On Mon, Mar 5, 2012 at 10:38 AM, Bernd Schmidt <ber...@codesourcery.com> wrote: > On 03/05/2012 05:24 PM, Peter Bigot wrote: >> And is there any reason (other than it doesn't seem to have been done >> before) to believe PSImode is the wrong way to support a >> general-purpose 20-bit integral type in gcc? > > If you're using 4.7.0, it should be possible to use FRACTIONAL_INT_MODE > and get reasonable results. However, it hasn't been tested much, since > the final bits of the patch series which would have added 40 bit int > support to the C frontend didn't make it in. See the discussion following > http://gcc.gnu.org/ml/gcc-patches/2011-07/msg00079.html
I stuck with PARTIAL_INT_MODE instead of FRACTIONAL_INT_MODE because in my case the new type should not appear in the widen/narrow hierarchy of MODE_INT, but the patches you added for this were critical to the success I've had: 4.7.0 is working very well for me. I've filed two bug reports for cases where BITSIZE needs to be updated to PRECISION. Since my back-end is out of tree I can't provide test cases, but if you could do so, or could apply the fixes as obvious, it might help future developers avoid the problems I found. Thanks. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52919 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52856 Peter
