE = 1L<<FIXED_BITS;
31const GGLfixed FIXED_HALF = 1L<<(FIXED_BITS-1);
32const GGLfixed FIXED_MIN = 0x80000000L;
33const GGLfixed FIXED_MAX = 0x7FFFFFFFL;
34
35inline GGLfixed gglIntToFixed(GGLfixed i) ALWAYS_INLINE ;
36inline GGLfixed gglFixedToIntRound(GGLfixed f) ALWAYS_INLINE ;
37inline GGLfixed gglFixedToIntFloor(GGLfixed f) ALWAYS_INLINE ;
38inline GGLfixed gglFixedToIntCeil(GGLfixed f) ALWAYS_INLINE ;
39inline GGLfixed gglFracx(GGLfixed v) ALWAYS_INLINE ;
40inline GGLfixed gglFloorx(GGLfixed v) ALWAYS_INLINE ;
41inline GGLfixed gglCeilx(GGLfixed v) ALWAYS_INLINE ;
42inline GGLfixed gglCenterx(GGLfixed v) ALWAYS_INLINE ;
43inline GGLfixed gglRoundx(GGLfixed v) ALWAYS_INLINE ;
44
45GGLfixed gglIntToFixed(GGLfixed i) {
46 return i<<FIXED_BITS;
47}
48GGLfixed gglFixedToIntRound(GGLfixed f) {
49 return (f + FIXED_HALF)>>FIXED_BITS;
50}
51GGLfixed gglFixedToIntFloor(GGLfixed f) {
52 return f>>FIXED_BITS;
53}
54GGLfixed gglFixedToIntCeil(GGLfixed f) {
55 return (f + ((1<<FIXED_BITS) - 1))>>FIXED_BITS;
56}
57
58GGLfixed gglFracx(GGLfixed v) {
59 return v & ((1<<FIXED_BITS)-1);
60}
61GGLfixed gglFloorx(GGLfixed v) {
62 return gglFixedToIntFloor(v)<<FIXED_BITS;
63}
64GGLfixed gglCeilx(GGLfixed v) {
65 return gglFixedToIntCeil(v)<<FIXED_BITS;
66}
67GGLfixed gglCenterx(GGLfixed v) {
68 return gglFloorx(v + FIXED_HALF) | FIXED_HALF;
69}
70GGLfixed gglRoundx(GGLfixed v) {
71 return gglFixedToIntRound(v)<<FIXED_BITS;
72}
73
74// conversion from (unsigned) int, short, byte to fixed...
75#define GGL_B_TO_X(_x) GGLfixed( ((int32_t(_x)+1)>>1)<<10 )
76#define GGL_S_TO_X(_x) GGLfixed( ((int32_t(_x)+1)>>1)<<2 )
77#define GGL_I_TO_X(_x) GGLfixed( ((int32_t(_x)>>1)+1)>>14 )
78#define GGL_UB_TO_X(_x) GGLfixed( uint32_t(_x) + \
79 (uint32_t(_x)<<8) + \
80 (uint32_t(_x)>>7) )
81#define GGL_US_TO_X(_x) GGLfixed( (_x) + ((_x)>>15) )
82#define GGL_UI_TO_X(_x) GGLfixed( (((_x)>>1)+1)>>15 )
83
84// ----------------------------------------------------------------------------
85
86GGLfixed gglPowx(GGLfixed x, GGLfixed y) CONST;
87GGLfixed gglSqrtx(GGLfixed a) CONST;
88GGLfixed gglSqrtRecipx(GGLfixed x) CONST;
89GGLfixed gglFastDivx(GGLfixed n, GGLfixed d) CONST;
90int32_t gglMulDivi(int32_t a, int32_t b, int32_t c);
91
92int32_t gglRecipQNormalized(int32_t x, int* exponent);
93int32_t gglRecipQ(GGLfixed x, int q) CONST;
94
95inline GGLfixed gglRecip(GGLfixed x) CONST;
96inline GGLfixed gglRecip(GGLfixed x) {
97 return gglRecipQ(x, 16);
98}
99
100inline GGLfixed gglRecip28(GGLfixed x) CONST;
101int32_t gglRecip28(GGLfixed x) {
102 return gglRecipQ(x, 28);
103}
104
105// ----------------------------------------------------------------------------
106
107#if defined(__arm__) && !defined(__thumb__)
108
109// inline ARM implementations
110inline GGLfixed gglMulx(GGLfixed x, GGLfixed y, int shift) CONST;
111inline GGLfixed gglMulx(GGLfixed x, GGLfixed y, int shift) {
112 GGLfixed result, t;
113 if (__builtin_constant_p(shift)) {
114 asm("smull %[lo], %[hi], %[x], %[y] \n"
115 "movs %[lo], %[lo], lsr %[rshift] \n"
116 "adc %[lo], %[lo], %[hi], lsl %[lshift] \n"
117 : [lo]"=r"(result), [hi]"=r"(t), [x]"=r"(x)
118 : "%[x]"(x), [y]"r"(y), [lshift] "I"(32-shift), [rshift] "I"(shift)
119 : "cc"
120 );
121 } else {
122 asm("smull %[lo], %[hi], %[x], %[y] \n"
123 "movs %[lo], %[lo], lsr %[rshift] \n"
124 "adc %[lo], %[lo], %[hi], lsl %[lshift] \n"
125 : [lo]"=&r"(result), [hi]"=&r"(t), [x]"=&r"(x)
126 : "%[x]"(x), [y]"r"(y), [lshift] "r"(32-shift), [rshift] "r"(shift)
127 : "cc"
128 );
129 }
130 return result;
131}
132
133inline GGLfixed gglMulAddx(GGLfixed x, GGLfixed y, GGLfixed a, int shift) CONST;
134inline GGLfixed gglMulAddx(GGLfixed x, GGLfixed y, GGLfixed a, int shift) {
135 GGLfixed result, t;
136 if (__builtin_constant_p(shift)) {
137 asm("smull %[lo], %[hi], %[x], %[y] \n"
138 "add %[lo], %[a], %[lo], lsr %[rshift] \n"
139 "add %[lo], %[lo], %[hi], lsl %[lshift] \n"
140 : [lo]"=&r"(result), [hi]"=&r"(t), [x]"=&r"(x)
141 : "%[x]"(x), [y]"r"(y), [a]"r"(a), [lshift] "I"(32-shift), [rshift] "I"(shift)
142 );
143 } else {
144 asm("smull %[lo], %[hi], %[x], %[y] \n"
145 "add %[lo], %[a], %[lo], lsr %[rshift] \n"
146 "add %[lo], %[lo], %[hi], lsl %[lshift] \n"
147 : [lo]"=&r"(result), [hi]"=&r"(t), [x]"=&r"(x)
148 : "%[x]"(x), [y]"r"(y), [a]"r"(a), [lshift] "r"(32-shift), [rshift] "r"(shift)
149 );
150 }
151 return result;
152}
153
154inline GGLfixed gglMulSubx(GGLfixed x, GGLfixed y, GGLfixed a, int shift) CONST;
155inline GGLfixed gglMulSubx(GGLfixed x, GGLfixed y, GGLfixed a, int shift) {
156 GGLfixed result, t;
157 if (__builtin_constant_p(shift)) {
158 asm("smull %[lo], %[hi], %[x], %[y] \n"
159 "rsb %[lo], %[a], %[lo], lsr %[rshift] \n"
160 "add %[lo], %[lo], %[hi], lsl %[lshift] \n"
161 : [lo]"=&r"(result), [hi]"=&r"(t), [x]"=&r"(x)
162 : "%[x]"(x), [y]"r"(y), [a]"r"(a), [lshift] "I"(32-shift), [rshift] "I"(shift)
163 );
164 } else {
165 asm("smull %[lo], %[hi], %[x], %[y] \n"
166 "rsb %[lo], %[a], %[lo], lsr %[rshift] \n"
167 "add %[lo], %[lo], %[hi], lsl %[lshift] \n"
168 : [lo]"=&r"(result), [hi]"=&r"(t), [x]"=&r"(x)
169 : "%[x]"(x), [y]"r"(y), [a]"r"(a), [lshift] "r"(32-shift), [rshift] "r"(shift)
170 );
171 }
172 return result;
173}
174
175inline int64_t gglMulii(int32_t x, int32_t y) CONST;
176inline int64_t gglMulii(int32_t x, int32_t y)
177{
178 // 64-bits result: r0=low, r1=high
179 union {
180 struct {
181 int32_t lo;
182 int32_t hi;
183 } s;
184 int64_t res;
185 };
186 asm("smull %0, %1, %2, %3 \n"
187 : "=r"(s.lo), "=&r"(s.hi)
188 : "%r"(x), "r"(y)
189 :
190 );
191 return res;
192}
Duane Sand09604112012-05-24 17:40:21 -0700[diff] [blame]193#elif defined(__mips__)
194
195/*inline MIPS implementations*/
196inline GGLfixed gglMulx(GGLfixed a, GGLfixed b, int shift) CONST;
197inline GGLfixed gglMulx(GGLfixed a, GGLfixed b, int shift) {
198 GGLfixed result,tmp,tmp1,tmp2;
199
200 if (__builtin_constant_p(shift)) {
201 if (shift == 0) {
202 asm ("mult %[a], %[b] \t\n"
203 "mflo %[res] \t\n"
204 : [res]"=&r"(result),[tmp]"=&r"(tmp)
205 : [a]"r"(a),[b]"r"(b)
206 : "%hi","%lo"
207 );
208 } else if (shift == 32)
209 {
210 asm ("mult %[a], %[b] \t\n"
211 "li %[tmp],1\t\n"
212 "sll %[tmp],%[tmp],0x1f\t\n"
213 "mflo %[res] \t\n"
214 "addu %[tmp1],%[tmp],%[res] \t\n"
215 "sltu %[tmp1],%[tmp1],%[tmp]\t\n" /*obit*/
216 "sra %[tmp],%[tmp],0x1f \t\n"
217 "mfhi %[res] \t\n"
218 "addu %[res],%[res],%[tmp]\t\n"
219 "addu %[res],%[res],%[tmp1]\t\n"
220 : [res]"=&r"(result),[tmp]"=&r"(tmp),[tmp1]"=&r"(tmp1)
221 : [a]"r"(a),[b]"r"(b),[shift]"I"(shift)
222 : "%hi","%lo"
223 );
224 } else if ((shift >0) && (shift < 32))
225 {
226 asm ("mult %[a], %[b] \t\n"
227 "li %[tmp],1 \t\n"
228 "sll %[tmp],%[tmp],%[shiftm1] \t\n"
229 "mflo %[res] \t\n"
230 "addu %[tmp1],%[tmp],%[res] \t\n"
231 "sltu %[tmp1],%[tmp1],%[tmp] \t\n" /*obit?*/
232 "addu %[res],%[res],%[tmp] \t\n"
233 "mfhi %[tmp] \t\n"
234 "addu %[tmp],%[tmp],%[tmp1] \t\n"
235 "sll %[tmp],%[tmp],%[lshift] \t\n"
236 "srl %[res],%[res],%[rshift] \t\n"
237 "or %[res],%[res],%[tmp] \t\n"
238 : [res]"=&r"(result),[tmp]"=&r"(tmp),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
239 : [a]"r"(a),[b]"r"(b),[lshift]"I"(32-shift),[rshift]"I"(shift),[shiftm1]"I"(shift-1)
240 : "%hi","%lo"
241 );
242 } else {
243 asm ("mult %[a], %[b] \t\n"
244 "li %[tmp],1 \t\n"
245 "sll %[tmp],%[tmp],%[shiftm1] \t\n"
246 "mflo %[res] \t\n"
247 "addu %[tmp1],%[tmp],%[res] \t\n"
248 "sltu %[tmp1],%[tmp1],%[tmp] \t\n" /*obit?*/
249 "sra %[tmp2],%[tmp],0x1f \t\n"
250 "addu %[res],%[res],%[tmp] \t\n"
251 "mfhi %[tmp] \t\n"
252 "addu %[tmp],%[tmp],%[tmp2] \t\n"
253 "addu %[tmp],%[tmp],%[tmp1] \t\n" /*tmp=hi*/
254 "srl %[tmp2],%[res],%[rshift] \t\n"
255 "srav %[res], %[tmp],%[rshift]\t\n"
256 "sll %[tmp],%[tmp],1 \t\n"
257 "sll %[tmp],%[tmp],%[norbits] \t\n"
258 "or %[tmp],%[tmp],%[tmp2] \t\n"
259 "movz %[res],%[tmp],%[bit5] \t\n"
260 : [res]"=&r"(result),[tmp]"=&r"(tmp),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
261 : [a]"r"(a),[b]"r"(b),[norbits]"I"(~(shift)),[rshift]"I"(shift),[shiftm1] "I"(shift-1),[bit5]"I"(shift & 0x20)
262 : "%hi","%lo"
263 );
264 }
265 } else {
266 asm ("mult %[a], %[b] \t\n"
267 "li %[tmp],1 \t\n"
268 "sll %[tmp],%[tmp],%[shiftm1] \t\n"
269 "mflo %[res] \t\n"
270 "addu %[tmp1],%[tmp],%[res] \t\n"
271 "sltu %[tmp1],%[tmp1],%[tmp] \t\n" /*obit?*/
272 "sra %[tmp2],%[tmp],0x1f \t\n"
273 "addu %[res],%[res],%[tmp] \t\n"
274 "mfhi %[tmp] \t\n"
275 "addu %[tmp],%[tmp],%[tmp2] \t\n"
276 "addu %[tmp],%[tmp],%[tmp1] \t\n" /*tmp=hi*/
277 "srl %[tmp2],%[res],%[rshift] \t\n"
278 "srav %[res], %[tmp],%[rshift]\t\n"
279 "sll %[tmp],%[tmp],1 \t\n"
280 "sll %[tmp],%[tmp],%[norbits] \t\n"
281 "or %[tmp],%[tmp],%[tmp2] \t\n"
282 "movz %[res],%[tmp],%[bit5] \t\n"
283 : [res]"=&r"(result),[tmp]"=&r"(tmp),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
284 : [a]"r"(a),[b]"r"(b),[norbits]"r"(~(shift)),[rshift] "r"(shift),[shiftm1]"r"(shift-1),[bit5] "r"(shift & 0x20)
285 : "%hi","%lo"
286 );
287 }
288
289 return result;
290}
291
292inline GGLfixed gglMulAddx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) CONST;
293inline GGLfixed gglMulAddx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) {
294 GGLfixed result,t,tmp1,tmp2;
295
296 if (__builtin_constant_p(shift)) {
297 if (shift == 0) {
298 asm ("mult %[a], %[b] \t\n"
299 "mflo %[lo] \t\n"
300 "addu %[lo],%[lo],%[c] \t\n"
301 : [lo]"=&r"(result)
302 : [a]"r"(a),[b]"r"(b),[c]"r"(c)
303 : "%hi","%lo"
304 );
305 } else if (shift == 32) {
306 asm ("mult %[a], %[b] \t\n"
307 "mfhi %[lo] \t\n"
308 "addu %[lo],%[lo],%[c] \t\n"
309 : [lo]"=&r"(result)
310 : [a]"r"(a),[b]"r"(b),[c]"r"(c)
311 : "%hi","%lo"
312 );
313 } else if ((shift>0) && (shift<32)) {
314 asm ("mult %[a], %[b] \t\n"
315 "mflo %[res] \t\n"
316 "mfhi %[t] \t\n"
317 "srl %[res],%[res],%[rshift] \t\n"
318 "sll %[t],%[t],%[lshift] \t\n"
319 "or %[res],%[res],%[t] \t\n"
320 "addu %[res],%[res],%[c] \t\n"
321 : [res]"=&r"(result),[t]"=&r"(t)
322 : [a]"r"(a),[b]"r"(b),[c]"r"(c),[lshift]"I"(32-shift),[rshift]"I"(shift)
323 : "%hi","%lo"
324 );
325 } else {
326 asm ("mult %[a], %[b] \t\n"
327 "nor %[tmp1],$zero,%[shift]\t\n"
328 "mflo %[res] \t\n"
329 "mfhi %[t] \t\n"
330 "srl %[res],%[res],%[shift] \t\n"
331 "sll %[tmp2],%[t],1 \t\n"
332 "sllv %[tmp2],%[tmp2],%[tmp1] \t\n"
333 "or %[tmp1],%[tmp2],%[res] \t\n"
334 "srav %[res],%[t],%[shift] \t\n"
335 "andi %[tmp2],%[shift],0x20\t\n"
336 "movz %[res],%[tmp1],%[tmp2]\t\n"
337 "addu %[res],%[res],%[c] \t\n"
338 : [res]"=&r"(result),[t]"=&r"(t),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
339 : [a]"r"(a),[b]"r"(b),[c]"r"(c),[shift]"I"(shift)
340 : "%hi","%lo"
341 );
342 }
343 } else {
344 asm ("mult %[a], %[b] \t\n"
345 "nor %[tmp1],$zero,%[shift]\t\n"
346 "mflo %[res] \t\n"
347 "mfhi %[t] \t\n"
348 "srl %[res],%[res],%[shift] \t\n"
349 "sll %[tmp2],%[t],1 \t\n"
350 "sllv %[tmp2],%[tmp2],%[tmp1] \t\n"
351 "or %[tmp1],%[tmp2],%[res] \t\n"
352 "srav %[res],%[t],%[shift] \t\n"
353 "andi %[tmp2],%[shift],0x20\t\n"
354 "movz %[res],%[tmp1],%[tmp2]\t\n"
355 "addu %[res],%[res],%[c] \t\n"
356 : [res]"=&r"(result),[t]"=&r"(t),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
357 : [a]"r"(a),[b]"r"(b),[c]"r"(c),[shift]"r"(shift)
358 : "%hi","%lo"
359 );
360 }
361 return result;
362}
363
364inline GGLfixed gglMulSubx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) CONST;
365inline GGLfixed gglMulSubx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) {
366 GGLfixed result,t,tmp1,tmp2;
367
368 if (__builtin_constant_p(shift)) {
369 if (shift == 0) {
370 asm ("mult %[a], %[b] \t\n"
371 "mflo %[lo] \t\n"
372 "subu %[lo],%[lo],%[c] \t\n"
373 : [lo]"=&r"(result)
374 : [a]"r"(a),[b]"r"(b),[c]"r"(c)
375 : "%hi","%lo"
376 );
377 } else if (shift == 32) {
378 asm ("mult %[a], %[b] \t\n"
379 "mfhi %[lo] \t\n"
380 "subu %[lo],%[lo],%[c] \t\n"
381 : [lo]"=&r"(result)
382 : [a]"r"(a),[b]"r"(b),[c]"r"(c)
383 : "%hi","%lo"
384 );
385 } else if ((shift>0) && (shift<32)) {
386 asm ("mult %[a], %[b] \t\n"
387 "mflo %[res] \t\n"
388 "mfhi %[t] \t\n"
389 "srl %[res],%[res],%[rshift] \t\n"
390 "sll %[t],%[t],%[lshift] \t\n"
391 "or %[res],%[res],%[t] \t\n"
392 "subu %[res],%[res],%[c] \t\n"
393 : [res]"=&r"(result),[t]"=&r"(t)
394 : [a]"r"(a),[b]"r"(b),[c]"r"(c),[lshift]"I"(32-shift),[rshift]"I"(shift)
395 : "%hi","%lo"
396 );
397 } else {
398 asm ("mult %[a], %[b] \t\n"
399 "nor %[tmp1],$zero,%[shift]\t\n"
400 "mflo %[res] \t\n"
401 "mfhi %[t] \t\n"
402 "srl %[res],%[res],%[shift] \t\n"
403 "sll %[tmp2],%[t],1 \t\n"
404 "sllv %[tmp2],%[tmp2],%[tmp1] \t\n"
405 "or %[tmp1],%[tmp2],%[res] \t\n"
406 "srav %[res],%[t],%[shift] \t\n"
407 "andi %[tmp2],%[shift],0x20\t\n"
408 "movz %[res],%[tmp1],%[tmp2]\t\n"
409 "subu %[res],%[res],%[c] \t\n"
410 : [res]"=&r"(result),[t]"=&r"(t),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
411 : [a]"r"(a),[b]"r"(b),[c]"r"(c),[shift]"I"(shift)
412 : "%hi","%lo"
413 );
414 }
415 } else {
416 asm ("mult %[a], %[b] \t\n"
417 "nor %[tmp1],$zero,%[shift]\t\n"
418 "mflo %[res] \t\n"
419 "mfhi %[t] \t\n"
420 "srl %[res],%[res],%[shift] \t\n"
421 "sll %[tmp2],%[t],1 \t\n"
422 "sllv %[tmp2],%[tmp2],%[tmp1] \t\n"
423 "or %[tmp1],%[tmp2],%[res] \t\n"
424 "srav %[res],%[t],%[shift] \t\n"
425 "andi %[tmp2],%[shift],0x20\t\n"
426 "movz %[res],%[tmp1],%[tmp2]\t\n"
427 "subu %[res],%[res],%[c] \t\n"
428 : [res]"=&r"(result),[t]"=&r"(t),[tmp1]"=&r"(tmp1),[tmp2]"=&r"(tmp2)
429 : [a]"r"(a),[b]"r"(b),[c]"r"(c),[shift]"r"(shift)
430 : "%hi","%lo"
431 );
432 }
433 return result;
434}
435
436inline int64_t gglMulii(int32_t x, int32_t y) CONST;
437inline int64_t gglMulii(int32_t x, int32_t y) {
438 union {
439 struct {
440#if defined(__MIPSEL__)
441 int32_t lo;
442 int32_t hi;
443#elif defined(__MIPSEB__)
444 int32_t hi;
445 int32_t lo;
446#endif
447 } s;
448 int64_t res;
449 }u;
450 asm("mult %2, %3 \t\n"
451 "mfhi %1 \t\n"
452 "mflo %0 \t\n"
453 : "=r"(u.s.lo), "=&r"(u.s.hi)
454 : "%r"(x), "r"(y)
455 : "%hi","%lo"
456 );
457 return u.res;
458}
The Android Open Source Projectdd7bc332009-03-03 19:32:55 -0800[diff] [blame]459
460#else // ----------------------------------------------------------------------
461
462inline GGLfixed gglMulx(GGLfixed a, GGLfixed b, int shift) CONST;
463inline GGLfixed gglMulx(GGLfixed a, GGLfixed b, int shift) {
464 return GGLfixed((int64_t(a)*b + (1<<(shift-1)))>>shift);
465}
466inline GGLfixed gglMulAddx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) CONST;
467inline GGLfixed gglMulAddx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) {
468 return GGLfixed((int64_t(a)*b)>>shift) + c;
469}
470inline GGLfixed gglMulSubx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) CONST;
471inline GGLfixed gglMulSubx(GGLfixed a, GGLfixed b, GGLfixed c, int shift) {
472 return GGLfixed((int64_t(a)*b)>>shift) - c;
473}
474inline int64_t gglMulii(int32_t a, int32_t b) CONST;
475inline int64_t gglMulii(int32_t a, int32_t b) {
476 return int64_t(a)*b;
477}
478
479#endif
480
481// ------------------------------------------------------------------------
482
483inline GGLfixed gglMulx(GGLfixed a, GGLfixed b) CONST;
484inline GGLfixed gglMulx(GGLfixed a, GGLfixed b) {
485 return gglMulx(a, b, 16);
486}
487inline GGLfixed gglMulAddx(GGLfixed a, GGLfixed b, GGLfixed c) CONST;
488inline GGLfixed gglMulAddx(GGLfixed a, GGLfixed b, GGLfixed c) {
489 return gglMulAddx(a, b, c, 16);
490}
491inline GGLfixed gglMulSubx(GGLfixed a, GGLfixed b, GGLfixed c) CONST;
492inline GGLfixed gglMulSubx(GGLfixed a, GGLfixed b, GGLfixed c) {
493 return gglMulSubx(a, b, c, 16);
494}
495
496// ------------------------------------------------------------------------
497
498inline int32_t gglClz(int32_t x) CONST;
499inline int32_t gglClz(int32_t x)
500{
Duane Sand09604112012-05-24 17:40:21 -0700[diff] [blame]501#if (defined(__arm__) && !defined(__thumb__)) || defined(__mips__)
The Android Open Source Projectdd7bc332009-03-03 19:32:55 -0800[diff] [blame]502 return __builtin_clz(x);
503#else
504 if (!x) return 32;
505 int32_t exp = 31;
506 if (x & 0xFFFF0000) { exp -=16; x >>= 16; }
507 if (x & 0x0000ff00) { exp -= 8; x >>= 8; }
508 if (x & 0x000000f0) { exp -= 4; x >>= 4; }
509 if (x & 0x0000000c) { exp -= 2; x >>= 2; }
510 if (x & 0x00000002) { exp -= 1; }
511 return exp;
512#endif
513}
514
515// ------------------------------------------------------------------------
516
517int32_t gglDivQ(GGLfixed n, GGLfixed d, int32_t i) CONST;
518
519inline int32_t gglDivQ16(GGLfixed n, GGLfixed d) CONST;
520inline int32_t gglDivQ16(GGLfixed n, GGLfixed d) {
521 return gglDivQ(n, d, 16);
522}
523
524inline int32_t gglDivx(GGLfixed n, GGLfixed d) CONST;
525inline int32_t gglDivx(GGLfixed n, GGLfixed d) {
526 return gglDivQ(n, d, 16);
527}
528
529// ------------------------------------------------------------------------
530
531inline GGLfixed gglRecipFast(GGLfixed x) CONST;
532inline GGLfixed gglRecipFast(GGLfixed x)
533{
534 // This is a really bad approximation of 1/x, but it's also
535 // very fast. x must be strictly positive.
536 // if x between [0.5, 1[ , then 1/x = 3-2*x
537 // (we use 2.30 fixed-point)
538 const int32_t lz = gglClz(x);
539 return (0xC0000000 - (x << (lz - 1))) >> (30-lz);
540}
541
542// ------------------------------------------------------------------------
543
544inline GGLfixed gglClampx(GGLfixed c) CONST;
545inline GGLfixed gglClampx(GGLfixed c)
546{
547#if defined(__thumb__)
548 // clamp without branches
549 c &= ~(c>>31); c = FIXED_ONE - c;
550 c &= ~(c>>31); c = FIXED_ONE - c;
551#else
552#if defined(__arm__)
553 // I don't know why gcc thinks its smarter than me! The code below
554 // clamps to zero in one instruction, but gcc won't generate it and
555 // replace it by a cmp + movlt (it's quite amazing actually).
556 asm("bic %0, %1, %1, asr #31\n" : "=r"(c) : "r"(c));
557#else
558 c &= ~(c>>31);
559#endif
560 if (c>FIXED_ONE)
561 c = FIXED_ONE;
562#endif
563 return c;
564}
565
566// ------------------------------------------------------------------------
567
568#endif // ANDROID_GGL_FIXED_H