https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78568
Bug ID: 78568
Summary: Wtype-limits warning regression
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: sirl at gcc dot gnu.org
Target Milestone: ---
Created attachment 40179
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40179&action=edit
testcase
The attached testcase produces warnings with gcc-4.4.7 on RHEL6, but somewhere
along the way it regressed. I've tested 4.6, 4.8, 4.9, 5, 6 and trunk, none of
them warns anymore, but they all still happily optimize the comparisons away.
gcc-4.4.7 produced:
$ gcc -O2 -Wtype-limits -c Wtype-limits.c
Wtype-limits.c: In function 'testa':
Wtype-limits.c:4: warning: comparison is always true due to limited range of
data type
Wtype-limits.c: In function 'testb':
Wtype-limits.c:12: warning: comparison is always true due to limited range of
data type
Wtype-limits.c: In function 'testc':
Wtype-limits.c:20: warning: comparison is always true due to limited range of
data type
