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* Fix x86, x86_64 fmax, fmin sNaN handling, add tests (bug 20947).Joseph Myers2016-12-152-7/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various fmax and fmin function implementations mishandle sNaN arguments: (a) When both arguments are NaNs, the return value should be a qNaN, but sometimes it is an sNaN if at least one argument is an sNaN. (b) Under TS 18661-1 semantics, if either argument is an sNaN then the result should be a qNaN (whereas if one argument is a qNaN and the other is not a NaN, the result should be the non-NaN argument). Various implementations treat sNaNs like qNaNs here. This patch fixes the x86 and x86_64 versions (ignoring float and double for 32-bit x86 given the inability to reliably avoid the sNaN turning into a qNaN before it gets to the called function). Tests of sNaN inputs to these functions are added. Note on architecture versions I haven't changed for this issue: AArch64 already gets this right (it uses a hardware instruction with the correct semantics for both quiet and signaling NaNs) and does not need changes. It's possible Alpha, IA64, SPARC might need changes (this would be shown by the testsuite if so). Tested for x86_64 and x86 (both i686 and i586 builds, to cover the different x86 implementations). [BZ #20947] * sysdeps/i386/fpu/s_fmaxl.S (__fmaxl): Add the arguments when either is a signaling NaN. * sysdeps/i386/fpu/s_fminl.S (__fminl): Likewise. Make code follow fmaxl more closely. * sysdeps/i386/i686/fpu/s_fmaxl.S (__fmaxl): Add the arguments when either is a signaling NaN. * sysdeps/i386/i686/fpu/s_fminl.S (__fminl): Likewise. * sysdeps/x86_64/fpu/s_fmax.S (__fmax): Likewise. * sysdeps/x86_64/fpu/s_fmaxf.S (__fmaxf): Likewise. * sysdeps/x86_64/fpu/s_fmaxl.S (__fmaxl): Likewise. * sysdeps/x86_64/fpu/s_fmin.S (__fmin): Likewise. * sysdeps/x86_64/fpu/s_fminf.S (__fminf): Likewise. * sysdeps/x86_64/fpu/s_fminl.S (__fminl): Likewise. * math/libm-test.inc (fmax_test_data): Add tests of sNaN inputs. (fmin_test_data): Likewise.
* Fix x86_64/x86 powl handling of sNaN arguments (bug 20916).Joseph Myers2016-12-061-5/+24
| | | | | | | | | | | | | | | | | | | | | | | | | The x86_64/x86 powl implementations mishandle sNaN arguments, both by returning sNaN in some cases (instead of doing arithmetic on the arguments to produce the result when NaN arguments result in NaN results) and by treating sNaN the same as qNaN for arguments (1, sNaN) and (sNaN, 0), contrary to TS 18661-1 which requires those cases to return qNaN instead of 1. This patch makes the x86_64/x86 powl implementations follow TS 18661-1 semantics for sNaN arguments; sNaN tests are also added for pow. Given the problems with testing float and double sNaN arguments on 32-bit x86 (sNaN tests disabled because the compiler may convert unnecessarily to a qNaN when passing arguments), no changes are made to the powf and pow implementations there. Tested for x86_64 and x86. [BZ #20916] * sysdeps/i386/fpu/e_powl.S (__ieee754_powl): Do not return 1 for arguments (sNaN, 0) or (1, sNaN). Do arithmetic on NaN arguments to compute result. * sysdeps/x86_64/fpu/e_powl.S (__ieee754_powl): Likewise. * math/libm-test.inc (pow_test_data): Add tests of sNaN arguments.
* Do not hardcode platform names in manual/libm-err-tab.pl (bug 14139).Joseph Myers2016-11-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | manual/libm-err-tab.pl hardcodes a list of names for particular platforms (mapping from sysdeps directory name to friendly name for the manual). This goes against the principle of keeping information about individual platforms in their corresponding sysdeps directory, and the list is also very out-of-date regarding supported platforms and their corresponding sysdeps directories. This patch fixes this by adding a libm-test-ulps-name file alongside each libm-test-ulps file. The script then gets the friendly name from that file, which is required to exist, so it no longer needs to allow for the mapping being missing. Tested for x86_64. [BZ #14139] * manual/libm-err-tab.pl (%pplatforms): Initialize to empty. (find_files): Obtain platform name from libm-test-ulps-name and store in %pplatforms. (canonicalize_platform): Remove. (print_platforms): Use $pplatforms directly. (by_platforms): Do not allow for platforms missing from %pplatforms. * sysdeps/aarch64/libm-test-ulps-name: New file. * sysdeps/alpha/fpu/libm-test-ulps-name: Likewise. * sysdeps/arm/libm-test-ulps-name: Likewise. * sysdeps/generic/libm-test-ulps-name: Likewise. * sysdeps/hppa/fpu/libm-test-ulps-name: Likewise. * sysdeps/i386/fpu/libm-test-ulps-name: Likewise. * sysdeps/i386/i686/fpu/multiarch/libm-test-ulps-name: Likewise. * sysdeps/ia64/fpu/libm-test-ulps-name: Likewise. * sysdeps/m68k/coldfire/fpu/libm-test-ulps-name: Likewise. * sysdeps/m68k/m680x0/fpu/libm-test-ulps-name: Likewise. * sysdeps/microblaze/libm-test-ulps-name: Likewise. * sysdeps/mips/mips32/libm-test-ulps-name: Likewise. * sysdeps/mips/mips64/libm-test-ulps-name: Likewise. * sysdeps/nios2/libm-test-ulps-name: Likewise. * sysdeps/powerpc/fpu/libm-test-ulps-name: Likewise. * sysdeps/powerpc/nofpu/libm-test-ulps-name: Likewise. * sysdeps/s390/fpu/libm-test-ulps-name: Likewise. * sysdeps/sh/libm-test-ulps-name: Likewise. * sysdeps/sparc/fpu/libm-test-ulps-name: Likewise. * sysdeps/tile/libm-test-ulps-name: Likewise. * sysdeps/x86_64/fpu/libm-test-ulps-name: Likewise.
* Add femode_t functions.Joseph Myers2016-09-072-0/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TS 18661-1 defines a type femode_t to represent the set of dynamic floating-point control modes (such as the rounding mode and trap enablement modes), and functions fegetmode and fesetmode to manipulate those modes (without affecting other state such as the raised exception flags) and a corresponding macro FE_DFL_MODE. This patch series implements those interfaces for glibc. This first patch adds the architecture-independent pieces, the x86 and x86_64 implementations, and the <bits/fenv.h> and ABI baseline updates for all architectures so glibc keeps building and passing the ABI tests on all architectures. Subsequent patches add the fegetmode and fesetmode implementations for other architectures. femode_t is generally an integer type - the same type as fenv_t, or as the single element of fenv_t where fenv_t is a structure containing a single integer (or the single relevant element, where it has elements for both status and control registers) - except where architecture properties or consistency with the fenv_t implementation indicate otherwise. FE_DFL_MODE follows FE_DFL_ENV in whether it's a magic pointer value (-1 cast to const femode_t *), a value that can be distinguished from valid pointers by its high bits but otherwise contains a representation of the desired register contents, or a pointer to a constant variable (the powerpc case; __fe_dfl_mode is added as an exported constant object, an alias to __fe_dfl_env). Note that where architectures (that share a register between control and status bits) gain definitions of new floating-point control or status bits in future, the implementations of fesetmode for those architectures may need updating (depending on whether the new bits are control or status bits and what the implementation does with previously unknown bits), just like existing implementations of <fenv.h> functions that take care not to touch reserved bits may need updating when the set of reserved bits changes. (As any new bits are outside the scope of ISO C, that's just a quality-of-implementation issue for supporting them, not a conformance issue.) As with fenv_t, femode_t should properly include any software DFP rounding mode (and for both fenv_t and femode_t I'd consider that fragment of DFP support appropriate for inclusion in glibc even in the absence of the rest of libdfp; hardware DFP rounding modes should already be included if the definitions of which bits are status / control bits are correct). Tested for x86_64, x86, mips64 (hard float, and soft float to test the fallback version), arm (hard float) and powerpc (hard float, soft float and e500). Other architecture versions are untested. * math/fegetmode.c: New file. * math/fesetmode.c: Likewise. * sysdeps/i386/fpu/fegetmode.c: Likewise. * sysdeps/i386/fpu/fesetmode.c: Likewise. * sysdeps/x86_64/fpu/fegetmode.c: Likewise. * sysdeps/x86_64/fpu/fesetmode.c: Likewise. * math/fenv.h: Update comment on inclusion of <bits/fenv.h>. [__GLIBC_USE (IEC_60559_BFP_EXT)] (fegetmode): New function declaration. [__GLIBC_USE (IEC_60559_BFP_EXT)] (fesetmode): Likewise. * bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/aarch64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/alpha/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/arm/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/hppa/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/ia64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/m68k/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/microblaze/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/mips/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/nios2/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/powerpc/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (__fe_dfl_mode): New variable declaration. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/s390/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/sh/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/sparc/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/tile/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/x86/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * manual/arith.texi (FE_DFL_MODE): Document macro. (fegetmode): Document function. (fesetmode): Likewise. * math/Versions (fegetmode): New libm symbol at version GLIBC_2.25. (fesetmode): Likewise. * math/Makefile (libm-support): Add fegetmode and fesetmode. (tests): Add test-femode and test-femode-traps. * math/test-femode-traps.c: New file. * math/test-femode.c: Likewise. * sysdeps/powerpc/fpu/fenv_const.c (__fe_dfl_mode): Declare as alias for __fe_dfl_env. * sysdeps/powerpc/nofpu/fenv_const.c (__fe_dfl_mode): Likewise. * sysdeps/powerpc/powerpc32/e500/nofpu/fenv_const.c (__fe_dfl_mode): Likewise. * sysdeps/powerpc/Versions (__fe_dfl_mode): New libm symbol at version GLIBC_2.25. * sysdeps/nacl/libm.abilist: Update. * sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* Remove unneeded stubs for k_rem_pio2l.Paul E. Murphy2016-09-011-3/+0
| | | | | | | | | | This is only used for the float and double variants. Instead, just add it to the type specific list of files, and remove all stubs, and remove the declaration from math_private.h. I verified x86_64, i486, ia64, m68k, and ppc64 build.
* Add fesetexcept.Joseph Myers2016-08-161-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TS 18661-1 defines an fesetexcept function for setting floating-point exception flags without the side-effect of causing enabled traps to be taken. This patch series implements this function for glibc. The present patch adds the fallback stub implementation, x86 and x86_64 implementations, documentation, tests and ABI baseline updates. The remaining patches, some of them untested, add implementations for other architectures. The implementations generally follow those of the fesetexceptflag function. As for fesetexceptflag, the approach taken for architectures where setting flags causes enabled traps to be taken is to set the flags (and potentially cause traps) rather than refusing to set the flags and returning an error. Since ISO C and TS 18661 provide no way to enable traps, this is formally in accordance with the standards. The NEWS entry should be considered a placeholder, since this patch series is intended to be followed by further such series adding other TS 18661-1 features, so that the NEWS entry would end up looking more like * New <fenv.h> features from TS 18661-1:2014 are added to libm: the fesetexcept, fetestexceptflag, fegetmode and fesetmode functions, the femode_t type and the FE_DFL_MODE macro. with hopefully more such entries for other features, rather than having an entry for a single function in the end. I believe we have consensus for adding TS 18661-1 interfaces as per <https://sourceware.org/ml/libc-alpha/2016-06/msg00421.html>. Tested for x86_64, x86, mips64 (hard float, and soft float to test the fallback version), arm (hard float) and powerpc (hard float, soft float and e500). * math/fesetexcept.c: New file. * sysdeps/i386/fpu/fesetexcept.c: Likewise. * sysdeps/x86_64/fpu/fesetexcept.c: Likewise. * math/fenv.h: Define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include <bits/libc-header-start.h> instead of including <features.h>. [__GLIBC_USE (IEC_60559_BFP_EXT)] (fesetexcept): New function declaration. * manual/arith.texi (fesetexcept): Document function. * math/Versions (fesetexcept): New libm symbol at version GLIBC_2.25. * math/Makefile (libm-support): Add fesetexcept. (tests): Add test-fesetexcept and test-fesetexcept-traps. * math/test-fesetexcept.c: New file. * math/test-fesetexcept-traps.c: Likewise. * sysdeps/nacl/libm.abilist: Update. * sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* Avoid "inexact" exceptions in i386/x86_64 trunc functions (bug 15479).Joseph Myers2016-06-273-18/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As discussed in <https://sourceware.org/ml/libc-alpha/2016-05/msg00577.html>, TS 18661-1 disallows ceil, floor, round and trunc functions from raising the "inexact" exception, in accordance with general IEEE 754 semantics for when that exception is raised. Fixing this for x87 floating point is more complicated than for the other versions of these functions, because they use the frndint instruction that raises "inexact" and this can only be avoided by saving and restoring the whole floating-point environment. As I noted in <https://sourceware.org/ml/libc-alpha/2016-06/msg00128.html>, I have now implemented a GCC option -fno-fp-int-builtin-inexact for GCC 7, such that GCC will inline these functions on x86, without caring about "inexact", when the default -ffp-int-builtin-inexact is in effect. This allows users to get optimized code depending on the options they pass to the compiler, while making the out-of-line functions follow TS 18661-1 semantics and avoid "inexact". This patch duly fixes the out-of-line trunc function implementations to avoid "inexact", in the same way as the nearbyint implementations. I do not know how the performance of implementations such as these based on saving the environment and changing the rounding mode temporarily compares to that of the C versions or SSE 4.1 versions (of course, for 32-bit x86 SSE implementations still need to get the return value in an x87 register); it's entirely possible other implementations could be faster in some cases. Tested for x86_64 and x86. [BZ #15479] * sysdeps/i386/fpu/s_trunc.S (__trunc): Save and restore floating-point environment rather than just control word. * sysdeps/i386/fpu/s_truncf.S (__truncf): Likewise. * sysdeps/i386/fpu/s_truncl.S (__truncl): Save and restore floating-point environment, with "invalid" exceptions merged in, rather than just control word. * sysdeps/x86_64/fpu/s_truncl.S (__truncl): Likewise. * math/libm-test.inc (trunc_test_data): Do not allow spurious "inexact" exceptions.
* Avoid "inexact" exceptions in i386/x86_64 floor functions (bug 15479).Joseph Myers2016-06-273-18/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As discussed in <https://sourceware.org/ml/libc-alpha/2016-05/msg00577.html>, TS 18661-1 disallows ceil, floor, round and trunc functions from raising the "inexact" exception, in accordance with general IEEE 754 semantics for when that exception is raised. Fixing this for x87 floating point is more complicated than for the other versions of these functions, because they use the frndint instruction that raises "inexact" and this can only be avoided by saving and restoring the whole floating-point environment. As I noted in <https://sourceware.org/ml/libc-alpha/2016-06/msg00128.html>, I have now implemented a GCC option -fno-fp-int-builtin-inexact for GCC 7, such that GCC will inline these functions on x86, without caring about "inexact", when the default -ffp-int-builtin-inexact is in effect. This allows users to get optimized code depending on the options they pass to the compiler, while making the out-of-line functions follow TS 18661-1 semantics and avoid "inexact". This patch duly fixes the out-of-line floor function implementations to avoid "inexact", in the same way as the nearbyint implementations. I do not know how the performance of implementations such as these based on saving the environment and changing the rounding mode temporarily compares to that of the C versions or SSE 4.1 versions (of course, for 32-bit x86 SSE implementations still need to get the return value in an x87 register); it's entirely possible other implementations could be faster in some cases. Tested for x86_64 and x86. [BZ #15479] * sysdeps/i386/fpu/s_floor.S (__floor): Save and restore floating-point environment rather than just control word. * sysdeps/i386/fpu/s_floorf.S (__floorf): Likewise. * sysdeps/i386/fpu/s_floorl.S (__floorl): Save and restore floating-point environment, with "invalid" exceptions merged in, rather than just control word. * sysdeps/x86_64/fpu/s_floorl.S (__floorl): Likewise. * math/libm-test.inc (floor_test_data): Do not allow spurious "inexact" exceptions.
* Avoid "inexact" exceptions in i386/x86_64 ceil functions (bug 15479).Joseph Myers2016-06-273-18/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As discussed in <https://sourceware.org/ml/libc-alpha/2016-05/msg00577.html>, TS 18661-1 disallows ceil, floor, round and trunc functions from raising the "inexact" exception, in accordance with general IEEE 754 semantics for when that exception is raised. Fixing this for x87 floating point is more complicated than for the other versions of these functions, because they use the frndint instruction that raises "inexact" and this can only be avoided by saving and restoring the whole floating-point environment. As I noted in <https://sourceware.org/ml/libc-alpha/2016-06/msg00128.html>, I have now implemented a GCC option -fno-fp-int-builtin-inexact for GCC 7, such that GCC will inline these functions on x86, without caring about "inexact", when the default -ffp-int-builtin-inexact is in effect. This allows users to get optimized code depending on the options they pass to the compiler, while making the out-of-line functions follow TS 18661-1 semantics and avoid "inexact". This patch duly fixes the out-of-line ceil function implementations to avoid "inexact", in the same way as the nearbyint implementations. I do not know how the performance of implementations such as these based on saving the environment and changing the rounding mode temporarily compares to that of the C versions or SSE 4.1 versions (of course, for 32-bit x86 SSE implementations still need to get the return value in an x87 register); it's entirely possible other implementations could be faster in some cases. Tested for x86_64 and x86. [BZ #15479] * sysdeps/i386/fpu/s_ceil.S (__ceil): Save and restore floating-point environment rather than just control word. * sysdeps/i386/fpu/s_ceilf.S (__ceilf): Likewise. * sysdeps/i386/fpu/s_ceill.S (__ceill): Save and restore floating-point environment, with "invalid" exceptions merged in, rather than just control word. * sysdeps/x86_64/fpu/s_ceill.S (__ceill): Likewise. * math/libm-test.inc (ceil_test_data): Do not allow spurious "inexact" exceptions.
* Fix i386/x86_64 scalbl with sNaN input (bug 20296).Joseph Myers2016-06-231-13/+3
| | | | | | | | | | | | | | | | | The x86_64 and i386 versions of scalbl return sNaN for some cases of sNaN input and are missing "invalid" exceptions for other cases. This results from overly complicated code that either returns a NaN input, or discards both inputs when one is NaN and loads a NaN from memory. This patch fixes this by simplifying the code to add the arguments when either one is NaN. Tested for x86_64 and x86. [BZ #20296] * sysdeps/i386/fpu/e_scalbl.S (__ieee754_scalbl): Add arguments when either argument is a NaN. * sysdeps/x86_64/fpu/e_scalbl.S (__ieee754_scalbl): Likewise. * math/libm-test.inc (scalb_test_data): Add sNaN tests.
* Simplify x86 nearbyint functions.Joseph Myers2016-06-223-12/+0
| | | | | | | | | | | | | | | | | | | | The i386 implementations of nearbyint functions, and x86_64 nearbyintl, contain code to mask the "inexact" exception. However, the fnstenv instruction has the effect of masking all exceptions, so this masking code has been redundant since fnstenv was added to those implementations (by commit 846d9a4a3acdb4939ca7bf6aed48f9f6f26911be; commit 71d1b0166b4ace0d804af2993b3815758b852efc added the test math/test-nearbyint-except-2.c that verifies these functions do work when called with "inexact" traps enabled); this patch removes the redundant code. Tested for x86_64 and x86. * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Do not mask "inexact" exceptions after fnstenv. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise.
* Fix i386 fdim double rounding (bug 20255).Joseph Myers2016-06-141-0/+50
| | | | | | | | | | | | | | | | | | | fdim suffers from double rounding on i386 because subtracting two double values can produce an inexact long double value exactly half way between two double values. This patch fixes this by creating an i386-specific version of fdim - C, based on the generic version, unlike the previous .S version - which sets the x87 precision control to double precision for the subtraction and then restores it afterwards. As noted in the comment added, there are no issues of double rounding for subnormals (a case that setting precision control does not address) because subtraction cannot produce an inexact result in the subnormal range. Tested for x86_64 and x86. [BZ #20255] * sysdeps/i386/fpu/s_fdim.c: New file. Based on math/s_fdim.c. * math/libm-test.inc (fdim_test_data): Add another test.
* Use generic fdim on more architectures (bug 6796, bug 20255, bug 20256).Joseph Myers2016-06-143-153/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some architectures have their own versions of fdim functions, which are missing errno setting (bug 6796) and may also return sNaN instead of qNaN for sNaN input, in the case of the x86 / x86_64 long double versions (bug 20256). These versions are not actually doing anything that a compiler couldn't generate, just straightforward comparisons / arithmetic (and, in the x86 / x86_64 case, testing for NaNs with fxam, which isn't actually needed once you use an unordered comparison and let the NaNs pass through the same subtraction as non-NaN inputs). This patch removes the x86 / x86_64 / powerpc versions, so that those architectures use the generic C versions, which correctly handle setting errno and deal properly with sNaN inputs. This seems better than dealing with setting errno in lots of .S versions. The i386 versions also return results with excess range and precision, which is not appropriate for a function exactly defined by reference to IEEE operations. For errno setting to work correctly on overflow, it's necessary to remove excess range with math_narrow_eval, which this patch duly does in the float and double versions so that the tests can reliably pass on x86. For float, this avoids any double rounding issues as the long double precision is more than twice that of float. For double, double rounding issues will need to be addressed separately, so this patch does not fully fix bug 20255. Tested for x86_64, x86 and powerpc. [BZ #6796] [BZ #20255] [BZ #20256] * math/s_fdim.c: Include <math_private.h>. (__fdim): Use math_narrow_eval on result. * math/s_fdimf.c: Include <math_private.h>. (__fdimf): Use math_narrow_eval on result. * sysdeps/i386/fpu/s_fdim.S: Remove file. * sysdeps/i386/fpu/s_fdimf.S: Likewise. * sysdeps/i386/fpu/s_fdiml.S: Likewise. * sysdeps/i386/i686/fpu/s_fdim.S: Likewise. * sysdeps/i386/i686/fpu/s_fdimf.S: Likewise. * sysdeps/i386/i686/fpu/s_fdiml.S: Likewise. * sysdeps/powerpc/fpu/s_fdim.c: Likewise. * sysdeps/powerpc/fpu/s_fdimf.c: Likewise. * sysdeps/powerpc/powerpc32/fpu/s_fdim.c: Likewise. * sysdeps/powerpc/powerpc64/fpu/s_fdim.c: Likewise. * sysdeps/x86_64/fpu/s_fdiml.S: Likewise. * math/libm-test.inc (fdim_test_data): Expect errno setting on overflow. Add sNaN tests.
* Fix frexp (NaN) (bug 20250).Joseph Myers2016-06-131-1/+8
| | | | | | | | | | | | | | | | | | | | | Various implementations of frexp functions return sNaN for sNaN input. This patch fixes them to add such arguments to themselves so that qNaN is returned. Tested for x86_64, x86, mips64 and powerpc. [BZ #20250] * sysdeps/i386/fpu/s_frexpl.S (__frexpl): Add non-finite input to itself. * sysdeps/ieee754/dbl-64/s_frexp.c (__frexp): Add non-finite or zero input to itself. * sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c (__frexp): Likewise. * sysdeps/ieee754/flt-32/s_frexpf.c (__frexpf): Likewise. * sysdeps/ieee754/ldbl-128/s_frexpl.c (__frexpl): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise. * sysdeps/ieee754/ldbl-96/s_frexpl.c (__frexpl): Likewise. * math/libm-test.inc (frexp_test_data): Add sNaN tests.
* Fix i386/x86_64 log2l (sNaN) (bug 20235).Joseph Myers2016-06-091-0/+1
| | | | | | | | | | | | | | The i386/x86_64 versions of log2l return sNaN for sNaN input. This patch fixes them to add NaN inputs to themselves so that qNaN is returned in this case. Tested for x86_64 and x86. [BZ #20235] * sysdeps/i386/fpu/e_log2l.S (__ieee754_log2l): Add NaN input to itself. * sysdeps/x86_64/fpu/e_log2l.S (__ieee754_log2l): Likewise. * math/libm-test.inc (log2_test_data): Add sNaN tests.
* Fix i386/x86_64 log1pl (sNaN) (bug 20229).Joseph Myers2016-06-081-0/+1
| | | | | | | | | | | | | The i386/x86_64 versions of log1pl return sNaN for sNaN input. This patch fixes them to add a NaN input to itself so that qNaN is returned in this case. Tested for x86_64 and x86. [BZ #20229] * sysdeps/i386/fpu/s_log1pl.S (__log1pl): Add NaN input to itself. * sysdeps/x86_64/fpu/s_log1pl.S (__log1pl): Likewise. * math/libm-test.inc (log1p_test_data): Add sNaN tests.
* Fix i386/x86_64 log10l (sNaN) (bug 20228).Joseph Myers2016-06-081-0/+1
| | | | | | | | | | | | | | The i386/x86_64 versions of log10l return sNaN for sNaN input. This patch fixes them to add a NaN input to itself so that qNaN is returned in this case. Tested for x86_64 and x86. [BZ #20228] * sysdeps/i386/fpu/e_log10l.S (__ieee754_log10l): Add NaN input to itself. * sysdeps/x86_64/fpu/e_log10l.S (__ieee754_log10l): Likewise. * math/libm-test.inc (log10_test_data): Add sNaN tests.
* Fix i386/x86_64 logl (sNaN) (bug 20227).Joseph Myers2016-06-081-0/+1
| | | | | | | | | | | | | | | | The i386/x86_64 versions of logl return sNaN for sNaN input. This patch fixes them to add a NaN input to itself so that qNaN is returned in this case. Tested for x86_64 and x86 (including a build for i586 to cover the non-i686 logl version). [BZ #20227] * sysdeps/i386/fpu/e_logl.S (__ieee754_logl): Add NaN input to itself. * sysdeps/i386/i686/fpu/e_logl.S (__ieee754_logl): Likewise. * sysdeps/x86_64/fpu/e_logl.S (__ieee754_logl): Likewise. * math/libm-test.inc (log_test_data): Add sNaN tests.
* Fix i386/x86_64 expl, exp10l, expm1l for sNaN input (bug 20226).Joseph Myers2016-06-081-2/+5
| | | | | | | | | | | | | | | | | The i386 and x86_64 implementations of expl, exp10l and expm1l (code shared between the functions) return sNaN for sNaN input. This patch fixes them to add NaN inputs to themselves so that qNaN is returned in this case. Tested for x86_64 and x86. [BZ #20226] * sysdeps/i386/fpu/e_expl.S (IEEE754_EXPL): Add NaN argument to itself. * sysdeps/x86_64/fpu/e_expl.S (IEEE754_EXPL): Likewise. * math/libm-test.inc (exp_test_data): Add sNaN tests. (exp10_test_data): Likewise. (expm1_test_data): Likewise.
* Fix i386 cbrtl (sNaN) (bug 20224).Joseph Myers2016-06-081-0/+1
| | | | | | | | | | | | | | | The i386 version of cbrtl returns sNaN (without raising any exceptions) for sNaN input. This patch fixes it to add non-finite arguments to themselves (the code path in question is also reached for zero arguments, for which adding them to themselves is also harmless), so that "invalid" is raised and qNaN returned. Tested for x86_64 and x86. [BZ #20224] * sysdeps/i386/fpu/s_cbrtl.S (__cbrtl): Add non-finite or zero argument to itself. * math/libm-test.inc (cbrt_test_data): Add sNaN tests.
* Fix i386 atanhl (sNaN) (bug 20219).Joseph Myers2016-06-071-0/+1
| | | | | | | | | | | | | The i386 version of atanhl returns sNaN for sNaN input. This patch fixes it to add NaN arguments to themselves so it returns qNaN in this case. Tested for x86_64 and x86. [BZ #20219] * sysdeps/i386/fpu/e_atanhl.S (__ieee754_atanhl): Add NaN argument to itself. * math/libm-test.inc (atanh_test_data): Add sNaN tests.
* Fix i386 asinhl (sNaN) (bug 20218).Joseph Myers2016-06-071-0/+1
| | | | | | | | | | | | | | The i386 version of asinhl returns sNaN (without raising any exceptions) for sNaN input. This patch fixes it to add non-finite arguments to themselves, so that "invalid" is raised and qNaN returned. Tested for x86_64 and x86. [BZ #20218] * sysdeps/i386/fpu/s_asinhl.S (__asinhl): Add non-finite argument to itself. * math/libm-test.inc (asinh_test_data): Add sNaN tests.
* Fix x86/x86_64 nextafterl incrementing negative subnormals (bug 20205).Joseph Myers2016-06-031-1/+1
| | | | | | | | | | | | | | | | | The x86 / x86_64 implementation of nextafterl (also used for nexttowardl) produces incorrect results (NaNs) when negative subnormals, the low 32 bits of whose mantissa are zero, are incremented towards zero. This patch fixes this by disabling the logic to decrement the exponent in that case. Tested for x86_64 and x86. [BZ #20205] * sysdeps/i386/fpu/s_nextafterl.c (__nextafterl): Do not adjust exponent when incrementing negative subnormal with low mantissa word zero. * math/libm-test.inc (nextafter_test_data) [TEST_COND_intel96]: Add another test.
* Fix x86_64 / x86 powl inaccuracy for integer exponents (bug 19848).Joseph Myers2016-03-241-5/+5
| | | | | | | | | | | | | | | | | | | | | | | Bug 19848 reports cases where powl on x86 / x86_64 has error accumulation, for small integer exponents, larger than permitted by glibc's accuracy goals, at least in some rounding modes. This patch further restricts the exponent range for which the small-integer-exponent logic is used to limit the possible error accumulation. Tested for x86_64 and x86 and ulps updated accordingly. [BZ #19848] * sysdeps/i386/fpu/e_powl.S (p3): Rename to p2 and change value from 8 to 4. (__ieee754_powl): Compare integer exponent against 4 not 8. * sysdeps/x86_64/fpu/e_powl.S (p3): Rename to p2 and change value from 8 to 4. (__ieee754_powl): Compare integer exponent against 4 not 8. * math/auto-libm-test-in: Add more tests of pow. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2016-01-0457-57/+57
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* i386: move ULPs to i686/multiarch and regenerate new ones for i386Aurelien Jarno2015-12-201-56/+70
| | | | | | | | | | | | | The i386 ULPs are actually the i686/multiarch ones. The i686/multiarch float ULPs are more precise as the SSE2 version (when available) uses double for the cosf and sinf functions. On the other hand the higher precision of the x86 FPU improves the precision for a few other math functions. * sysdeps/i386/fpu/libm-test-ulps: Move to .... * sysdeps/i386/i686/multiarch/fpu/libm-test-ulps: ...here. * sysdeps/i386/fpu/libm-test-ulps: Regenerate.
* Fix math_private.h multiple include guards.Joseph Myers2015-11-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various math_private.h headers are guarded by "#ifndef _MATH_PRIVATE_H", but never define the macro. Nothing else defines the macro either (the generic math_private.h that they include defines a different macro, _MATH_PRIVATE_H_), so those guards are ineffective. With the recent inclusion of s_sin.c in s_sincos.c, this breaks the build for MIPS, since the build of s_sincos.c ends up including <math_private.h> twice and the MIPS version defines inline functions such as libc_feholdexcept_mips, without a separate fenv_private.h header with its own guards such as some architectures have. This patch fixes all the problem headers to use architecture-specific guard macro names, and to define those macros in the headers they guard, just as some architectures already do. Tested for x86 (testsuite, and that installed shared libraries are unchanged by the patch), and for mips64 (that it fixes the build). * sysdeps/arm/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!ARM_MATH_PRIVATE_H]. [!ARM_MATH_PRIVATE_H] (ARM_MATH_PRIVATE_H): Define macro. * sysdeps/hppa/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!HPPA_MATH_PRIVATE_H]. [!HPPA_MATH_PRIVATE_H] (HPPA_MATH_PRIVATE_H): Define macro. * sysdeps/i386/fpu/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!I386_MATH_PRIVATE_H]. [!I386_MATH_PRIVATE_H] (I386_MATH_PRIVATE_H): Define macro. * sysdeps/m68k/m680x0/fpu/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!M68K_MATH_PRIVATE_H]. [!M68K_MATH_PRIVATE_H] (M68K_MATH_PRIVATE_H): Define macro. * sysdeps/microblaze/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!MICROBLAZE_MATH_PRIVATE_H]. [!MICROBLAZE_MATH_PRIVATE_H] (MICROBLAZE_MATH_PRIVATE_H): Define macro. * sysdeps/mips/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!MIPS_MATH_PRIVATE_H]. [!MIPS_MATH_PRIVATE_H] (MIPS_MATH_PRIVATE_H): Define macro. * sysdeps/nios2/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!NIO2_MATH_PRIVATE_H]. [!NIO2_MATH_PRIVATE_H] (NIO2_MATH_PRIVATE_H): Define macro. * sysdeps/tile/math_private.h [!_MATH_PRIVATE_H]: Change guard to [!TILE_MATH_PRIVATE_H]. [!TILE_MATH_PRIVATE_H] (TILE_MATH_PRIVATE_H): Define macro.
* Fix i386/x86_64 log* (1) zero sign for -ffinite-math-only (bug 19213).Joseph Myers2015-11-053-3/+21
| | | | | | | | | | | | | | | | | | | | | For the -ffinite-math-only versions of various x86_64 and x86 log* functions, a zero result from log* (1) is returned with incorrect sign in round-downward mode. This patch fixes this in a similar way to the previous fixes for the non-*_finite versions of the functions. Tested for x86_64 and x86 (including an i586 build), together with a patch that will be applied separately to enable the main libm-test.inc tests for the finite-math-only functions. [BZ #19213] * sysdeps/i386/fpu/e_log.S (__log_finite): Ensure +0 is always returned for argument 1. * sysdeps/i386/fpu/e_logf.S (__logf_finite): Likewise. * sysdeps/i386/fpu/e_logl.S (__logl_finite): Likewise. * sysdeps/i386/i686/fpu/e_logl.S (__logl_finite): Likewise. * sysdeps/x86_64/fpu/e_log10l.S (__log10l_finite): Likewise. * sysdeps/x86_64/fpu/e_log2l.S (__log2l_finite): Likewise. * sysdeps/x86_64/fpu/e_logl.S (__logl_finite): Likewise.
* Add more libm tests (scalb*, signbit, sin, sincos, sinh, sqrt, tan, tanh, ↵Joseph Myers2015-11-041-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | tgamma, y0, y1, yn, significand). This patch improves the libm test coverage for a few more functions. Tested for x86_64 and x86. * math/auto-libm-test-in: Add more tests of sin, sincos, sinh, sqrt, tan, tanh, y0, y1 and yn. * math/auto-libm-test-out: Regenerated. * math/libm-test.inc (scalb_test_data): Add more tests. (scalbn_test_data): Likewise. (scalbln_test_data): Likewise. (signbit_test_data): Likewise. (sin_test_data): Likewise. (sincos_test_data): Likewise. (sinh_test_data): Likewise. (sqrt_test_data): Likewise. (tan_test_data): Likewise. (tanh_test_data): Likewise. (tgamma_test_data): Likewise. (y0_test_data): Likewise. (y1_test_data): Likewise. (yn_test_data): Likewise. (significand_test_data): Likewise. * sysdeps/i386/fpu/libm-test-ulps: Update.
* Make nextafter, nexttoward set errno (bug 6799).Joseph Myers2015-11-023-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nextafter and nexttoward fail to set errno on overflow and underflow. This patch makes them do so in cases that should include all the cases where such errno setting is required by glibc's goals for when to set errno (but not all cases of underflow where the result is nonzero and so glibc's goals do not require errno setting). Tested for x86_64, x86, mips64 and powerpc. [BZ #6799] * math/s_nextafter.c: Include <errno.h>. (__nextafter): Set errno on overflow and underflow. * math/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/i386/fpu/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * sysdeps/i386/fpu/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/i386/fpu/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/flt-32/s_nextafterf.c: Include <errno.h>. (__nextafterf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-96/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include <errno.h>. (__nldbl_nexttowardf): Set errno on overflow and underflow. * sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * math/libm-test.inc (nextafter_test_data): Do not allow errno setting to be missing on overflow. Add more tests. (nexttoward_test_data): Likewise.
* Handle more state in i386/x86_64 fesetenv (bug 16068).Joseph Myers2015-10-281-10/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fenv_t should include architecture-specific floating-point modes and status flags. i386 and x86_64 fesetenv limit which bits they use from the x87 status and control words, when using saved state, and limit which parts of the state they set to fixed values, when using FE_DFL_ENV / FE_NOMASK_ENV. The following should be included but are excluded in at least some cases: status and masking for the "denormal operand" exception (which isn't part of FE_ALL_EXCEPT); precision control (explicitly mentioned in Annex F as something that counts as part of the floating-point environment); MXCSR FZ and DAZ bits (for FE_DFL_ENV and FE_NOMASK_ENV). This patch arranges for this extra state to be handled by fesetenv (and thereby by feupdateenv, which calls fesetenv). (Note that glibc functions using floating point are not generally expected to work correctly with non-default values of this state, especially precision control, but it is still logically part of the floating-point environment and should be handled as such by fesetenv. Changes to the state relating to subnormals ought generally to work with libm functions when the arguments aren't subnormal and neither are the expected results; that's a consequence of functions avoiding spurious internal underflows.) A question arising from this is whether FE_NOMASK_ENV should or should not mask the "denormal operand" exception. I decided it should mask that exception. This is the status quo - previously that exception could only be unmasked by direct manipulation of control registers (possibly via <fpu_control.h>). In addition, it means that use of FE_NOMASK_ENV leaves a floating-point environment the same as could be obtained by fesetenv (FE_DFL_ENV); feenableexcept (FE_ALL_EXCEPT);, rather than an environment in which an exception is unmasked that could only be masked again by using fesetenv with FE_DFL_ENV (or a previously saved environment) - this exception not being usable with other <fenv.h> functions because it's outside FE_ALL_EXCEPT. Tested for x86_64 and x86. [BZ #16068] * sysdeps/i386/fpu/fesetenv.c: Include <fpu_control.h>. (FE_ALL_EXCEPT_X86): New macro. (__fesetenv): Use FE_ALL_EXCEPT_X86 in most places instead of FE_ALL_EXCEPT. Ensure precision control is included in floating-point state. Ensure that FE_DFL_ENV and FE_NOMASK_ENV handle "denormal operand exception" and clear FZ and DAZ bits. * sysdeps/x86_64/fpu/fesetenv.c: Include <fpu_control.h>. (FE_ALL_EXCEPT_X86): New macro. (__fesetenv): Use FE_ALL_EXCEPT_X86 in most places instead of FE_ALL_EXCEPT. Ensure precision control is included in floating-point state. Ensure that FE_DFL_ENV and FE_NOMASK_ENV handle "denormal operand exception" and clear FZ and DAZ bits. * sysdeps/x86/fpu/test-fenv-sse-2.c: New file. * sysdeps/x86/fpu/test-fenv-x87.c: Likewise. * sysdeps/x86/fpu/Makefile [$(subdir) = math] (tests): Add test-fenv-x87 and test-fenv-sse-2. [$(subdir) = math] (CFLAGS-test-fenv-sse-2.c): New variable.
* Fix i386/x86_64 fesetenv SSE exception clearing (bug 19181).Joseph Myers2015-10-281-0/+4
| | | | | | | | | | | | | | | | | | | | | | | The i386 and x86_64 versions of fesetenv, when called with FE_DFL_ENV or FE_NOMASK_ENV as argument, do not clear SSE exceptions raised in MXCSR. These arguments should, like other fenv_t values, represent the whole of the floating-point state, so such exceptions should be cleared; this patch adds the required clearing. (Discovered while working on bug 16068.) Tested for x86_64 and x86. [BZ #19181] * sysdeps/i386/fpu/fesetenv.c (__fesetenv): Clear already-raised SSE exceptions when argument is FE_DFL_ENV or FE_NOMASK_ENV. * sysdeps/x86_64/fpu/fesetenv.c (__fesetenv): Likewise. * math/test-fenv-clear-main.c: New file. * math/test-fenv-clear.c: Likewise. * math/Makefile (tests): Add test-fenv-clear. * sysdeps/x86/fpu/test-fenv-clear-sse.c: New file. * sysdeps/x86/fpu/Makefile [$(subdir) = math] (tests): Add test-fenv-clear-sse. [$(subdir) = math] (CFLAGS-test-fenv-clear-sse.c): New variable.
* Fix i386 / x86_64 nearbyint exception clearing (bug 15491).Joseph Myers2015-10-223-42/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
* Fix nexttoward overflow in non-default rounding modes (bug 19059).Joseph Myers2015-10-022-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ISO C requires overflowing results from nexttoward to be the appropriate infinity independent of the rounding mode, but some implementations use a rounding-mode-dependent result (this is the same issue as was fixed for nextafter in bug 16677). This patch fixes the problem by making the nexttoward implementations discard the result from the floating-point computation that forced an overflow exception and then return the infinity previously computed with integer arithmetic. Tested for x86_64, x86, mips64 and powerpc. [BZ #19059] * math/s_nexttowardf.c (__nexttowardf): Do not return value from overflowing computation. * sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise. * sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Likewise. * sysdeps/ieee754/ldbl-128/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Likewise. * sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf): Likewise. * math/libm-test.inc (nexttoward_test_data): Add more tests.
* Fix i386 acosh (-qNaN) spurious "invalid" exception.Joseph Myers2015-09-302-4/+6
| | | | | | | | | | | | | | | | | | The i386 versions of acoshf and acosh raise a spurious "invalid" exception for an argument that is a quiet NaN with the sign bit set. The integer arithmetic to detect arguments < 1 also detects -NaN, and then the computation 0 / 0 in that case raises the exception. This patch fixes this by using (x - x) / (x - x) as the computation in that case instead, which will always raise the exception for non-NaN arguments reaching that code, but not for quiet NaN arguments. Tested for x86_64 and x86. [BZ #19032] * sysdeps/i386/fpu/e_acosh.S (__ieee754_acosh): For arguments < 1, compute result as (x - x) / (x - x) not as 0 / 0. * sysdeps/i386/fpu/e_acoshf.S (__ieee754_acoshf): Likewise. * math/libm-test.inc (acosh_test_data): Add another test of acosh.
* Fix clog, clog10 inaccuracy (bug 19016).Joseph Myers2015-09-281-40/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For arguments with X^2 + Y^2 close to 1, clog and clog10 avoid large errors from log(hypot) by computing X^2 + Y^2 - 1 in a way that avoids cancellation error and then using log1p. However, the thresholds for using that approach still result in log being used on argument as large as sqrt(13/16) > 0.9, leading to significant errors, in some cases above the 9ulp maximum allowed in glibc libm. This patch arranges for the approach using log1p to be used in any cases where |X|, |Y| < 1 and X^2 + Y^2 >= 0.5 (with the existing allowance for cases where one of X and Y is very small), adjusting the __x2y2m1 functions to work with the wider range of inputs. This way, log only gets used on arguments below sqrt(1/2) (or substantially above 1), where the error involved is much less. Tested for x86_64, x86, mips64 and powerpc. For the ulps regeneration I removed the existing clog and clog10 ulps before regenerating to allow any reduced ulps to appear. Tests added include those found by random test generation to produce large ulps either before or after the patch, and some found by trying inputs close to the (0.75, 0.5) threshold where the potential errors from using log are largest. [BZ #19016] * sysdeps/generic/math_private.h (__x2y2m1f): Update comment to allow more cases with X^2 + Y^2 >= 0.5. * sysdeps/ieee754/dbl-64/x2y2m1.c (__x2y2m1): Likewise. Add -1 as normal element in sum instead of special-casing based on values of arguments. * sysdeps/ieee754/dbl-64/x2y2m1f.c (__x2y2m1f): Update comment. * sysdeps/ieee754/ldbl-128/x2y2m1l.c (__x2y2m1l): Likewise. Add -1 as normal element in sum instead of special-casing based on values of arguments. * sysdeps/ieee754/ldbl-128ibm/x2y2m1l.c (__x2y2m1l): Likewise. * sysdeps/ieee754/ldbl-96/x2y2m1.c [FLT_EVAL_METHOD != 0] (__x2y2m1): Update comment. * sysdeps/ieee754/ldbl-96/x2y2m1l.c (__x2y2m1l): Likewise. Add -1 as normal element in sum instead of special-casing based on values of arguments. * math/s_clog.c (__clog): Handle more cases using log1p without hypot. * math/s_clog10.c (__clog10): Likewise. * math/s_clog10f.c (__clog10f): Likewise. * math/s_clog10l.c (__clog10l): Likewise. * math/s_clogf.c (__clogf): Likewise. * math/s_clogl.c (__clogl): Likewise. * math/auto-libm-test-in: Add more tests of clog and clog10. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
* Fix pow missing underflows (bug 18825).Joseph Myers2015-09-254-5/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to various other bugs in this area, pow functions can fail to raise the underflow exception when the result is tiny and inexact but one or more low bits of the intermediate result that is scaled down (or, in the i386 case, converted from a wider evaluation format) are zero. This patch forces the exception in a similar way to previous fixes, thereby concluding the fixes for known bugs with missing underflow exceptions currently filed in Bugzilla. Tested for x86_64, x86, mips64 and powerpc. [BZ #18825] * sysdeps/i386/fpu/i386-math-asm.h (FLT_NARROW_EVAL_UFLOW_NONNAN): New macro. (DBL_NARROW_EVAL_UFLOW_NONNAN): Likewise. (LDBL_CHECK_FORCE_UFLOW_NONNAN): Likewise. * sysdeps/i386/fpu/e_pow.S: Use DEFINE_DBL_MIN. (__ieee754_pow): Use DBL_NARROW_EVAL_UFLOW_NONNAN instead of DBL_NARROW_EVAL, reloading the PIC register as needed. * sysdeps/i386/fpu/e_powf.S: Use DEFINE_FLT_MIN. (__ieee754_powf): Use FLT_NARROW_EVAL_UFLOW_NONNAN instead of FLT_NARROW_EVAL. Use separate return path for case when first argument is NaN. * sysdeps/i386/fpu/e_powl.S: Include <i386-math-asm.h>. Use DEFINE_LDBL_MIN. (__ieee754_powl): Use LDBL_CHECK_FORCE_UFLOW_NONNAN, reloading the PIC register. * sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Use math_check_force_underflow_nonneg. * sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): Force underflow for subnormal result. * sysdeps/ieee754/ldbl-128/e_powl.c (__ieee754_powl): Likewise. * sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Use math_check_force_underflow_nonneg. * sysdeps/x86/fpu/powl_helper.c (__powl_helper): Use math_check_force_underflow. * sysdeps/x86_64/fpu/x86_64-math-asm.h (LDBL_CHECK_FORCE_UFLOW_NONNAN): New macro. * sysdeps/x86_64/fpu/e_powl.S: Include <x86_64-math-asm.h>. Use DEFINE_LDBL_MIN. (__ieee754_powl): Use LDBL_CHECK_FORCE_UFLOW_NONNAN. * math/auto-libm-test-in: Add more tests of pow. * math/auto-libm-test-out: Regenerated.
* Fix hypot missing underflows (bug 18803).Joseph Myers2015-09-241-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to various other bugs in this area, hypot functions can fail to raise the underflow exception when the result is tiny and inexact but one or more low bits of the intermediate result that is scaled down (or, in the i386 case, converted from a wider evaluation format) are zero. This patch forces the exception in a similar way to previous fixes. Note that this issue cannot arise for implementations of hypotf using double (or wider) for intermediate evaluation (if hypotf should underflow, that means the double square root is being computed of some number of the form N*2^-298, for 0 < N < 2^46, which is exactly represented as a double, and whatever the rounding mode such a square root cannot have a mantissa with all zeroes after the initial 23 bits). Thus no changes are made to hypotf implementations in this patch, only to hypot and hypotl. Tested for x86_64, x86, mips64 and powerpc. [BZ #18803] * sysdeps/i386/fpu/e_hypot.S: Use DEFINE_DBL_MIN. (MO): New macro. (__ieee754_hypot) [PIC]: Load PIC register. (__ieee754_hypot): Use DBL_NARROW_EVAL_UFLOW_NONNEG instead of DBL_NARROW_EVAL. * sysdeps/ieee754/dbl-64/e_hypot.c (__ieee754_hypot): Use math_check_force_underflow_nonneg in case where result might be tiny. * sysdeps/ieee754/ldbl-128/e_hypotl.c (__ieee754_hypotl): Likewise. * sysdeps/ieee754/ldbl-128ibm/e_hypotl.c (__ieee754_hypotl): Likewise. * sysdeps/ieee754/ldbl-96/e_hypotl.c (__ieee754_hypotl): Likewise. * sysdeps/powerpc/fpu/e_hypot.c (__ieee754_hypot): Likewise. * math/auto-libm-test-in: Add more tests of hypot. * math/auto-libm-test-out: Regenerated.
* Use LOAD_PIC_REG in i386 atanh.Joseph Myers2015-09-241-5/+1
| | | | | | | | | | | | | sysdeps/i386/fpu/e_atanh.S, unlike all other functions in that directory, loads the PIC register with its own code using _GLOBAL_OFFSET_TABLE_, rather than with the LOAD_PIC_REG macro. I see no good reason for the difference; this patch makes it use the common macro. Tested for x86. * sysdeps/i386/fpu/e_atanh.S (__ieee754_atanh) [PIC]: Use LOAD_PIC_REG.
* Refactor i386 libm code forcing underflow exceptions.Joseph Myers2015-09-2416-316/+244
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch refactors code in sysdeps/i386/fpu that forces underflow exceptions to use common macros for that purpose as far as possible. (Although some of the macros end up used in only one place, I think it's cleanest to define all these macros together so that all the code forcing underflow uses such macros. Some more uses of such macros will also be introduced when fixing remaining bugs about missing underflow exceptions, and it would be possible to do further refactoring of the macros in i386-math-asm.h to share more code by using other macros internally. Places that test for underflow by examining the representation of the argument with integer operations, rather that using floating-point comparisons on the argument or result, are unchanged by this patch.) Most of this code uses a macro MO to abstract away the differences between PIC and non-PIC memory references to constants. log1p functions, however, hardcoded PIC conditionals for this. Because the common macros rely on the use of MO, I changed the log1p functions to use the normal style here, and, for consistency, also made that change to log1pl which is otherwise unaffected by this patch. Tested for x86. * sysdeps/i386/fpu/i386-math-asm.h (DEFINE_LDBL_MIN): New macro. (FLT_CHECK_FORCE_UFLOW): Likewise. (DBL_CHECK_FORCE_UFLOW): Likewise. (FLT_CHECK_FORCE_UFLOW_NARROW): Likewise. (DBL_CHECK_FORCE_UFLOW_NARROW): Likewise. (LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN): Likewise. (FLT_CHECK_FORCE_UFLOW_NONNAN): Likewise. (DBL_CHECK_FORCE_UFLOW_NONNAN): Likewise. (FLT_CHECK_FORCE_UFLOW_NONNEG): Likewise. (DBL_CHECK_FORCE_UFLOW_NONNEG): Likewise. (LDBL_CHECK_FORCE_UFLOW_NONNEG): Likewise. * sysdeps/i386/fpu/e_asin.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_asin): Use DBL_CHECK_FORCE_UFLOW. * sysdeps/i386/fpu/e_asinf.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_asinf): Use FLT_CHECK_FORCE_UFLOW. * sysdeps/i386/fpu/e_atan2.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_atan2): Use DBL_CHECK_FORCE_UFLOW_NARROW. * sysdeps/i386/fpu/e_atan2f.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_atan2f): Use FLT_CHECK_FORCE_UFLOW_NARROW. * sysdeps/i386/fpu/e_atanh.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_atanh): Use DBL_CHECK_FORCE_UFLOW_NONNEG. * sysdeps/i386/fpu/e_atanhf.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_atanhf): Use FLT_CHECK_FORCE_UFLOW_NONNEG. * sysdeps/i386/fpu/e_exp2l.S: Include <i386-math-asm.h>. (ldbl_min): Replace with use of DEFINE_LDBL_MIN. (__ieee754_exp2l): Use LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_expl.S: Include <i386-math-asm.h>. [!USE_AS_EXPM1L] (cmin): Replace with use of DEFINE_LDBL_MIN. (IEEE754_EXPL): Use LDBL_CHECK_FORCE_UFLOW_NONNEG. * sysdeps/i386/fpu/s_atan.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__atan): Use DBL_CHECK_FORCE_UFLOW. * sysdeps/i386/fpu/s_atanf.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__atanf): Use FLT_CHECK_FORCE_UFLOW. * sysdeps/i386/fpu/s_expm1.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__expm1): Use DBL_CHECK_FORCE_UFLOW. Move underflow check after main computation. * sysdeps/i386/fpu/s_expm1f.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__expm1f): Use FLT_CHECK_FORCE_UFLOW. Move underflow check after main computation. * sysdeps/i386/fpu/s_log1p.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (MO): New macro. (__log1p): Use MO. Use DBL_CHECK_FORCE_UFLOW_NONNAN. * sysdeps/i386/fpu/s_log1pf.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (MO): New macro. (__log1pf): Use MO. Use FLT_CHECK_FORCE_UFLOW_NONNAN. * sysdeps/i386/fpu/s_log1pl.S (MO): New macro. (__log1pl): Use MO.
* Use math_narrow_eval more consistently.Joseph Myers2015-09-232-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Where glibc code needs to avoid excess range and precision in floating-point arithmetic, code variously uses either asms or volatile to force the results of that arithmetic to memory; mostly this is conditional on FLT_EVAL_METHOD, but in the case of lrint / llrint functions some use of volatile is unconditional (and is present unnecessarily in versions for long double). This patch make such code use the recently-added math_narrow_eval macro consistently, removing the unnecessary uses of volatile in long double lrint / llrint implementations completely. Tested for x86_64, x86, mips64 and powerpc. * math/s_nexttowardf.c (__nexttowardf): Use math_narrow_eval. * stdlib/strtod_l.c: Include <math_private.h>. (overflow_value): Use math_narrow_eval. (underflow_value): Likewise. * sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise. * sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Likewise. (__ieee754_gamma_r): Likewise. * sysdeps/ieee754/dbl-64/gamma_productf.c (__gamma_productf): Likewise. * sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2): Likewise. * sysdeps/ieee754/dbl-64/lgamma_neg.c (__lgamma_neg): Likewise. * sysdeps/ieee754/dbl-64/s_erf.c (__erfc): Likewise. * sysdeps/ieee754/dbl-64/s_llrint.c (__llrint): Likewise. * sysdeps/ieee754/dbl-64/s_lrint.c (__lrint): Likewise. * sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Likewise. (__ieee754_gammaf_r): Likewise. * sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f): Likewise. * sysdeps/ieee754/flt-32/lgamma_negf.c (__lgamma_negf): Likewise. * sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Likewise. * sysdeps/ieee754/flt-32/s_llrintf.c (__llrintf): Likewise. * sysdeps/ieee754/flt-32/s_lrintf.c (__lrintf): Likewise. * sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl): Do not use volatile. * sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl): Likewise. * sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Use math_narrow_eval. * sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/ldbl-96/gamma_product.c (__gamma_product): Likewise. * sysdeps/ieee754/ldbl-96/s_llrintl.c (__llrintl): Do not use volatile. * sysdeps/ieee754/ldbl-96/s_lrintl.c (__lrintl): Likewise. * sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Use math_narrow_eval. * sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf): Likewise. * sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf): Likewise.
* Avoid excess range in results from i386 exp, hypot, pow functions (bug 18980).Joseph Myers2015-09-1812-278/+244
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | i386 exp, hypot and pow functions can return overflowing and underflowing values with excess range and precision; ; Wilco Dijkstra's patches to make isfinite etc. expand inline cause this pre-existing issue to result in test failures. This patch fixes those functions to avoid excess range and precision in their return values. Appropriate macros are added for the repeated code sequences; in future I'll add more such macros and refactor existing code forcing underflow (with or without also eliminating excess range and precision from the return value) to use such macros. Tested for x86. If, after this patch, you still see x86 libm test failures with excess range or precision, please file bugs in Bugzilla. [BZ #18980] * sysdeps/i386/fpu/i386-math-asm.h (DEFINE_FLT_MIN): New macro. (DEFINE_DBL_MIN): Likewise. (FLT_NARROW_EVAL_UFLOW_NONNEG_NAN): Likewise. (DBL_NARROW_EVAL_UFLOW_NONNEG_NAN): Likewise. (FLT_NARROW_EVAL_UFLOW_NONNEG): Likewise. (DBL_NARROW_EVAL_UFLOW_NONNEG): Likewise. * sysdeps/i386/fpu/e_exp.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_exp): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN. (__exp_finite): Use DBL_NARROW_EVAL_UFLOW_NONNEG. * sysdeps/i386/fpu/e_exp10.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_exp10): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_exp10f.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_exp10f): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_exp2.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_exp2): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_exp2f.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_exp2f): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_expf.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_expf): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN. (__expf_finite): Use FLT_NARROW_EVAL_UFLOW_NONNEG. * sysdeps/i386/fpu/e_hypot.S: Include <i386-math-asm.h>. (__ieee754_hypot): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/e_hypotf.S: Include <i386-math-asm.h>. (__ieee754_hypotf): Use FLT_NARROW_EVAL. * sysdeps/i386/fpu/e_pow.S: Include <i386-math-asm.h>. (__ieee754_pow): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/e_powf.S: Include <i386-math-asm.h>. (__ieee754_powf): Use FLT_NARROW_EVAL. * sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S (__ieee754_expf_sse2): Convert double-precision result to single precision. * sysdeps/i386/fpu/libm-test-ulps: Update.
* Avoid excess range in results from i386 scalb functions (bug 18981).Joseph Myers2015-09-185-0/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | i386 scalb / scalbn / scalbln (and thus ldexp) functions for float and double can return results with excess range (and consequently excess precision for subnormal results). As the results of these functions are fully determined by reference to IEEE 754 operations, this is unambiguously a bug, apart from the testsuite failures it causes. This patch makes those functions store their results on the stack and load them back to eliminate the excess range. Double rounding is not a problem, as the only cases where it could occur are when the result overflows or underflows for extended precision, and then the double-rounded results are the same as the single-rounded results. The new macros will be used for more functions, more such macros added, and existing code refactored to use such macros, in subsequent patches. Tested for x86. Committed. [BZ #18981] * sysdeps/i386/fpu/i386-math-asm.h: New file. * sysdeps/i386/fpu/e_scalb.S: Include <i386-math-asm.h>. (__ieee754_scalb): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/e_scalbf.S: Include <i386-math-asm.h>. (__ieee754_scalbf): Use FLT_NARROW_EVAL. * sysdeps/i386/fpu/s_scalbn.S: Include <i386-math-asm.h>. (__scalbn): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/s_scalbnf.S: Include <i386-math-asm.h>. (__scalbnf): Use FLT_NARROW_EVAL.
* Make scalbn set errno (bug 6803).Joseph Myers2015-09-163-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As noted in bug 6803, scalbn fails to set errno on overflow and underflow. This patch fixes this by making scalbn an alias of ldexp, which has exactly the same semantics (for floating-point types with radix 2) and already has wrappers that deal with setting errno, instead of an alias of the internal __scalbn (which ldexp calls). Notes: * Where compat symbols were defined for scalbn functions, I didn't change what they point to (to keep the patch minimal), so such compat symbols continue to go directly to the non-errno-setting functions. * Mike, I didn't do anything with the IA64 versions of these functions, where I think both the ldexp and scalbn functions already deal with setting errno. As a cleanup (not needed to fix this bug) however you might want to make those functions into aliases for IA64; there is no need for them to be separate function implementations at all. * This concludes the fix for bug 6803 since the scalb and scalbln cases of that bug were fixed some time ago. Tested for x86_64, x86, mips64 and powerpc. [BZ #6803] * math/s_ldexp.c (scalbn): Define as weak alias of __ldexp. [NO_LONG_DOUBLE] (scalbnl): Define as weak alias of __ldexp. * math/s_ldexpf.c (scalbnf): Define as weak alias of __ldexpf. * math/s_ldexpl.c (scalbnl): Define as weak alias of __ldexpl. * sysdeps/i386/fpu/s_scalbn.S (scalbn): Remove alias. * sysdeps/i386/fpu/s_scalbnf.S (scalbnf): Likewise. * sysdeps/i386/fpu/s_scalbnl.S (scalbnl): Likewise. * sysdeps/ieee754/dbl-64/s_scalbn.c (scalbn): Likewise. [NO_LONG_DOUBLE] (scalbnl): Likewise. * sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c (scalbn): Likewise. [NO_LONG_DOUBLE] (scalbnl): Likewise. * sysdeps/ieee754/flt-32/s_scalbnf.c (scalbnf): Likewise. * sysdeps/ieee754/ldbl-128/s_scalbnl.c (scalbnl): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c (scalbnl): Remove long_double_symbol calls. * sysdeps/ieee754/ldbl-64-128/s_scalbnl.c (scalbnl): Likewise. * sysdeps/ieee754/ldbl-opt/s_ldexpl.c (__ldexpl_2): Define as strong alias of __ldexpl. (scalbnl): Define using long_double_symbol. * sysdeps/m68k/m680x0/fpu/s_scalbn.c (__CONCATX(scalbn,suffix)): Remove alias. * sysdeps/sparc/sparc64/soft-fp/s_scalbnl.c (scalbnl): Likewise. * sysdeps/x86_64/fpu/s_scalbnl.S (scalbnl): Likewise. * math/libm-test.inc (scalbn_test_data): Add errno expectations. (scalbln_test_data): Add more errno expectations.
* Fix i386 exp10 missing underflows (bug 18966).Joseph Myers2015-09-152-2/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | On i386, the double version of exp10 can miss underflow exceptions if the result is in the subnormal range for double but the last 11 bits of the 64-bit extended-precision mantissa happen to be zero. This patch forces the exception in a similar way to previous fixes. As with the exp2 and exp fixes, the exp10f changes may in fact not be needed to ensure underflow exceptions, but are included for consistency and to fix the exp10 part of bug 18875 by ensuring that excess range and precision is removed from underflowing return values. Tested for x86_64 and x86. [BZ #18875] [BZ #18966] * sysdeps/i386/fpu/e_exp10.S (dbl_min): New object. (MO): New macro. (__ieee754_exp10): For small results, force underflow exception and remove excess range and precision from return value. * sysdeps/i386/fpu/e_exp10f.S (flt_min): New object. (MO): New macro. (__ieee754_exp10f): For small results, force underflow exception and remove excess range and precision from return value. * math/auto-libm-test-in: Add more tests of exp10. * math/auto-libm-test-out: Regenerated.
* Fix i386 exp missing underflows (bug 18961).Joseph Myers2015-09-142-4/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | On i386, the double version of exp can miss underflow exceptions if the result is in the subnormal range for double but the last 11 bits of the 64-bit extended-precision mantissa happen to be zero. This patch forces the exception in a similar way to previous fixes. As with the exp2 fixes, the expf changes may in fact not be needed to ensure underflow exceptions, but are included for consistency and to fix the exp part of bug 18875 by ensuring that excess range and precision is removed from underflowing return values. Tested for x86_64 and x86. [BZ #18875] [BZ #18961] * sysdeps/i386/fpu/e_exp.S (dbl_min): New object. (MO): New macro. (__ieee754_exp): For small results, force underflow exception and remove excess range and precision from return value. (__exp_finite): Likewise. * sysdeps/i386/fpu/e_expf.S (flt_min): New object. (MO): New macro. (__ieee754_expf): For small results, force underflow exception and remove excess range and precision from return value. (__expf_finite): Likewise. * math/auto-libm-test-in: Add more tests of exp. * math/auto-libm-test-out: Regenerated.
* Fix exp2 missing underflows (bug 16521).Joseph Myers2015-09-143-3/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various exp2 implementations in glibc can miss underflow exceptions when the scaling down part of the calculation is exact (or, in the x86 case, when the conversion from extended precision to the target precision is exact). This patch forces the exception in a similar way to previous fixes. The x86 exp2f changes may in fact not be needed for this purpose - it's likely to be the case that no argument of type float has an exp2 result so close to an exact subnormal float value that it equals that value when rounded to 64 bits (even taking account of variation between different x86 implementations). However, they are included for consistency with the changes to exp2 and so as to fix the exp2f part of bug 18875 by ensuring that excess range and precision is removed from underflowing return values. Tested for x86_64, x86 and mips64. [BZ #16521] [BZ #18875] * math/e_exp2l.c (__ieee754_exp2l): Force underflow exception for small results. * sysdeps/i386/fpu/e_exp2.S (dbl_min): New object. (MO): New macro. (__ieee754_exp2): For small results, force underflow exception and remove excess range and precision from return value. * sysdeps/i386/fpu/e_exp2f.S (flt_min): New object. (MO): New macro. (__ieee754_exp2f): For small results, force underflow exception and remove excess range and precision from return value. * sysdeps/i386/fpu/e_exp2l.S (ldbl_min): New object. (MO): New macro. (__ieee754_exp2l): Force underflow exception for small results. * sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Likewise. * sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise. * sysdeps/x86_64/fpu/e_exp2l.S (ldbl_min): New object. (MO): New macro. (__ieee754_exp2l): Force underflow exception for small results. * math/auto-libm-test-in: Add more tests or exp2. * math/auto-libm-test-out: Regenerated.
* Add more random libm test inputs (mainly for ldbl-128).Joseph Myers2015-09-121-2/+2
| | | | | | | | | | | | | | | | | | | | | This patch adds more libm test inputs found through random test generation to increase previously known ulps. This particular test generation was run for mips64, so most of the increased ulps are for ldbl-128 (float and double having been fairly well covered by such testing for x86_64), but there's the odd ulps increase for other formats. Tested for x86_64, x86 and mips64. * math/auto-libm-test-in: Add more tests of acos, acosh, asin, asinh, atan, atan2, atanh, cabs, carg, cos, csqrt, erfc, exp, exp10, exp2, log, log1p, log2, pow, sin, sincos, sinh, tan and tanh. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/mips/mips32/libm-test-ulps: Likewise. * sysdeps/mips/mips64/libm-test-ulps: Likewise. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
* Add more randomly-generated libm tests.Joseph Myers2015-09-111-6/+6
| | | | | | | | | | | | | This patch adds more libm test inputs found through random test generation to increase observed ulps on x86_64. Tested for x86_64 and x86. * math/auto-libm-test-in: Add more tests of acosh, atanh, cbrt, cosh, csqrt, erfc, expm1 and lgamma. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
* Fix lgamma (negative) inaccuracy (bug 2542, bug 2543, bug 2558).Joseph Myers2015-09-101-48/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing implementations of lgamma functions (except for the ia64 versions) use the reflection formula for negative arguments. This suffers large inaccuracy from cancellation near zeros of lgamma (near where the gamma function is +/- 1). This patch fixes this inaccuracy. For arguments above -2, there are no zeros and no large cancellation, while for sufficiently large negative arguments the zeros are so close to integers that even for integers +/- 1ulp the log(gamma(1-x)) term dominates and cancellation is not significant. Thus, it is only necessary to take special care about cancellation for arguments around a limited number of zeros. Accordingly, this patch uses precomputed tables of relevant zeros, expressed as the sum of two floating-point values. The log of the ratio of two sines can be computed accurately using log1p in cases where log would lose accuracy. The log of the ratio of two gamma(1-x) values can be computed using Stirling's approximation (the difference between two values of that approximation to lgamma being computable without computing the two values and then subtracting), with appropriate adjustments (which don't reduce accuracy too much) in cases where 1-x is too small to use Stirling's approximation directly. In the interval from -3 to -2, using the ratios of sines and of gamma(1-x) can still produce too much cancellation between those two parts of the computation (and that interval is also the worst interval for computing the ratio between gamma(1-x) values, which computation becomes more accurate, while being less critical for the final result, for larger 1-x). Because this can result in errors slightly above those accepted in glibc, this interval is instead dealt with by polynomial approximations. Separate polynomial approximations to (|gamma(x)|-1)(x-n)/(x-x0) are used for each interval of length 1/8 from -3 to -2, where n (-3 or -2) is the nearest integer to the 1/8-interval and x0 is the zero of lgamma in the relevant half-integer interval (-3 to -2.5 or -2.5 to -2). Together, the two approaches are intended to give sufficient accuracy for all negative arguments in the problem range. Outside that range, the previous implementation continues to be used. Tested for x86_64, x86, mips64 and powerpc. The mips64 and powerpc testing shows up pre-existing problems for ldbl-128 and ldbl-128ibm with large negative arguments giving spurious "invalid" exceptions (exposed by newly added tests for cases this patch doesn't affect the logic for); I'll address those problems separately. [BZ #2542] [BZ #2543] [BZ #2558] * sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r): Call __lgamma_neg for arguments from -28.0 to -2.0. * sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Call __lgamma_negf for arguments from -15.0 to -2.0. * sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r): Call __lgamma_negl for arguments from -48.0 or -50.0 to -2.0. * sysdeps/ieee754/ldbl-96/e_lgammal_r.c (__ieee754_lgammal_r): Call __lgamma_negl for arguments from -33.0 to -2.0. * sysdeps/ieee754/dbl-64/lgamma_neg.c: New file. * sysdeps/ieee754/dbl-64/lgamma_product.c: Likewise. * sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise. * sysdeps/ieee754/flt-32/lgamma_productf.c: Likewise. * sysdeps/ieee754/ldbl-128/lgamma_negl.c: Likewise. * sysdeps/ieee754/ldbl-128/lgamma_productl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/lgamma_negl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/lgamma_productl.c: Likewise. * sysdeps/ieee754/ldbl-96/lgamma_negl.c: Likewise. * sysdeps/ieee754/ldbl-96/lgamma_product.c: Likewise. * sysdeps/ieee754/ldbl-96/lgamma_productl.c: Likewise. * sysdeps/generic/math_private.h (__lgamma_negf): New prototype. (__lgamma_neg): Likewise. (__lgamma_negl): Likewise. (__lgamma_product): Likewise. (__lgamma_productl): Likewise. * math/Makefile (libm-calls): Add lgamma_neg and lgamma_product. * math/auto-libm-test-in: Add more tests of lgamma. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
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