Hi Mike, Thanks for the feedback regarding the ABI. I have added Nick and DJ in the loop to see if they can review this patch posted last month, https://gcc.gnu.org/ml/gcc-patches/2015-12/msg00733.html
Best Regards, Kaushik On Wed, Dec 9, 2015 at 10:23 PM, Mike Stump <mikest...@comcast.net> wrote: > On Dec 9, 2015, at 1:53 AM, Kaushik M Phatak <kpha...@gmail.com> wrote: >> Thank you for your feedback on my patch. (27 August 2015) >> I have posted an updated patch for this issue, >> https://gcc.gnu.org/ml/gcc-patches/2015-12/msg00733.html >> >> To reply to your question, the RL78 ABI does not specify anything for the >> MDUC >> registers (Multiply/Divide). > > Three options then, either you're inventing the abi, then you decide and > document what you did, you ask someone else what the abi is, or you follow > the abi set by another compiler. You cannot escape the abi. As port > contributor, you get to pick and make the best choice you can. If you > cannot, then I will pick, the registers are always saved. Correspondingly, > they are free to code-gen to be used by the compiler and optimizer. If > that's the case, then there should be no flag. An os (aka target) that wants > a different choice will responsible for adding in the code that can do > something else. > > Let us know what your choice is. Maybe Nick knows of a reason why the abi > should be a certain way, Nick? One we know the choice, we can then judge the > patch to see if it implements the abi.
