Ian Lance Taylor writes: > Gabriel Dos Reis <[EMAIL PROTECTED]> writes: > > > Ian, do you believe something along the line of > > > > # > I mean, could not we generate the following for "%": > > # > > > # > rem a b := > > # > if abs(b) == 1 > > # > return 0 > > # > return <machine-instruction> a b > > # > > # On x86 processors that have conditional moves, why not do the equivalent > > # of > > # > > # neg_b = -b; > > # cmov(last result is negative,neg_b,b) > > # __machine_rem(a,b) > > # > > # Then there's no disruption of the pipeline. > > > > is workable for the affected targets? > > Sure, I think the only real issue is where the code should be > inserted.
>From a performance/convenience angle, the best place to handle this is either libc or the kernel. Either of these can quite easily fix up the operands when a trap happens, with zero performance degradation of existing code. I don't think there's any need for gcc to be altered to handle this. Andrew.
