> On October 14, 2015 6:27:02 PM GMT+02:00, Jan Hubicka <hubi...@ucw.cz> wrote: > >Hi, > >this patch adds the CONSTRUCTOR case discussed while back. Only empty > >constructors are matched, as those are only appearing in gimple > >operand. > >I tested that during bootstrap about 7500 matches are for empty ctors. > >There are couple hundred for non-empty probably used on generic. > > > >Bootstrapped/regtested x86_64-linux, OK? > > > >Honza > > > > * fold-const.c (operand_equal_p): Match empty constructors. > >Index: fold-const.c > >=================================================================== > >--- fold-const.c (revision 228735) > >+++ fold-const.c (working copy) > >@@ -2890,6 +2891,11 @@ operand_equal_p (const_tree arg0, const_ > > return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, > >0), > > flags | OEP_ADDRESS_OF > > | OEP_CONSTANT_ADDRESS_OF); > >+ case CONSTRUCTOR: > >+ /* In GIMPLE empty constructors are allowed in initializers of > >+ vector types. */ > > The comment is wrong (or at least odd), > On gimple an empty vector constructor should be folded to a VECTOR_CST.
Hmm, I tought we have a={} i.e. for clearing whole structure. If we never have constructors appearing as gimple operands, I guess we don't really need the code at gimple level (because at least so far ipa-icf has separate path to compare constructors). Honza > > >+ return (!vec_safe_length (CONSTRUCTOR_ELTS (arg0)) > >+ && !vec_safe_length (CONSTRUCTOR_ELTS (arg1))); > > default: > > break; > > } >