On Sun, 29 May 2016, Marc Glisse wrote: > On Sat, 28 May 2016, Alexander Monakov wrote: > > For unsigned A, B, 'A > -1 / B' is a nice predicate for checking whether > > 'A*B' > > overflows (or 'B && A > -1 / B' if B may be zero). Let's optimize it to an > > invocation of __builtin_mul_overflow to avoid the divide operation. > [snip] > Any plan on optimizing the 'B && ovf' form?
Not in the immediate future; I don't have a good approach in mind to do that. (if I get back to this topic I'd try to CSE the product with the IFN result) Thanks for the discussion and help -- I've applied the patch. Alexander
