llvmpipe: use single swizzled tile

Use a single swizzled tile per colorbuf (and per thread) to avoid
accumulating large amounts of cached swizzled data.

Now that the SSE3 code has been merged to master, the performance delta
of this change is minimal, the main benefit is reduced memory usage
due to no longer keeping swizzled copies of render targets.

It's clear from the performance of the in-place version of this code
that there is still quite a bit of time being spent swizzling &
unswizzling, but it's not clear exactly how to reduce that.

1 files changed, 13 insertions, 28 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_memory.c b/src/gallium/drivers/llvmpipe/lp_memory.c
index 61d16668eb9..0f55d4a80ae 100644
--- a/src/gallium/drivers/llvmpipe/lp_memory.c
+++ b/src/gallium/drivers/llvmpipe/lp_memory.c
@@ -29,32 +29,17 @@
 #include "lp_limits.h"
 #include "lp_memory.h"
 
-
-/** 32bpp RGBA dummy tile to use in out of memory conditions */
-static PIPE_ALIGN_VAR(16) uint8_t lp_dummy_tile[TILE_SIZE * TILE_SIZE * 4];
-
-static unsigned lp_out_of_memory = 0;
-
-
-uint8_t *
-lp_get_dummy_tile(void)
-{
-   if (lp_out_of_memory++ < 10) {
-      debug_printf("llvmpipe: out of memory.  Using dummy tile memory.\n");
-   }
-   return lp_dummy_tile;
-}
-
-uint8_t *
-lp_get_dummy_tile_silent(void)
-{
-   return lp_dummy_tile;
-}
-
-
-boolean
-lp_is_dummy_tile(void *tile)
-{
-   return tile == lp_dummy_tile;
-}
+/**
+ * 32bpp RGBA swizzled tiles.  One for for each thread and each
+ * possible colorbuf.  Adds up to quite a bit 8*8*64*64*4 == 1MB.
+ * Several schemes exist to reduce this, such as scaling back the
+ * number of threads or using a smaller tilesize when multiple
+ * colorbuffers are bound.
+ */
+PIPE_ALIGN_VAR(16) uint8_t lp_swizzled_cbuf[LP_MAX_THREADS][PIPE_MAX_COLOR_BUFS][TILE_SIZE * TILE_SIZE * 4];
+
+
+/* A single dummy tile used in a couple of out-of-memory situations. 
+ */
+PIPE_ALIGN_VAR(16) uint8_t lp_dummy_tile[TILE_SIZE * TILE_SIZE * 4];