On Wed, Sep 4, 2024 at 8:32 PM Jeff Law <j...@ventanamicro.com> wrote: > On 9/2/24 2:01 PM, Raphael Moreira Zinsly wrote: > ... > > + bool bit31 = (hival & 0x80000000) != 0; > > + int trailing_shift = ctz_hwi (loval) - ctz_hwi (hival); > > + int leading_shift = clz_hwi (loval) - clz_hwi (hival); > > + int shiftval = 0; > > + > > + /* Adjust the shift into the high half accordingly. */ > > + if ((trailing_shift > 0 && hival == (loval >> trailing_shift)) > > + || (trailing_shift < 0 && hival == (loval << trailing_shift))) > > + shiftval = 32 - trailing_shift; > > + else if ((leading_shift < 0 && hival == (loval >> leading_shift)) > > + || (leading_shift > 0 && hival == (loval << leading_shift))) > Don't these trigger undefined behavior when tailing_shift or > leading_shift is < 0? We shouldn't ever generate negative shift counts.
The value of trailing/leading_shift is added to 32, we will never have negative shift counts. -- Raphael Moreira Zinsly
