------- Comment #27 from baldrick at free dot fr 2007-03-08 16:06 ------- Subject: Re: [4.3 regression] ACATS cxh1001 fails
> > y = __builtin_nop(x); valid = (y>=lower_bound && y <=upper_bound); > > The point is that the intrinsic would be opaque to the optimizers, > > and would only be lowered to the identity function *after* the tree > > optimizers have run. One annoyance is that presumably intrinsics > > would be needed for all integer and float precisions, eg > > __builtin_nop8, __builtin_nop16, etc. > > More than each precision. The VIEW_CONVERT_EXPR is to the base type > and there can be an unlimited number of them for each precision. I don't see what the problem is - you don't have to convert to the base type, you can always convert to some standard type of that precision, eg int32, before calling the builtin. > Because it has to work with arbitrary types, a builtin won't do it. See above. > We could certainly add a new tree expression that says "don't look through > this for VRP purposes", but we already have V_C_E. Sure, it's just that overloading V_C_E like this feels somehow wrong to me. However I haven't been able to put my finger on any technical obstacle to this use of V_C_E. Ciao, D. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26797