On Thu, Apr 28, 2022 at 7:30 PM Xi Ruoyao via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Ping.
OK. > On Wed, 2022-04-06 at 23:26 +0800, Xi Ruoyao via Gcc-patches wrote: > > Document ABI changes in r12-7961, 7962, and 8023. Ok for wwwdocs? > > > > --- > > htdocs/gcc-12/changes.html | 25 ++++++++++++++++++++++++- > > 1 file changed, 24 insertions(+), 1 deletion(-) > > > > diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html > > index 4f2ee77f..c924bca3 100644 > > --- a/htdocs/gcc-12/changes.html > > +++ b/htdocs/gcc-12/changes.html > > @@ -50,6 +50,10 @@ a work-in-progress.</p> > > (so there is a C++ ABI incompatibility, GCC 4.4 and earlier compatible > > with GCC 12 or later, incompatible with GCC 4.5 through GCC 11). > > RISC-V has changed the handling of these already starting with GCC 10. > > + As the ABI requires, MIPS takes them into account handling function > > + return values so there is a C++ ABI incompatibility with GCC 4.5 > > + through 11. For function arguments on MIPS, refer to > > + <a href="#mips_zero_width_fields">the MIPS specific entry</a>. > > GCC 12 on the above targets will report such incompatibilities as > > warnings or other diagnostics unless <code>-Wno-psabi</code> is used. > > </li> > > @@ -549,7 +553,26 @@ a work-in-progress.</p> > > </li> > > </ul> > > > > -<!-- <h3 id="mips">MIPS</h3> --> > > +<h3 id="mips">MIPS</h3> > > +<ul> > > + <li>The <a name="mips_zero_width_fields">ABI</a> passing arguments > > + containing zero-width fields (for example, C/C++ zero-width > > + bit-fields, GNU C/C++ zero-length arrays, and GNU C empty structs) > > + has changed. Now a zero-width field will not prevent an aligned > > + 64-bit floating-point field next to it from being passed through > > + FPR. This is compatible with LLVM, but incompatible with previous > > + GCC releases. GCC 12 on MIPS will report such incompatibilities as > > + an inform unless <code>-Wno-psabi</code> is used. > > + </li> > > + <li>The <a name="mips_cxx17_empty_bases">ABI</a> returning values > > + containing C++17 empty bases has changed. Now an empty base will > > + not prevent an aggregate containing only one or two floating-point > > + fields from being returned through FPR. This is compatible with > > + GCC 6 and earlier, but incompatible with GCC 7 through 11. GCC 12 on > > + MIPS will report such incompatibilities as an inform unless > > + <code>-Wno-psabi</code> is used. > > + </li> > > +</ul> > > > > <!-- <h3 id="mep">MeP</h3> --> > > > > -- > Xi Ruoyao <xry...@mengyan1223.wang> > School of Aerospace Science and Technology, Xidian University
