On Wed, 26 Nov 2014, Jakub Jelinek wrote:
> On Tue, Nov 25, 2014 at 09:20:13AM +0100, Jakub Jelinek wrote:
> > Actually, thinking about it more, at least according to
> > commutative_operand_precedence the canonical order is
> > what we used to return (i.e. (something - _G_O_T_) + (symbol_ref)
> > or
> > (something - _G_O_T_) + (const (symbol_ref +- const))
> > So perhaps better fix is to follow find_base_value, which does something
> > like:
> > /* Guess which operand is the base address:
> > If either operand is a symbol, then it is the base. If
> > either operand is a CONST_INT, then the other is the base. */
> > if (CONST_INT_P (src_1) || CONSTANT_P (src_0))
> > return find_base_value (src_0);
> > else if (CONST_INT_P (src_0) || CONSTANT_P (src_1))
> > return find_base_value (src_1);
> > and do something similar in find_base_term too. I.e. perhaps even with
> > higher precedence over REG_P with REG_POINTER (or lower, in these cases
> > it doesn't really matter, neither argument is REG_P), choose first
> > operand that is CONSTANT_P and not CONST_INT_P.
Yeah, that makes sense.
> Here it is. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
Ok.
Thanks,
Richard.
> 2014-11-26 Jakub Jelinek <ja...@redhat.com>
>
> PR lto/64025
> * alias.c (find_base_term): Use std::swap. Prefer tmp2
> if it is CONSTANT_P other than CONST_INT.
>
> --- gcc/alias.c.jj 2014-11-21 10:17:17.000000000 +0100
> +++ gcc/alias.c 2014-11-26 12:31:24.719485590 +0100
> @@ -1756,11 +1756,11 @@ find_base_term (rtx x)
> if (REG_P (tmp1) && REG_POINTER (tmp1))
> ;
> else if (REG_P (tmp2) && REG_POINTER (tmp2))
> - {
> - rtx tem = tmp1;
> - tmp1 = tmp2;
> - tmp2 = tem;
> - }
> + std::swap (tmp1, tmp2);
> + /* If second argument is constant which has base term, prefer it
> + over variable tmp1. See PR64025. */
> + else if (CONSTANT_P (tmp2) && !CONST_INT_P (tmp2))
> + std::swap (tmp1, tmp2);
>
> /* Go ahead and find the base term for both operands. If either base
> term is from a pointer or is a named object or a special address
>
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendoerffer, HRB 21284
(AG Nuernberg)
Maxfeldstrasse 5, 90409 Nuernberg, Germany
