------- Comment #8 from vda dot linux at googlemail dot com 2008-08-04 11:28
-------
Created an attachment (id=16010)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16010&action=view)
Example program which is compiled differently with this patch.
The difference is here:
movl (%edx), %eax #,
call bb_simple_perror_msg #
.L40:
- orl $1, 12(%esp) #, errs
+ movl $1, 12(%esp) #, errs
.L19:
addl $4, 24(%esp) #, argv.78
movl 24(%esp), %eax # argv.78,
With improved VRP on (a | b), gcc now can deduce that in this program, errs |=
1 is always equivalent to errs = 1.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28632
