On 22/07/11 13:34, Bernd Schmidt wrote:
@@ -1242,7 +1242,8 @@ expand_binop_directly (enum machine_mode mode, optab
binoptab,
> rtx target, int unsignedp, enum optab_methods methods,
> rtx last)
> {
> - enum insn_code icode = optab_handler (binoptab, mode);
> + enum machine_mode from_mode = GET_MODE (op0);
> + enum insn_code icode = widening_optab_handler (binoptab, mode, from_mode);
Please add a new function along the lines of
enum machine_mode
widened_mode (enum machine_mode to_mode, rtx op0, rtx op1)
{
if (GET_MODE (op1) == VOIDmode)
return GET_MODE (op0);
gcc_assert (GET_MODE (op0) == GET_MODE (op1);
return GET_MODE (op0);
}
I'll want to extend this at some point to allow widening multiplies
where only one operand is widened (with a new set of optabs).
Sorry, I don't quite understand what you're getting at here?
expand_binop_directly is only ever used, I think, when the tree
optimizer has already identified what insn to use. Both before and after
my patch, the tree-cfg gimple verification requires that both op0 and
op1 are the same mode, and non-widening operation are always he same
mode, so I think my code is perfectly adequate. Is that not so?
If you want to add support for machine instructions that only widen one
input, then that's surely a separate problem? If the target mode is
smaller than the combined size of the inputs, then the changes to the
widening_mul pass would be non-trivial.
If the point is just to be absolutely certain that the inputs are valid
then I'm happy to add the function. BTW, did you mean the have the
unused parameter?
Andrew
