From bb8081f57f23a3e1b28b1b7104f24d17da9a3d82 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 23 Sep 2016 21:54:21 +0000 Subject: Add iszero. TS 18661-1 adds an iszero classification macro to . This patch implements it for glibc. There are no new underlying functions in libm because the implementation uses fpclassify when sNaN support is required and a direct comparison otherwise; any optimizations for this macro should be done through adding __builtin_iszero in GCC and using it in the header for suitable GCC versions, not through adding other optimized inline or out-of-line versions to glibc. Tested for x86_64 and x86. * math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (iszero): New macro. * math/libm-test.inc (iszero_test_data): New array. (iszero_test): New function. (main): Call iszero_test. * manual/arith.texi (Floating Point Classes): Document iszero. * manual/libm-err-tab.pl: Update comment on interfaces without ulps tabulated. --- math/libm-test.inc | 28 +++++++++++++++++++++++++++- math/math.h | 7 +++++++ 2 files changed, 34 insertions(+), 1 deletion(-) (limited to 'math') diff --git a/math/libm-test.inc b/math/libm-test.inc index 385ec5c..872bafd 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -46,7 +46,7 @@ cbrt, ceil, copysign, cos, cosh, drem, erf, erfc, exp, exp10, exp2, expm1, fabs, fdim, finite, floor, fma, fmax, fmin, fmod, fpclassify, frexp, gamma, hypot, - ilogb, isfinite, isinf, isnan, isnormal, issignaling, issubnormal, + ilogb, isfinite, isinf, isnan, isnormal, issignaling, issubnormal, iszero, isless, islessequal, isgreater, isgreaterequal, islessgreater, isunordered, j0, j1, jn, ldexp, lgamma, log, log10, log1p, log2, logb, @@ -8671,6 +8671,31 @@ isunordered_test (void) ALL_RM_TEST (isunordered, 1, isunordered_test_data, RUN_TEST_LOOP_ff_i_tg, END); } +static const struct test_f_i_data iszero_test_data[] = + { + TEST_f_b (iszero, 0, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, minus_zero, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, 10, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, min_subnorm_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, -min_subnorm_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, min_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, -min_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, max_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, -max_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, plus_infty, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, minus_infty, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, qnan_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, -qnan_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, snan_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_b (iszero, -snan_value, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + }; + +static void +iszero_test (void) +{ + ALL_RM_TEST (iszero, 1, iszero_test_data, RUN_TEST_LOOP_f_b_tg, END); +} + static const struct test_f_f_data j0_test_data[] = { /* j0 is the Bessel function of the first kind of order 0 */ @@ -12694,6 +12719,7 @@ main (int argc, char **argv) isnormal_test (); issignaling_test (); issubnormal_test (); + iszero_test (); signbit_test (); /* Trigonometric functions: */ diff --git a/math/math.h b/math/math.h index 064cc56..0a09959 100644 --- a/math/math.h +++ b/math/math.h @@ -331,6 +331,13 @@ enum /* Return nonzero value if X is subnormal. */ # define issubnormal(x) (fpclassify (x) == FP_SUBNORMAL) + +/* Return nonzero value if X is zero. */ +# ifdef __SUPPORT_SNAN__ +# define iszero(x) (fpclassify (x) == FP_ZERO) +# else +# define iszero(x) ((x) == 0) +# endif #endif /* Use IEC_60559_BFP_EXT. */ #ifdef __USE_MISC -- cgit v1.1