----Original Message---- >From: Richard Earnshaw >Sent: 15 April 2005 18:08
>> In any case, the ARM or Alpha isn't prevented from working in such a >> fashion just because the rounding mode is encoded in the instruction; it >> just means that fp primitives have to be compiled as intrinsics that test >> whatever flag controls the rounding mode and then branch to an fp insn of >> the appropriate form. > Code that changes the rounding has to be wrapped with certain pragmas to > inform the compiler that this might happen: on something like ARM+FPA > that might permit dynamic code switching, but I doubt anyone would > really want to pay that price. It's a very arch-dependent price, though. On an arch where you have conditional execution per-instruction, it could be a very low overhead indeed. cheers, DaveK -- Can't think of a witty .sigline today....