6 Commits

Author	SHA1	Message	Date
Joseph Myers	eb65a3d545	Remove some math_private.h libc_feholdexcept_setround overrides. ... math_private.h headers for configurations lacking support for floating-point exceptions and rounding modes define libc_feholdexcept_setround to override the default version with one that discards its rounding mode argument. Unlike other such libc_fe* macros that I removed, this one is actually used for such configurations (in dbl-64/e_sqrt.c). However, this does not make the macro required. It's only used for such configurations with FE_TONEAREST as the rounding mode (anything needing another mode should not be used when that mode is unavailable), and the default definition just calls __feholdexcept and __fesetround. Since we now have suitable inline do-nothing definitions of __feholdexcept and __fesetround for the cases of no exceptions and rounding modes, we can just rely on those inlines to achieve the same optimization as this macro definition. Thus, this patch removes those macro definitions (and the math_private.h headers containing them, when no longer needed after that removal). Tested with build-many-glibcs.py that installed stripped shared libraries are unchanged by the patch. * sysdeps/m68k/coldfire/fpu/math_private.h: Move to .... * sysdeps/m68k/coldfire/math_private.h: ... here. * sysdeps/m68k/coldfire/nofpu/math_private.h: Remove file. * sysdeps/tile/math_private.h: Likewise. * sysdeps/microblaze/math_private.h (libc_feholdexcept_setround): Remove macro. * sysdeps/nios2/math_private.h (libc_feholdexcept_setround): Likewise.	2018-02-01 20:58:57 +00:00
Joseph Myers	8a6bb1d086	Remove some math_private.h libc_fe* overrides. ... math_private.h headers for configurations lacking support for floating-point exceptions and rounding modes define various libc_fe* macros to override the default versions with ones that discard any exception or rounding mode arguments. Three of the four macros defined in these headers are no longer needed there: those macros are only used in fma implementations that are not used for such configurations, now all those configurations properly use soft-fp fma implementations instead. (Effectively, those macros were a workaround to allow glibc to build in the absence of a proper fma implementation for this case - now there is such an implementation, there is no need to support building the wrong implementation for those configurations.) Thus, this patch removes the unnecessary macros. Tested with build-many-glibcs.py that installed stripped shared libraries are unchanged by the patch. * sysdeps/m68k/coldfire/nofpu/math_private.h (libc_fesetround): Remove macro. (libc_fetestexcept): Likewise. (libc_feupdateenv_test): Likewise. * sysdeps/microblaze/math_private.h (libc_fesetround): Likewise. (libc_fetestexcept): Likewise. (libc_feupdateenv_test): Likewise. * sysdeps/nios2/math_private.h (libc_fesetround): Likewise. (libc_fetestexcept): Likewise. (libc_feupdateenv_test): Likewise. * sysdeps/tile/math_private.h (libc_fesetround): Likewise. (libc_fetestexcept): Likewise. (libc_feupdateenv_test): Likewise.	2018-02-01 20:57:22 +00:00
Joseph Myers	d23a4962bb	Move some fenv.h override macros to generic math_private.h. ... Various configurations lacking support for floating-point exceptions and rounding modes have a math_private.h that overrides certain functions and macros, internal and external, to avoid references to FE_* constants that are undefined in those configurations. For example, there are unconditional feraiseexcept (FE_INVALID) calls in generic libm code, and these macro definitions duly define feraiseexcept to ignore its argument to avoid an error from FE_INVALID being undefined. In fact it is easy to tell in an architecture-independent way whether this is needed, by testing whether FE_ALL_EXCEPT == 0. Thus, this patch puts such a test, and feraiseexcept and __feraiseexcept macros, in the generic math_private.h, so reducing the duplication between architecture versions of this header. The feclearexcept macro present in several versions of this header, and fetestexcept in the tile version, are not needed; they would have been needed before there were proper soft-fp fma implementations (when generic versions, that depend on FE_TOWARDZERO and FE_INEXACT, were being used for configurations not supporting those features), but aren't needed any more, and so are removed. The tile version of this header has several inline functions for fenv.h functions to optimize calls to them away in such configurations where they do nothing useful, and all these header versions also have definitions of some of the libc_fe* internal macros. I intend to make those generic in subsequent patches. Tested with build-many-glibcs.py that installed stripped shared libraries are unchanged by this patch. * sysdeps/generic/math_private.h [FE_ALL_EXCEPT == 0] (feraiseexcept): New macro. [FE_ALL_EXCEPT == 0] (__feraiseexcept): Likewise. * sysdeps/m68k/coldfire/nofpu/math_private.h (feraiseexcept): Remove macro. (__feraiseexcept): Likewise. (feclearexcept): Likewise. * sysdeps/microblaze/math_private.h (feraiseexcept): Likewise. (__feraiseexcept): Likewise. (feclearexcept): Likewise. * sysdeps/nios2/math_private.h (feraiseexcept): Likewise. (__feraiseexcept): Likewise. (feclearexcept): Likewise. * sysdeps/tile/math_private.h (feraiseexcept): Likewise. (__feraiseexcept): Likewise. (feclearexcept): Likewise. (fetestexcept): Likewise.	2018-02-01 20:52:59 +00:00
Joseph Myers	d4c7e1d0fd	Add no-FPU ColdFire math_private.h. ... As with some other soft-float configurations, no-FPU ColdFire needs various fenv.h functions and glibc-internal macros overridden in math_private.h to avoid references to undefined FE_* macros when building glibc. This patch adds a suitable math_private.h, based on the MicroBlaze one (Nios II and Tile also have similar files). There's a case for having such a file in sysdeps/ieee754/soft-fp so this logic is applied more generally to configurations without exceptions and rounding modes, even when the relevant macros are defined in fenv.h - the only case where that might be inappropriate is ARM soft-float (where the fenv.h functions might or might not work at runtime, depending on whether the processor used at runtime supports VFP). There's also a case that soft-float configurations (on processors with both hard-float and soft-float) should more consistently avoid defining FE_* macros in bits/fenv.h when not actually supported. But both of those are separate potential cleanups. This allows the no-FPU ColdFire build to get further (another fix is needed to allow the build to complete). * sysdeps/m68k/coldfire/nofpu/math_private.h: New file. Based on MicroBlaze file.	2018-01-24 23:33:03 +00:00
Joseph Myers	6f7c009282	Add sysdeps/ieee754/soft-fp. ... The default sysdeps/ieee754 fma implementations rely on exceptions and rounding modes to achieve correct results through internal use of round-to-odd. Thus, glibc configurations without support for exceptions and rounding modes instead need to use implementations of fma based on soft-fp. At present, this is achieved via having implementation files in soft-fp/ that are #included by sysdeps files for each glibc configuration that needs them. In general this means such a configuration has its own s_fma.c and s_fmaf.c. TS 18661-1 adds functions that do an operation (+ - * / sqrt fma) on arguments wider than the return type, with a single rounding of the infinite-precision result to that return type. These are also naturally implemented using round-to-odd on platforms with hardware support for rounding modes and exceptions but lacking hardware support for these narrowing operations themselves. (Platforms that have direct hardware support for such narrowing operations include at least ia64, and Power ISA 2.07 or later, which I think means POWER8 or later.) So adding the remaining TS 18661-1 functions would mean at least six narrowing function implementations (fadd fsub fmul fdiv ffma fsqrt), with aliases for other types and further implementations in some configurations, that need to be overridden for configurations lacking hardware exceptions and rounding modes. Requiring all such configurations (currently seven of them) to have their own source files for all those functions seems undesirable. Thus, this patch adds a directory sysdeps/ieee754/soft-fp to contain libm function implementations based on soft-fp. This directory is then used via Implies from all the configurations that need it, so no more files need adding to every such configuration when adding more functions with soft-fp implementations. A configuration can still selectively #include a particular file from this directory if desired; thus, the MIPS #include of the fmal implementation is retained, since that's appropriate even for hard float (because long double is always implementated in software for MIPS64, so the soft-fp implementation of fmal is better than the ldbl-128 one). This also provides additional motivation for my recent patch removing --with-fp / --without-fp: previously there was no need for correct use of --without-fp for no-FPU ARM or SH3, and now we have autodetection nofpu/ sysdeps directories can be used by this patch for those configurations without imposing any new requirements on how glibc is configured. (The mips64/*/fpu/s_fma.c files added by this patch are needed to keep the dbl-64 version of fma for double, rather than the ldbl-128 one, used in that case.) Tested with build-many-glibcs.py that installed stripped shared libraries are unchanged by this patch. * soft-fp/fmadf4.c: Move to .... * sysdeps/ieee754/soft-fp/s_fma.c: ... here. * soft-fp/fmasf4.c: Move to .... * sysdeps/ieee754/soft-fp/s_fmaf.c: ... here. * soft-fp/fmatf4.c: Move to .... * sysdeps/ieee754/soft-fp/s_fmal.c: ... here. * sysdeps/ieee754/soft-fp/Makefile: New file. * sysdeps/arm/preconfigure.ac: Define with_fp_cond. * sysdeps/arm/preconfigure: Regenerated. * sysdeps/arm/nofpu/Implies: New file. * sysdeps/arm/s_fma.c: Remove file. * sysdeps/arm/s_fmaf.c: Likewise. * sysdeps/m68k/coldfire/nofpu/Implies: New file. * sysdeps/m68k/coldfire/nofpu/s_fma.c: Remove file. * sysdeps/m68k/coldfire/nofpu/s_fmaf.c: Likewise. * sysdeps/microblaze/Implies: Add ieee754/soft-fp. * sysdeps/microblaze/s_fma.c: Remove file. * sysdeps/microblaze/s_fmaf.c: Likewise. * sysdeps/mips/mips32/nofpu/Implies: New file. * sysdeps/mips/mips64/n32/fpu/s_fma.c: Likewise. * sysdeps/mips/mips64/n32/nofpu/Implies: Likewise. * sysdeps/mips/mips64/n64/fpu/s_fma.c: Likewise. * sysdeps/mips/mips64/n64/nofpu/Implies: Likewise. * sysdeps/mips/ieee754/s_fma.c: Remove file. * sysdeps/mips/ieee754/s_fmaf.c: Likewise. * sysdeps/mips/ieee754/s_fmal.c: Update include for move of fmal implementation. * sysdeps/nios2/Implies: Add ieee754/soft-fp. * sysdeps/nios2/s_fma.c: Remove file. * sysdeps/nios2/s_fmaf.c: Likewise. * sysdeps/sh/nofpu/Implies: New file. * sysdeps/sh/s_fma.c: Remove file. * sysdeps/sh/s_fmaf.c: Likewise. * sysdeps/tile/Implies: Add ieee754/soft-fp. * sysdeps/tile/s_fma.c: Remove file. * sysdeps/tile/s_fmaf.c: Likewise.	2017-12-12 23:35:21 +00:00
Joseph Myers	775e99641e	Use soft-fp fma for no-FPU ColdFire (bug 13304). ... Systems without floating-point exceptions and rounding modes should use the soft-fp versions of fmaf and fma, not the sysdeps/ieee754 versions that rely on setting rounding to zero and testing for the "inexact" exception; this has been noted on <https://sourceware.org/glibc/wiki/PortStatus> for some time. This patch makes no-FPU ColdFire use the soft-fp files; sfp-machine.h is made to include the nios2 version of sfp-machine.h which seems sufficiently generic for 32-bit systems. [BZ #13304] * sysdeps/m68k/coldfire/nofpu/s_fma.c: New file. * sysdeps/m68k/coldfire/nofpu/s_fmaf.c: Likewise. * sysdeps/m68k/coldfire/nofpu/sfp-machine.h: Likewise.	2015-09-25 17:30:56 +00:00