operator new[] overflow (PR 19351)

[Joseph S. Myers]

On Sun, 5 Dec 2010, Richard Guenther wrote:

> Ah, you're using intrinsics.  I thought of re-using the saturating arithmetic
> and types we have, thus basically do
> 
>   size = (unsigned sat int) count * 4;
> 
> and defer optimal expansion to an optab.  It of course requires saturating
> arithmetic emulation for targets that don't provide an expander but would
> allow optimal expansion at least.
> 
> And it'll unleash all the latent bugs we have with saturating types ...

And I thought that defining saturated operations for normal integer types 
would be better than trying to use fixed-point types on targets that don't 
have an ABI for them or where they may not match the types on which you 
want saturated operations.  That is, I think saturated operations would be 
a better internal representation at the GIMPLE level than saturated types 
(this may also apply to lowering existing fixed-point saturated type 
support) and then they could be expanded to various forms of RTL including 
direct saturated instructions, comparisons or overflow flags checks.

-- 
Joseph S. Myers
joseph@codesourcery.com