From ccb1ea8a1502286124b48030dac9b898a6c7caaa Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Mon, 26 May 2014 11:44:09 -0700 Subject: [PATCH] Revert "i965/fs: Reduce restrictions on interference in register coalescing." This reverts commit f770123f58b46459e8dbd27525162ee8ba89f30b. Cc: "10.2" Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78692 --- src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp index 13b678a..b2ab386 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp @@ -83,6 +83,19 @@ can_coalesce_vars(brw::fs_live_variables *live_intervals, if (!live_intervals->vars_interfere(var_from, var_to)) return true; + /* We know that the live ranges of A (var_from) and B (var_to) + * interfere because of the ->vars_interfere() call above. If the end + * of B's live range is after the end of A's range, then we know two + * things: + * - the start of B's live range must be in A's live range (since we + * already know the two ranges interfere, this is the only remaining + * possibility) + * - the interference isn't of the form we're looking for (where B is + * entirely inside A) + */ + if (live_intervals->end[var_to] > live_intervals->end[var_from]) + return false; + assert(ip >= live_intervals->start[var_to]); fs_inst *scan_inst; -- 2.7.4