From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard Henderson <rth@cygnus.com>
To: ak@muc.de, egcs@cygnus.com
Subject: Re: Feature request: ability to describe x86 register halves as contraints.
Date: Tue, 30 Jun 1998 00:42:00 -0000
Message-id: <19980630004629.A20825@dot.cygnus.com>
References: <19980629184404.62482@kali.lrz-muenchen.de>
X-SW-Source: 1998-06/msg01101.html

On Mon, Jun 29, 1998 at 06:44:04PM +0200, ak@muc.de wrote:
> The only way to do this is to use fixed input registers and hardcode the 
> register halves. Unfortunately this adds some compiler version dependencies
> to my code, and also limits the possibilities of the compiler to do other
> optimizations. 

Incorrect:

   b -- print the QImode name of the register for the indicated operand.
        %b0 would print %al if operands[0] is reg 0.
   w --  likewise, print the HImode name of the register.
   k --  likewise, print the SImode name of the register.
   h --  print the QImode name for a "high" register, either ah, bh, ch or dh.

So:

	asm ("# %0 %b0 %h0 %w0 %k0" : : "q"(x));

yields

	# %eax %al %ah %ax %eax


r~