diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_gs.h | 6 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_gs_emit.c | 84 |
2 files changed, 72 insertions, 18 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_gs.h b/src/mesa/drivers/dri/i965/brw_gs.h index 7bf2248a5ed..2ab8b724eac 100644 --- a/src/mesa/drivers/dri/i965/brw_gs.h +++ b/src/mesa/drivers/dri/i965/brw_gs.h @@ -83,6 +83,12 @@ struct brw_gs_compile { struct brw_reg vertex[MAX_GS_VERTS]; struct brw_reg header; struct brw_reg temp; + + /** + * Register holding destination indices for streamed buffer writes. + * Only used for SOL programs. + */ + struct brw_reg destination_indices; } reg; /* Number of registers used to store vertex data */ diff --git a/src/mesa/drivers/dri/i965/brw_gs_emit.c b/src/mesa/drivers/dri/i965/brw_gs_emit.c index 1f96a164637..607ee7516eb 100644 --- a/src/mesa/drivers/dri/i965/brw_gs_emit.c +++ b/src/mesa/drivers/dri/i965/brw_gs_emit.c @@ -45,13 +45,16 @@ /** * Allocate registers for GS. * - * If svbi_payload_enable 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. + * 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, - bool svbi_payload_enable ) + bool sol_program ) { GLuint i = 0,j; @@ -60,7 +63,7 @@ static void brw_gs_alloc_regs( struct brw_gs_compile *c, c->reg.R0 = retype(brw_vec8_grf(i, 0), BRW_REGISTER_TYPE_UD); i++; /* Streamed vertex buffer indices */ - if (svbi_payload_enable) + if (sol_program) c->reg.SVBI = retype(brw_vec8_grf(i++, 0), BRW_REGISTER_TYPE_UD); /* Payload vertices plus space for more generated vertices: @@ -73,6 +76,11 @@ static void brw_gs_alloc_regs( struct brw_gs_compile *c, 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; } @@ -351,16 +359,17 @@ gen6_sol_program(struct brw_gs_compile *c, struct brw_gs_prog_key *key, 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_MOV(p, get_element_ud(c->reg.header, 5), - get_element_ud(c->reg.SVBI, 0)); - - /* 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, @@ -368,10 +377,58 @@ gen6_sol_program(struct brw_gs_compile *c, struct brw_gs_prog_key *key, 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 vert_result = @@ -398,15 +455,6 @@ gen6_sol_program(struct brw_gs_compile *c, struct brw_gs_prog_key *key, SURF_INDEX_SOL_BINDING(binding), /* binding_table_index */ final_write); /* send_commit_msg */ } - - /* If there are more vertices to output, increment the pointer so - * that we will start outputting to the next location in the - * transform feedback buffers. - */ - if (vertex != num_verts - 1) { - brw_ADD(p, get_element_ud(c->reg.header, 5), - get_element_ud(c->reg.header, 5), brw_imm_ud(1)); - } } brw_ENDIF(p); |