From a291c59bbae7d9d96487a984f81a298a1fd71389 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Fri, 9 Aug 2013 18:27:22 -0700 Subject: [PATCH] i965/fs: Simplify liveout calculation. Excluding the existing liveout bits is a deviation from the textbook algorithm. The reason for doing so was to determine if the value changed, which means the fixed-point algorithm needs to run for another iteration. The simpler way to do that is to save the value from step (N-1) and compare it to the new value at step N. Signed-off-by: Kenneth Graunke Reviewed-by: Paul Berry --- src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp index 424d7b52dcc..0078c871c5d 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp @@ -186,13 +186,12 @@ fs_copy_prop_dataflow::run() /* Update liveout for all blocks. */ for (int b = 0; b < cfg->num_blocks; b++) { for (int i = 0; i < bitset_words; i++) { - BITSET_WORD new_liveout = (bd[b].livein[i] & - ~bd[b].kill[i] & - ~bd[b].liveout[i]); - if (new_liveout) { - bd[b].liveout[i] |= new_liveout; + const BITSET_WORD old_liveout = bd[b].liveout[i]; + + bd[b].liveout[i] |= bd[b].livein[i] & ~bd[b].kill[i]; + + if (old_liveout != bd[b].liveout[i]) progress = true; - } } } -- 2.30.2