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-rw-r--r--Documentation/arm/nwfpe/NOTES29
-rw-r--r--Documentation/arm/nwfpe/README70
-rw-r--r--Documentation/arm/nwfpe/README.FPE156
-rw-r--r--Documentation/arm/nwfpe/TODO67
4 files changed, 0 insertions, 322 deletions
diff --git a/Documentation/arm/nwfpe/NOTES b/Documentation/arm/nwfpe/NOTES
deleted file mode 100644
index 40577b5a49d..00000000000
--- a/Documentation/arm/nwfpe/NOTES
+++ /dev/null
@@ -1,29 +0,0 @@
-There seems to be a problem with exp(double) and our emulator. I haven't
-been able to track it down yet. This does not occur with the emulator
-supplied by Russell King.
-
-I also found one oddity in the emulator. I don't think it is serious but
-will point it out. The ARM calling conventions require floating point
-registers f4-f7 to be preserved over a function call. The compiler quite
-often uses an stfe instruction to save f4 on the stack upon entry to a
-function, and an ldfe instruction to restore it before returning.
-
-I was looking at some code, that calculated a double result, stored it in f4
-then made a function call. Upon return from the function call the number in
-f4 had been converted to an extended value in the emulator.
-
-This is a side effect of the stfe instruction. The double in f4 had to be
-converted to extended, then stored. If an lfm/sfm combination had been used,
-then no conversion would occur. This has performance considerations. The
-result from the function call and f4 were used in a multiplication. If the
-emulator sees a multiply of a double and extended, it promotes the double to
-extended, then does the multiply in extended precision.
-
-This code will cause this problem:
-
-double x, y, z;
-z = log(x)/log(y);
-
-The result of log(x) (a double) will be calculated, returned in f0, then
-moved to f4 to preserve it over the log(y) call. The division will be done
-in extended precision, due to the stfe instruction used to save f4 in log(y).
diff --git a/Documentation/arm/nwfpe/README b/Documentation/arm/nwfpe/README
deleted file mode 100644
index 771871de0c8..00000000000
--- a/Documentation/arm/nwfpe/README
+++ /dev/null
@@ -1,70 +0,0 @@
-This directory contains the version 0.92 test release of the NetWinder
-Floating Point Emulator.
-
-The majority of the code was written by me, Scott Bambrough It is
-written in C, with a small number of routines in inline assembler
-where required. It was written quickly, with a goal of implementing a
-working version of all the floating point instructions the compiler
-emits as the first target. I have attempted to be as optimal as
-possible, but there remains much room for improvement.
-
-I have attempted to make the emulator as portable as possible. One of
-the problems is with leading underscores on kernel symbols. Elf
-kernels have no leading underscores, a.out compiled kernels do. I
-have attempted to use the C_SYMBOL_NAME macro wherever this may be
-important.
-
-Another choice I made was in the file structure. I have attempted to
-contain all operating system specific code in one module (fpmodule.*).
-All the other files contain emulator specific code. This should allow
-others to port the emulator to NetBSD for instance relatively easily.
-
-The floating point operations are based on SoftFloat Release 2, by
-John Hauser. SoftFloat is a software implementation of floating-point
-that conforms to the IEC/IEEE Standard for Binary Floating-point
-Arithmetic. As many as four formats are supported: single precision,
-double precision, extended double precision, and quadruple precision.
-All operations required by the standard are implemented, except for
-conversions to and from decimal. We use only the single precision,
-double precision and extended double precision formats. The port of
-SoftFloat to the ARM was done by Phil Blundell, based on an earlier
-port of SoftFloat version 1 by Neil Carson for NetBSD/arm32.
-
-The file README.FPE contains a description of what has been implemented
-so far in the emulator. The file TODO contains a information on what
-remains to be done, and other ideas for the emulator.
-
-Bug reports, comments, suggestions should be directed to me at
-<scottb@netwinder.org>. General reports of "this program doesn't
-work correctly when your emulator is installed" are useful for
-determining that bugs still exist; but are virtually useless when
-attempting to isolate the problem. Please report them, but don't
-expect quick action. Bugs still exist. The problem remains in isolating
-which instruction contains the bug. Small programs illustrating a specific
-problem are a godsend.
-
-Legal Notices
--------------
-
-The NetWinder Floating Point Emulator is free software. Everything Rebel.com
-has written is provided under the GNU GPL. See the file COPYING for copying
-conditions. Excluded from the above is the SoftFloat code. John Hauser's
-legal notice for SoftFloat is included below.
-
--------------------------------------------------------------------------------
-SoftFloat Legal Notice
-
-SoftFloat was written by John R. Hauser. This work was made possible in
-part by the International Computer Science Institute, located at Suite 600,
-1947 Center Street, Berkeley, California 94704. Funding was partially
-provided by the National Science Foundation under grant MIP-9311980. The
-original version of this code was written as part of a project to build
-a fixed-point vector processor in collaboration with the University of
-California at Berkeley, overseen by Profs. Nelson Morgan and John Wawrzynek.
-
-THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
-has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
-TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
-PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
-AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
--------------------------------------------------------------------------------
diff --git a/Documentation/arm/nwfpe/README.FPE b/Documentation/arm/nwfpe/README.FPE
deleted file mode 100644
index 26f5d7bb9a4..00000000000
--- a/Documentation/arm/nwfpe/README.FPE
+++ /dev/null
@@ -1,156 +0,0 @@
-The following describes the current state of the NetWinder's floating point
-emulator.
-
-In the following nomenclature is used to describe the floating point
-instructions. It follows the conventions in the ARM manual.
-
-<S|D|E> = <single|double|extended>, no default
-{P|M|Z} = {round to +infinity,round to -infinity,round to zero},
- default = round to nearest
-
-Note: items enclosed in {} are optional.
-
-Floating Point Coprocessor Data Transfer Instructions (CPDT)
-------------------------------------------------------------
-
-LDF/STF - load and store floating
-
-<LDF|STF>{cond}<S|D|E> Fd, Rn
-<LDF|STF>{cond}<S|D|E> Fd, [Rn, #<expression>]{!}
-<LDF|STF>{cond}<S|D|E> Fd, [Rn], #<expression>
-
-These instructions are fully implemented.
-
-LFM/SFM - load and store multiple floating
-
-Form 1 syntax:
-<LFM|SFM>{cond}<S|D|E> Fd, <count>, [Rn]
-<LFM|SFM>{cond}<S|D|E> Fd, <count>, [Rn, #<expression>]{!}
-<LFM|SFM>{cond}<S|D|E> Fd, <count>, [Rn], #<expression>
-
-Form 2 syntax:
-<LFM|SFM>{cond}<FD,EA> Fd, <count>, [Rn]{!}
-
-These instructions are fully implemented. They store/load three words
-for each floating point register into the memory location given in the
-instruction. The format in memory is unlikely to be compatible with
-other implementations, in particular the actual hardware. Specific
-mention of this is made in the ARM manuals.
-
-Floating Point Coprocessor Register Transfer Instructions (CPRT)
-----------------------------------------------------------------
-
-Conversions, read/write status/control register instructions
-
-FLT{cond}<S,D,E>{P,M,Z} Fn, Rd Convert integer to floating point
-FIX{cond}{P,M,Z} Rd, Fn Convert floating point to integer
-WFS{cond} Rd Write floating point status register
-RFS{cond} Rd Read floating point status register
-WFC{cond} Rd Write floating point control register
-RFC{cond} Rd Read floating point control register
-
-FLT/FIX are fully implemented.
-
-RFS/WFS are fully implemented.
-
-RFC/WFC are fully implemented. RFC/WFC are supervisor only instructions, and
-presently check the CPU mode, and do an invalid instruction trap if not called
-from supervisor mode.
-
-Compare instructions
-
-CMF{cond} Fn, Fm Compare floating
-CMFE{cond} Fn, Fm Compare floating with exception
-CNF{cond} Fn, Fm Compare negated floating
-CNFE{cond} Fn, Fm Compare negated floating with exception
-
-These are fully implemented.
-
-Floating Point Coprocessor Data Instructions (CPDT)
----------------------------------------------------
-
-Dyadic operations:
-
-ADF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - add
-SUF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - subtract
-RSF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse subtract
-MUF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - multiply
-DVF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - divide
-RDV{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse divide
-
-These are fully implemented.
-
-FML{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - fast multiply
-FDV{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - fast divide
-FRD{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - fast reverse divide
-
-These are fully implemented as well. They use the same algorithm as the
-non-fast versions. Hence, in this implementation their performance is
-equivalent to the MUF/DVF/RDV instructions. This is acceptable according
-to the ARM manual. The manual notes these are defined only for single
-operands, on the actual FPA11 hardware they do not work for double or
-extended precision operands. The emulator currently does not check
-the requested permissions conditions, and performs the requested operation.
-
-RMF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - IEEE remainder
-
-This is fully implemented.
-
-Monadic operations:
-
-MVF{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - move
-MNF{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - move negated
-
-These are fully implemented.
-
-ABS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - absolute value
-SQT{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - square root
-RND{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - round
-
-These are fully implemented.
-
-URD{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - unnormalized round
-NRM{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - normalize
-
-These are implemented. URD is implemented using the same code as the RND
-instruction. Since URD cannot return a unnormalized number, NRM becomes
-a NOP.
-
-Library calls:
-
-POW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - power
-RPW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse power
-POL{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - polar angle (arctan2)
-
-LOG{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base 10
-LGN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base e
-EXP{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - exponent
-SIN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - sine
-COS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - cosine
-TAN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - tangent
-ASN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arcsine
-ACS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arccosine
-ATN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arctangent
-
-These are not implemented. They are not currently issued by the compiler,
-and are handled by routines in libc. These are not implemented by the FPA11
-hardware, but are handled by the floating point support code. They should
-be implemented in future versions.
-
-Signalling:
-
-Signals are implemented. However current ELF kernels produced by Rebel.com
-have a bug in them that prevents the module from generating a SIGFPE. This
-is caused by a failure to alias fp_current to the kernel variable
-current_set[0] correctly.
-
-The kernel provided with this distribution (vmlinux-nwfpe-0.93) contains
-a fix for this problem and also incorporates the current version of the
-emulator directly. It is possible to run with no floating point module
-loaded with this kernel. It is provided as a demonstration of the
-technology and for those who want to do floating point work that depends
-on signals. It is not strictly necessary to use the module.
-
-A module (either the one provided by Russell King, or the one in this
-distribution) can be loaded to replace the functionality of the emulator
-built into the kernel.
diff --git a/Documentation/arm/nwfpe/TODO b/Documentation/arm/nwfpe/TODO
deleted file mode 100644
index 8027061b60e..00000000000
--- a/Documentation/arm/nwfpe/TODO
+++ /dev/null
@@ -1,67 +0,0 @@
-TODO LIST
----------
-
-POW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - power
-RPW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse power
-POL{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - polar angle (arctan2)
-
-LOG{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base 10
-LGN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base e
-EXP{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - exponent
-SIN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - sine
-COS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - cosine
-TAN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - tangent
-ASN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arcsine
-ACS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arccosine
-ATN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arctangent
-
-These are not implemented. They are not currently issued by the compiler,
-and are handled by routines in libc. These are not implemented by the FPA11
-hardware, but are handled by the floating point support code. They should
-be implemented in future versions.
-
-There are a couple of ways to approach the implementation of these. One
-method would be to use accurate table methods for these routines. I have
-a couple of papers by S. Gal from IBM's research labs in Haifa, Israel that
-seem to promise extreme accuracy (in the order of 99.8%) and reasonable speed.
-These methods are used in GLIBC for some of the transcendental functions.
-
-Another approach, which I know little about is CORDIC. This stands for
-Coordinate Rotation Digital Computer, and is a method of computing
-transcendental functions using mostly shifts and adds and a few
-multiplications and divisions. The ARM excels at shifts and adds,
-so such a method could be promising, but requires more research to
-determine if it is feasible.
-
-Rounding Methods
-
-The IEEE standard defines 4 rounding modes. Round to nearest is the
-default, but rounding to + or - infinity or round to zero are also allowed.
-Many architectures allow the rounding mode to be specified by modifying bits
-in a control register. Not so with the ARM FPA11 architecture. To change
-the rounding mode one must specify it with each instruction.
-
-This has made porting some benchmarks difficult. It is possible to
-introduce such a capability into the emulator. The FPCR contains
-bits describing the rounding mode. The emulator could be altered to
-examine a flag, which if set forced it to ignore the rounding mode in
-the instruction, and use the mode specified in the bits in the FPCR.
-
-This would require a method of getting/setting the flag, and the bits
-in the FPCR. This requires a kernel call in ArmLinux, as WFC/RFC are
-supervisor only instructions. If anyone has any ideas or comments I
-would like to hear them.
-
-[NOTE: pulled out from some docs on ARM floating point, specifically
- for the Acorn FPE, but not limited to it:
-
- The floating point control register (FPCR) may only be present in some
- implementations: it is there to control the hardware in an implementation-
- specific manner, for example to disable the floating point system. The user
- mode of the ARM is not permitted to use this register (since the right is
- reserved to alter it between implementations) and the WFC and RFC
- instructions will trap if tried in user mode.
-
- Hence, the answer is yes, you could do this, but then you will run a high
- risk of becoming isolated if and when hardware FP emulation comes out
- -- Russell].