[patch, tree-ssa] PR54295 Incorrect value extension in widening multiply-accumulate

[Richard Earnshaw]

On 17/08/12 15:22, Andrew Stubbs wrote:
> On 17/08/12 15:04, Richard Earnshaw wrote:
>> The fix is to make is_widening_mult_p note that it has been called with
>> a WIDEN_MULT_EXPR and rather than decompose the operands again, to
>> simply extract the existing operands, which have already been formulated
>> correctly for a widening multiply operation.
> 
> As long as the existing test cases work, I think the only problem with 
> this idea is if some architecture has a wider range of widening 
> multiply-and-accumulate than it does plain widening multiply.

But surely in that case step1 wouldn't have applied and we'd then be
looking at a MULT_EXPR not a WIDEN_MULT_EXPR.

R.