#include "brw_eu.h"
#include "brw_gs.h"
+/**
+ * Allocate registers for GS.
+ *
+ * If sol_program is true, then:
+ *
+ * - The thread will be spawned with the "SVBI Payload Enable" bit set, so GRF
+ * 1 needs to be set aside to hold the streamed vertex buffer indices.
+ *
+ * - The thread will need to use the destination_indices register.
+ */
static void brw_gs_alloc_regs( struct brw_gs_compile *c,
- GLuint nr_verts )
+ GLuint nr_verts,
+ bool sol_program )
{
GLuint i = 0,j;
*/
c->reg.R0 = retype(brw_vec8_grf(i, 0), BRW_REGISTER_TYPE_UD); i++;
+ /* Streamed vertex buffer indices */
+ if (sol_program)
+ c->reg.SVBI = retype(brw_vec8_grf(i++, 0), BRW_REGISTER_TYPE_UD);
+
/* Payload vertices plus space for more generated vertices:
*/
for (j = 0; j < nr_verts; j++) {
c->reg.header = retype(brw_vec8_grf(i++, 0), BRW_REGISTER_TYPE_UD);
c->reg.temp = retype(brw_vec8_grf(i++, 0), BRW_REGISTER_TYPE_UD);
+ if (sol_program) {
+ c->reg.destination_indices =
+ retype(brw_vec4_grf(i++, 0), BRW_REGISTER_TYPE_UD);
+ }
+
c->prog_data.urb_read_length = c->nr_regs;
c->prog_data.total_grf = i;
}
brw_MOV(p, get_element_ud(c->reg.header, 2), brw_imm_ud(dw2));
}
+/**
+ * Overwrite DWORD 2 of c->reg.header with the primitive type from c->reg.R0.
+ *
+ * When the thread is spawned, GRF 0 contains the primitive type in bits 4:0
+ * of DWORD 2. URB_WRITE messages need the primitive type in bits 6:2 of
+ * DWORD 2. So this function extracts the primitive type field, bitshifts it
+ * appropriately, and stores it in c->reg.header.
+ */
+static void brw_gs_overwrite_header_dw2_from_r0(struct brw_gs_compile *c)
+{
+ struct brw_compile *p = &c->func;
+ brw_AND(p, get_element_ud(c->reg.header, 2), get_element_ud(c->reg.R0, 2),
+ brw_imm_ud(0x1f));
+ brw_SHL(p, get_element_ud(c->reg.header, 2),
+ get_element_ud(c->reg.header, 2), brw_imm_ud(2));
+}
+
+/**
+ * Apply an additive offset to DWORD 2 of c->reg.header.
+ *
+ * This is used to set/unset the "PrimStart" and "PrimEnd" flags appropriately
+ * for each vertex.
+ */
+static void brw_gs_offset_header_dw2(struct brw_gs_compile *c, int offset)
+{
+ struct brw_compile *p = &c->func;
+ brw_ADD(p, get_element_d(c->reg.header, 2), get_element_d(c->reg.header, 2),
+ brw_imm_d(offset));
+}
+
+
/**
* Emit a vertex using the URB_WRITE message. Use the contents of
* c->reg.header for the message header, and the registers starting at \c vert
: retype(brw_null_reg(), BRW_REGISTER_TYPE_UD),
0,
c->reg.header,
- allocate,
- 1, /* used */
+ allocate ? BRW_URB_WRITE_ALLOCATE_COMPLETE
+ : BRW_URB_WRITE_EOT_COMPLETE,
c->nr_regs + 1, /* msg length */
allocate ? 1 : 0, /* response length */
- allocate ? 0 : 1, /* eot */
- 1, /* writes_complete */
0, /* urb offset */
BRW_URB_SWIZZLE_NONE);
/**
* Send an FF_SYNC message to ensure that all previously spawned GS threads
* have finished sending primitives down the pipeline, and to allocate a URB
- * entry for the first output vertex. Only needed when intel->needs_ff_sync
- * is true.
+ * entry for the first output vertex. Only needed on Ironlake+.
*
* This function modifies c->reg.header: in DWORD 1, it stores num_prim (which
* is needed by the FF_SYNC message), and in DWORD 0, it stores the handle to
void brw_gs_quads( struct brw_gs_compile *c, struct brw_gs_prog_key *key )
{
- struct intel_context *intel = &c->func.brw->intel;
+ struct brw_context *brw = c->func.brw;
- brw_gs_alloc_regs(c, 4);
+ brw_gs_alloc_regs(c, 4, false);
brw_gs_initialize_header(c);
/* Use polygons for correct edgeflag behaviour. Note that vertex 3
* is the PV for quads, but vertex 0 for polygons:
*/
- if (intel->needs_ff_sync)
+ if (brw->gen == 5)
brw_gs_ff_sync(c, 1);
brw_gs_overwrite_header_dw2(
c, ((_3DPRIM_POLYGON << URB_WRITE_PRIM_TYPE_SHIFT)
void brw_gs_quad_strip( struct brw_gs_compile *c, struct brw_gs_prog_key *key )
{
- struct intel_context *intel = &c->func.brw->intel;
+ struct brw_context *brw = c->func.brw;
- brw_gs_alloc_regs(c, 4);
+ brw_gs_alloc_regs(c, 4, false);
brw_gs_initialize_header(c);
- if (intel->needs_ff_sync)
+ if (brw->gen == 5)
brw_gs_ff_sync(c, 1);
brw_gs_overwrite_header_dw2(
c, ((_3DPRIM_POLYGON << URB_WRITE_PRIM_TYPE_SHIFT)
void brw_gs_lines( struct brw_gs_compile *c )
{
- struct intel_context *intel = &c->func.brw->intel;
+ struct brw_context *brw = c->func.brw;
- brw_gs_alloc_regs(c, 2);
+ brw_gs_alloc_regs(c, 2, false);
brw_gs_initialize_header(c);
- if (intel->needs_ff_sync)
+ if (brw->gen == 5)
brw_gs_ff_sync(c, 1);
brw_gs_overwrite_header_dw2(
c, ((_3DPRIM_LINESTRIP << URB_WRITE_PRIM_TYPE_SHIFT)
| URB_WRITE_PRIM_END));
brw_gs_emit_vue(c, c->reg.vertex[1], 1);
}
+
+/**
+ * Generate the geometry shader program used on Gen6 to perform stream output
+ * (transform feedback).
+ */
+void
+gen6_sol_program(struct brw_gs_compile *c, struct brw_gs_prog_key *key,
+ unsigned num_verts, bool check_edge_flags)
+{
+ struct brw_compile *p = &c->func;
+ c->prog_data.svbi_postincrement_value = num_verts;
+
+ brw_gs_alloc_regs(c, num_verts, true);
+ brw_gs_initialize_header(c);
+
+ if (key->num_transform_feedback_bindings > 0) {
+ unsigned vertex, binding;
+ struct brw_reg destination_indices_uw =
+ vec8(retype(c->reg.destination_indices, BRW_REGISTER_TYPE_UW));
+
+ /* Note: since we use the binding table to keep track of buffer offsets
+ * and stride, the GS doesn't need to keep track of a separate pointer
+ * into each buffer; it uses a single pointer which increments by 1 for
+ * each vertex. So we use SVBI0 for this pointer, regardless of whether
+ * transform feedback is in interleaved or separate attribs mode.
+ *
+ * Make sure that the buffers have enough room for all the vertices.
+ */
+ brw_ADD(p, get_element_ud(c->reg.temp, 0),
+ get_element_ud(c->reg.SVBI, 0), brw_imm_ud(num_verts));
+ brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_LE,
+ get_element_ud(c->reg.temp, 0),
+ get_element_ud(c->reg.SVBI, 4));
+ brw_IF(p, BRW_EXECUTE_1);
+
+ /* Compute the destination indices to write to. Usually we use SVBI[0]
+ * + (0, 1, 2). However, for odd-numbered triangles in tristrips, the
+ * vertices come down the pipeline in reversed winding order, so we need
+ * to flip the order when writing to the transform feedback buffer. To
+ * ensure that flatshading accuracy is preserved, we need to write them
+ * in order SVBI[0] + (0, 2, 1) if we're using the first provoking
+ * vertex convention, and in order SVBI[0] + (1, 0, 2) if we're using
+ * the last provoking vertex convention.
+ *
+ * Note: since brw_imm_v can only be used in instructions in
+ * packed-word execution mode, and SVBI is a double-word, we need to
+ * first move the appropriate immediate constant ((0, 1, 2), (0, 2, 1),
+ * or (1, 0, 2)) to the destination_indices register, and then add SVBI
+ * using a separate instruction. Also, since the immediate constant is
+ * expressed as packed words, and we need to load double-words into
+ * destination_indices, we need to intersperse zeros to fill the upper
+ * halves of each double-word.
+ */
+ brw_MOV(p, destination_indices_uw,
+ brw_imm_v(0x00020100)); /* (0, 1, 2) */
+ if (num_verts == 3) {
+ /* Get primitive type into temp register. */
+ brw_AND(p, get_element_ud(c->reg.temp, 0),
+ get_element_ud(c->reg.R0, 2), brw_imm_ud(0x1f));
+
+ /* Test if primitive type is TRISTRIP_REVERSE. We need to do this as
+ * an 8-wide comparison so that the conditional MOV that follows
+ * moves all 8 words correctly.
+ */
+ brw_CMP(p, vec8(brw_null_reg()), BRW_CONDITIONAL_EQ,
+ get_element_ud(c->reg.temp, 0),
+ brw_imm_ud(_3DPRIM_TRISTRIP_REVERSE));
+
+ /* If so, then overwrite destination_indices_uw with the appropriate
+ * reordering.
+ */
+ brw_MOV(p, destination_indices_uw,
+ brw_imm_v(key->pv_first ? 0x00010200 /* (0, 2, 1) */
+ : 0x00020001)); /* (1, 0, 2) */
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+ }
+ brw_ADD(p, c->reg.destination_indices,
+ c->reg.destination_indices, get_element_ud(c->reg.SVBI, 0));
+
+ /* For each vertex, generate code to output each varying using the
+ * appropriate binding table entry.
+ */
+ for (vertex = 0; vertex < num_verts; ++vertex) {
+ /* Set up the correct destination index for this vertex */
+ brw_MOV(p, get_element_ud(c->reg.header, 5),
+ get_element_ud(c->reg.destination_indices, vertex));
+
+ for (binding = 0; binding < key->num_transform_feedback_bindings;
+ ++binding) {
+ unsigned char varying =
+ key->transform_feedback_bindings[binding];
+ unsigned char slot = c->vue_map.varying_to_slot[varying];
+ /* From the Sandybridge PRM, Volume 2, Part 1, Section 4.5.1:
+ *
+ * "Prior to End of Thread with a URB_WRITE, the kernel must
+ * ensure that all writes are complete by sending the final
+ * write as a committed write."
+ */
+ bool final_write =
+ binding == key->num_transform_feedback_bindings - 1 &&
+ vertex == num_verts - 1;
+ struct brw_reg vertex_slot = c->reg.vertex[vertex];
+ vertex_slot.nr += slot / 2;
+ vertex_slot.subnr = (slot % 2) * 16;
+ /* gl_PointSize is stored in VARYING_SLOT_PSIZ.w. */
+ vertex_slot.dw1.bits.swizzle = varying == VARYING_SLOT_PSIZ
+ ? BRW_SWIZZLE_WWWW : key->transform_feedback_swizzles[binding];
+ brw_set_access_mode(p, BRW_ALIGN_16);
+ brw_MOV(p, stride(c->reg.header, 4, 4, 1),
+ retype(vertex_slot, BRW_REGISTER_TYPE_UD));
+ brw_set_access_mode(p, BRW_ALIGN_1);
+ brw_svb_write(p,
+ final_write ? c->reg.temp : brw_null_reg(), /* dest */
+ 1, /* msg_reg_nr */
+ c->reg.header, /* src0 */
+ SURF_INDEX_SOL_BINDING(binding), /* binding_table_index */
+ final_write); /* send_commit_msg */
+ }
+ }
+ brw_ENDIF(p);
+
+ /* Now, reinitialize the header register from R0 to restore the parts of
+ * the register that we overwrote while streaming out transform feedback
+ * data.
+ */
+ brw_gs_initialize_header(c);
+
+ /* Finally, wait for the write commit to occur so that we can proceed to
+ * other things safely.
+ *
+ * From the Sandybridge PRM, Volume 4, Part 1, Section 3.3:
+ *
+ * The write commit does not modify the destination register, but
+ * merely clears the dependency associated with the destination
+ * register. Thus, a simple “mov” instruction using the register as a
+ * source is sufficient to wait for the write commit to occur.
+ */
+ brw_MOV(p, c->reg.temp, c->reg.temp);
+ }
+
+ brw_gs_ff_sync(c, 1);
+
+ brw_gs_overwrite_header_dw2_from_r0(c);
+ switch (num_verts) {
+ case 1:
+ brw_gs_offset_header_dw2(c, URB_WRITE_PRIM_START | URB_WRITE_PRIM_END);
+ brw_gs_emit_vue(c, c->reg.vertex[0], true);
+ break;
+ case 2:
+ brw_gs_offset_header_dw2(c, URB_WRITE_PRIM_START);
+ brw_gs_emit_vue(c, c->reg.vertex[0], false);
+ brw_gs_offset_header_dw2(c, URB_WRITE_PRIM_END - URB_WRITE_PRIM_START);
+ brw_gs_emit_vue(c, c->reg.vertex[1], true);
+ break;
+ case 3:
+ if (check_edge_flags) {
+ /* Only emit vertices 0 and 1 if this is the first triangle of the
+ * polygon. Otherwise they are redundant.
+ */
+ brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+ brw_AND(p, retype(brw_null_reg(), BRW_REGISTER_TYPE_UD),
+ get_element_ud(c->reg.R0, 2),
+ brw_imm_ud(BRW_GS_EDGE_INDICATOR_0));
+ brw_IF(p, BRW_EXECUTE_1);
+ }
+ brw_gs_offset_header_dw2(c, URB_WRITE_PRIM_START);
+ brw_gs_emit_vue(c, c->reg.vertex[0], false);
+ brw_gs_offset_header_dw2(c, -URB_WRITE_PRIM_START);
+ brw_gs_emit_vue(c, c->reg.vertex[1], false);
+ if (check_edge_flags) {
+ brw_ENDIF(p);
+ /* Only emit vertex 2 in PRIM_END mode if this is the last triangle
+ * of the polygon. Otherwise leave the primitive incomplete because
+ * there are more polygon vertices coming.
+ */
+ brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+ brw_AND(p, retype(brw_null_reg(), BRW_REGISTER_TYPE_UD),
+ get_element_ud(c->reg.R0, 2),
+ brw_imm_ud(BRW_GS_EDGE_INDICATOR_1));
+ brw_set_predicate_control(p, BRW_PREDICATE_NORMAL);
+ }
+ brw_gs_offset_header_dw2(c, URB_WRITE_PRIM_END);
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+ brw_gs_emit_vue(c, c->reg.vertex[2], true);
+ break;
+ }
+}
projects / mesa.git / blobdiff