[Bug tree-optimization/56354] New: [4.8 Regression] -O2 creates incorrect for loop code

[orion at cora dot nwra.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56354



             Bug #: 56354

           Summary: [4.8 Regression] -O2 creates incorrect for loop code

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: major

          Priority: P3

         Component: tree-optimization

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: or...@cora.nwra.com





Created attachment 29479

  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29479

loop.c test case



With the attached program compiled with:



gcc  -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector

--param=ssp-buffer-size=4  -m64 -mtune=generic -fPIC -O1 loop.c



I get the correct output:



Creating arrays...

i=0

i=1

i=2

i=3

i=4

i=5

i=6

i=7

i=8

i=9



But with -O2:



gcc  -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector

--param=ssp-buffer-size=4  -m64 -mtune=generic -fPIC -O2 loop.c



Creating arrays...

i=0

i=1

i=2

i=3

i=4

i=5

i=6

i=7

i=8

i=9

i=10

....

i=55

Segmentation fault



Version-Release number of selected component (if applicable):

gcc-4.8.0-0.12.fc19.x86_64