Re: Pb with clearing const_tiny_rtx in clear_const_double_mem

[Olivier Hainque <hainque at act-europe dot fr>]

Thanks for the prompt reply :)

Richard Henderson writes:
 > On Fri, Aug 24, 2001 at 03:53:03PM +0200, Olivier Hainque wrote:
 > >        float f1 = 1.0;
 > > 
 > >        void bar (void)
 > > 	 {
 > > 	 }
 > > 
 > >        float f2 = 1.0;
 > 
 > Ug.
 
 Indeed :/

 > > I'm unclear as to what the initial problem was.
 > 
 > The nested function wouldn't use the canonical values, which means all of
 > the checks for CONST0_RTX etc fail, which causes instructions to not match
 > in the alpha backend, as well as lots o missed optimizations.
 
 Humm, I actually discovered that part of the code while investigating the
 externally visible infinite loop in the first place, so I don't quite
 understand everything here. I'll study more to fill the blanks.

 > One way to solve this problem is to swap out these tiny_rtx's in the nested
 > context so that they are not shared, but we still match CONST0_RTX.  Care
 > should be taken so that the original functions are restored by the time we
 > get to integrate.c.
 
 I think I see, modulo the before mentioned blanks.
 
 > A larger issue is that it is damned stupid to not share constants between
 > functions on machines that just dump constants in .rodata and don't have
 > in-function constant pools. 

 :) 

 > That's a somewhat large cleanup though.

 OK.

 Thanks for the hints,

 Kind Regards,

 Olivier