Using shifts by 1 on K6,K7 and i386

[Martin Erhardsen]

Why doesn't gcc use logical shifts, arithmetric shifts and rotates by 1 
instead of immediate operands on the K6,K7 and i386.
It saves a byte and has the same latency (except on i486, 
where it uses an extra cycle). I have measured this on 
my K6-2 and looked it up for K7 and i386
I propose that the current predicate for using shifts 
and rotates by 1

(TARGET_PENTIUM || TARGET_PENTIUMPRO)

be replaced by this

(!TARGET_I486 || optimize_size)