Subject: Re: I want to rid ugly float load/stores used only for data
To: David Edelsohn <>
From: Richard Earnshaw <>
List: tech-toolchain
Date: 02/24/2003 11:24:30
> MLR> What I want to do is modify gcc to stop generating code like that, but
> MLR> not shut down generating float instructions entirely, as in
> MLR> "soft_float".  

> 	Your intent cannot be implemented safely in GCC.  If GCC knows it
> has FPRs and FPRs hold 64-bit values (which they must), it will use them
> for 64-bit moves.  Cannot be avoided safely.

It ought to be possible to severely discourage use of fp registers for non 
fp objects by arranging for MEMORY_MOVE_COST to return a large value when 
given an FP register class and a non-FP mode.

This won't eliminate the use of such registers but it should cut it down 
significantly if the compiler respects this correctly.