[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

2017-10-11 Thread jakub at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

Jakub Jelinek  changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution|--- |FIXED

--- Comment #6 from Jakub Jelinek  ---
Fixed.

[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

2017-10-10 Thread jakub at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

--- Comment #5 from Jakub Jelinek  ---
Author: jakub
Date: Tue Oct 10 16:17:47 2017
New Revision: 253589

URL: https://gcc.gnu.org/viewcvs?rev=253589=gcc=rev
Log:
PR c/82437
* c-warn.c (warn_tautological_bitwise_comparison): Use wi::to_wide
instead of wide_int::from.

* c-c++-common/Wtautological-compare-7.c: New test.

Added:
trunk/gcc/testsuite/c-c++-common/Wtautological-compare-7.c
Modified:
trunk/gcc/c-family/ChangeLog
trunk/gcc/c-family/c-warn.c
trunk/gcc/testsuite/ChangeLog

[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

2017-10-06 Thread jakub at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

--- Comment #4 from Jakub Jelinek  ---
Author: jakub
Date: Fri Oct  6 07:11:25 2017
New Revision: 253476

URL: https://gcc.gnu.org/viewcvs?rev=253476=gcc=rev
Log:
PR c/82437
* c-warn.c (warn_tautological_bitwise_comparison): Instead of
using to_widest use wide_int with the larger of the two precisions.

* c-c++-common/Wtautological-compare-6.c: New test.

Added:
trunk/gcc/testsuite/c-c++-common/Wtautological-compare-6.c
Modified:
trunk/gcc/c-family/ChangeLog
trunk/gcc/c-family/c-warn.c
trunk/gcc/testsuite/ChangeLog

[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

2017-10-05 Thread arnd at linaro dot org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

--- Comment #3 from Arnd Bergmann  ---
(In reply to Jakub Jelinek from comment #2)
> Untested fix.

This appears to address all instances of the problem for me, thanks!

[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

2017-10-05 Thread jakub at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

--- Comment #2 from Jakub Jelinek  ---
Created attachment 42309
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42309=edit
gcc8-pr82437.patch

Untested fix.

[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

2017-10-05 Thread jakub at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

Jakub Jelinek  changed:

   What|Removed |Added

 Status|UNCONFIRMED |ASSIGNED
   Last reconfirmed||2017-10-05
 CC||jakub at gcc dot gnu.org
   Assignee|unassigned at gcc dot gnu.org  |jakub at gcc dot gnu.org
   Target Milestone|--- |8.0
Summary|false-positive  |[8 Regression]
   |-Wtautological-compare  |false-positive
   |warning with -std=gnu89 |-Wtautological-compare
   ||warning with -std=gnu89
 Ever confirmed|0   |1

--- Comment #1 from Jakub Jelinek  ---
The problem is that warn_tautological_cmp is called on the original arguments,
not yet converted to the common type.  So one of them is negative, the other
positive.