Ian Lance Taylor writes: > I'm not entirely sure, but I don't think Jim said the opposite. He said > that the way truncate works is machine dependent. I said that the > output of truncate is machine independent. Since truncate is only > defined for fixed-point modes, I think both statements are true.
OK but in that way every operation is machine dependent not just truncate. BTW, why is being fixed-point relevant here? >From that little excerpt I just gathered that maybe my misunderstanding of treating truncate as a blackbox was not completely without precedence. But anyway I think I understand now. JTBS, can you agree with other statement in my email?: > And IIUC this don't-care nature of the other bits that allows backends to > define the upper bits. For example to have sign-bit copies there in registers > to enforce the MIPS64 SI mode representation. And treating the don't care > bits outside SI mode in this way is true for any other SI-mode operations > performed on registers not just truncate, right? Hmm, nice. Thanks for all the explanations. Adam
