[PATCH] Fix PR82488 - signed integer overflow in expr.c

[Jeff Law]

On 11/26/2017 02:12 AM, Markus Trippelsdorf wrote:
> bootstrap-ubsan shows:
>  gcc/expr.c:4103:17: runtime error: signed integer overflow: 0 - -9223372036854775808 cannot be represented in type 'long int'
> 
> Fix by handling the saw_unknown case earlier.
> 
> bootstrap-ubsan on X86_64 and ppc64le. Tested on ppc64le.
> 
> OK for trunk?
> 
> 	PR rtl-optimization/82488
> 	* expr.c (fixup_args_size_notes): Avoid signed integer overflow.
OK.
jeff