public inbox for
help / color / mirror / Atom feed
* gcc-wwwdocs branch master updated. ae68cb61741297974f4a76dc7c8fc2ed7a3515c7
@ 2022-04-29  7:02 Xi Ruoyao
  0 siblings, 0 replies; only message in thread
From: Xi Ruoyao @ 2022-04-29  7:02 UTC (permalink / raw)
  To: gcc-cvs-wwwdocs

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "gcc-wwwdocs".

The branch, master has been updated
       via  ae68cb61741297974f4a76dc7c8fc2ed7a3515c7 (commit)
      from  60f057d93758717de29d45f8ae2df846efd0101b (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit ae68cb61741297974f4a76dc7c8fc2ed7a3515c7
Author: Xi Ruoyao <>
Date:   Sat Apr 2 00:23:18 2022 +0800

    document zero-width field ABI changes on MIPS

diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html
index e9f132c0..5281c966 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.
@@ -656,7 +660,26 @@ function Multiply (S1, S2 : Sign) return Sign is
-<!-- <h3 id="mips">MIPS</h3> -->
+<h3 id="mips">MIPS</h3>
+  <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>
 <!-- <h3 id="mep">MeP</h3> -->


Summary of changes:
 htdocs/gcc-12/changes.html | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)


^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2022-04-29  7:02 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-29  7:02 gcc-wwwdocs branch master updated. ae68cb61741297974f4a76dc7c8fc2ed7a3515c7 Xi Ruoyao

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).