diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_sinhl.c | 3 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c | 43 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_ctanl.c | 48 | ||||
| -rw-r--r-- | sysdeps/powerpc/fpu/libm-test-ulps | 77 |
5 files changed, 148 insertions, 33 deletions
diff --git a/ChangeLog b/ChangeLog index 7d2d1089d4..0ad5a64691 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2012-04-26 Adhemerval Zanella <azanella@linux.vnet.ibm.com> + + [BZ #11521] + * sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c (__ctanhl): Avoid internal + overflow or cancellation in calculating denominator. + * sysdeps/ieee754/ldbl-128ibm/s_ctanl.c (__ctanl): Likewise. + * sysdeps/ieee754/ldbl-128ibm/e_sinhl.c (__ieee754_sinhl): Breaking + down expression to avoid unexpected rounding in newer GCCs. + * sysdeps/powerpc/fpu/libm-test-ulps: Update for ctan, ctanh fix. + 2012-04-26 David S. Miller <davem@davemloft.net> * sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_ceil.S: Generate diff --git a/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c b/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c index 4bae85a5a4..4e8481c419 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c @@ -54,7 +54,8 @@ __ieee754_sinhl(long double x) if(shuge+x>one) return x;/* sinhl(tiny) = tiny with inexact */ t = __expm1l(fabsl(x)); if(ix<0x3ff0000000000000LL) return h*(2.0*t-t*t/(t+one)); - return h*(t+t/(t+one)); + w = t/(t+one); + return h*(t+w); } /* |x| in [40, log(maxdouble)] return 0.5*exp(|x|) */ diff --git a/sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c b/sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c index e4126395bd..2ab80a2246 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c @@ -1,5 +1,5 @@ /* Complex hyperbole tangent for long double. IBM extended format version. - Copyright (C) 1997,2005,2006 Free Software Foundation, Inc. + Copyright (C) 1997-2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. @@ -19,6 +19,7 @@ #include <complex.h> #include <fenv.h> +#include <float.h> #include <math.h> #include <math_ldbl_opt.h> @@ -54,24 +55,44 @@ __ctanhl (__complex__ long double x) } else { - long double sin2ix, cos2ix; + long double sinix, cosix; long double den; + const int t = (int) ((LDBL_MAX_EXP - 1) * M_LN2l / 2); - __sincosl (2.0 * __imag__ x, &sin2ix, &cos2ix); + /* tanh(x+iy) = (sinh(2x) + i*sin(2y))/(cosh(2x) + cos(2y)) + = (sinh(x)*cosh(x) + i*sin(y)*cos(y))/(sinh(x)^2 + cos(y)^2). */ - den = (__ieee754_coshl (2.0 * __real__ x) + cos2ix); + __sincosl (__imag__ x, &sinix, &cosix); - if (den == 0.0L) + if (fabsl (__real__ x) > t) { - __complex__ long double ez = __cexpl (x); - __complex__ long double emz = __cexpl (-x); - - res = (ez - emz) / (ez + emz); + /* Avoid intermediate overflow when the imaginary part of + the result may be subnormal. Ignoring negligible terms, + the real part is +/- 1, the imaginary part is + sin(y)*cos(y)/sinh(x)^2 = 4*sin(y)*cos(y)/exp(2x). */ + long double exp_2t = __ieee754_expl (2 * t); + __real__ res = __copysignl (1.0, __real__ x); + __imag__ res = 4 * sinix * cosix; + __real__ x = fabsl (__real__ x); + __real__ x -= t; + __imag__ res /= exp_2t; + if (__real__ x > t) + { + /* Underflow (original real part of x has absolute value + > 2t). */ + __imag__ res /= exp_2t; + } + else + __imag__ res /= __ieee754_expl (2 * __real__ x); } else { - __real__ res = __ieee754_sinhl (2.0 * __real__ x) / den; - __imag__ res = sin2ix / den; + long double sinhrx = __ieee754_sinhl (__real__ x); + long double coshrx = __ieee754_coshl (__real__ x); + + den = sinhrx * sinhrx + cosix * cosix; + __real__ res = sinhrx * coshrx / den; + __imag__ res = sinix * cosix / den; } /* __gcc_qmul does not respect -0.0 so we need the following fixup. */ if ((__real__ res == 0.0) && (__real__ x == 0.0)) diff --git a/sysdeps/ieee754/ldbl-128ibm/s_ctanl.c b/sysdeps/ieee754/ldbl-128ibm/s_ctanl.c index 0b1bc4f70e..9d89bbe311 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_ctanl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_ctanl.c @@ -1,5 +1,5 @@ /* Complex tangent function for long double. IBM extended format version. - Copyright (C) 1997,2005,2006 Free Software Foundation, Inc. + Copyright (C) 1997-2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. @@ -21,6 +21,7 @@ #include <fenv.h> #include <math.h> #include <math_ldbl_opt.h> +#include <float.h> #include <math_private.h> @@ -46,34 +47,53 @@ __ctanl (__complex__ long double x) __real__ res = __nanl (""); __imag__ res = __nanl (""); -#ifdef FE_INVALID - if (__isinfl (__real__ x)) + if (__isinf_nsl (__real__ x)) feraiseexcept (FE_INVALID); -#endif } } else { - long double sin2rx, cos2rx; + long double sinrx, cosrx; long double den; + const int t = (int) ((LDBL_MAX_EXP - 1) * M_LN2l / 2); - __sincosl (2.0 * __real__ x, &sin2rx, &cos2rx); + /* tan(x+iy) = (sin(2x) + i*sinh(2y))/(cos(2x) + cosh(2y)) + = (sin(x)*cos(x) + i*sinh(y)*cosh(y)/(cos(x)^2 + sinh(y)^2). */ - den = cos2rx + __ieee754_coshl (2.0 * __imag__ x); + __sincosl (__real__ x, &sinrx, &cosrx); - - if (den == 0.0) + if (fabsl (__imag__ x) > t) { - __complex__ long double ez = __cexpl (1.0i * x); - __complex__ long double emz = __cexpl (-1.0i * x); + /* Avoid intermediate overflow when the real part of the + result may be subnormal. Ignoring negligible terms, the + imaginary part is +/- 1, the real part is + sin(x)*cos(x)/sinh(y)^2 = 4*sin(x)*cos(x)/exp(2y). */ + long double exp_2t = __ieee754_expl (2 * t); - res = (ez - emz) / (ez + emz) * -1.0i; + __imag__ res = __copysignl (1.0, __imag__ x); + __real__ res = 4 * sinrx * cosrx; + __imag__ x = fabsl (__imag__ x); + __imag__ x -= t; + __real__ res /= exp_2t; + if (__imag__ x > t) + { + /* Underflow (original imaginary part of x has absolute + value > 2t). */ + __real__ res /= exp_2t; + } + else + __real__ res /= __ieee754_expl (2 * __imag__ x); } else { - __real__ res = sin2rx / den; - __imag__ res = __ieee754_sinhl (2.0 * __imag__ x) / den; + long double sinhix = __ieee754_sinhl (__imag__ x); + long double coshix = __ieee754_coshl (__imag__ x); + + den = cosrx * cosrx + sinhix * sinhix; + __real__ res = sinrx * cosrx / den; + __imag__ res = sinhix * coshix / den; } + /* __gcc_qmul does not respect -0.0 so we need the following fixup. */ if ((__real__ res == 0.0) && (__real__ x == 0.0)) __real__ res = __real__ x; diff --git a/sysdeps/powerpc/fpu/libm-test-ulps b/sysdeps/powerpc/fpu/libm-test-ulps index c555297db5..43fa64289d 100644 --- a/sysdeps/powerpc/fpu/libm-test-ulps +++ b/sysdeps/powerpc/fpu/libm-test-ulps @@ -1051,16 +1051,44 @@ ifloat: 2 # ctan Test "Real part of: ctan (-2 - 3 i) == 0.376402564150424829275122113032269084e-2 - 1.00323862735360980144635859782192726 i": +float: 1 +ifloat: 1 double: 1 idouble: 1 +ldouble: 1 +ildouble: 1 +Test "Real part of: ctan (1 + 47 i) == 2.729321264492904590777293425576722354636e-41 + 1.0 i": +ldouble: 2 +ildouble: 2 Test "Imaginary part of: ctan (-2 - 3 i) == 0.376402564150424829275122113032269084e-2 - 1.00323862735360980144635859782192726 i": +double: 1 +idouble: 1 ildouble: 1 ldouble: 1 +Test "Real part of: ctan (0.75 + 1.25 i) == 0.160807785916206426725166058173438663 + 0.975363285031235646193581759755216379 i": +float: 1 +ifloat: 1 Test "Imaginary part of: ctan (0.75 + 1.25 i) == 0.160807785916206426725166058173438663 + 0.975363285031235646193581759755216379 i": +float: 1 +ifloat: 1 double: 1 idouble: 1 ildouble: 1 ldouble: 1 +Test "Real part of: ctan (0x1p1023 + 1 i) == -0.2254627924997545057926782581695274244229 + 0.8786063118883068695462540226219865087189 i": +double: 1 +idouble: 1 +Test "Real part of: ctan (0x1p127 + 1 i) == 0.2446359391192790896381501310437708987204 + 0.9101334047676183761532873794426475906201 i": +float: 1 +ifloat: 1 +Test "Imaginary part of: ctan (0x1p127 + 1 i) == 0.2446359391192790896381501310437708987204 + 0.9101334047676183761532873794426475906201 i": +float: 1 +ifloat: 1 +double: 1 +idouble: 1 +Test "Real part of: ctan (0x3.243f6cp-1 + 0 i) == -2.287733242885645987394874673945769518150e7 + 0.0 i": +float: 1 +ifloat: 1 # ctanh Test "Real part of: ctanh (-2 - 3 i) == -0.965385879022133124278480269394560686 + 0.988437503832249372031403430350121098e-2 i": @@ -1068,14 +1096,43 @@ double: 1 float: 2 idouble: 1 ifloat: 2 +Test "Imaginary part of: ctanh (-2 - 3 i) == -0.965385879022133124278480269394560686 + 0.988437503832249372031403430350121098e-2 i": +double: 1 +idouble: 1 Test "Imaginary part of: ctanh (0 + pi/4 i) == 0.0 + 1.0 i": float: 1 ifloat: 1 +double: 1 +idouble: 1 Test "Real part of: ctanh (0.75 + 1.25 i) == 1.37260757053378320258048606571226857 + 0.385795952609750664177596760720790220 i": double: 1 idouble: 1 ildouble: 1 -ldouble: 1 +ldouble: 3 +ildouble: 3 +Test "Imaginary part of: ctanh (0.75 + 1.25 i) == 1.37260757053378320258048606571226857 + 0.385795952609750664177596760720790220 i": +float: 1 +ifloat: 1 +ldouble: 2 +ildouble: 2 +Test "Imaginary part of: ctanh (47 + 1 i) == 1.0 + 2.729321264492904590777293425576722354636e-41 i": +ldouble: 2 +ildouble: 2 +Test "Imaginary part of: ctanh (0 + 0x3.243f6cp-1 i) == 0.0 - 2.287733242885645987394874673945769518150e7 i": +float: 1 +ifloat: 1 +Test "Imaginary part of: ctanh (1 + 0x1p1023 i) == 0.8786063118883068695462540226219865087189 - 0.2254627924997545057926782581695274244229 i": +double: 1 +idouble: 1 +Test "Real part of: ctanh (1 + 0x1p127 i) == 0.9101334047676183761532873794426475906201 + 0.2446359391192790896381501310437708987204 i": +float: 1 +ifloat: 1 +double: 1 +idouble: 1 +Test "Imaginary part of: ctanh (1 + 0x1p127 i) == 0.9101334047676183761532873794426475906201 + 0.2446359391192790896381501310437708987204 i": +float: 1 +ifloat: 1 +double: 1 # erf Test "erf (1.25) == 0.922900128256458230136523481197281140": @@ -2309,12 +2366,16 @@ ildouble: 1 ldouble: 1 Function: Real part of "ctan": +float: 1 +ifloat: 1 double: 1 idouble: 1 -ildouble: 1 -ldouble: 1 +ildouble: 2 +ldouble: 2 Function: Imaginary part of "ctan": +float: 1 +ifloat: 1 double: 1 idouble: 1 ildouble: 1 @@ -2325,14 +2386,16 @@ double: 1 float: 2 idouble: 1 ifloat: 2 -ildouble: 1 -ldouble: 1 +ildouble: 3 +ldouble: 3 Function: Imaginary part of "ctanh": float: 1 ifloat: 1 -ildouble: 1 -ldouble: 1 +double: 1 +idouble: 1 +ildouble: 2 +ldouble: 2 Function: "erf": double: 1 |