On Wed, May 20, 2015 at 11:38:44PM -0600, Jeff Law wrote: > I've also verified this is one of the changes ultimately necessary to > resolve the code generation regressions caused by Venkat's combine.c > change on the PA across my 300+ testfiles for a PA cross compiler.
How much does it help, do you know? > OK for the trunk? Yes, please commit. Thanks. (One tiny comment below). Segher > diff --git a/gcc/ChangeLog b/gcc/ChangeLog > index 490386e..250fa0a 100644 > --- a/gcc/ChangeLog > +++ b/gcc/ChangeLog > @@ -1,5 +1,8 @@ > 2015-05-20 Jeff Law <l...@redhat.com> > > + * combine.c (find_split_point): Handle ASHIFT like MULT to encourage > + multiply-accumulate/shift-add insn generation. > + > * config/pa/pa.c (pa_print_operand): New 'o' output modifier. > (pa_mem_shadd_constant_p): Renamed from pa_shadd_constant_p. > (pa_shadd_constant_p): Allow constants for shadd insns rather > diff --git a/gcc/combine.c b/gcc/combine.c > index a90849e..ab6de3a 100644 > --- a/gcc/combine.c > +++ b/gcc/combine.c > @@ -5145,7 +5163,9 @@ find_split_point (rtx *loc, rtx_insn *insn, bool > set_src) > /* Split at a multiply-accumulate instruction. However if this is > the SET_SRC, we likely do not have such an instruction and it's > worthless to try this split. */ > - if (!set_src && GET_CODE (XEXP (x, 0)) == MULT) > + if (!set_src > + && (GET_CODE (XEXP (x, 0)) == MULT > + || GET_CODE (XEXP (x, 0)) == ASHIFT)) > return loc; It might be better to also check if it is shifting by a CONST_INT. I doubt it matters much, but it is closer to the original. Segher
