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* Update math: redirect roundeven functionH.J. Lu2022-09-291-0/+1
| | | | | | | Redirect target specific roundeven functions for aarch64, ldbl-128ibm and riscv. (cherry picked from commit 3213ed770cbc5821920d16caa93c85e92dd7b9f6)
* Use GCC builtins for roundeven functions if desired.Shen-Ta Hsieh2022-09-294-0/+17
| | | | | | | | | | | | | | This patch is using the corresponding GCC builtin for roundevenf, roundeven and roundevenl if the USE_FUNCTION_BUILTIN macros are defined to one in math-use-builtins.h. These builtin functions is supported since GCC 10. The code of the generic implementation is not changed. Signed-off-by: Shen-Ta Hsieh <ibmibmibm.tw@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com> (cherry picked from commit eb9066203f6e07128d42f771def4b7ad37b25dc1)
* math: redirect roundeven functionShen-Ta Hsieh2022-09-295-1/+9
| | | | | | | | This patch redirect roundeven function for futhermore changes. Signed-off-by: Shen-Ta Hsieh <ibmibmibm.tw@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com> (cherry picked from commit 447954a206837b5f153869cfeeeab44631c3fac9)
* math: Add BZ#18980 fix back on dbl-64 coshAdhemerval Zanella2021-01-111-1/+2
| | | | | | | It is regression from 9e97f239eae1f2b1 (Remove dbl-64/wordsize-64 (part 2)) where is missed to add the BZ#18980 fix (9e97f239eae1f2b1). Checked on i686-linux-gnu.
* Remove dbl-64/wordsize-64 (part 2)Wilco Dijkstra2021-01-0734-1837/+422
| | | | | | | | Remove the wordsize-64 implementations by merging them into the main dbl-64 directory. The second patch just moves all wordsize-64 files and removes a few wordsize-64 uses in comments and Implies files. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove dbl-64/wordsize-64Wilco Dijkstra2021-01-074-4/+31
| | | | | | | | | | Remove the wordsize-64 implementations by merging them into the main dbl-64 directory. The first patch adds special cases needed for 32-bit targets (FIX_INT_FP_CONVERT_ZERO and FIX_DBL_LONG_CONVERT_OVERFLOW) to the wordsize-64 versions. This has no effect on 64-bit targets since they don't define these macros. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Drop nan-pseudo-number.h usage from testsSiddhesh Poyarekar2021-01-041-3/+1
| | | | | | | | | | Make the tests use TEST_COND_intel96 to decide on whether to build the unnormal tests instead of the macro in nan-pseudo-number.h and then drop the header inclusion. This unbreaks test runs on all architectures that do not have ldbl-96. Also drop the HANDLE_PSEUDO_NUMBERS macro since it is not used anywhere.
* Move generic nan-pseudo-number.h to ldbl-96Siddhesh Poyarekar2021-01-041-0/+31
| | | | | The concept of pseudo number formats only exists in the realm of the 96 bit long double format.
* Update copyright dates with scripts/update-copyrightsPaul Eggert2021-01-02475-475/+475
| | | | | | | | | | | | | | | | I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
* x86 long double: Consider pseudo numbers as signalingSiddhesh Poyarekar2020-12-301-3/+8
| | | | | | | Add support to treat pseudo-numbers specially and implement x86 version to consider all of them as signaling. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* ieee754: Remove unused __sin32 and __cos32Anssi Hannula2020-12-181-62/+0
| | | | | The __sin32 and __cos32 functions were only used in the now removed slow path of asin and acos.
* ieee754: Remove slow paths from asin and acosAnssi Hannula2020-12-181-61/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | asin and acos have slow paths for rounding the last bit that cause some calls to be 500-1500x slower than average calls. These slow paths are rare, a test of a trillion (1.000.000.000.000) random inputs between -1 and 1 showed 32870 slow calls for acos and 4473 for asin, with most occurrences between -1.0 .. -0.9 and 0.9 .. 1.0. The slow paths claim correct rounding and use __sin32() and __cos32() (which compare two result candidates and return the closest one) as the final step, with the second result candidate (res1) having a small offset applied from res. This suggests that res and res1 are intended to be 1 ULP apart (which makes sense for rounding), barring bugs, allowing us to pick either one and still remain within 1 ULP of the exact result. Remove the slow paths as the accuracy is better than 1 ULP even without them, which is enough for glibc. Also remove code comments claiming correctly rounded results. After slow path removal, checking the accuracy of 14.400.000.000 random asin() and acos() inputs showed only three incorrectly rounded (error > 0.5 ULP) results: - asin(-0x1.ee2b43286db75p-1) (0.500002 ULP, same as before) - asin(-0x1.f692ba202abcp-4) (0.500003 ULP, same as before) - asin(-0x1.9915e876fc062p-1) (0.50000000001 ULP, previously exact) The first two had the same error even before this commit, and they did not use the slow path at all. Checking 4934 known randomly found previously-slow-path asin inputs shows 25 calls with incorrectly rounded results, with a maximum error of 0.500000002 ULP (for 0x1.fcd5742999ab8p-1). The previous slow-path code rounded all these inputs correctly (error < 0.5 ULP). The observed average speed increase was 130x. Checking 36240 known randomly found previously-slow-path acos inputs shows 42 calls with incorrectly rounded results, with a maximum error of 0.500000008 ULP (for 0x1.f63845056f35ep-1). The previous "exact" slow-path code showed 34 calls with incorrectly rounded results, with the same maximum error of 0.500000008 ULP (for 0x1.f63845056f35ep-1). The observed average speed increase was 130x. The functions could likely be trimmed more while keeping acceptable accuracy, but this at least gets rid of the egregiously slow cases. Tested on x86_64.
* Remove tls.h inclusion from internal errno.hAdhemerval Zanella2020-11-131-3/+0
| | | | | | | | | | | | The tls.h inclusion is not really required and limits possible definition on more arch specific headers. This is a cleanup to allow inline functions on sysdep.h, more specifically on i386 and ia64 which requires to access some tls definitions its own. No semantic changes expected, checked with a build against all affected ABIs.
* math: Fix inaccuracy of j0f for x >= 2^127 when sin(x)+cos(x) is tinyPaul Zimmermann2020-08-071-1/+16
| | | | Checked on x86_64-linux-gnu and i686-linux-gnu.
* Use C2x return value from getpayload of non-NaN (bug 26073).Joseph Myers2020-07-066-0/+18
| | | | | | | | | | | | | | | In TS 18661-1, getpayload had an unspecified return value for a non-NaN argument, while C2x requires the return value -1 in that case. This patch implements the return value of -1. I don't think this is worth having a new symbol version that's an alias of the old one, although occasionally we do that in such cases where the new function semantics are a refinement of the old ones (to avoid programs relying on the new semantics running on older glibc versions but not behaving as intended). Tested for x86_64 and x86; also ran math/ tests for aarch64 and powerpc.
* New exp10f version without SVID compat wrapperAdhemerval Zanella2020-06-191-1/+15
| | | | | | | | | | | | | | | | | | | | | | | This patch changes the exp10f error handling semantics to only set errno according to POSIX rules. New symbol version is introduced at GLIBC_2.32. The old wrappers are kept for compat symbols. There are some outliers that need special handling: - ia64 provides an optimized implementation of exp10f that uses ia64 specific routines to set SVID compatibility. The new symbol version is aliased to the exp10f one. - m68k also provides an optimized implementation, and the new version uses it instead of the sysdeps/ieee754/flt32 one. - riscv and csky uses the generic template implementation that does not provide SVID support. For both cases a new exp10f version is not added, but rather the symbols version of the generic sysdeps/ieee754/flt32 is adjusted instead. Checked on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu.
* math: Optimized generic exp10f with wrappersPaul Zimmermann2020-06-192-1/+199
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is inspired by expf and reuses its tables and internal functions. The error checks are inlined and errno setting is in separate tail called functions, but the wrappers are kept in this patch to handle the _LIB_VERSION==_SVID_ case. Double precision arithmetics is used which is expected to be faster on most targets (including soft-float) than using single precision and it is easier to get good precision result with it. Result for x86_64 (i7-4790K CPU @ 4.00GHz) are: Before new code: "exp10f": { "workload-spec2017.wrf (adapted)": { "duration": 4.0414e+09, "iterations": 1.00128e+08, "reciprocal-throughput": 26.6818, "latency": 54.043, "max-throughput": 3.74787e+07, "min-throughput": 1.85038e+07 } With new code: "exp10f": { "workload-spec2017.wrf (adapted)": { "duration": 4.11951e+09, "iterations": 1.23968e+08, "reciprocal-throughput": 21.0581, "latency": 45.4028, "max-throughput": 4.74876e+07, "min-throughput": 2.20251e+07 } Result for aarch64 (A72 @ 2GHz) are: Before new code: "exp10f": { "workload-spec2017.wrf (adapted)": { "duration": 4.62362e+09, "iterations": 3.3376e+07, "reciprocal-throughput": 127.698, "latency": 149.365, "max-throughput": 7.831e+06, "min-throughput": 6.69501e+06 } With new code: "exp10f": { "workload-spec2017.wrf (adapted)": { "duration": 4.29108e+09, "iterations": 6.6752e+07, "reciprocal-throughput": 51.2111, "latency": 77.3568, "max-throughput": 1.9527e+07, "min-throughput": 1.29271e+07 } Checked on x86_64-linux-gnu, powerpc64le-linux-gnu, aarch64-linux-gnu, and sparc64-linux-gnu.
* ieee754/dbl-64: Reduce the scope of temporary storage variablesVineet Gupta2020-06-157-223/+193
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This came to light when adding hard-flaot support to ARC glibc port without hardware sqrt support causing glibc build to fail: | ../sysdeps/ieee754/dbl-64/e_sqrt.c: In function '__ieee754_sqrt': | ../sysdeps/ieee754/dbl-64/e_sqrt.c:58:54: error: unused variable 'ty' [-Werror=unused-variable] | double y, t, del, res, res1, hy, z, zz, p, hx, tx, ty, s; The reason being EMULV() macro uses the hardware provided __builtin_fma() variant, leaving temporary variables 'p, hx, tx, hy, ty' unused hence compiler warning and ensuing error. The intent of the patch was to fix that error, but EMULV is pervasive and used fair bit indirectly via othe rmacros, hence this patch. Functionally it should not result in code gen changes and if at all those would be better since the scope of those temporaries is greatly reduced now Built tested with aarch64-linux-gnu arm-linux-gnueabi arm-linux-gnueabihf hppa-linux-gnu x86_64-linux-gnu arm-linux-gnueabihf riscv64-linux-gnu-rv64imac-lp64 riscv64-linux-gnu-rv64imafdc-lp64 powerpc-linux-gnu microblaze-linux-gnu nios2-linux-gnu hppa-linux-gnu Also as suggested by Joseph [1] used --strip and compared the libs with and w/o patch and they are byte-for-byte unchanged (with gcc 9). | for i in `find . -name libm-2.31.9000.so`; | do | echo $i; diff $i /SCRATCH/vgupta/gnu2/install/glibcs/$i ; echo $?; | done | ./aarch64-linux-gnu/lib64/libm-2.31.9000.so | 0 | ./arm-linux-gnueabi/lib/libm-2.31.9000.so | 0 | ./x86_64-linux-gnu/lib64/libm-2.31.9000.so | 0 | ./arm-linux-gnueabihf/lib/libm-2.31.9000.so | 0 | ./riscv64-linux-gnu-rv64imac-lp64/lib64/lp64/libm-2.31.9000.so | 0 | ./riscv64-linux-gnu-rv64imafdc-lp64/lib64/lp64/libm-2.31.9000.so | 0 | ./powerpc-linux-gnu/lib/libm-2.31.9000.so | 0 | ./microblaze-linux-gnu/lib/libm-2.31.9000.so | 0 | ./nios2-linux-gnu/lib/libm-2.31.9000.so | 0 | ./hppa-linux-gnu/lib/libm-2.31.9000.so | 0 | ./s390x-linux-gnu/lib64/libm-2.31.9000.so [1] https://sourceware.org/pipermail/libc-alpha/2019-November/108267.html
* ieee754: provide gcc builtins based generic fma functionsVineet Gupta2020-06-035-0/+24
| | | | Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* ieee754: provide gcc builtins based generic sqrt functionsVineet Gupta2020-06-032-6/+16
| | | | Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* float128: use builtin_signbitf128 alwaysPaul E. Murphy2020-05-041-18/+1
| | | | | | | | | The minimum GCC version has been raised to 6.2 for building glibc. Therefore, follow the advice inside the implementation and remove the GCC < 6 codepath. Likewise, remove the hidden_proto as all internal usages should inline now.
* powerpc64le: blacklist broken GCC compilers (e.g GCC 7.5.0)Paul E. Murphy2020-04-301-12/+0
| | | | | | | | | | | GCC 7.5.0 (PR94200) will refuse to compile if both -mabi=% and -mlong-double-128 are passed on the command line. Surprisingly, it will work happily if the latter is not. For the sake of maintaining status quo, test for and blacklist such compilers. Tested with a GCC 8.3.1 and GCC 7.5.0 compiler for ppc64le. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* Rename __LONG_DOUBLE_USES_FLOAT128 to __LDOUBLE_REDIRECTS_TO_FLOAT128_ABIPaul E. Murphy2020-04-308-14/+11
| | | | | | | | | | | | | | | Improve the commentary to aid future developers who will stumble upon this novel, yet not always perfect, mechanism to support alternative formats for long double. Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work has settled down. The command used was git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \ xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g' Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* ldbl-128ibm: simplify iscanonical.hPaul E. Murphy2020-04-061-8/+2
| | | | | | | | | | | | | The test for enabling _Float128 or IEEE 128 long double can be greatly simplified knowing that there is no ibm128, thus we require no special cases, and everything is canonical. This reverts the changes to ldbl-128ibm iscanonical.h from commit 8dbfea3a2094798a52cebddde01d255483f49665 and extends the check for __NO_LONG_DOUBLE_MATH to include a check for float128 redirects to long double. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* Makeconfig: sandwich gnulib-tests between libc/ld linking of testsPaul E. Murphy2020-03-251-13/+0
| | | | | | | This better resembles the default linking process with the gnulibs, and also resolves the increasingly difficult to maintain f128-loader-link usage on powerpc64le as some libgcc symbols are dependent on those found in the loader (ld).
* ldbl-128ibm-compat: PLT redirects for using ldbl redirects internallyPaul E. Murphy2020-03-2511-3/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tweak the PLT bypass magic when building glibc with long double redirects. This is made more difficult by the fact we only get one chance to redirect functions. This happens via the public headers. There are roughly three classes of redirect we need to attend to today: 1. Simple redirects, redirected via cdef macro overrides and and new libc_hidden_ldbl_proto macro. 2. Internal usage of internal API, e.g __snprintf, which has no direct analogue. This is bypassed directly on case-by- case basis. 3. Double redirects, e.g sscanf and related. These require a heavier handed approach of macro renaming to existing symbols. Most simple redirects are handled via 1. Ideally, the libc_* macro would live in libc-symbols.h, but in practice the macros needed for it to do anything useful live in cdefs.h, so they are defined in the local override. Notably, the internal name of the asprintf generated for ieee ldbl redirects is renamed to work with internal prefixed usage. This resolves the local plt usage introduced when building glibc with ldbl == ieee128 on ppc64le. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* math: Remove inline math testsAdhemerval Zanella2020-03-191-2/+0
| | | | | | | | | | | | | With mathinline removal there is no need to keep building and testing inline math tests. The gen-libm-tests.py support to generate ULP_I_* is removed and all libm-test-ulps files are updated to longer have the i{float,double,ldouble} entries. The support for no-test-inline is also removed from both gen-auto-libm-tests and the auto-libm-test-out-* were regenerated. Checked on x86_64-linux-gnu and i686-linux-gnu.
* ldbl-128ibm: Let long double files have specific compiler flagsTulio Magno Quites Machado Filho2020-03-061-3/+19
| | | | | | Soon, powerpc64le will need to provide extra compiler flags to the long double files in order to continue to build using the IBM 128-bit extended floating point type as long double.
* ldbl-128ibm-compat: Add tests for IBM long double functionsRajalakshmi Srinivasaraghavan2020-03-061-0/+3
| | | | | | | | | | | | This patch creates test-ibm128* tests from the long double function tests. In order to explicitly test IBM long double functions -mabi=ibmlongdouble is added to CFLAGS. Likewise, update the test headers to correct choose ULPs when redirects are enabled. Co-authored-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com> Co-authored-by: Paul E. Murphy <murphyp@linux.vnet.ibm.com>
* ldbl-128ibm-compat: link tst-ldbl-efgcvt against loader tooPaul E. Murphy2020-02-281-0/+1
| | | | | | This also requires the linker workaround to ensure everything links correctly. See comment in sysdeps/powerpc/powerpc64/le/Makefile for details.
* ldbl-128ibm-compat: enforce ibm128 on compat testsPaul E. Murphy2020-02-281-0/+9
| | | | | | For lack of a more comprehensive solution, tack on the ibm128 ABI compiler options for the totalorder{,mag}l compat tests which exist prior to enabling this feature.
* ldbl-128ibm-compat: Provide nexttoward functionsGabriel F. T. Gomes2020-02-285-4/+65
| | | | | | | | | | | | | | | | | | | | | | | | | The functions in the nexttoward family are special, in the sense that they always have a long double argument, regardless of their suffix (i.e.: nexttowardf and nexttoward have a long double argument, besides the float and double arguments). On top of that, they are also special because nexttoward functions are not part of the _FloatN API, hence __nexttowardf128 do not exist. This patch adds 4 new function implementations for the new long double format: __nexttoward_to_ieee128 __nexttowardf_to_ieee128 __nexttowardieee128 (as an alias to __nextafterieee128) Likewise, rename "long double" "_Float128" in shared ldbl-128 files to ensure correct type is used irrespective of ABI switches. Thank you to those who helped out with this patch: Co-Authored-By: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* ldbl-128ibm-compat: Provide a significand implementationTulio Magno Quites Machado Filho2020-02-282-0/+26
| | | | | Reuse the template in order to provide the global symbol __significandieee128.
* ldbl-128ibm-compat: Redirect long double functions to f128/ieee128 functionsTulio Magno Quites Machado Filho2020-02-281-1/+7
| | | | | | | | | | | | | | | | Modify the headers to redirect long double functions to global __*f128 symbols or to __*ieee128 otherwise. Most of the functions in math.h benefit from the infrastructure already available for __LDBL_COMPAT. The only exceptions are nexttowardf and nexttoward that need especial treatment. Both math/bits/mathcalls-helper-functions.h and math/bits/mathcalls.h were modified in order to provide alternative redirection destinations that are essential to support functions that should not be redirected to the same name pattern of the rest of the functions, i.e.: __fpclassify, __signbit, __iseqsig, __issignaling, isinf, finite and isnan, which will be redirected to __*f128 instead of __*ieee128 used for the rest.
* ldbl-128ibm: make ieee754.h work with IEEE 128 long doublePaul E. Murphy2020-02-212-2/+96
| | | | | | | | | | | | | Instead of attempting something more creative, just copy the small struct from ldbl-128 and enable it when IEEE long double is present, and update the ibm long double variant if supported. Likewise, provide a shadow copy of math_ldbl.h to prevent the ibm128 specific long double header from poisoning unrelated files due to it's usage in math_private.h. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* ldbl-128ibm-compat: fixup subdir location of several funcsPaul E. Murphy2020-02-211-16/+16
| | | | | | | | | | | | | | | | | We want to ensure that if a second file is built to support ieee128 long double, we built its companion implementation with ibm128 long double. The shared object versions of these files build correctly because the aliasing is sufficiently complex to prevent the redirects from applying when defining them. However, this does not prevent the static object variants from becoming quietly broken due to redirects. This is intentionally avoided by marking such objects to be built with -mabi=ibmlongdouble. Shuffle the misplaced routines to build against the subdir which defines the needed symbols.
* ldbl-128ibm-compat: enforce correct abi flags on internal filePaul E. Murphy2020-02-211-0/+11
| | | | | | A number of utility files and helper objects should also be explicitly configured to build with the ibm128 ABI to prevent gremlins when enabling IEEE long double.
* ldbl-128ibm-compat: Provide ieee128 symbols to narrow functionsTulio Magno Quites Machado Filho2020-02-202-0/+42
| | | | | | | | | | Move the narrow math aliasing macros into a new sysdep header file math-narrow-alias-float128.h. Then, provide an override header to supply the necessary changes to supply the *ieee128 aliases of these symbols. This adds ieee128 aliases for faddl, fdivl, fmull, fsubl, daddl, ddivl, dmull, dsubl.
* Undefine redirections after long double definition on __LDBL_COMPAT [BZ #23294]Tulio Magno Quites Machado Filho2020-02-202-1/+90
| | | | | | After defining the long double redirections to double, __MATHDECL_1 has to be redefined to its previous state in order to avoid redirecting all subsequent types.
* ldbl-128ibm-compat: Provide a scalb implementationTulio Magno Quites Machado Filho2020-02-143-0/+54
| | | | | | Reuse the template in order to provide the redirect for scalbl to __scalbieee128, but avoid any extra aliasing as this is intended to support long double redirects only.
* Add a generic scalb implementationTulio Magno Quites Machado Filho2020-02-143-1/+6
| | | | | | | | | | | | | | | | | | | | | | | This is a preparatory patch to enable building a _Float128 variant to ease reuse when building a _Float128 variant to alias this long double only symbol. Notably, stubs are added where missing to the native _Float128 sysdep dir to prevent building these newly templated variants created inside the build directories. Also noteworthy are the changes around LIBM_SVID_COMPAT. These changes are not intuitive. The templated version is only enabled when !LIBM_SVID_COMPAT, and the compat version is predicated entirely on LIBM_SVID_COMPAT. Thus, exactly one is stubbed out entirely when building. The nldbl scalb compat files are updated to account for this. Likewise, fixup the reuse of m68k's e_scalb{f,l}.c to include it's override of e_scalb.c. Otherwise, the search path finds the templated copy in the build directory. This could be futher simplified by providing an overridden template, but I lack the hardware to verify.
* Adjust thresholds in Bessel function implementations (bug 14469).Joseph Myers2020-02-144-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent discussion in bug 14469 notes that a threshold in float Bessel function implementations, used to determine when to use a simpler implementation approach, results in substantially inaccurate results. As I discussed in <https://sourceware.org/ml/libc-alpha/2013-03/msg00345.html>, a heuristic argument suggests 2^(S+P) as the right order of magnitude for a suitable threshold, where S is the number of significand bits in the floating-point type and P is the number of significant bits in the representation of the floating-point type, and the float and ldbl-96 implementations use thresholds that are too small. Some threshold does need using, there or elsewhere in the implementation, to avoid spurious underflow and overflow for large arguments. This patch sets the thresholds in the affected implementations to more heuristically justifiable values. Results will still be inaccurate close to zeroes of the functions (thus this patch does *not* fix any of the bugs for Bessel function inaccuracy); fixing that would require a different implementation approach, likely along the lines described in <http://www.cl.cam.ac.uk/~jrh13/papers/bessel.ps.gz>. So the justification for a change such as this would be statistical rather than based on particular tests that had excessive errors and no longer do so (no doubt such tests could be found, but would probably be too fragile to add to the testsuite, as liable to give large errors again from very small implementation changes or even from compiler changes). See <https://sourceware.org/ml/libc-alpha/2020-02/msg00638.html> for such statistics of the resulting improvements for float functions. Tested (glibc testsuite) for x86_64.
* math/test-sinl-pseudo: Use stack protector only if availableFlorian Weimer2020-02-131-0/+2
| | | | | This fixes commit 9333498794cde1d5cca518bad ("Avoid ldbl-96 stack corruption from range reduction of pseudo-zero (bug 25487).").
* Avoid ldbl-96 stack corruption from range reduction of pseudo-zero (bug 25487).Joseph Myers2020-02-123-1/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bug 25487 reports stack corruption in ldbl-96 sinl on a pseudo-zero argument (an representation where all the significand bits, including the explicit high bit, are zero, but the exponent is not zero, which is not a valid representation for the long double type). Although this is not a valid long double representation, existing practice in this area (see bug 4586, originally marked invalid but subsequently fixed) is that we still seek to avoid invalid memory accesses as a result, in case of programs that treat arbitrary binary data as long double representations, although the invalid representations of the ldbl-96 format do not need to be consistently handled the same as any particular valid representation. This patch makes the range reduction detect pseudo-zero and unnormal representations that would otherwise go to __kernel_rem_pio2, and returns a NaN for them instead of continuing with the range reduction process. (Pseudo-zero and unnormal representations whose unbiased exponent is less than -1 have already been safely returned from the function before this point without going through the rest of range reduction.) Pseudo-zero representations would previously result in the value passed to __kernel_rem_pio2 being all-zero, which is definitely unsafe; unnormal representations would previously result in a value passed whose high bit is zero, which might well be unsafe since that is not a form of input expected by __kernel_rem_pio2. Tested for x86_64.
* ldbl-128ibm-compat: set PRINTF_CHK flag in {,v}sprintf_chkPaul E. Murphy2020-02-102-0/+8
| | | | | | | This should be unconditionally set to match the common implementation, and fixes multiple test failures related to sprintf. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* Remove a comment claiming that sin/cos round correctly.Wilco Dijkstra2020-02-071-4/+4
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* Fix maybe-uninitialized error on powerpcMatheus Castanho2020-01-171-0/+7
| | | | | | | | | | | | | | | | | | | | | | The build has been failing on powerpc64le-linux-gnu with GCC 10 due to a maybe-uninitialized error: ../sysdeps/ieee754/dbl-64/mpa.c:875:6: error: ‘w.e’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 875 | EY -= EX; | ^~ The warning is thrown because when __inv is called by __dvd *y is not initialized and if t == 0 before calling __dbl_mp, EY will stay uninitialized, as the function does not touch it in this case. However, since t will be set to 1/t before calling __dbl_mp, t == 0 will never happen, so we can instruct the compiler to ignore this case, which suppresses the warning. Tested on powerpc64le. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* Add libm_alias_finite for _finite symbolsWilco Dijkstra2020-01-03104-131/+293
| | | | | | | | | | | | | | | | | | | This patch adds a new macro, libm_alias_finite, to define all _finite symbol. It sets all _finite symbol as compat symbol based on its first version (obtained from the definition at built generated first-versions.h). The <fn>f128_finite symbols were introduced in GLIBC 2.26 and so need special treatment in code that is shared between long double and float128. It is done by adding a list, similar to internal symbol redifinition, on sysdeps/ieee754/float128/float128_private.h. Alpha also needs some tricky changes to ensure we still emit 2 compat symbols for sqrt(f). Passes buildmanyglibc. Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Update copyright dates with scripts/update-copyrights.Joseph Myers2020-01-01464-464/+464
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* ldbl-128ibm-compat: Do not mix -mabi=*longdouble and -mlong-double-128Gabriel F. T. Gomes2019-12-271-0/+14
| | | | | | | | | | | | | | | Some compiler versions, e.g. GCC 7, complain when -mlong-double-128 is used together with -mabi=ibmlongdouble or -mabi=ieeelongdouble, producing the following error message: cc1: error: ‘-mabi=ibmlongdouble’ requires ‘-mlong-double-128’ This patch removes -mlong-double-128 from the compilation lines that explicitly request -mabi=*longdouble. Tested for powerpc64le. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>