Re: Feature request: ability to describe x86 register halves as contraints.

[Jeffrey A Law <law@cygnus.com>]

  In message < 19980630004629.A20825@dot.cygnus.com >you write:
  > 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.> 
And does the compiler just assume that the whole register is trashed
since it doesn't ever look at the asm strings?

Maybe we're talking about two different issues.

jeff