As a general ROT I always use explicit casts. On 21/07/2013, at 4:24 AM, Charles Mills <charl...@mcn.org> wrote:
> Cross-posted to IBM-MAIN and MVS-OE. > > I have the following code fragment in an inline function, compiled by the > IBM XLC compiler as C++: > > unsigned long long valueToTest; > unsigned int testWord; > testWord = valueToTest >> 32; > > It *appears* to me (from somewhat circumstantial evidence in a much more > complex big picture) when valueToTest has a value of 0x0034000000000000 then > > - If I compile Opt(0),NoInline then testWord gets the value I expect, > 0x00340000; but > - If I compile Opt(2),Inline then testWord gets a value of 0. > > Questions: > > 1. Does that seem plausible? That the code would work as intended > Opt(0),NoInline but that with Opt(2),Inline the compiler would (I am > guessing here) first cast valueToTest to an int of 0, then shift it right > 32, and then assign it to testWord? > > 2. What should I code to avoid that? I guess I could shift valueToTest first > (I don't need it again) and then in a separate statement assign it to > testWord. Is that the "proper" coding technique? > > It's fairly involved to test the whole thing so I took the liberty of > imposing on you folks rather than just trying stuff. Thanks much. > > Charles > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
