glibc/math, branch master

Implement C23 exp2m1, exp10m1

2024-06-17T16:31:49Z

C23 adds various function families originally defined in TS 18661-4. Add the exp2m1 and exp10m1 functions (exp2(x)-1 and exp10(x)-1, like expm1). As with other such functions, these use type-generic templates that could be replaced with faster and more accurate type-specific implementations in future. Test inputs are copied from those for expm1, plus some additions close to the overflow threshold (copied from exp2 and exp10) and also some near the underflow threshold. exp2m1 has the unusual property of having an input (M_MAX_EXP) where whether the function overflows (under IEEE semantics) depends on the rounding mode. Although these could reasonably be XFAILed in the testsuite (as we do in some cases for arguments very close to a function's overflow threshold when an error of a few ulps in the implementation can result in the implementation not agreeing with an ideal one on whether overflow takes place - the testsuite isn't smart enough to handle this automatically), since these functions aren't required to be correctly rounding, I made the implementation check for and handle this case specially. The Makefile ordering expected by lint-makefiles for the new functions is a bit peculiar, but I implemented it in this patch so that the test passes; I don't know why log2 also needed moving in one Makefile variable setting when it didn't in my previous patches, but the failure showed a different place was expected for that function as well. The powerpc64le IFUNC setup seems not to be as self-contained as one might hope; it shouldn't be necessary to add IFUNCs for new functions such as these simply to get them building, but without setting up IFUNCs for the new functions, there were undefined references to __GI___expm1f128 (that IFUNC machinery results in no such function being defined, but doesn't stop include/math.h from doing the redirection resulting in the exp2m1f128 and exp10m1f128 implementations expecting to call it). Tested for x86_64 and x86, and with build-many-glibcs.py.

Implement C23 log10p1

2024-06-17T13:48:13Z

C23 adds various function families originally defined in TS 18661-4. Add the log10p1 functions (log10(1+x): like log1p, but for base-10 logarithms). This is directly analogous to the log2p1 implementation (except that whereas log2p1 has a smaller underflow range than log1p, log10p1 has a larger underflow range). The test inputs are copied from those for log1p and log2p1, plus a few more inputs in that wider underflow range. Tested for x86_64 and x86, and with build-many-glibcs.py.

Implement C23 logp1

2024-06-17T13:47:09Z

C23 adds various function families originally defined in TS 18661-4. Add the logp1 functions (aliases for log1p functions - the name is intended to be more consistent with the new log2p1 and log10p1, where clearly it would have been very confusing to name those functions log21p and log101p). As aliases rather than new functions, the content of this patch is somewhat different from those actually adding new functions. Tests are shared with log1p, so this patch *does* mechanically update all affected libm-test-ulps files to expect the same errors for both functions. The vector versions of log1p on aarch64 and x86_64 are *not* updated to have logp1 aliases (and thus there are no corresponding header, tests, abilist or ulps changes for vector functions either). It would be reasonable for such vector aliases and corresponding changes to other files to be made separately. For now, the log1p tests instead avoid testing logp1 in the vector case (a Makefile change is needed to avoid problems with grep, used in generating the .c files for vector function tests, matching more than one ALL_RM_TEST line in a file testing multiple functions with the same inputs, when it assumes that the .inc file only has a single such line). Tested for x86_64 and x86, and with build-many-glibcs.py.

Don't provide scalb/significand _FloatN aliases [BZ #31760]

2024-05-22T13:10:54Z

scalb is a deprecated interface which was obsolescent in POSIX.1-2001, removed in POSIX.1-2008, never made to C standard. significant was originally from BSD and never made in any standard. Fix BZ #31760 by not providing _FloatN aliases for them. Signed-off-by: H.J. Lu Reviewed-by: Adhemerval Zanella

math: Add support for auto static math tests

2024-05-21T19:53:27Z

It basically copy the already in place rules for dynamic tests for auto-generated math functions for all support types. To avoid the need to duplicate .inc files, a .SECONDEXPANSION rules is adeed for the gen-libm-test.py generation. New tests are added on the new rules 'libm-test-funcs-auto-static', 'libm-test-funcs-noauto-static', and 'libm-test-funcs-narrow-static'; similar to the non-static counterparts. To avoid add extra build and disk requirement, the new math static tests are only enable with a new define 'build-math-static-tests'. Reviewed-by: H.J. Lu

math: Add more details to the test driver output.

2024-05-20T14:09:54Z

Add start and end indicators that identify the test being run in the verbose output. Better identify the tests for max errors in the summary output. Count each exception checked for each test. Remove double counting of tests for the check_ functions other than check_float_internal. Rename print_max_error and print_complex_max_error to check_max_error and check_complex_max_error respectively since they have side effects. Co-Authored-By: Carlos O'Donell Reviewed-By: Joseph Myers

Implement C23 log2p1

2024-05-20T13:41:39Z

C23 adds various function families originally defined in TS 18661-4. Add the log2p1 functions (log2(1+x): like log1p, but for base-2 logarithms). This illustrates the intended structure of implementations of all these function families: define them initially with a type-generic template implementation. If someone wishes to add type-specific implementations, it is likely such implementations can be both faster and more accurate than the type-generic one and can then override it for types for which they are implemented (adding benchmarks would be desirable in such cases to demonstrate that a new implementation is indeed faster). The test inputs are copied from those for log1p. Note that these changes make gen-auto-libm-tests depend on MPFR 4.2 (or later). The bulk of the changes are fairly generic for any such new function. (sysdeps/powerpc/nofpu/Makefile only needs changing for those type-generic templates that use fabs.) Tested for x86_64 and x86, and with build-many-glibcs.py.

math: Add GLIBC_TEST_LIBM_VERBOSE environment variable support.

2024-05-14T14:39:38Z

Allow the libm-test-driver based tests to have their verbosity set based on the GLIBC_TEST_LIBM_VERBOSE environment variable. This allows the entire testsuite to be run with a non-default verbosity. While here check the conversion for the verbose option as well. Reviewed-by: Carlos O'Donell

Add crt1-2.0.o for glibc 2.0 compatibility tests

2024-05-06T14:49:40Z

Starting from glibc 2.1, crt1.o contains _IO_stdin_used which is checked by _IO_check_libio to provide binary compatibility for glibc 2.0. Add crt1-2.0.o for tests against glibc 2.0. Define tests-2.0 for glibc 2.0 compatibility tests. Add and update glibc 2.0 compatibility tests for stderr, matherr and pthread_kill. Reviewed-by: Carlos O'Donell

math: x86 trunc traps when FE_INEXACT is enabled (BZ 31603)

2024-04-04T17:29:28Z

The implementations of trunc functions using x87 floating point (i386 and x86_64 long double only) traps when FE_INEXACT is enabled. Although this is a GNU extension outside the scope of the C standard, other architectures that also support traps do not show this behavior. The fix moves the implementation to a common one that holds any exceptions with a 'fnclex' (libc_feholdexcept_setround_387). Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: H.J. Lu