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Re: s390: SImode pointers vs LR


On 06/02/2015 07:13 PM, Jeff Law wrote:
> But isn't that 3 registers used in the address computation if the 
> (const_int 1) gets reloaded?  one of the value shifted, two for the 
> shift count?  I'm not familiar with the s390, so if you can handle that 
> kind of insn, then, umm, cool.
The address style operand is only the shift count. Our instructions support base + displacement
here. E.g. sll     %r2,%r3(3)    is r2 << (r3 + 3)

> The only other thing that comes immediately to mind would be secondary 
> reloads.  But I always hate suggesting them.
I don't see how this would help here. It is not really that reload needs help moving something
to/from a register. In fact the INSN is good as is and we are trying to prevent reload from doing
anything.

Bye,

-Andreas-


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