This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: loop hoisting fails


On 10/02/11 17:59, Richard Henderson wrote:

If constants are never valid as the source of a store,

They are but it really depends to which registers they are going to. If the destination belongs to a certain class it is ok, for all the others it is not. It is tricky even to define costs when you are given:


rtx_costs of (const_int 0), outer_code SET.

This might be very, very cheap or very, very expensive for certain classes of registers.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]