fpu/softfloat: check for Inf / x or 0 / x before /0

The re-factoring of div_floats changed the order of checking meaning
an operation like -inf/0 erroneously raises the divbyzero flag.
IEEE-754 (200

fpu/softfloat: check for Inf / x or 0 / x before /0

The re-factoring of div_floats changed the order of checking meaning
an operation like -inf/0 erroneously raises the divbyzero flag.
IEEE-754 (2008) specifies this should only occur for operations on
finite operands.

We fix this by moving the check on the dividend being Inf/0 to before
the divisor is zero check.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180416135442.30606-1-alex.bennee@linaro.org
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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fpu/softfloat: raise float_invalid for NaN/Inf in round_to_int_and_pack

The re-factor broke the raising of INVALID when NaN/Inf is passed to
the float_to_int conversion functions. round_to_uint_and_

fpu/softfloat: raise float_invalid for NaN/Inf in round_to_int_and_pack

The re-factor broke the raising of INVALID when NaN/Inf is passed to
the float_to_int conversion functions. round_to_uint_and_pack got this
right for NaN but also missed out the Inf handling.

Fixes https://bugs.launchpad.net/qemu/+bug/1759264

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20180413140334.26622-3-alex.bennee@linaro.org
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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softfloat: fix {min, max}nummag for same-abs-value inputs

Before 8936006 ("fpu/softfloat: re-factor minmax", 2018-02-21),
we used to return +Zero for maxnummag(-Zero,+Zero); after that
commit, we re

softfloat: fix {min, max}nummag for same-abs-value inputs

Before 8936006 ("fpu/softfloat: re-factor minmax", 2018-02-21),
we used to return +Zero for maxnummag(-Zero,+Zero); after that
commit, we return -Zero.

Fix it by making {min,max}nummag consistent with {min,max}num,
deferring to the latter when the absolute value of the operands
is the same.

With this fix we now pass fp-test.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180413140334.26622-2-alex.bennee@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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fpu: Fix rounding mode for floatN_to_uintM_round_to_zero

We incorrectly passed in the current rounding mode
instead of float_round_to_zero.

Signed-off-by: Richard Henderson <richard.henderson@linar

fpu: Fix rounding mode for floatN_to_uintM_round_to_zero

We incorrectly passed in the current rounding mode
instead of float_round_to_zero.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180410055912.934-1-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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softfloat: fix crash on int conversion of SNaN

Signed-off-by: Stef O'Rear <sorear2@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

RISC-V FPU Support

Helper routines for FPU instructions and NaN definitions.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Sagar Karandikar <sagark@eecs.berkeley.edu>

RISC-V FPU Support

Helper routines for FPU instructions and NaN definitions.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Sagar Karandikar <sagark@eecs.berkeley.edu>
Signed-off-by: Michael Clark <mjc@sifive.com>

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softfloat: use floatx80_infinity in softfloat

Since f3218a8 ("softfloat: add floatx80 constants")
floatx80_infinity is defined but never used.

This patch updates floatx80 functions to use
this defi

softfloat: use floatx80_infinity in softfloat

Since f3218a8 ("softfloat: add floatx80 constants")
floatx80_infinity is defined but never used.

This patch updates floatx80 functions to use
this definition.

This allows to define a different default Infinity
value on m68k: the m68k FPU defines infinity with
all bits set to zero in the mantissa.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180224201802.911-4-laurent@vivier.eu>

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softfloat: export some functions

Move fpu/softfloat-macros.h to include/fpu/

Export floatx80 functions to be used by target floatx80
specific implementations.

Exports:
propagateFloatx80NaN(), ex

softfloat: export some functions

Move fpu/softfloat-macros.h to include/fpu/

Export floatx80 functions to be used by target floatx80
specific implementations.

Exports:
propagateFloatx80NaN(), extractFloatx80Frac(),
extractFloatx80Exp(), extractFloatx80Sign(),
normalizeFloatx80Subnormal(), packFloatx80(),
roundAndPackFloatx80(), normalizeRoundAndPackFloatx80()

Also exports packFloat32() that will be used to implement
m68k fsinh, fcos, fsin, ftan operations.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180224201802.911-2-laurent@vivier.eu>

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fpu/softfloat: re-factor sqrt

This is a little bit of a departure from softfloat's original approach
as we skip the estimate step in favour of a straight iteration. There
is a minor optimisation to

fpu/softfloat: re-factor sqrt

This is a little bit of a departure from softfloat's original approach
as we skip the estimate step in favour of a straight iteration. There
is a minor optimisation to avoid calculating more bits of precision
than we need however this still brings a performance drop, especially
for float64 operations.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: re-factor compare

The compare function was already expanded from a macro. I keep the
macro expansion but move most of the logic into a compare_decomposed.

Signed-off-by: Alex Bennée

fpu/softfloat: re-factor compare

The compare function was already expanded from a macro. I keep the
macro expansion but move most of the logic into a compare_decomposed.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: re-factor minmax

Let's do the same re-factor treatment for minmax functions. I still
use the MACRO trick to expand but now all the checking code is common.

Signed-off-by: Alex Bennée

fpu/softfloat: re-factor minmax

Let's do the same re-factor treatment for minmax functions. I still
use the MACRO trick to expand but now all the checking code is common.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: re-factor scalbn

This is one of the simpler manipulations you could make to a floating
point number.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderso

fpu/softfloat: re-factor scalbn

This is one of the simpler manipulations you could make to a floating
point number.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: re-factor int/uint to float

These are considerably simpler as the lower order integers can just
use the higher order conversion function. As the decomposed fractional
part is a full 6

fpu/softfloat: re-factor int/uint to float

These are considerably simpler as the lower order integers can just
use the higher order conversion function. As the decomposed fractional
part is a full 64 bit rounding and inexact handling comes from the
pack functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: re-factor float to int/uint

We share the common int64/uint64_pack_decomposed function across all
the helpers and simply limit the final result depending on the final
size.

Signed-off

fpu/softfloat: re-factor float to int/uint

We share the common int64/uint64_pack_decomposed function across all
the helpers and simply limit the final result depending on the final
size.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: re-factor round_to_int

We can now add float16_round_to_int and use the common round_decomposed and
canonicalize functions to have a single implementation for
float16/32/64 round_to_in

fpu/softfloat: re-factor round_to_int

We can now add float16_round_to_int and use the common round_decomposed and
canonicalize functions to have a single implementation for
float16/32/64 round_to_int functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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fpu/softfloat: re-factor muladd

We can now add float16_muladd and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 muladd functions.

Signed-off-

fpu/softfloat: re-factor muladd

We can now add float16_muladd and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 muladd functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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fpu/softfloat: re-factor div

We can now add float16_div and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Benné

fpu/softfloat: re-factor div

We can now add float16_div and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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fpu/softfloat: re-factor mul

We can now add float16_mul and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Benné

fpu/softfloat: re-factor mul

We can now add float16_mul and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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fpu/softfloat: re-factor add/sub

We can now add float16_add/sub and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 add and sub functions.

Sign

fpu/softfloat: re-factor add/sub

We can now add float16_add/sub and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 add and sub functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

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fpu/softfloat: define decompose structures

These structures pave the way for generic softfloat helper routines
that will operate on fully decomposed numbers.

Signed-off-by: Alex Bennée <alex.bennee

fpu/softfloat: define decompose structures

These structures pave the way for generic softfloat helper routines
that will operate on fully decomposed numbers.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

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fpu/softfloat: move the extract functions to the top of the file

This is pure code-motion during re-factoring as the helpers will be
needed earlier.

Signed-off-by: Alex Bennée <alex.bennee@linaro.o

fpu/softfloat: move the extract functions to the top of the file

This is pure code-motion during re-factoring as the helpers will be
needed earlier.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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fpu/softfloat: improve comments on ARM NaN propagation

Mention the pseudo-code fragment from which this is based.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson

fpu/softfloat: improve comments on ARM NaN propagation

Mention the pseudo-code fragment from which this is based.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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fpu/softfloat: implement float16_squash_input_denormal

This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.

Signed-off-by: Alex Bennée <alex.bennee@linaro.o

fpu/softfloat: implement float16_squash_input_denormal

This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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