diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | NEWS | 2 | ||||
| -rw-r--r-- | math/libm-test.inc | 5 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c | 23 |
4 files changed, 33 insertions, 5 deletions
@@ -1,3 +1,11 @@ +2015-02-26 Joseph Myers <joseph@codesourcery.com> + + [BZ #18029] + * sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c (__ieee754_ilogbl): + Adjust exponent of power of 2 down when low part has opposite + sign. + * math/libm-test.inc (ilogb_test_data): Add more tests. + 2015-02-26 Alexandre Oliva <aoliva@redhat.com> [BZ #15969] @@ -12,7 +12,7 @@ Version 2.22 4719, 14841, 13064, 14094, 15319, 15467, 15790, 15969, 16560, 16783, 17269, 17523, 17569, 17588, 17792, 17836, 17912, 17916, 17932, 17944, 17949, 17964, 17965, 17967, 17969, 17978, 17987, 17991, 17996, 17998, - 17999, 18019, 18020. + 17999, 18019, 18020, 18029. * Character encoding and ctype tables were updated to Unicode 7.0.0, using new generator scripts contributed by Pravin Satpute and Mike FABIAN (Red diff --git a/math/libm-test.inc b/math/libm-test.inc index b3396b6a79..6045764fd3 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -7219,6 +7219,11 @@ static const struct test_f_i_data ilogb_test_data[] = TEST_f_i (ilogb, 1024, 10, NO_INEXACT_EXCEPTION), TEST_f_i (ilogb, -2000, 10, NO_INEXACT_EXCEPTION), +#if defined TEST_LDOUBLE && LDBL_MANT_DIG >= 57 + TEST_f_i (ilogb, 0x1.ffffffffffffffp1L, 1, NO_INEXACT_EXCEPTION), + TEST_f_i (ilogb, -0x1.ffffffffffffffp1L, 1, NO_INEXACT_EXCEPTION), +#endif + /* ilogb (0.0) == FP_ILOGB0 plus invalid exception */ TEST_f_i (ilogb, 0.0, FP_ILOGB0, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION|ERRNO_EDOM), /* ilogb (qNaN) == FP_ILOGBNAN plus invalid exception */ diff --git a/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c b/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c index aeace7c977..4088238f30 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c @@ -31,12 +31,13 @@ static char rcsid[] = "$NetBSD: $"; int __ieee754_ilogbl(long double x) { - int64_t hx; + int64_t hx, hxs; int ix; - double xhi; + double xhi, xlo; - xhi = ldbl_high (x); + ldbl_unpack (x, &xhi, &xlo); EXTRACT_WORDS64 (hx, xhi); + hxs = hx; hx &= 0x7fffffffffffffffLL; if(hx <= 0x0010000000000000LL) { if(hx==0) @@ -45,7 +46,21 @@ int __ieee754_ilogbl(long double x) for (ix = -1022, hx<<=11; hx>0; hx<<=1) ix -=1; return ix; } - else if (hx<0x7ff0000000000000LL) return (hx>>52)-0x3ff; + else if (hx < 0x7ff0000000000000LL) + { + int hexp = (hx >> 52) - 0x3ff; + /* If the high part is a power of 2, and the low part is + nonzero with the opposite sign, the low part affects + the exponent. */ + if ((hx & 0x000fffffffffffffLL) == 0) + { + int64_t lx; + EXTRACT_WORDS64 (lx, xlo); + if ((hxs ^ lx) < 0 && (lx & 0x7fffffffffffffffLL) != 0) + hexp--; + } + return hexp; + } else if (FP_ILOGBNAN != INT_MAX) { /* ISO C99 requires ilogbl(+-Inf) == INT_MAX. */ if (hx==0x7ff0000000000000LL) |