On Fri, Jul 8, 2011 at 2:44 PM, Andrew Stubbs <a...@codesourcery.com> wrote:
> On 07/07/11 13:37, Richard Guenther wrote:
>>>
>>> I'll cook up a quick patch for VRP.
>>
>> Like the attached. I'll finish and properly test it.
>
> Your patch appears to do the wrong thing for this test case:
>
> int
> foo (int a, short b, short c)
> {
> int bc = b * c;
> return a + (short)bc;
> }
>
> With your patch, the input to the widening-mult pass now looks like this:
>
> foo (int a, short int b, short int c)
> {
> int bc;
> int D.2016;
> int D.2015;
> int D.2014;
>
> <bb 2>:
> D.2014_2 = (int) b_1(D);
> D.2015_4 = (int) c_3(D);
> bc_5 = D.2014_2 * D.2015_4;
> D.2016_9 = bc_5 + a_8(D);
> return D.2016_9;
>
> }
>
> It looks like when the user tries to deliberately break the maths your patch
> seems to unbreak it.
Yeah, I fixed that in the checked in version.
Richard.
> Andrew
>
