Different multiply operator for pointers and integers

[Laura Tosoratto <Laura dot Tosoratto at roma1 dot infn dot it>]

Hi,
we're porting GCC on a parallel architecture with a large register file 
and where pointers and integers have the same 64 bit format.
However the machine manages pointers arithmetics and integers 
arithmetics through two different multiply instructions.
In the same time, it needs all addresses to be hold in a specific part 
of register file (we defined a reg_class to represent this set of regs) .
We found two ways to implement these features:
-defining Pmode as different from other integer modes ( PSImode or 
similar), and so providing different sets of insn patterns for pointers 
and integers
or
-introducing the address multiply operator at the tree level.

Which choice do you think would be the most effective?



Thanks,
Laura