[PATCH 08/08] PR/64003 workaround (uninit memory in i386.md)

[Jeff Law]

On 11/25/14 18:39, David Malcolm wrote:
> I suspect this is papering over a real problem, but I've been
> applying this workaround locally to keep my valgrind output clean.
>
> gcc/ChangeLog:
> 	PR/64003
> 	* final.c (shorten_branches): Allocate insn_lengths with
> 	XCNEWVEC rather than XNEWVEC; remove subsequent per-element
> 	initialization.
I'd like more information on this one.

My first thought is that something must be creating a new insn after 
shorten_branches is complete or an existing insn that was not on the 
chain when we called shorten-branches, but got threaded onto the chain 
later.  Either would be considered bad in various ways, so we'd like to 
fix it.

Presumably you're not doing an out-of-range access into insn_lengths? 
Right?

Do you have a reasonable testcase for this?

jeff