r255059 - in /trunk/gcc: ChangeLog wide-int.cc

[rsandifo@gcc.gnu.org]

Author: rsandifo
Date: Wed Nov 22 13:58:57 2017
New Revision: 255059

URL: https://gcc.gnu.org/viewcvs?rev=255059&root=gcc&view=rev
Log:
PR82547: Undetected overflow for UNSIGNED wide_ints

wi::add_large and wi::sub_large weren't setting the overflow bit
correctly for unsigned operations if the result needed fewer HWIs
than the precision.

2017-11-22  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	PR middle-end/82547
	* wide-int.cc (wi::add_large, wi::sub_large): Fix overflow detection
	for unsigned values with fewer HWIs than the precision.
	(test_overflow): New function.
	(wide_int_cc_tests): Call it.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/wide-int.cc