[Bug c/52691] New: va_start to builtin_next_arg optimization lost

[Bug c/52691] New: va_start to builtin_next_arg optimization lost

[bigotp at acm dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52691

             Bug #: 52691
           Summary: va_start to builtin_next_arg optimization lost
    Classification: Unclassified
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: bigotp@acm.org


In the commit below, the following edit was made which inverted the sense of
the test, preventing the optimization from applying when it should.  A ! must
be inserted before builtin_decl_explicit_p.

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index e207e23..31c31c1 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -2175,7 +2175,7 @@ optimize_stdarg_builtin (gimple call)
     case BUILT_IN_VA_START:
       if (!va_list_simple_ptr
          || targetm.expand_builtin_va_start != NULL
-          || built_in_decls[BUILT_IN_NEXT_ARG] == NULL)
+          || builtin_decl_explicit_p (BUILT_IN_NEXT_ARG))
        return NULL_TREE;

       if (gimple_call_num_args (call) != 2)


commit b9a1687032fc1afb5f4e9d8dfa775a134abe21ba
Author: meissner <meissner@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Tue Oct 11 19:55:09 2011 +0000

    Convert standard builtin functions from being arrays to using a functional
interface

    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@179820
138bc75d-0d04-0410-961f-82ee72b054a4

[Bug middle-end/52691] [4.7/4.8 Regression] va_start to builtin_next_arg optimization lost

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52691

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
            Version|tree-ssa                    |4.7.0
   Last reconfirmed|                            |2012-03-26
          Component|c                           |middle-end
                 CC|                            |meissner at gcc dot gnu.org
     Ever Confirmed|0                           |1
            Summary|va_start to                 |[4.7/4.8 Regression]
                   |builtin_next_arg            |va_start to
                   |optimization lost           |builtin_next_arg
                   |                            |optimization lost
   Target Milestone|---                         |4.7.1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-26 08:23:05 UTC ---
Confirmed.  Michael, can you please fix trunk and the 4.7 branch?  Thx.

[Bug middle-end/52691] [4.7/4.8 Regression] va_start to builtin_next_arg optimization lost

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52691

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-28 14:47:59 UTC ---
Author: jakub
Date: Wed Mar 28 14:47:45 2012
New Revision: 185917

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185917
Log:
    PR middle-end/52691
    * tree-ssa-ccp.c (optimize_stdarg_builtin): Optimize
    __builtin_va_start to __builtin_next_arg if the latter is
    builtin_decl_explicit_p rather than when it is not.

    * gcc.dg/pr52691.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr52691.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-ccp.c

[Bug middle-end/52691] [4.7/4.8 Regression] va_start to builtin_next_arg optimization lost

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52691

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-28 14:49:40 UTC ---
Author: jakub
Date: Wed Mar 28 14:49:26 2012
New Revision: 185918

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185918
Log:
    PR middle-end/52691
    * tree-ssa-ccp.c (optimize_stdarg_builtin): Optimize
    __builtin_va_start to __builtin_next_arg if the latter is
    builtin_decl_explicit_p rather than when it is not.

    * gcc.dg/pr52691.c: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/pr52691.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_7-branch/gcc/tree-ssa-ccp.c

[Bug middle-end/52691] [4.7/4.8 Regression] va_start to builtin_next_arg optimization lost

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52691

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |jakub at gcc dot gnu.org
         Resolution|                            |FIXED

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-28 14:58:12 UTC ---
Fixed.