From e86ae1b0a32bbbe4fb02ae9cee5b447a75d7e27f Mon Sep 17 00:00:00 2001 From: Samuel Iglesias Gonsalvez Date: Fri, 18 Jul 2014 10:36:10 +0200 Subject: [PATCH] i965/gen6/gs: implement GS_OPCODE_SVB_WRITE opcode This opcode will be used when sending SVB WRITE messages to save transform feedback outputs into Streamed Vertex Buffers. Signed-off-by: Samuel Iglesias Gonsalvez Acked-by: Kenneth Graunke Reviewed-by: Jordan Justen --- src/mesa/drivers/dri/i965/brw_defines.h | 12 +++++++ src/mesa/drivers/dri/i965/brw_shader.cpp | 2 ++ src/mesa/drivers/dri/i965/brw_vec4.h | 7 ++++ src/mesa/drivers/dri/i965/brw_vec4_generator.cpp | 42 ++++++++++++++++++++++++ 4 files changed, 63 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h index e359c45..1fe4bb5 100644 --- a/src/mesa/drivers/dri/i965/brw_defines.h +++ b/src/mesa/drivers/dri/i965/brw_defines.h @@ -1043,6 +1043,18 @@ enum opcode { * - dst is the GRF where PrimitiveID information will be moved. */ GS_OPCODE_SET_PRIMITIVE_ID, + + /** + * Write transform feedback data to the SVB by sending a SVB WRITE message. + * Used in gen6. + * + * - dst is the MRF register containing the message header. + * + * - src0 is the register where the vertex data is going to be copied from. + * + * - src1 is the destination register when write commit occurs. + */ + GS_OPCODE_SVB_WRITE, }; enum brw_derivative_quality { diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp index e4c3948..45e126f 100644 --- a/src/mesa/drivers/dri/i965/brw_shader.cpp +++ b/src/mesa/drivers/dri/i965/brw_shader.cpp @@ -528,6 +528,8 @@ brw_instruction_name(enum opcode op) return "ff_sync"; case GS_OPCODE_SET_PRIMITIVE_ID: return "set_primitive_id"; + case GS_OPCODE_SVB_WRITE: + return "gs_svb_write"; default: /* Yes, this leaks. It's in debug code, it should never occur, and if diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h index f2ec26a..8391319 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4.h +++ b/src/mesa/drivers/dri/i965/brw_vec4.h @@ -220,6 +220,9 @@ public: enum brw_urb_write_flags urb_write_flags; bool header_present; + unsigned sol_binding; /**< gen6: SOL binding table index */ + bool sol_final_write; /**< gen6: send commit message */ + bool is_send_from_grf(); bool can_reswizzle(int dst_writemask, int swizzle, int swizzle_mask); void reswizzle(int dst_writemask, int swizzle); @@ -654,6 +657,10 @@ private: struct brw_reg src1); void generate_gs_set_vertex_count(struct brw_reg dst, struct brw_reg src); + void generate_gs_svb_write(vec4_instruction *inst, + struct brw_reg dst, + struct brw_reg src0, + struct brw_reg src1); void generate_gs_set_dword_2(struct brw_reg dst, struct brw_reg src); void generate_gs_prepare_channel_masks(struct brw_reg dst); void generate_gs_set_channel_masks(struct brw_reg dst, struct brw_reg src); diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp index c2d0d2e..db93620 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp @@ -574,6 +574,44 @@ vec4_generator::generate_gs_set_vertex_count(struct brw_reg dst, } void +vec4_generator::generate_gs_svb_write(vec4_instruction *inst, + struct brw_reg dst, + struct brw_reg src0, + struct brw_reg src1) +{ + int binding = inst->sol_binding; + bool final_write = inst->sol_final_write; + + brw_push_insn_state(p); + /* Copy Vertex data into M0.x */ + brw_MOV(p, stride(dst, 4, 4, 1), + stride(retype(src0, BRW_REGISTER_TYPE_UD), 4, 4, 1)); + + /* Send SVB Write */ + brw_svb_write(p, + final_write ? src1 : brw_null_reg(), /* dest == src1 */ + 1, /* msg_reg_nr */ + dst, /* src0 == previous dst */ + SURF_INDEX_GEN6_SOL_BINDING(binding), /* binding_table_index */ + final_write); /* send_commit_msg */ + + /* 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. + */ + if (final_write) { + brw_MOV(p, src1, src1); + } + brw_pop_insn_state(p); +} + +void vec4_generator::generate_gs_set_dword_2(struct brw_reg dst, struct brw_reg src) { brw_push_insn_state(p); @@ -1347,6 +1385,10 @@ vec4_generator::generate_code(const cfg_t *cfg) generate_gs_urb_write_allocate(inst); break; + case GS_OPCODE_SVB_WRITE: + generate_gs_svb_write(inst, dst, src[0], src[1]); + break; + case GS_OPCODE_THREAD_END: generate_gs_thread_end(inst); break; -- 2.7.4