Problem while writing Machine-description.

[Peter Kuschnerus]

Hi,

> 
> Try zero_extend or sign_extend patterns that also allow memory operands.
> 

I assumed already that this RTL-template is not ok.

My Problem is only with registers.
For all instructions that write a result into a register
smaller than the width of the register,
there are two variants of that instruction.
One that does zero-extend and one that does sign-extend
to the full width of the register.
I must choose one of it.

The question is then, how to decide which one is right.
The prefered is the same signedness as the type is.
I expected to get this information by using
SUBREG_PROMOTED_UNSIGNED_P in the output template.

May be that this information is not avalable there.
Or I did it wrong.


Regards
Peter Kuschnerus