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