Re: mspgcc "undefines" too-many-bits shifts in weird way
Grant Edwards <[email protected]>
| Newsgroups | gmane.comp.hardware.texas-instruments.msp430.gcc.user |
|---|---|
| Message-ID | <[email protected]> |
On 2013-04-21, Paul Sokolovsky <[email protected]> wrote: > On Sun, 21 Apr 2013 17:06:51 -0500 Peter Bigot <[email protected]> wrote: > >> This decision was intentional, as documented in >> https://sourceforge.net/p/mspgcc/bugs/118/. My recollection is that >> the choice of how to make things consistent was informed by similar >> behavior in the contemporaneous gcc for x86 or at least one other >> target architecture. > > Thanks for the reference. So, I tested it with x86 gcc 4.4, 4.5, 4.6, > 4.7 (packages as shipped by Ubuntu), all of them produce > mathematically expected result. That's irrelevent. > msp430-gcc 4.5.3, 4.7.0 both produce unexpected result. That's per the standard. If you write code that depends on some particular behavior for somethign that's "undefined", then that code is wrong. -- Grant Edwards grant.b.edwards Yow! I'm wearing PAMPERS!! at gmail.com ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter