Commit Graph

12 Commits

Author SHA1 Message Date
Maciej W. Rozycki 90d53a91fb MIPS: math-emu: Add IEEE Std 754-2008 NaN encoding emulation
Implement IEEE Std 754-2008 NaN encoding wired to the state of the
FCSR.NAN2008 bit.  Make the interpretation of the quiet bit in NaN data
as follows:

* in the legacy mode originally defined by the MIPS architecture the
  value of 1 denotes an sNaN whereas the value of 0 denotes a qNaN,

* in the 2008 mode introduced with revision 5 of the MIPS architecture
  the value of 0 denotes an sNaN whereas the value of 1 denotes a qNaN,
  following the definition of the preferred NaN encoding introduced with
  IEEE Std 754-2008.

In the 2008 mode, following the requirement of the said standard, quiet
an sNaN where needed by setting the quiet bit to 1 and leaving all the
NaN payload bits unchanged.

Update format conversion operations according to the rules set by IEEE
Std 754-2008 and the MIPS architecture.  Specifically:

* propagate NaN payload bits through conversions between floating-point
  formats such that as much information as possible is preserved and
  specifically a conversion from a narrower format to a wider format and
  then back to the original format does not change a qNaN payload in any
  way,

* conversions from a floating-point to an integer format where the
  source is a NaN, infinity or a value that would convert to an integer
  outside the range of the result format produce, under the default
  exception handling, the respective values defined by the MIPS
  architecture.

In full FPU emulation set the FIR.HAS2008 bit to 1, however do not make
any further FCSR bits writable.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11477/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-20 00:39:20 +01:00
Ralf Baechle 56a6473339 MIPS: math-emu: Switch to using the MIPS rounding modes.
Previously math-emu was using the IEEE-754 constants internally.  These
were differing by having the constants for rounding to +/- infinity
switched, so a conversion was necessary.  This would be entirely
avoidable if the MIPS constants were used throughout, so get rid of
the bloat.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:12:38 +02:00
Ralf Baechle 3f7cac416b MIPS: math-emu: Cleanup coding style.
o Only define variables in the outermost block
 o One empty line at most
 o Format comments as per CodingStyle
 o Update FSF address in licensing term comment
 o Spell FPU and MIPS in all capitals.
 o Remove ####-type of lines in comments.
 o Try to make things a bit most consistent between sp_*.c / dp_*.c files.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:15 +02:00
Ralf Baechle 90efba36ed MIPS: math-emu: Get rid of the useless parts of exception handling.
All it really did was throw a printk for no obvious reason.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:14 +02:00
Ralf Baechle dfbf42b844 MIPS: math-emu: Remove unused code.
Shrinks the FPU emulator by 4528 bytes.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:14 +02:00
Ralf Baechle b3a7ad2b0c MIPS: math-emu: Eleminate duplicate definitions of identical macros.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:13 +02:00
Ralf Baechle ad8fb5537a MIPS: math-emu: Replace DP_MBITS with DP_FBITS and SP_MBITS with SP_FBITS.
Both were defined as 23 rsp. 52 though the mentissa is actually a bit more
than the fraction.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:13 +02:00
Ralf Baechle 9e8bad1f9c MIPS: math-emu: Turn macros into functions where possible.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-21 11:12:57 +02:00
Ralf Baechle 2209bcb131 MIPS: math-emu: Get rid of typedefs.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-21 11:12:48 +02:00
Justin P. Mattock 50a23e6eec Update broken web addresses in arch directory.
The patch below updates broken web addresses in the arch directory.

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-18 11:03:21 +02:00
Andrea Gelmini abb86dc543 MIPS: math-emu: Checkpatch cleanup
arch/mips/math-emu/sp_tlong.c:75: ERROR: else should follow close brace '}'

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1276/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-08-05 13:25:43 +01:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00