[Bug tree-optimization/60712] New: "restrict" qualifier ignored on local variable or after inlining

[Bug tree-optimization/60712] New: "restrict" qualifier ignored on local variable or after inlining

[gbugcc at binkmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60712

            Bug ID: 60712
           Summary: "restrict" qualifier ignored on local variable or
                    after inlining
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gbugcc at binkmail dot com

Created attachment 32490
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32490&action=edit
Test case

Version: x86_64-w64-mingw32-gcc 4.8.2 (standard Cygwin binaries)
Flags: gcc -std=c99 -O3

sum()'s loop is optimized into a single multiply, as it should.

But when inlined automatically by the compiler or "manually" by applying
restrict qualifiers to local variables, the optimization fails.

This is might be the same as bug 58526. However, -fdump-tree-alias shows that
inlining removed all restrict qualifiers, whereas they are still present in the
type information of bug_when_local_variable(), so perhaps there are two
distinct bugs here.

[Bug tree-optimization/60712] "restrict" qualifier ignored on local variable or after inlining

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60712

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The inline issue is recorded as 58526.

[Bug tree-optimization/60712] "restrict" qualifier ignored on local variable or after inlining

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60712

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-03-31
             Blocks|                            |49774
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Only restrict on parameters is implemented.

[Bug tree-optimization/60712] "restrict" qualifier ignored on local variable

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60712

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|"restrict" qualifier        |"restrict" qualifier
                   |ignored on local variable   |ignored on local variable
                   |or after inlining           |
             Blocks|104466                      |

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
After inlining works as expected now (see comment#4 which shows this).  We do
not honor __restrict on local variables because we cannot adhere to the
language constraints within our implementation framework.  We only can do that
for function parameters.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104466
[Bug 104466] Inlining functions with restrict parameters can inhibit lim (e.g.
in 554.roms_r)