[Bug c/63843] New: wrong code generation at -O1 and higher

[Bug c/63843] New: wrong code generation at -O1 and higher

[mednafen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63843

            Bug ID: 63843
           Summary: wrong code generation at -O1 and higher
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mednafen at gmail dot com

Created attachment 33955
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33955&action=edit
Testcase, good output is 8181.

trunk revision 217451
gcc (GCC) 5.0.0 20141112 (experimental)
Linux x86_64

$ ~mednafen/gcc-dev/bin/gcc -O0 -o tc tc.c
$ ./tc
8181

$ ~mednafen/gcc-dev/bin/gcc -O1 -o tc tc.c
$ ./tc 
ff81

$ ~mednafen/gcc-dev/bin/gcc -O1 -fno-tree-copyrename -o tc tc.c
$ ./tc 
8181

[Bug tree-optimization/63843] [5 Regression] wrong code generation at -O1 and higher

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63843

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |x86_64-*-*
           Priority|P3                          |P1

[Bug rtl-optimization/63843] [5 Regression] wrong code generation at -O1 and higher

[Alex.Velenko at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63843

Alex Velenko <Alex.Velenko at arm dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Alex.Velenko at arm dot com

--- Comment #3 from Alex Velenko <Alex.Velenko at arm dot com> ---
Hi,
Didn't have a gcc.gnu.org account yet, couldn't assign the ticket to myself.
Came to the same conclusion. Also testing.
Kind regards,
Alex

[Bug rtl-optimization/63843] [5 Regression] wrong code generation at -O1 and higher

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63843

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Nov 19 08:18:53 2014
New Revision: 217753

URL: https://gcc.gnu.org/viewcvs?rev=217753&root=gcc&view=rev
Log:
    PR rtl-optimization/63843
    * simplify-rtx.c (simplify_binary_operation_1) <case ASHIFTRT>: For
    optimization of ashiftrt of subreg of lshiftrt, check that code
    is ASHIFTRT.

    * gcc.c-torture/execute/pr63843.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr63843.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c
    trunk/gcc/testsuite/ChangeLog