1 /**************************************************************************
2 *
3 * Copyright 2012 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 #include "pipe/p_state.h"
29 #include "util/u_debug.h"
30
31 #include "gallivm/lp_bld_type.h"
32 #include "gallivm/lp_bld_arit.h"
33 #include "gallivm/lp_bld_const.h"
34 #include "gallivm/lp_bld_logic.h"
35 #include "gallivm/lp_bld_swizzle.h"
36 #include "gallivm/lp_bld_flow.h"
37 #include "gallivm/lp_bld_debug.h"
38 #include "gallivm/lp_bld_pack.h"
39
40 #include "lp_bld_blend.h"
41
42 /**
43 * Is (a OP b) == (b OP a)?
44 */
45 boolean
lp_build_blend_func_commutative(enum pipe_blend_func func)46 lp_build_blend_func_commutative(enum pipe_blend_func func)
47 {
48 switch (func) {
49 case PIPE_BLEND_ADD:
50 case PIPE_BLEND_MIN:
51 case PIPE_BLEND_MAX:
52 return TRUE;
53 case PIPE_BLEND_SUBTRACT:
54 case PIPE_BLEND_REVERSE_SUBTRACT:
55 return FALSE;
56 default:
57 assert(0);
58 return TRUE;
59 }
60 }
61
62
63 /**
64 * Whether the blending functions are the reverse of each other.
65 */
66 boolean
lp_build_blend_func_reverse(enum pipe_blend_func rgb_func,enum pipe_blend_func alpha_func)67 lp_build_blend_func_reverse(enum pipe_blend_func rgb_func,
68 enum pipe_blend_func alpha_func)
69 {
70 if (rgb_func == alpha_func)
71 return FALSE;
72 if (rgb_func == PIPE_BLEND_SUBTRACT && alpha_func == PIPE_BLEND_REVERSE_SUBTRACT)
73 return TRUE;
74 if (rgb_func == PIPE_BLEND_REVERSE_SUBTRACT && alpha_func == PIPE_BLEND_SUBTRACT)
75 return TRUE;
76 return FALSE;
77 }
78
79
80 /**
81 * Whether the blending factors are complementary of each other.
82 */
83 static inline boolean
lp_build_blend_factor_complementary(unsigned src_factor,unsigned dst_factor)84 lp_build_blend_factor_complementary(unsigned src_factor, unsigned dst_factor)
85 {
86 STATIC_ASSERT((PIPE_BLENDFACTOR_ZERO ^ 0x10) == PIPE_BLENDFACTOR_ONE);
87 STATIC_ASSERT((PIPE_BLENDFACTOR_CONST_COLOR ^ 0x10) ==
88 PIPE_BLENDFACTOR_INV_CONST_COLOR);
89 return dst_factor == (src_factor ^ 0x10);
90 }
91
92
93 /**
94 * Whether this is a inverse blend factor
95 */
96 static inline boolean
is_inverse_factor(unsigned factor)97 is_inverse_factor(unsigned factor)
98 {
99 STATIC_ASSERT(PIPE_BLENDFACTOR_ZERO == 0x11);
100 return factor > 0x11;
101 }
102
103
104 /**
105 * Calculates the (expanded to wider type) multiplication
106 * of 2 normalized numbers.
107 */
108 static void
lp_build_mul_norm_expand(struct lp_build_context * bld,LLVMValueRef a,LLVMValueRef b,LLVMValueRef * resl,LLVMValueRef * resh,boolean signedness_differs)109 lp_build_mul_norm_expand(struct lp_build_context *bld,
110 LLVMValueRef a, LLVMValueRef b,
111 LLVMValueRef *resl, LLVMValueRef *resh,
112 boolean signedness_differs)
113 {
114 const struct lp_type type = bld->type;
115 struct lp_type wide_type = lp_wider_type(type);
116 struct lp_type wide_type2 = wide_type;
117 struct lp_type type2 = type;
118 LLVMValueRef al, ah, bl, bh;
119
120 assert(lp_check_value(type, a));
121 assert(lp_check_value(type, b));
122 assert(!type.floating && !type.fixed && type.norm);
123
124 if (a == bld->zero || b == bld->zero) {
125 LLVMValueRef zero = LLVMConstNull(lp_build_vec_type(bld->gallivm, wide_type));
126 *resl = zero;
127 *resh = zero;
128 return;
129 }
130
131 if (signedness_differs) {
132 type2.sign = !type.sign;
133 wide_type2.sign = !wide_type2.sign;
134 }
135
136 lp_build_unpack2_native(bld->gallivm, type, wide_type, a, &al, &ah);
137 lp_build_unpack2_native(bld->gallivm, type2, wide_type2, b, &bl, &bh);
138
139 *resl = lp_build_mul_norm(bld->gallivm, wide_type, al, bl);
140 *resh = lp_build_mul_norm(bld->gallivm, wide_type, ah, bh);
141 }
142
143
144 /**
145 * @sa http://www.opengl.org/sdk/docs/man/xhtml/glBlendEquationSeparate.xml
146 */
147 LLVMValueRef
lp_build_blend_func(struct lp_build_context * bld,enum pipe_blend_func func,LLVMValueRef term1,LLVMValueRef term2)148 lp_build_blend_func(struct lp_build_context *bld,
149 enum pipe_blend_func func,
150 LLVMValueRef term1,
151 LLVMValueRef term2)
152 {
153 switch (func) {
154 case PIPE_BLEND_ADD:
155 return lp_build_add(bld, term1, term2);
156 case PIPE_BLEND_SUBTRACT:
157 return lp_build_sub(bld, term1, term2);
158 case PIPE_BLEND_REVERSE_SUBTRACT:
159 return lp_build_sub(bld, term2, term1);
160 case PIPE_BLEND_MIN:
161 return lp_build_min(bld, term1, term2);
162 case PIPE_BLEND_MAX:
163 return lp_build_max(bld, term1, term2);
164 default:
165 assert(0);
166 return bld->zero;
167 }
168 }
169
170
171 /**
172 * Performs optimizations and blending independent of SoA/AoS
173 *
174 * @param func the blend function
175 * @param factor_src PIPE_BLENDFACTOR_xxx
176 * @param factor_dst PIPE_BLENDFACTOR_xxx
177 * @param src source rgba
178 * @param dst dest rgba
179 * @param src_factor src factor computed value
180 * @param dst_factor dst factor computed value
181 * @param not_alpha_dependent same factors accross all channels of src/dst
182 *
183 * not_alpha_dependent should be:
184 * SoA: always true as it is only one channel at a time
185 * AoS: rgb_src_factor == alpha_src_factor && rgb_dst_factor == alpha_dst_factor
186 *
187 * Note that pretty much every possible optimisation can only be done on non-unorm targets
188 * due to unorm values not going above 1.0 meaning factorisation can change results.
189 * e.g. (0.9 * 0.9) + (0.9 * 0.9) != 0.9 * (0.9 + 0.9) as result of + is always <= 1.
190 */
191 LLVMValueRef
lp_build_blend(struct lp_build_context * bld,enum pipe_blend_func func,enum pipe_blendfactor factor_src,enum pipe_blendfactor factor_dst,LLVMValueRef src,LLVMValueRef dst,LLVMValueRef src_factor,LLVMValueRef dst_factor,boolean not_alpha_dependent,boolean optimise_only)192 lp_build_blend(struct lp_build_context *bld,
193 enum pipe_blend_func func,
194 enum pipe_blendfactor factor_src,
195 enum pipe_blendfactor factor_dst,
196 LLVMValueRef src,
197 LLVMValueRef dst,
198 LLVMValueRef src_factor,
199 LLVMValueRef dst_factor,
200 boolean not_alpha_dependent,
201 boolean optimise_only)
202 {
203 LLVMValueRef result, src_term, dst_term;
204
205 /* If we are not alpha dependent we can mess with the src/dst factors */
206 if (not_alpha_dependent) {
207 if (lp_build_blend_factor_complementary(factor_src, factor_dst)) {
208 if (func == PIPE_BLEND_ADD) {
209 if (factor_src < factor_dst) {
210 return lp_build_lerp(bld, src_factor, dst, src, 0);
211 } else {
212 return lp_build_lerp(bld, dst_factor, src, dst, 0);
213 }
214 } else if (bld->type.floating && func == PIPE_BLEND_SUBTRACT) {
215 result = lp_build_add(bld, src, dst);
216
217 if (factor_src < factor_dst) {
218 result = lp_build_mul(bld, result, src_factor);
219 return lp_build_sub(bld, result, dst);
220 } else {
221 result = lp_build_mul(bld, result, dst_factor);
222 return lp_build_sub(bld, src, result);
223 }
224 } else if (bld->type.floating && func == PIPE_BLEND_REVERSE_SUBTRACT) {
225 result = lp_build_add(bld, src, dst);
226
227 if (factor_src < factor_dst) {
228 result = lp_build_mul(bld, result, src_factor);
229 return lp_build_sub(bld, dst, result);
230 } else {
231 result = lp_build_mul(bld, result, dst_factor);
232 return lp_build_sub(bld, result, src);
233 }
234 }
235 }
236
237 if (bld->type.floating && factor_src == factor_dst) {
238 if (func == PIPE_BLEND_ADD ||
239 func == PIPE_BLEND_SUBTRACT ||
240 func == PIPE_BLEND_REVERSE_SUBTRACT) {
241 LLVMValueRef result;
242 result = lp_build_blend_func(bld, func, src, dst);
243 return lp_build_mul(bld, result, src_factor);
244 }
245 }
246 }
247
248 if (optimise_only)
249 return NULL;
250
251 if ((bld->type.norm && bld->type.sign) &&
252 (is_inverse_factor(factor_src) || is_inverse_factor(factor_dst))) {
253 /*
254 * With snorm blending, the inverse blend factors range from [0,2]
255 * instead of [-1,1], so the ordinary signed normalized arithmetic
256 * doesn't quite work. Unpack must be unsigned, and the add/sub
257 * must be done with wider type.
258 * (Note that it's not quite obvious what the blend equation wrt to
259 * clamping should actually be based on GL spec in this case, but
260 * really the incoming src values are clamped to [-1,1] (the dst is
261 * always clamped already), and then NO further clamping occurs until
262 * the end.)
263 */
264 struct lp_build_context bldw;
265 struct lp_type wide_type = lp_wider_type(bld->type);
266 LLVMValueRef src_terml, src_termh, dst_terml, dst_termh;
267 LLVMValueRef resl, resh;
268
269 /*
270 * We don't need saturate math for the sub/add, since we have
271 * x+1 bit numbers in x*2 wide type (result is x+2 bits).
272 * (Doesn't really matter on x86 sse2 though as we use saturated
273 * intrinsics.)
274 */
275 wide_type.norm = 0;
276 lp_build_context_init(&bldw, bld->gallivm, wide_type);
277
278 /*
279 * XXX This is a bit hackish. Note that -128 really should
280 * be -1.0, the same as -127. However, we did not actually clamp
281 * things anywhere (relying on pack intrinsics instead) therefore
282 * we will get -128, and the inverted factor then 255. But the mul
283 * can overflow in this case (rather the rounding fixups for the mul,
284 * -128*255 will be positive).
285 * So we clamp the src and dst up here but only when necessary (we
286 * should do this before calculating blend factors but it's enough
287 * for avoiding overflow).
288 */
289 if (is_inverse_factor(factor_src)) {
290 src = lp_build_max(bld, src,
291 lp_build_const_vec(bld->gallivm, bld->type, -1.0));
292 }
293 if (is_inverse_factor(factor_dst)) {
294 dst = lp_build_max(bld, dst,
295 lp_build_const_vec(bld->gallivm, bld->type, -1.0));
296 }
297
298 lp_build_mul_norm_expand(bld, src, src_factor, &src_terml, &src_termh,
299 is_inverse_factor(factor_src) ? TRUE : FALSE);
300 lp_build_mul_norm_expand(bld, dst, dst_factor, &dst_terml, &dst_termh,
301 is_inverse_factor(factor_dst) ? TRUE : FALSE);
302 resl = lp_build_blend_func(&bldw, func, src_terml, dst_terml);
303 resh = lp_build_blend_func(&bldw, func, src_termh, dst_termh);
304
305 /*
306 * XXX pack2_native is not ok because the values have to be in dst
307 * range. We need native pack though for the correct order on avx2.
308 * Will break on everything not implementing clamping pack intrinsics
309 * (i.e. everything but sse2 and altivec).
310 */
311 return lp_build_pack2_native(bld->gallivm, wide_type, bld->type, resl, resh);
312 } else {
313 src_term = lp_build_mul(bld, src, src_factor);
314 dst_term = lp_build_mul(bld, dst, dst_factor);
315 return lp_build_blend_func(bld, func, src_term, dst_term);
316 }
317 }
318
319 void
lp_build_alpha_to_coverage(struct gallivm_state * gallivm,struct lp_type type,struct lp_build_mask_context * mask,LLVMValueRef alpha,boolean do_branch)320 lp_build_alpha_to_coverage(struct gallivm_state *gallivm,
321 struct lp_type type,
322 struct lp_build_mask_context *mask,
323 LLVMValueRef alpha,
324 boolean do_branch)
325 {
326 struct lp_build_context bld;
327 LLVMValueRef test;
328 LLVMValueRef alpha_ref_value;
329
330 lp_build_context_init(&bld, gallivm, type);
331
332 alpha_ref_value = lp_build_const_vec(gallivm, type, 0.5);
333
334 test = lp_build_cmp(&bld, PIPE_FUNC_GREATER, alpha, alpha_ref_value);
335
336 lp_build_name(test, "alpha_to_coverage");
337
338 lp_build_mask_update(mask, test);
339
340 if (do_branch)
341 lp_build_mask_check(mask);
342 }
343