path: root/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
diff options
authorEric Anholt <>2013-04-30 15:00:40 -0700
committerEric Anholt <>2013-05-09 14:38:05 -0700
commite290372542d0475e612e4d10a27b22eae3158ecd (patch)
treead199a00e38af2fa46c665283856e3659e64845e /src/mesa/drivers/dri/i965/brw_fs_cse.cpp
parentdd6152b6cacb869d6db028656927ea2af168448d (diff)
i965/fs: Make virtual grf live intervals actually cover their used range.
Previously, we would sometimes not consider a write to a register to extend the end of the interval, nor would we consider a read before a write to extend the start. This made for a bunch of complicated logic related to how to treat the results when dead code might be present. Instead, just extend the interval and fix dead code elimination to know how to remove it. Interestingly, this actually results in a tiny bit more optimization: total instructions in shared programs: 1391220 -> 1390799 (-0.03%) instructions in affected programs: 14037 -> 13616 (-3.00%) v2: Fix a theoretical problem with the simd16 workaround if dst == src, where we would revert the bump of the live range. Reviewed-by: Ian Romanick <> (v1)
Diffstat (limited to 'src/mesa/drivers/dri/i965/brw_fs_cse.cpp')
1 files changed, 1 insertions, 1 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
index b5c220090c..9b60d9be41 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
@@ -194,7 +194,7 @@ fs_visitor::opt_cse_local(bblock_t *block, exec_list *aeb)
/* Kill any AEB entries using registers that don't get reused any
* more -- a sure sign they'll fail operands_match().
- if (src_reg->file == GRF && virtual_grf_use[src_reg->reg] < ip) {
+ if (src_reg->file == GRF && virtual_grf_end[src_reg->reg] < ip) {