extra instructions lost from -O0 to -O1

[Thomas A.M. Bernard]

Hi,

I inserted some extra instructions in the Alpha back-end (MD files). 
They are properly emitted when the flag -O0 is enabled. Since they have 
no side effects and no dependencies on other instructions, they are 
omitted when flag -O1 is engaged. Is there a way (I mean 
attribute/constraint in their MD patterns) to avoid that and keep the 
extra instructions in any case ?

Thanks,
Thomas