On Fri, 19 May 2017, Joseph Myers wrote: > On Fri, 19 May 2017, Alexander Monakov wrote: > > (to be precise, if the multiplication is done in a signed type and the > > middle > > constant factor was a negated power of two, the sign change needs to remain: > > > > a * -4 * b * 2 > > > > needs to be transformed to > > > > a * -1 * b * 8 ) > > Shouldn't that only be the case if the middle constant was -1 and the > outer constant was 1? If a * -4 * b is INT_MIN, a * b won't overflow and > so a * b * -8 should be a safe transformation.
Indeed, I should have considered the situation more carefully. Thank you for the correction. Alexander
