From: Kenneth Graunke <kenneth@whitecape.org>
Date: Mon, 9 Jun 2014 09:59:21 +0000 (-0700)
Subject: i965: Don't use the head sentinel as an fs_inst in Gen4 workaround code.
X-Git-Tag: upstream/10.3~1587
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ecc78eab119ac8fa3df380a80bc94975e986523c;p=platform%2Fupstream%2Fmesa.git

i965: Don't use the head sentinel as an fs_inst in Gen4 workaround code.

When walking backwards, we want to stop at the head sentinel, which is
where scan_inst->prev->prev == NULL, not scan_inst->prev == NULL.

Fixes random crashes, as well as valgrind errors.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Cc: mesa-stable@lists.freedesktop.org
---

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index a8ca9bc..b485e65 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2355,7 +2355,7 @@ fs_visitor::insert_gen4_pre_send_dependency_workarounds(fs_inst *inst)
     * program.
     */
    for (fs_inst *scan_inst = (fs_inst *)inst->prev;
-        scan_inst != NULL;
+        !scan_inst->is_head_sentinel();
         scan_inst = (fs_inst *)scan_inst->prev) {
 
       /* If we hit control flow, assume that there *are* outstanding