Mesa (master): svga: implement an index buffer translation cache
Brian Paul
brianp at kemper.freedesktop.org
Sat Sep 17 16:26:31 UTC 2016
Module: Mesa
Branch: master
Commit: 4f74b379aa05e133cdd19865662eceacee4f63f4
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=4f74b379aa05e133cdd19865662eceacee4f63f4
Author: Brian Paul <brianp at vmware.com>
Date: Wed Aug 31 14:49:41 2016 -0600
svga: implement an index buffer translation cache
Some OpenGL apps, like Cinebench R15, have many glDrawElements(GL_QUADS)
calls. Since we don't directly support quads we have to convert these
calls into GL_TRIANGLES which involves generating a new index buffer.
This patch saves the new/translated index buffer in the hope that it
can be reused for a later draw call.
Cinebench R15 increases by about 20% with this change.
The NobelClinician Viewer app also hits this code.
Tested with full piglit run.
Reviewed-by: Charmaine Lee <charmainel at vmware.com>
---
src/gallium/drivers/svga/svga_draw_elements.c | 67 ++++++++++++++++++++++---
src/gallium/drivers/svga/svga_resource_buffer.c | 9 ++++
src/gallium/drivers/svga/svga_resource_buffer.h | 11 ++++
src/gallium/drivers/svga/svga_screen.c | 2 +
src/gallium/drivers/svga/svga_screen.h | 1 +
5 files changed, 84 insertions(+), 6 deletions(-)
diff --git a/src/gallium/drivers/svga/svga_draw_elements.c b/src/gallium/drivers/svga/svga_draw_elements.c
index f7953bc..37d1fdb 100644
--- a/src/gallium/drivers/svga/svga_draw_elements.c
+++ b/src/gallium/drivers/svga/svga_draw_elements.c
@@ -37,26 +37,66 @@
#include "svga_hw_reg.h"
+/**
+ * Return a new index buffer which contains a translation of the original
+ * index buffer. An example of a translation is converting from QUAD
+ * primitives to TRIANGLE primitives. Each set of four indexes for a quad
+ * will be converted to six indices for two triangles.
+ *
+ * Before generating the new index buffer we'll check if the incoming
+ * buffer already has a translated buffer that can be re-used.
+ * This benefits demos like Cinebench R15 which has many
+ * glDrawElements(GL_QUADS) commands (we can't draw quads natively).
+ *
+ * \param offset offset in bytes to first index to translate in src buffer
+ * \param orig_prim original primitive type (like PIPE_PRIM_QUADS)
+ * \param gen_prim new/generated primitive type (like PIPE_PRIM_TRIANGLES)
+ * \param orig_nr number of indexes to translate in source buffer
+ * \param gen_nr number of indexes to write into new/dest buffer
+ * \param index_size bytes per index (2 or 4)
+ * \param translate the translation function from the u_translate module
+ * \param out_buf returns the new/translated index buffer
+ * \return error code to indicate success failure
+ */
static enum pipe_error
translate_indices(struct svga_hwtnl *hwtnl, struct pipe_resource *src,
- unsigned offset, enum pipe_prim_type prim, unsigned nr,
+ unsigned offset,
+ enum pipe_prim_type orig_prim, enum pipe_prim_type gen_prim,
+ unsigned orig_nr, unsigned gen_nr,
unsigned index_size,
u_translate_func translate, struct pipe_resource **out_buf)
{
struct pipe_context *pipe = &hwtnl->svga->pipe;
+ struct svga_screen *screen = svga_screen(pipe->screen);
+ struct svga_buffer *src_sbuf = svga_buffer(src);
struct pipe_transfer *src_transfer = NULL;
struct pipe_transfer *dst_transfer = NULL;
- unsigned size = index_size * nr;
+ unsigned size = index_size * gen_nr;
const void *src_map = NULL;
struct pipe_resource *dst = NULL;
void *dst_map = NULL;
+ assert(index_size == 2 || index_size == 4);
+
+ if (!screen->debug.no_cache_index_buffers) {
+ /* Check if we already have a translated index buffer */
+ if (src_sbuf->translated_indices.buffer &&
+ src_sbuf->translated_indices.orig_prim == PIPE_PRIM_QUADS &&
+ src_sbuf->translated_indices.new_prim == gen_prim &&
+ src_sbuf->translated_indices.offset == offset &&
+ src_sbuf->translated_indices.count == orig_nr &&
+ src_sbuf->translated_indices.index_size == index_size) {
+ pipe_resource_reference(out_buf, src_sbuf->translated_indices.buffer);
+ return PIPE_OK;
+ }
+ }
+
/* Need to trim vertex count to make sure we don't write too much data
* to the dst buffer in the translate() call.
*/
- u_trim_pipe_prim(prim, &nr);
+ u_trim_pipe_prim(gen_prim, &gen_nr);
- size = index_size * nr;
+ size = index_size * gen_nr;
dst = pipe_buffer_create(pipe->screen,
PIPE_BIND_INDEX_BUFFER, PIPE_USAGE_DEFAULT, size);
@@ -71,12 +111,25 @@ translate_indices(struct svga_hwtnl *hwtnl, struct pipe_resource *src,
if (!dst_map)
goto fail;
- translate((const char *) src_map + offset, 0, 0, nr, 0, dst_map);
+ translate((const char *) src_map + offset, 0, 0, gen_nr, 0, dst_map);
pipe_buffer_unmap(pipe, src_transfer);
pipe_buffer_unmap(pipe, dst_transfer);
*out_buf = dst;
+
+ if (!screen->debug.no_cache_index_buffers) {
+ /* Save the new, translated index buffer in the hope we can use it
+ * again in the future.
+ */
+ pipe_resource_reference(&src_sbuf->translated_indices.buffer, dst);
+ src_sbuf->translated_indices.orig_prim = PIPE_PRIM_QUADS;
+ src_sbuf->translated_indices.new_prim = gen_prim;
+ src_sbuf->translated_indices.offset = offset;
+ src_sbuf->translated_indices.count = orig_nr;
+ src_sbuf->translated_indices.index_size = index_size;
+ }
+
return PIPE_OK;
fail:
@@ -186,7 +239,9 @@ svga_hwtnl_draw_range_elements(struct svga_hwtnl *hwtnl,
ret = translate_indices(hwtnl,
index_buffer,
start * index_size,
- gen_prim, gen_nr, gen_size, gen_func, &gen_buf);
+ prim, gen_prim,
+ count, gen_nr, gen_size,
+ gen_func, &gen_buf);
if (ret != PIPE_OK)
goto done;
diff --git a/src/gallium/drivers/svga/svga_resource_buffer.c b/src/gallium/drivers/svga/svga_resource_buffer.c
index b47b07b..99ed1a2 100644
--- a/src/gallium/drivers/svga/svga_resource_buffer.c
+++ b/src/gallium/drivers/svga/svga_resource_buffer.c
@@ -98,6 +98,13 @@ svga_buffer_transfer_map(struct pipe_context *pipe,
transfer->stride = 0;
transfer->layer_stride = 0;
+ if (usage & PIPE_TRANSFER_WRITE) {
+ /* If we write to the buffer for any reason, free any saved translated
+ * vertices.
+ */
+ pipe_resource_reference(&sbuf->translated_indices.buffer, NULL);
+ }
+
if ((usage & PIPE_TRANSFER_READ) && sbuf->dirty) {
enum pipe_error ret;
@@ -361,6 +368,8 @@ svga_buffer_destroy( struct pipe_screen *screen,
if (sbuf->swbuf && !sbuf->user)
align_free(sbuf->swbuf);
+ pipe_resource_reference(&sbuf->translated_indices.buffer, NULL);
+
ss->hud.total_resource_bytes -= sbuf->size;
assert(ss->hud.num_resources > 0);
if (ss->hud.num_resources > 0)
diff --git a/src/gallium/drivers/svga/svga_resource_buffer.h b/src/gallium/drivers/svga/svga_resource_buffer.h
index daf9c18..6907588 100644
--- a/src/gallium/drivers/svga/svga_resource_buffer.h
+++ b/src/gallium/drivers/svga/svga_resource_buffer.h
@@ -192,6 +192,17 @@ struct svga_buffer
unsigned size; /**< Approximate size in bytes */
boolean dirty; /**< Need to do a readback before mapping? */
+
+ /** In some cases we try to keep the results of the translate_indices()
+ * function from svga_draw_elements.c
+ */
+ struct {
+ enum pipe_prim_type orig_prim, new_prim;
+ struct pipe_resource *buffer;
+ unsigned index_size;
+ unsigned offset; /**< first index */
+ unsigned count; /**< num indices */
+ } translated_indices;
};
diff --git a/src/gallium/drivers/svga/svga_screen.c b/src/gallium/drivers/svga/svga_screen.c
index ec29ae9..4c2d671 100644
--- a/src/gallium/drivers/svga/svga_screen.c
+++ b/src/gallium/drivers/svga/svga_screen.c
@@ -944,6 +944,8 @@ svga_screen_create(struct svga_winsys_screen *sws)
debug_get_bool_option("SVGA_NO_SURFACE_VIEW", FALSE);
svgascreen->debug.no_sampler_view =
debug_get_bool_option("SVGA_NO_SAMPLER_VIEW", FALSE);
+ svgascreen->debug.no_cache_index_buffers =
+ debug_get_bool_option("SVGA_NO_CACHE_INDEX_BUFFERS", FALSE);
screen = &svgascreen->screen;
diff --git a/src/gallium/drivers/svga/svga_screen.h b/src/gallium/drivers/svga/svga_screen.h
index 98b56b2..6cafeba 100644
--- a/src/gallium/drivers/svga/svga_screen.h
+++ b/src/gallium/drivers/svga/svga_screen.h
@@ -62,6 +62,7 @@ struct svga_screen
boolean no_surface_view;
boolean force_sampler_view;
boolean no_sampler_view;
+ boolean no_cache_index_buffers;
} debug;
unsigned texture_timestamp;
More information about the mesa-commit
mailing list