2007-05-23 17:13:59 +00:00
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#include <fenv.h>
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#include <fpu_control.h>
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2000-09-05 08:37:09 +00:00
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#define _FP_W_TYPE_SIZE 64
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2003-03-17 15:47:13 +00:00
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#define _FP_W_TYPE unsigned long long
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#define _FP_WS_TYPE signed long long
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#define _FP_I_TYPE long long
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2000-09-05 08:37:09 +00:00
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#define _FP_MUL_MEAT_S(R,X,Y) \
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_FP_MUL_MEAT_1_imm(_FP_WFRACBITS_S,R,X,Y)
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#define _FP_MUL_MEAT_D(R,X,Y) \
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_FP_MUL_MEAT_1_wide(_FP_WFRACBITS_D,R,X,Y,umul_ppmm)
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#define _FP_MUL_MEAT_Q(R,X,Y) \
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_FP_MUL_MEAT_2_wide_3mul(_FP_WFRACBITS_Q,R,X,Y,umul_ppmm)
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2013-07-02 14:55:32 +00:00
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#define _FP_MUL_MEAT_DW_S(R,X,Y) \
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_FP_MUL_MEAT_DW_1_imm(_FP_WFRACBITS_S,R,X,Y)
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#define _FP_MUL_MEAT_DW_D(R,X,Y) \
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_FP_MUL_MEAT_DW_1_wide(_FP_WFRACBITS_D,R,X,Y,umul_ppmm)
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#define _FP_MUL_MEAT_DW_Q(R,X,Y) \
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_FP_MUL_MEAT_DW_2_wide_3mul(_FP_WFRACBITS_Q,R,X,Y,umul_ppmm)
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2000-09-05 08:37:09 +00:00
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#define _FP_DIV_MEAT_S(R,X,Y) _FP_DIV_MEAT_1_imm(S,R,X,Y,_FP_DIV_HELP_imm)
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#define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_1_udiv_norm(D,R,X,Y)
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#define _FP_DIV_MEAT_Q(R,X,Y) _FP_DIV_MEAT_2_udiv(Q,R,X,Y)
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MIPS: IEEE 754-2008 NaN encoding support
It has been a long practice for software using IEEE 754 floating-point
arithmetic run on MIPS processors to use an encoding of Not-a-Number
(NaN) data different to one used by software run on other processors.
And as of IEEE 754-2008 revision [1] this encoding does not follow one
recommended in the standard, as specified in section 6.2.1, where it
is stated that quiet NaNs should have the first bit (d1) of their
significand set to 1 while signalling NaNs should have that bit set to
0, but MIPS software interprets the two bits in the opposite manner.
As from revision 3.50 [2][3] the MIPS Architecture provides for
processors that support the IEEE 754-2008 preferred NaN encoding format.
As the two formats (further referred to as "legacy NaN" and "2008 NaN")
are incompatible to each other, tools have to provide support for the
two formats to help people avoid using incompatible binary modules.
The change is comprised of two functional groups of features, both of
which are required for correct support.
1. Dynamic linker support.
To enforce the NaN encoding requirement in dynamic linking a new ELF
file header flag has been defined. This flag is set for 2008-NaN
shared modules and executables and clear for legacy-NaN ones. The
dynamic linker silently ignores any incompatible modules it
encounters in dependency processing.
To avoid unnecessary processing of incompatible modules in the
presence of a shared module cache, a set of new cache flags has been
defined to mark 2008-NaN modules for the three ABIs supported.
Changes to sysdeps/unix/sysv/linux/mips/readelflib.c have been made
following an earlier code quality suggestion made here:
http://sourceware.org/ml/libc-ports/2009-03/msg00036.html
and are therefore a little bit more extensive than the minimum
required.
Finally a new name has been defined for the dynamic linker so that
2008-NaN and legacy-NaN binaries can coexist on a single system that
supports dual-mode operation and that a legacy dynamic linker that
does not support verifying the 2008-NaN ELF file header flag is not
chosen to interpret a 2008-NaN binary by accident.
2. Floating environment support.
IEEE 754-2008 features are controlled in the Floating-Point Control
and Status (FCSR) register and updates are needed to floating
environment support so that the 2008-NaN flag is set correctly and
the kernel default, inferred from the 2008-NaN ELF file header flag
at the time an executable is loaded, respected.
As the NaN encoding format is a property of GCC code generation that is
both a user-selected GCC configuration default and can be overridden
with GCC options, code that needs to know what NaN encoding standard it
has been configured for checks for the __mips_nan2008 macro that is
defined internally by GCC whenever the 2008-NaN mode has been selected.
This mode is determined at the glibc configuration time and therefore a
few consistency checks have been added to catch cases where compilation
flags have been overridden by the user.
The 2008 NaN set of features relies on kernel support as the in-kernel
floating-point emulator needs to be aware of the NaN encoding used even
on hard-float processors and configure the FPU context according to the
value of the 2008 NaN ELF file header flag of the executable being
started. As at this time work on kernel support is still in progress
and the relevant changes have not made their way yet to linux.org master
repository.
Therefore the minimum version supported has been artificially set to
10.0.0 so that 2008-NaN code is not accidentally run on a Linux kernel
that does not suppport it. It is anticipated that the version is
adjusted later on to the actual initial linux.org kernel version to
support this feature. Legacy NaN encoding support is unaffected, older
kernel versions remain supported.
[1] "IEEE Standard for Floating-Point Arithmetic", IEEE Computer
Society, IEEE Std 754-2008, 29 August 2008
[2] "MIPS Architecture For Programmers, Volume I-A: Introduction to the
MIPS32 Architecture", MIPS Technologies, Inc., Document Number:
MD00082, Revision 3.50, September 20, 2012
[3] "MIPS Architecture For Programmers, Volume I-A: Introduction to the
MIPS64 Architecture", MIPS Technologies, Inc., Document Number:
MD00083, Revision 3.50, September 20, 2012
2013-09-18 20:04:27 +00:00
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#ifdef __mips_nan2008
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# define _FP_NANFRAC_S ((_FP_QNANBIT_S << 1) - 1)
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# define _FP_NANFRAC_D ((_FP_QNANBIT_D << 1) - 1)
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# define _FP_NANFRAC_Q ((_FP_QNANBIT_Q << 1) - 1), -1
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#else
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# define _FP_NANFRAC_S (_FP_QNANBIT_S - 1)
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# define _FP_NANFRAC_D (_FP_QNANBIT_D - 1)
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# define _FP_NANFRAC_Q (_FP_QNANBIT_Q - 1), -1
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#endif
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2000-09-05 08:37:09 +00:00
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#define _FP_NANSIGN_S 0
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#define _FP_NANSIGN_D 0
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#define _FP_NANSIGN_Q 0
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#define _FP_KEEPNANFRACP 1
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MIPS: IEEE 754-2008 NaN encoding support
It has been a long practice for software using IEEE 754 floating-point
arithmetic run on MIPS processors to use an encoding of Not-a-Number
(NaN) data different to one used by software run on other processors.
And as of IEEE 754-2008 revision [1] this encoding does not follow one
recommended in the standard, as specified in section 6.2.1, where it
is stated that quiet NaNs should have the first bit (d1) of their
significand set to 1 while signalling NaNs should have that bit set to
0, but MIPS software interprets the two bits in the opposite manner.
As from revision 3.50 [2][3] the MIPS Architecture provides for
processors that support the IEEE 754-2008 preferred NaN encoding format.
As the two formats (further referred to as "legacy NaN" and "2008 NaN")
are incompatible to each other, tools have to provide support for the
two formats to help people avoid using incompatible binary modules.
The change is comprised of two functional groups of features, both of
which are required for correct support.
1. Dynamic linker support.
To enforce the NaN encoding requirement in dynamic linking a new ELF
file header flag has been defined. This flag is set for 2008-NaN
shared modules and executables and clear for legacy-NaN ones. The
dynamic linker silently ignores any incompatible modules it
encounters in dependency processing.
To avoid unnecessary processing of incompatible modules in the
presence of a shared module cache, a set of new cache flags has been
defined to mark 2008-NaN modules for the three ABIs supported.
Changes to sysdeps/unix/sysv/linux/mips/readelflib.c have been made
following an earlier code quality suggestion made here:
http://sourceware.org/ml/libc-ports/2009-03/msg00036.html
and are therefore a little bit more extensive than the minimum
required.
Finally a new name has been defined for the dynamic linker so that
2008-NaN and legacy-NaN binaries can coexist on a single system that
supports dual-mode operation and that a legacy dynamic linker that
does not support verifying the 2008-NaN ELF file header flag is not
chosen to interpret a 2008-NaN binary by accident.
2. Floating environment support.
IEEE 754-2008 features are controlled in the Floating-Point Control
and Status (FCSR) register and updates are needed to floating
environment support so that the 2008-NaN flag is set correctly and
the kernel default, inferred from the 2008-NaN ELF file header flag
at the time an executable is loaded, respected.
As the NaN encoding format is a property of GCC code generation that is
both a user-selected GCC configuration default and can be overridden
with GCC options, code that needs to know what NaN encoding standard it
has been configured for checks for the __mips_nan2008 macro that is
defined internally by GCC whenever the 2008-NaN mode has been selected.
This mode is determined at the glibc configuration time and therefore a
few consistency checks have been added to catch cases where compilation
flags have been overridden by the user.
The 2008 NaN set of features relies on kernel support as the in-kernel
floating-point emulator needs to be aware of the NaN encoding used even
on hard-float processors and configure the FPU context according to the
value of the 2008 NaN ELF file header flag of the executable being
started. As at this time work on kernel support is still in progress
and the relevant changes have not made their way yet to linux.org master
repository.
Therefore the minimum version supported has been artificially set to
10.0.0 so that 2008-NaN code is not accidentally run on a Linux kernel
that does not suppport it. It is anticipated that the version is
adjusted later on to the actual initial linux.org kernel version to
support this feature. Legacy NaN encoding support is unaffected, older
kernel versions remain supported.
[1] "IEEE Standard for Floating-Point Arithmetic", IEEE Computer
Society, IEEE Std 754-2008, 29 August 2008
[2] "MIPS Architecture For Programmers, Volume I-A: Introduction to the
MIPS32 Architecture", MIPS Technologies, Inc., Document Number:
MD00082, Revision 3.50, September 20, 2012
[3] "MIPS Architecture For Programmers, Volume I-A: Introduction to the
MIPS64 Architecture", MIPS Technologies, Inc., Document Number:
MD00083, Revision 3.50, September 20, 2012
2013-09-18 20:04:27 +00:00
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#ifdef __mips_nan2008
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# define _FP_QNANNEGATEDP 0
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#else
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# define _FP_QNANNEGATEDP 1
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#endif
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2013-05-16 22:33:55 +00:00
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2017-01-04 17:15:39 +00:00
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#ifdef __mips_nan2008
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/* NaN payloads should be preserved for NAN2008. */
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# define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \
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do \
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{ \
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R##_s = X##_s; \
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_FP_FRAC_COPY_##wc (R, X); \
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R##_c = FP_CLS_NAN; \
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} \
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while (0)
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#else
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2000-09-05 08:37:09 +00:00
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/* From my experiments it seems X is chosen unless one of the
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NaNs is sNaN, in which case the result is NANSIGN/NANFRAC. */
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2017-01-04 17:15:39 +00:00
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# define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \
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2000-09-05 08:37:09 +00:00
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do { \
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2019-02-25 13:19:19 +00:00
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if ((_FP_FRAC_HIGH_RAW_##fs(X) \
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| _FP_FRAC_HIGH_RAW_##fs(Y)) & _FP_QNANBIT_##fs) \
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2000-09-05 08:37:09 +00:00
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{ \
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R##_s = _FP_NANSIGN_##fs; \
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_FP_FRAC_SET_##wc(R,_FP_NANFRAC_##fs); \
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} \
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else \
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{ \
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R##_s = X##_s; \
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_FP_FRAC_COPY_##wc(R,X); \
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} \
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R##_c = FP_CLS_NAN; \
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} while (0)
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2017-01-04 17:15:39 +00:00
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#endif
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2000-09-05 08:37:09 +00:00
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Do not define various fenv.h macros for MIPS soft-float (bug 23479).
MIPS soft-float glibc does not support floating-point exceptions and
rounding modes, and uses a different ABI from hard-float so a
soft-float compilation cannot use a glibc that does support
floating-point exceptions and rounding modes. Thus, bits/fenv.h
should not, when compiling for soft-float, define macros for the
unsupported features.
This patch changes it accordingly to define those macros only for
hard-float. None of the exception macros are defined for soft-float,
with FE_ALL_EXCEPT defined to 0 in that case, and only FE_TONEAREST is
defined of the rounding-mode macros, and FE_NOMASK_ENV is not defined;
this is consistent with how architectures lacking exception and
rounding mode support generally define things in this header. As well
as making the header more correct for this case, this also means the
generic math_private.h optimizations for this case automatically apply
(inlining libm-internal fenv.h function calls that are trivial when
exceptions and rounding modes are not supported).
The mips64 sfp-machine.h then needs similar changes to disable more of
the exception and rounding mode handling for soft-float. (The mips32
sfp-machine.h is already used only for soft-float, has no integration
with hardware exceptions or rounding modes and so needs no changes.)
Existing binaries might use the old FE_NOMASK_ENV value as an argument
to fesetenv / feupdateenv and expect an error for it (given that it
was defined in a header that also defined FE_ALL_EXCEPT to a nonzero
value). To preserve that error, wrappers for the fallback fesetenv
and feupdateenv are created in sysdeps/mips/nofpu/.
Tested for mips64 (hard-float and soft-float, all three ABIs).
[BZ #23479]
* sysdeps/mips/bits/fenv.h (FE_INEXACT): Define only if
[__mips_hard_float].
(FE_UNDERFLOW): Likewise.
(FE_OVERFLOW): Likewise.
(FE_DIVBYZERO): Likewise.
(FE_INVALID): Likewise.
(FE_ALL_EXCEPT): Define to 0 if [!__mips_hard_float].
(FE_TOWARDZERO): Define only if [__mips_hard_float].
(FE_UPWARD): Likewise.
(FE_DOWNWARD): Likewise.
(__FE_UNDEFINED): Define if [!__mips_hard_float]
(FE_NOMASK_ENV): Define only if [__mips_hard_float].
* sysdeps/mips/mips64/sfp-machine.h (_FP_DECL_EX): Define only if
[__mips_hard_float].
(FP_ROUNDMODE): Likewise.
(FP_RND_NEAREST): Likewise.
(FP_RND_ZERO): Likewise.
(FP_RND_PINF): Likewise.
(FP_RND_MINF): Likewise.
(FP_EX_INVALID): Likewise.
(FP_EX_OVERFLOW): Likewise.
(FP_EX_UNDERFLOW): Likewise.
(FP_EX_DIVZERO): Likewise.
(FP_EX_INEXACT): Likewise.
(FP_INIT_ROUNDMODE): Likewise.
* sysdeps/mips/nofpu/fesetenv.c: New file.
* sysdeps/mips/nofpu/feupdateenv.c: Likewise.
2018-08-02 15:53:29 +00:00
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#define _FP_TININESS_AFTER_ROUNDING 1
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#ifdef __mips_hard_float
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2007-05-23 17:13:59 +00:00
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#define _FP_DECL_EX fpu_control_t _fcw
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#define FP_ROUNDMODE (_fcw & 0x3)
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#define FP_RND_NEAREST FE_TONEAREST
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#define FP_RND_ZERO FE_TOWARDZERO
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#define FP_RND_PINF FE_UPWARD
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#define FP_RND_MINF FE_DOWNWARD
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#define FP_EX_INVALID FE_INVALID
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#define FP_EX_OVERFLOW FE_OVERFLOW
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#define FP_EX_UNDERFLOW FE_UNDERFLOW
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#define FP_EX_DIVZERO FE_DIVBYZERO
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#define FP_EX_INEXACT FE_INEXACT
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#define FP_INIT_ROUNDMODE \
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do { \
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_FPU_GETCW (_fcw); \
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} while (0)
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#define FP_HANDLE_EXCEPTIONS \
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do { \
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if (__builtin_expect (_fex, 0)) \
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_FPU_SETCW (_fcw | _fex | (_fex << 10)); \
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} while (0)
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2012-05-30 21:35:11 +00:00
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#define FP_TRAPPING_EXCEPTIONS ((_fcw >> 5) & 0x7c)
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2007-05-23 17:13:59 +00:00
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#endif
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