Paolo Bonzini <[EMAIL PROTECTED]> writes:
> Index: cse.c
> ===================================================================
> --- cse.c (revision 134435)
> +++ cse.c (working copy)
> @@ -3161,10 +3161,8 @@ fold_rtx (rtx x, rtx insn)
> FIXME: those ports should be fixed. */
> if (new != 0 && is_const
> && GET_CODE (new) == PLUS
> - && (GET_CODE (XEXP (new, 0)) == SYMBOL_REF
> - || GET_CODE (XEXP (new, 0)) == LABEL_REF)
> && GET_CODE (XEXP (new, 1)) == CONST_INT)
> - new = gen_rtx_CONST (mode, new);
> + new = plus_constant (XEXP (new, 0), XEXP (new, 1));
> + else
> + new = plus_constant (new, 0);
> }
> break;
I'm not sure about this bit.
First of all, isn't the whole of the original "if" statement
redundant these days? "new" is the result of simplify_unary_operation,
and I'd have expected that function to return:
(const (plus [symbol_ref|label_ref] (const_int X)))
rather than:
(plus [symbol_ref|label_ref] (const_int X))
I think the same true of the revised "if" statement too: if plus_constant
could add a CONST, simplify_unary_operation should already have done that.
(The "else" bit isn't safe against "new" being NULL, btw.)
Couldn't:
{
int is_const = 0;
/* We can't simplify extension ops unless we know the
original mode. */
if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
&& mode_arg0 == VOIDmode)
break;
/* If we had a CONST, strip it off and put it back later if we
fold. */
if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST)
is_const = 1, const_arg0 = XEXP (const_arg0, 0);
new = simplify_unary_operation (code, mode,
const_arg0 ? const_arg0 : folded_arg0,
mode_arg0);
/* NEG of PLUS could be converted into MINUS, but that causes
expressions of the form
(CONST (MINUS (CONST_INT) (SYMBOL_REF)))
which many ports mistakenly treat as LEGITIMATE_CONSTANT_P.
FIXME: those ports should be fixed. */
if (new != 0 && is_const
&& GET_CODE (new) == PLUS
&& (GET_CODE (XEXP (new, 0)) == SYMBOL_REF
|| GET_CODE (XEXP (new, 0)) == LABEL_REF)
&& GET_CODE (XEXP (new, 1)) == CONST_INT)
new = gen_rtx_CONST (mode, new);
}
simply be replaced by:
/* We can't simplify extension ops unless we know the
original mode. */
if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
&& mode_arg0 == VOIDmode)
break;
new = simplify_unary_operation (code, mode,
const_arg0 ? const_arg0 : folded_arg0,
mode_arg0);
?
(Sorry if I'm repeating earlier discussion here.)
Richard
