2 * Copyright © 2013 Intel Corporation
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9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
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15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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21 * DEALINGS IN THE SOFTWARE.
31 vec4_vs_visitor::emit_prolog()
33 dst_reg sign_recovery_shift;
34 dst_reg normalize_factor;
35 dst_reg es3_normalize_factor;
37 for (int i = 0; i < VERT_ATTRIB_MAX; i++) {
38 if (vs_prog_data->inputs_read & BITFIELD64_BIT(i)) {
39 uint8_t wa_flags = key->gl_attrib_wa_flags[i];
42 reg_d.type = BRW_REGISTER_TYPE_D;
44 reg_ud.type = BRW_REGISTER_TYPE_UD;
46 /* Do GL_FIXED rescaling for GLES2.0. Our GL_FIXED attributes
47 * come in as floating point conversions of the integer values.
49 if (wa_flags & BRW_ATTRIB_WA_COMPONENT_MASK) {
51 dst.type = brw_type_for_base_type(glsl_type::vec4_type);
52 dst.writemask = (1 << (wa_flags & BRW_ATTRIB_WA_COMPONENT_MASK)) - 1;
53 emit(MUL(dst, src_reg(dst), brw_imm_f(1.0f / 65536.0f)));
56 /* Do sign recovery for 2101010 formats if required. */
57 if (wa_flags & BRW_ATTRIB_WA_SIGN) {
58 if (sign_recovery_shift.file == BAD_FILE) {
59 /* shift constant: <22,22,22,30> */
60 sign_recovery_shift = dst_reg(this, glsl_type::uvec4_type);
61 emit(MOV(writemask(sign_recovery_shift, WRITEMASK_XYZ), brw_imm_ud(22u)));
62 emit(MOV(writemask(sign_recovery_shift, WRITEMASK_W), brw_imm_ud(30u)));
65 emit(SHL(reg_ud, src_reg(reg_ud), src_reg(sign_recovery_shift)));
66 emit(ASR(reg_d, src_reg(reg_d), src_reg(sign_recovery_shift)));
69 /* Apply BGRA swizzle if required. */
70 if (wa_flags & BRW_ATTRIB_WA_BGRA) {
71 src_reg temp = src_reg(reg);
72 temp.swizzle = BRW_SWIZZLE4(2,1,0,3);
76 if (wa_flags & BRW_ATTRIB_WA_NORMALIZE) {
77 /* ES 3.0 has different rules for converting signed normalized
78 * fixed-point numbers than desktop GL.
80 if ((wa_flags & BRW_ATTRIB_WA_SIGN) && !use_legacy_snorm_formula) {
81 /* According to equation 2.2 of the ES 3.0 specification,
82 * signed normalization conversion is done by:
86 if (es3_normalize_factor.file == BAD_FILE) {
87 /* mul constant: 1 / (2^(b-1) - 1) */
88 es3_normalize_factor = dst_reg(this, glsl_type::vec4_type);
89 emit(MOV(writemask(es3_normalize_factor, WRITEMASK_XYZ),
90 brw_imm_f(1.0f / ((1<<9) - 1))));
91 emit(MOV(writemask(es3_normalize_factor, WRITEMASK_W),
92 brw_imm_f(1.0f / ((1<<1) - 1))));
96 dst.type = brw_type_for_base_type(glsl_type::vec4_type);
97 emit(MOV(dst, src_reg(reg_d)));
98 emit(MUL(dst, src_reg(dst), src_reg(es3_normalize_factor)));
99 emit_minmax(BRW_CONDITIONAL_GE, dst, src_reg(dst), brw_imm_f(-1.0f));
101 /* The following equations are from the OpenGL 3.2 specification:
103 * 2.1 unsigned normalization
106 * 2.2 signed normalization
109 * Both of these share a common divisor, which is represented by
110 * "normalize_factor" in the code below.
112 if (normalize_factor.file == BAD_FILE) {
113 /* 1 / (2^b - 1) for b=<10,10,10,2> */
114 normalize_factor = dst_reg(this, glsl_type::vec4_type);
115 emit(MOV(writemask(normalize_factor, WRITEMASK_XYZ),
116 brw_imm_f(1.0f / ((1<<10) - 1))));
117 emit(MOV(writemask(normalize_factor, WRITEMASK_W),
118 brw_imm_f(1.0f / ((1<<2) - 1))));
122 dst.type = brw_type_for_base_type(glsl_type::vec4_type);
123 emit(MOV(dst, src_reg((wa_flags & BRW_ATTRIB_WA_SIGN) ? reg_d : reg_ud)));
125 /* For signed normalization, we want the numerator to be 2c+1. */
126 if (wa_flags & BRW_ATTRIB_WA_SIGN) {
127 emit(MUL(dst, src_reg(dst), brw_imm_f(2.0f)));
128 emit(ADD(dst, src_reg(dst), brw_imm_f(1.0f)));
131 emit(MUL(dst, src_reg(dst), src_reg(normalize_factor)));
135 if (wa_flags & BRW_ATTRIB_WA_SCALE) {
137 dst.type = brw_type_for_base_type(glsl_type::vec4_type);
138 emit(MOV(dst, src_reg((wa_flags & BRW_ATTRIB_WA_SIGN) ? reg_d : reg_ud)));
146 vec4_vs_visitor::make_reg_for_system_value(int location,
147 const glsl_type *type)
149 /* VertexID is stored by the VF as the last vertex element, but
150 * we don't represent it with a flag in inputs_read, so we call
151 * it VERT_ATTRIB_MAX, which setup_attributes() picks up on.
153 dst_reg *reg = new(mem_ctx) dst_reg(ATTR, VERT_ATTRIB_MAX);
156 case SYSTEM_VALUE_BASE_VERTEX:
157 reg->writemask = WRITEMASK_X;
158 vs_prog_data->uses_basevertex = true;
160 case SYSTEM_VALUE_BASE_INSTANCE:
161 reg->writemask = WRITEMASK_Y;
162 vs_prog_data->uses_baseinstance = true;
164 case SYSTEM_VALUE_VERTEX_ID:
165 case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
166 reg->writemask = WRITEMASK_Z;
167 vs_prog_data->uses_vertexid = true;
169 case SYSTEM_VALUE_INSTANCE_ID:
170 reg->writemask = WRITEMASK_W;
171 vs_prog_data->uses_instanceid = true;
173 case SYSTEM_VALUE_DRAW_ID:
174 reg = new(mem_ctx) dst_reg(ATTR, VERT_ATTRIB_MAX + 1);
175 reg->writemask = WRITEMASK_X;
176 vs_prog_data->uses_drawid = true;
179 unreachable("not reached");
187 vec4_vs_visitor::emit_urb_write_header(int mrf)
189 /* No need to do anything for VS; an implied write to this MRF will be
190 * performed by VS_OPCODE_URB_WRITE.
197 vec4_vs_visitor::emit_urb_write_opcode(bool complete)
199 /* For VS, the URB writes end the thread. */
201 if (INTEL_DEBUG & DEBUG_SHADER_TIME)
202 emit_shader_time_end();
205 vec4_instruction *inst = emit(VS_OPCODE_URB_WRITE);
206 inst->urb_write_flags = complete ?
207 BRW_URB_WRITE_EOT_COMPLETE : BRW_URB_WRITE_NO_FLAGS;
214 vec4_vs_visitor::emit_urb_slot(dst_reg reg, int varying)
216 reg.type = BRW_REGISTER_TYPE_F;
217 output_reg[varying].type = reg.type;
220 case VARYING_SLOT_COL0:
221 case VARYING_SLOT_COL1:
222 case VARYING_SLOT_BFC0:
223 case VARYING_SLOT_BFC1: {
224 /* These built-in varyings are only supported in compatibility mode,
225 * and we only support GS in core profile. So, this must be a vertex
228 vec4_instruction *inst = emit_generic_urb_slot(reg, varying);
229 if (inst && key->clamp_vertex_color)
230 inst->saturate = true;
234 return vec4_visitor::emit_urb_slot(reg, varying);
240 vec4_vs_visitor::emit_clip_distances(dst_reg reg, int offset)
242 /* From the GLSL 1.30 spec, section 7.1 (Vertex Shader Special Variables):
244 * "If a linked set of shaders forming the vertex stage contains no
245 * static write to gl_ClipVertex or gl_ClipDistance, but the
246 * application has requested clipping against user clip planes through
247 * the API, then the coordinate written to gl_Position is used for
248 * comparison against the user clip planes."
250 * This function is only called if the shader didn't write to
251 * gl_ClipDistance. Accordingly, we use gl_ClipVertex to perform clipping
252 * if the user wrote to it; otherwise we use gl_Position.
254 gl_varying_slot clip_vertex = VARYING_SLOT_CLIP_VERTEX;
255 if (!(prog_data->vue_map.slots_valid & VARYING_BIT_CLIP_VERTEX)) {
256 clip_vertex = VARYING_SLOT_POS;
259 for (int i = 0; i + offset < key->nr_userclip_plane_consts && i < 4;
261 reg.writemask = 1 << i;
263 src_reg(output_reg[clip_vertex]),
264 src_reg(this->userplane[i + offset])));
270 vec4_vs_visitor::setup_uniform_clipplane_values()
272 for (int i = 0; i < key->nr_userclip_plane_consts; ++i) {
273 this->userplane[i] = dst_reg(UNIFORM, this->uniforms);
274 this->userplane[i].type = BRW_REGISTER_TYPE_F;
275 for (int j = 0; j < 4; ++j) {
276 stage_prog_data->param[this->uniforms * 4 + j] =
277 (gl_constant_value *) &clip_planes[i][j];
285 vec4_vs_visitor::emit_thread_end()
287 setup_uniform_clipplane_values();
289 /* Lower legacy ff and ClipVertex clipping to clip distances */
290 if (key->nr_userclip_plane_consts > 0) {
291 current_annotation = "user clip distances";
293 output_reg[VARYING_SLOT_CLIP_DIST0] = dst_reg(this, glsl_type::vec4_type);
294 output_reg[VARYING_SLOT_CLIP_DIST1] = dst_reg(this, glsl_type::vec4_type);
296 emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST0], 0);
297 emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST1], 4);
300 /* For VS, we always end the thread by emitting a single vertex.
301 * emit_urb_write_opcode() will take care of setting the eot flag on the
308 vec4_vs_visitor::vec4_vs_visitor(const struct brw_compiler *compiler,
310 const struct brw_vs_prog_key *key,
311 struct brw_vs_prog_data *vs_prog_data,
312 const nir_shader *shader,
313 gl_clip_plane *clip_planes,
315 int shader_time_index,
316 bool use_legacy_snorm_formula)
317 : vec4_visitor(compiler, log_data, &key->tex, &vs_prog_data->base, shader,
318 mem_ctx, false /* no_spills */, shader_time_index),
320 vs_prog_data(vs_prog_data),
321 clip_planes(clip_planes),
322 use_legacy_snorm_formula(use_legacy_snorm_formula)
327 } /* namespace brw */