On Wed, Jan 23, 2019 at 4:16 PM Warren D Smith <warren....@gmail.com> wrote: > > x = x^x; > > The purpose of the above is to load "x" with zero. > For very wide types, say 256 bits wide, explicitly loading 0 > is deprecated by Intel since taking too much memory. > XORing x with itself always yields 0 and is allegedly > a better thing to do. > > But the problem is, gcc complains: > variable 'x' is uninitialized when used here [-Wuninitialized] > note: initialize the variable 'x' to silence this warning > > Well, the thing is, it DOES NOT MATTER that x is not initialized, > or initialized with wrong data. No matter what was in x, it becomes 0. > > So, how to get Gcc to shut up and quit whining about this? > I do not want to actually load 0.
I don't see why you think the compiler will not do the right thing and do the xor trick when there is a zero in the code. Thanks, Andrew Pinski > > -- > Warren D. Smith > http://RangeVoting.org <-- add your endorsement (by clicking > "endorse" as 1st step)
