Help with constraint for single register0

[Ulrich Weigand]

Robert Baruch wrote:

>The problem is that gcc is generating register moves that don't go
>through the W register, such as:

Reload assumes it can generate all register-to-register moves.  If this
assumption is incorrect, you need to employ the 'secondary reload'
mechanism.  In your case, you'll need to define the SECONDARY_INPUT_RELOAD
and SECONDARY_OUTPUT_RELOAD macros, and specify there that moves of
anything but the W register into (or out of) any other register requires
an intermediate register of class W_REG (i.e. the W register).

Reload will then generate appropriate intermediate moves.


Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

--
  Dr. Ulrich Weigand
  Linux for S/390 Design & Development
  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
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