[Bug middle-end/85164] poly-int.h:845:5: runtime error: signed integer overflow

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85164

--- Comment #10 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 
---
Author: rsandifo
Date: Thu Apr 18 12:30:36 2019
New Revision: 270443

URL: https://gcc.gnu.org/viewcvs?rev=270443&root=gcc&view=rev
Log:
Fix UB in int_const_binop

When testing PR 85164, the baseline bootstrap-ubsan results had
a lot of failures from int_const_binop.  This is because with the
new overflow handling we can sometimes do:

      poly_res = res;

on an uninitialised res.

2019-04-18  Richard Sandiford  <richard.sandif...@arm.com>

gcc/
        * fold-const.c (int_const_binop): Return early on failure.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c