Commit Graph

33 Commits

Author SHA1 Message Date
Aleksandar Markovic a58f85b5d5 MIPS: math-emu: Use preferred flavor of unsigned integer declarations
Fix occurences of unsigned integer variable declarations that are
not preferred by standards of checkpatch scripts. This removes a
significant number of checkpatch warnings for files in math-emu
directory (several files become completely warning-free), and thus
makes easier to spot (now and in the future) other, perhaps more
significant, checkpatch errors and warnings.

Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Reviewed-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17582/
Signed-off-by: James Hogan <jhogan@kernel.org>
2017-11-07 18:33:16 +00:00
Aleksandar Markovic 3ec404d88c MIPS: math-emu: RINT.<D|S>: Fix several problems by reimplementation
Reimplement RINT.<D|S> kernel emulation so that all RINT.<D|S>
specifications are met.

For the sake of simplicity, let's analyze RINT.S only. Prior to
this patch, RINT.S emulation was essentially implemented as (in
pseudocode) <output> = ieee754sp_flong(ieee754sp_tlong(<input>)),
where ieee754sp_tlong() and ieee754sp_flong() are functions
providing conversion from double to integer, and from integer
to double, respectively. On surface, this implementation looks
correct, but actually fails in many cases. Following problems
were detected:

1. NaN and infinity cases will not be handled properly. The
   function ieee754sp_flong() never returns NaN nor infinity.
2. For RINT.S, for all inputs larger than LONG_MAX, and smaller
   than FLT_MAX, the result will be wrong, and the overflow
   exception will be erroneously set. A similar problem for
   negative inputs exists as well.
3. For some rounding modes, for some negative inputs close to zero,
   the return value will be zero, and should be -zero. This is
   because ieee754sp_flong() never returns -zero.

This patch removes the problems above by implementing dedicated
functions for RINT.<D|S> emulation.

The core of the new function functionality is adapted version of
the core of the function ieee754sp_tlong(). However, there are many
details that are implemented to match RINT.<D|S> specification. It
should be said that the functionality of ieee754sp_tlong() actually
closely corresponds to CVT.L.S instruction, and it is used while
emulating CVT.L.S. However, RINT.S and CVT.L.S instructions differ
in many aspects. This patch fulfills missing support for RINT.<D|S>.

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17141/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-29 15:21:56 +02:00
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
Markos Chandras a79f5f9ba5 MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction
MIPS R6 introduced the following instruction:
Scalar Floating-Point Maximum and
Scalar Floating-Point argument with Maximum Absolute Value
MAX.fmt writes the maximum value of the inputs fs and ft to the
destination fd.
MAXA.fmt takes input arguments fs and ft and writes the argument with
the maximum absolute value to the destination fd.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10961/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:08:14 +02:00
Markos Chandras 4e9561b20e MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction
MIPS R6 introduced the following instruction:
Scalar Floating-Point Minimum and
Scalar Floating-Point argument with Minimum Absolute Value

MIN.fmt writes the minimum value of the inputs fs and ft to the
destination fd.
MINA.fmt takes input arguments fs and ft and writes the argument with
the minimum absolute value to the destination fd.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10960/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:08:14 +02:00
Markos Chandras 38db37ba06 MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction
MIPS R6 introduced the following instruction:
Stores in fd a bit mask reflecting the floating-point class of the
floating point scalar value fs.

CLASS.fmt: FPR[fd] = class(FPR[fs])

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10959/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:08:14 +02:00
Markos Chandras 83d43305a1 MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction
MIPS R6 introduced the following instruction:
Floating Point Fused Multiply Subtract:
MSUBF.fmt To perform a fused multiply-subtract of FP values.

MSUBF.fmt: FPR[fd] = FPR[fd] - (FPR[fs] x FPR[ft])

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10957/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:08:13 +02:00
Markos Chandras e24c3bec3e MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction
MIPS R6 introduced the following instruction:
Floating Point Fused Multiply Add:
MADDF.fmt To perform a fused multiply-add of FP values.

MADDF.fmt: FPR[fd] = FPR[fd] + (FPR[fs] x FPR[ft])

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10956/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:08:13 +02:00
Maciej W. Rozycki f1f3b7ebac MIPS: math-emu: Define IEEE 754-2008 feature control bits
Define IEEE 754-2008 feature control bits: FIR.HAS2008, FCSR.ABS2008 and
FCSR.NAN2008, and update the `_ieee754_csr' structure accordingly.

For completeness define FIR.UFRP too.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9709/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08 01:10:31 +02:00
Maciej W. Rozycki 42fa242421 MIPS: math-emu: Remove dead comparison helpers
None of the comparison helpers in ieee754.h is used, remove them.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9691/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08 01:09:42 +02:00
Maciej W. Rozycki 1796ec7742 MIPS: ieee754.h: Supplement comments for special values
Add the remaining missing comments for IEEE 754 special value array
indices.  Reindent macro definitions for consistency.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9671/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08 01:08:44 +02:00
Maciej W. Rozycki b3fea96269 MIPS: ieee754.h: Correct comments for special values
IEEE754_SPCVAL_NMIN denotes the index into the special value array where
the closest to zero negative normal number expressible is stored.
Similarly IEEE754_SPCVAL_NMIND denotes such index for the closest to
zero negative subnormal number expressible.  Make comments match that.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9670/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08 01:08:41 +02:00
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 aef3fb76aa MIPS: math-emu: Nuke alternative names for IEEE-754 rounding modes.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:12:37 +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 49548b09e0 MIPS: math-emu: Cleanup definition of structs describe sp/dp floats.
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 3a33db2321 MIPS: math-emu: Inline ieee754dp_finite and ieee754dp_finite().
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:13 +02:00
Ralf Baechle 1eaf198d3a MIPS: math-emu: Cleanup stdarg usage including apparently bogus comment.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:12 +02:00
Ralf Baechle e812a73932 MIPS: math-emu: Cleanup ieee754si_indef() / ieee754di_indef().
LONG_LONG_MAX is a symbol defined in <limits.h> which may not be available
so better rely on something provided by a kernel header.  While at it,
turn these function-like macros into inline functions.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:08 +02:00
Ralf Baechle fcfe2285e5 MIPS: math-emu: Get rid of unuable extended precision support.
No usable functionality and nothig does ever define IEEE854_XP anyway.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:11:02 +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
Ralf Baechle 2370881821 MIPS: math-emu: Use English spelling of `constant' rather than Danish.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-21 11:12:48 +02:00
Ralf Baechle cae55066cb MIPS: math-emu: Mark exception handling functions as __cold.
Optimizes the code flow and shaves of half a percent of the math-emu
code size.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-21 11:12:47 +02:00
Ralf Baechle f80cc08d78 MIPS: math-emu: Use __BITFIELD_FIELD to eleminate redundant definitions.
Union _ieee754sp was even duplicated even though there are no endian
dependencies in it all.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-21 11:12:46 +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
Atsushi Nemoto eae89076e6 [MIPS] Unify mips_fpu_soft_struct and mips_fpu_hard_structs.
The struct mips_fpu_soft_struct and mips_fpu_hard_struct are
completely same now and the kernel fpu emulator assumes that.  This
patch unifies them to mips_fpu_struct and get rid of mips_fpu_union.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-19 17:39:18 +01:00
Ralf Baechle 3c5c8f6748 Delete unused ieee754_cname[] and declaration.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:52 +01:00
Ralf Baechle a663bf906d Protect against multiple inclusion.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:51 +01:00
Ralf Baechle cd21dfcfbb Fix preemption and SMP problems in the FP emulator code.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:12 +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