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* [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2 not in 4.8.3); switch statement versus &
[not found] <bug-64614-4@http.gcc.gnu.org/bugzilla/>
@ 2015-01-15 16:27 ` mpolacek at gcc dot gnu.org
2015-01-16 10:31 ` [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); " rguenth at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-01-15 16:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64614
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mpolacek at gcc dot gnu.org
Component|c |middle-end
--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
We have tons of these -W*uninitialized bugs, so there's likely a dup.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); switch statement versus &
[not found] <bug-64614-4@http.gcc.gnu.org/bugzilla/>
2015-01-15 16:27 ` [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2 not in 4.8.3); switch statement versus & mpolacek at gcc dot gnu.org
@ 2015-01-16 10:31 ` rguenth at gcc dot gnu.org
2015-01-16 13:12 ` rguenth at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-01-16 10:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64614
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 34461
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34461&action=edit
preliminary patch
I think the uninit pass doesn't even try to handle switch case input conditions
(convert_control_dep_chain_into_preds). Nor does predicate handling deal with
bar & 3 predicates.
Preliminary patch attached - still needs to handle the default case - but
it seems we don't warn about the return value with the patch.
With the patch:
[CHECK] Found def edge 1 in tmp_1 = PHI <tmp_6(D)(3), baz_7(D)(8)>
[BEFORE SIMPLICATION -- [USE]:
MEM[(char *)tmp_1 + 11B] = 15;
is guarded by :
bar_4(D) == 2
[BEFORE SIMPLICATION -- [DEF]:
tmp_1 = PHI <tmp_6(D)(3), baz_7(D)(8)>
is guarded by :
_5 != 0
[AFTER NORMALIZATION -- [DEF]:
tmp_1 = PHI <tmp_6(D)(3), baz_7(D)(8)>
is guarded by :
bar_4(D) & 3
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); switch statement versus &
[not found] <bug-64614-4@http.gcc.gnu.org/bugzilla/>
2015-01-15 16:27 ` [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2 not in 4.8.3); switch statement versus & mpolacek at gcc dot gnu.org
2015-01-16 10:31 ` [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); " rguenth at gcc dot gnu.org
@ 2015-01-16 13:12 ` rguenth at gcc dot gnu.org
2015-01-16 13:26 ` rguenth at gcc dot gnu.org
` (2 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-01-16 13:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64614
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |2.95.2, 3.4.6, 4.1.2
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fails for all versions I tested btw, so nowhere near a regression.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); switch statement versus &
[not found] <bug-64614-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2015-01-16 13:12 ` rguenth at gcc dot gnu.org
@ 2015-01-16 13:26 ` rguenth at gcc dot gnu.org
2015-01-16 18:05 ` dgilbert at redhat dot com
2015-01-19 9:41 ` rguenth at gcc dot gnu.org
5 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-01-16 13:26 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64614
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Jan 16 13:26:10 2015
New Revision: 219739
URL: https://gcc.gnu.org/viewcvs?rev=219739&root=gcc&view=rev
Log:
2015-01-16 Richard Biener <rguenther@suse.de>
PR middle-end/64614
* tree-ssa-uninit.c: Include tree-cfg.h.
(MAX_SWITCH_CASES): New define.
(convert_control_dep_chain_into_preds): Handle switch statements.
(is_pred_expr_subset_of): Handle x == CST vs. (x & CST) != 0.
(normalize_one_pred_1): Do not split bit-manipulations.
Record (x & CST).
* gcc.dg/uninit-18.c: New testcase.
Added:
trunk/gcc/testsuite/gcc.dg/uninit-18.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-ssa-uninit.c
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); switch statement versus &
[not found] <bug-64614-4@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2015-01-16 13:26 ` rguenth at gcc dot gnu.org
@ 2015-01-16 18:05 ` dgilbert at redhat dot com
2015-01-19 9:41 ` rguenth at gcc dot gnu.org
5 siblings, 0 replies; 6+ messages in thread
From: dgilbert at redhat dot com @ 2015-01-16 18:05 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64614
--- Comment #8 from Dr. David Alan Gilbert <dgilbert at redhat dot com> ---
Richard: Thanks for the fix, and apologies again for my screwed up regression
test.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); switch statement versus &
[not found] <bug-64614-4@http.gcc.gnu.org/bugzilla/>
` (4 preceding siblings ...)
2015-01-16 18:05 ` dgilbert at redhat dot com
@ 2015-01-19 9:41 ` rguenth at gcc dot gnu.org
5 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-01-19 9:41 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64614
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |diagnostic
Status|UNCONFIRMED |RESOLVED
Known to work| |5.0
Resolution|--- |FIXED
Known to fail| |4.9.2
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2015-01-15 16:27 ` [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2 not in 4.8.3); switch statement versus & mpolacek at gcc dot gnu.org
2015-01-16 10:31 ` [Bug middle-end/64614] bogus used initialized warning (in gcc 4.9.2); " rguenth at gcc dot gnu.org
2015-01-16 13:12 ` rguenth at gcc dot gnu.org
2015-01-16 13:26 ` rguenth at gcc dot gnu.org
2015-01-16 18:05 ` dgilbert at redhat dot com
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