* RFA: Fix bug in optimize_mode_switching
@ 2011-07-11 9:36 Joern Rennecke
0 siblings, 0 replies; only message in thread
From: Joern Rennecke @ 2011-07-11 9:36 UTC (permalink / raw)
To: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 380 bytes --]
I work on target with complex mode switching needs, so it can happen that
in some block, for an entity a mode is provided without the need for a set.
This causes the current optimize_mode_switching to crash when it later
dereferences a NULL seginfo pointer.
Fixed by using an actual flag to keep track if we have allocated any seginfo.
Bootstrappded on x86_64-unknown-linux-gnu.
[-- Attachment #2: mode-switch-fix --]
[-- Type: text/plain, Size: 1350 bytes --]
2011-07-08 Joern Rennecke <joern.rennecke@embecosm.com>
* mode-switching.c (optimize_mode_switching): Fix bug in MODE_AFTER
handling.
Index: mode-switching.c
===================================================================
--- mode-switching.c (revision 1670)
+++ mode-switching.c (revision 1671)
@@ -499,6 +499,7 @@ optimize_mode_switching (void)
{
struct seginfo *ptr;
int last_mode = no_mode;
+ bool any_set_required = false;
HARD_REG_SET live_now;
REG_SET_TO_HARD_REG_SET (live_now, df_get_live_in (bb));
@@ -527,6 +528,7 @@ optimize_mode_switching (void)
if (mode != no_mode && mode != last_mode)
{
+ any_set_required = true;
last_mode = mode;
ptr = new_seginfo (mode, insn, bb->index, live_now);
add_seginfo (info + bb->index, ptr);
@@ -548,8 +550,10 @@ optimize_mode_switching (void)
}
info[bb->index].computing = last_mode;
- /* Check for blocks without ANY mode requirements. */
- if (last_mode == no_mode)
+ /* Check for blocks without ANY mode requirements.
+ N.B. because of MODE_AFTER, last_mode might still be different
+ from no_mode. */
+ if (!any_set_required)
{
ptr = new_seginfo (no_mode, BB_END (bb), bb->index, live_now);
add_seginfo (info + bb->index, ptr);
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2011-07-11 9:08 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-07-11 9:36 RFA: Fix bug in optimize_mode_switching Joern Rennecke
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).