This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

RE: [PATCHv4, MIPS] Add support for O32 FPXX and program header based ABI information

Here's my first attempt at a news entry for this.  I suspect it is too
verbose but covers the kind of things I believe are important.


	* NEWS: Announce support for new MIPS ABI extensions.
 NEWS | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/NEWS b/NEWS
index 63918df..d1fa510 100644
--- a/NEWS
+++ b/NEWS
@@ -49,6 +49,26 @@ Version 2.21
 * Merged gettext 0.19.3 into the intl subdirectory.  This fixes building
   with newer versions of bison.
+* Support for MIPS o32 FPXX, FP64A and FP64 ABI Extensions.
+  The original MIPS o32 hard-float ABI requires an FPU where double-precision
+  registers overlay two consecutive single-precision registers.  MIPS32R2
+  introduced a new FPU mode (FR=1) where double-precision registers extend the
+  corresponding single-precision registers which is incompatible with the
+  o32 hard-float ABI.  The MIPS SIMD ASE and the MIPSR6 architecture both
+  require the use of FR=1 making a transition necessary.  New o32 ABI
+  extensions enable users to migrate over time from the original o32 ABI
+  through to the updated o32 FP64 ABI.  To achieve this the dynamic linker now
+  tracks the ABI of any loaded object and verifies that new objects are
+  compatible.  Mode transitions will also be requested as required and
+  unsupportable objects will be rejected.  The ABI checks include both soft and
+  hard float ABIs for o32, n32 and n64.
+  GCC 5.0 onwards:
+  It is strongly recommended that all o32 system libraries are built using the
+  new o32 FPXX ABI (-mfpxx) to facilitate the transition as this is compatible
+  with the original and all new o32 ABI extensions.  Configure a native
+  MIPS GCC compiler using --with-fp-32=xx to set this by default.

 Version 2.20

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]