On 12/01/2015 09:07 AM, Andrew Haley wrote:
Do we support left shift of a negative value? Technically it's undefined and ubsan warns about it. However, a ton of software would surely break if we didn't do the obvious right thing. I can't find anything in the GCC manual.
I believe gcc does the expected thing but see bug 65179: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=65179 There have been discussions on gcc-patches about some of the issues the warning has exposed (real or otherwise), for example: https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00696.html Martin
