i965: Combine assembly annotations if possible.

Often annotations are identical between sets of consecutive
instructions. We can perhaps avoid some memory allocations by reusing
the previous annotation.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 18 insertions, 5 deletions

diff --git a/src/mesa/drivers/dri/i965/intel_asm_annotation.c b/src/mesa/drivers/dri/i965/intel_asm_annotation.c
index f87a9bb..fe9d80a 100644
--- a/src/mesa/drivers/dri/i965/intel_asm_annotation.c
+++ b/src/mesa/drivers/dri/i965/intel_asm_annotation.c
@@ -112,6 +112,24 @@ void annotate(const struct brw_device_info *devinfo,
       ann->block_start = cfg->blocks[annotation->cur_block];
    }
 
+   if (bblock_end(cfg->blocks[annotation->cur_block]) == inst) {
+      ann->block_end = cfg->blocks[annotation->cur_block];
+      annotation->cur_block++;
+   }
+
+   /* Merge this annotation with the previous if possible. */
+   struct annotation *prev = annotation->ann_count > 1 ?
+         &annotation->ann[annotation->ann_count - 2] : NULL;
+   if (prev != NULL &&
+       ann->ir == prev->ir &&
+       ann->annotation == prev->annotation &&
+       ann->block_start == NULL &&
+       prev->block_end == NULL) {
+      if (ann->block_end == NULL)
+         annotation->ann_count--;
+      return;
+   }
+
    /* There is no hardware DO instruction on Gen6+, so since DO always
     * starts a basic block, we need to set the .block_start of the next
     * instruction's annotation with a pointer to the bblock started by
@@ -123,11 +141,6 @@ void annotate(const struct brw_device_info *devinfo,
    if (devinfo->gen >= 6 && inst->opcode == BRW_OPCODE_DO) {
       annotation->ann_count--;
    }
-
-   if (bblock_end(cfg->blocks[annotation->cur_block]) == inst) {
-      ann->block_end = cfg->blocks[annotation->cur_block];
-      annotation->cur_block++;
-   }
 }
 
 void