[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