On 09 April 2007 22:12, Richard Henderson wrote:
> On Mon, Apr 09, 2007 at 07:37:31PM +0100, Dave Korn wrote:
>> Should promotion of function arguments be explicitly represented in
>> GIMPLE, or should it be performed when generating the corresponding RTL?
>
> There are two things here:
>
> (1) Promotion of arguments to their devlared types, should
> be at the tree level.
>
> (2) Promotion of arguments to wider types, as specified by
> the abi, should be done when generating rtl.
>
> The problem you're tracking is in (1).
>
>
> r~
Thanks, I think you're right on there. The comments on PR31136 make it
fairly clear what's wrong; perhaps the best solution might be for
STRIP_SIGN_NOPS to mask out the high bits when it's discarding a size-reducing
NOP_EXPR? Or perhaps fold_unary should simplify it before passing to
STRIP_SIGN_NOPS for minimal peturbation?
cheers,
DaveK
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