On Wed, May 26, 2010 at 4:27 PM, roy rosen <roy.1ro...@gmail.com> wrote:
> Hi,
>
> I have tried vectorization and encountered a problem which I can see
> is common to some ports (I tried ia64 and bfin).
>
> For this function:
>
> #define ts unsigned short
> void f(ts* __restrict__ a, ts* __restrict__ b, ts* __restrict__ x)
> {
> int i;
> for (i=0;i<1024;i++)
> x[i] = a[i] + b[i];
> }
>
> the loop is vectorized.
> But if I define ts as follows: #define ts short
> then the loop is not vectorized. The message I get is:
>
> ./a.c:21: note: no optab.
> ./a.c:21: note: not vectorized: relevant stmt not supported: D.1279_12
> = (short unsigned int) D.1278_11;
>
> I have tried to look a bit in the vectorizer code and it seems that
> for this stmt I get to vectorizable_operation with code==NOP_EXPR
> which is not handled.
>
> Does anyone knows anything about this problem?
The addition is done in type int (according to promotion rules),
but we fold it to an unsigned short addition. You probably
lack a vector unsigned short -> vector short conversion
operation (which the middle-end should handle transparently).
Please file a bugreport.
Richard.
>
> Thanks, Roy.
>
