From 26fdb7e51e9f6b407ad8c635850ccffbd01876bc Mon Sep 17 00:00:00 2001 From: Topi Pohjolainen Date: Tue, 19 Apr 2016 19:57:43 +0300 Subject: [PATCH] i965/blorp: Reduce the size of vertex buffer Previously the vertex buffer consisted of eight floats per vertex of which six where constants. These can be as easily provided by vertex fetcher as it is capable of filling vertex elements with constant one and zero. This reduces the size of the vertex buffer from 3 * 8 * 4 = 96 to 3 * 2 * 4 = 24 bytes. Signed-off-by: Topi Pohjolainen Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/gen6_blorp.cpp | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/src/mesa/drivers/dri/i965/gen6_blorp.cpp b/src/mesa/drivers/dri/i965/gen6_blorp.cpp index b741e19..cf30f71 100644 --- a/src/mesa/drivers/dri/i965/gen6_blorp.cpp +++ b/src/mesa/drivers/dri/i965/gen6_blorp.cpp @@ -159,14 +159,21 @@ gen6_blorp_emit_vertices(struct brw_context *brw, * * For details, see the Sandybridge PRM, Volume 2, Part 1, Section 1.5.1 * "Vertex URB Entry (VUE) Formats". + * + * Only vertex position X and Y are going to be variable, Z is fixed to + * zero and W to one. Header words dw0-3 are all zero. There is no need to + * include the fixed values in the vertex buffer. Vertex fetcher can be + * instructed to fill vertex elements with constant values of one and zero + * instead of reading them from the buffer. See the vertex element setup + * below. */ { float *vertex_data; const float vertices[] = { - /* v0 */ 0, 0, 0, 0, (float)params->x0, (float)params->y1, 0, 1, - /* v1 */ 0, 0, 0, 0, (float)params->x1, (float)params->y1, 0, 1, - /* v2 */ 0, 0, 0, 0, (float)params->x0, (float)params->y0, 0, 1, + /* v0 */ (float)params->x0, (float)params->y1, + /* v1 */ (float)params->x1, (float)params->y1, + /* v2 */ (float)params->x0, (float)params->y0, }; vertex_data = (float *) brw_state_batch(brw, AUB_TRACE_VERTEX_BUFFER, @@ -174,7 +181,7 @@ gen6_blorp_emit_vertices(struct brw_context *brw, &vertex_offset); memcpy(vertex_data, vertices, sizeof(vertices)); - const unsigned blorp_num_vue_elems = 8; + const unsigned blorp_num_vue_elems = 2; gen6_blorp_emit_vertex_buffer_state(brw, blorp_num_vue_elems, sizeof(vertices), vertex_offset); } @@ -194,18 +201,18 @@ gen6_blorp_emit_vertices(struct brw_context *brw, OUT_BATCH(GEN6_VE0_VALID | BRW_SURFACEFORMAT_R32G32B32A32_FLOAT << BRW_VE0_FORMAT_SHIFT | 0 << BRW_VE0_SRC_OFFSET_SHIFT); - OUT_BATCH(BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_0_SHIFT | - BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_1_SHIFT | - BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_2_SHIFT | - BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_3_SHIFT); + OUT_BATCH(BRW_VE1_COMPONENT_STORE_0 << BRW_VE1_COMPONENT_0_SHIFT | + BRW_VE1_COMPONENT_STORE_0 << BRW_VE1_COMPONENT_1_SHIFT | + BRW_VE1_COMPONENT_STORE_0 << BRW_VE1_COMPONENT_2_SHIFT | + BRW_VE1_COMPONENT_STORE_0 << BRW_VE1_COMPONENT_3_SHIFT); /* Element 1 */ OUT_BATCH(GEN6_VE0_VALID | - BRW_SURFACEFORMAT_R32G32B32A32_FLOAT << BRW_VE0_FORMAT_SHIFT | - 16 << BRW_VE0_SRC_OFFSET_SHIFT); + BRW_SURFACEFORMAT_R32G32_FLOAT << BRW_VE0_FORMAT_SHIFT | + 0 << BRW_VE0_SRC_OFFSET_SHIFT); OUT_BATCH(BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_0_SHIFT | BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_1_SHIFT | - BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_2_SHIFT | - BRW_VE1_COMPONENT_STORE_SRC << BRW_VE1_COMPONENT_3_SHIFT); + BRW_VE1_COMPONENT_STORE_0 << BRW_VE1_COMPONENT_2_SHIFT | + BRW_VE1_COMPONENT_STORE_1_FLT << BRW_VE1_COMPONENT_3_SHIFT); ADVANCE_BATCH(); } } -- 2.7.4