From patchwork Wed Feb 25 11:14:25 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Myers X-Patchwork-Id: 5278 Received: (qmail 81799 invoked by alias); 25 Feb 2015 11:14:35 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 81774 invoked by uid 89); 25 Feb 2015 11:14:33 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 X-HELO: relay1.mentorg.com Date: Wed, 25 Feb 2015 11:14:25 +0000 From: Joseph Myers To: Subject: Fix ldbl-128ibm asinhl inaccuracy (bug 18020) [committed] Message-ID: User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 The ldbl-128ibm implementation of asinhl uses cut-offs of 0x1p28 and 0x1p-29 to determine when to use simpler formulas that avoid possible overflow / underflow. Both those cut-offs are inappropriate for this format, resulting in large errors. This patch changes the code to use more appropriate cut-offs of 0x1p56 and 0x1p-56, adding tests around the cut-offs for various floating-point formats. Tested for powerpc. Also tested for x86_64 and x86 and updated ulps. Committed. (auto-libm-test-out diffs omitted below.) 2015-02-25 Joseph Myers [BZ #18020] * sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Use 2**56 and 2**-56 not 2**28 and 2**-29 as thresholds for simpler formulas. * math/auto-libm-test-in: Add more tests of asinh. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise. diff --git a/math/auto-libm-test-in b/math/auto-libm-test-in index a4bd972..df51c26 100644 --- a/math/auto-libm-test-in +++ b/math/auto-libm-test-in @@ -104,8 +104,69 @@ asinh 1 asinh 10 asinh 100 asinh 1e6 +asinh 0x1p8 +asinh 0x1p9 +asinh 0x1p10 +asinh 0x1p11 +asinh 0x1p12 +asinh 0x1p13 +asinh 0x1p24 +asinh 0x1p25 +asinh 0x1p26 +asinh 0x1p27 +asinh 0x1p28 +asinh 0x1p29 +asinh 0x1p30 +asinh 0x1p31 +asinh 0x1p32 +asinh 0x1p33 +asinh 0x1p48 +asinh 0x1p49 +asinh 0x1p50 +asinh 0x1p51 +asinh 0x1p52 +asinh 0x1p53 +asinh 0x1p54 +asinh 0x1p55 +asinh 0x1p56 +asinh 0x1p57 +asinh 0x1p58 +asinh 0x1p59 asinh 0x1p100 +asinh 0x1p500 +asinh 0x1p5000 +asinh 0x1p-8 +asinh 0x1p-9 +asinh 0x1p-10 +asinh 0x1p-11 +asinh 0x1p-12 +asinh 0x1p-13 +asinh 0x1p-24 +asinh 0x1p-25 +asinh 0x1p-26 +asinh 0x1p-27 +asinh 0x1p-28 +asinh 0x1p-29 +asinh 0x1p-30 +asinh 0x1p-31 +asinh 0x1p-32 +asinh 0x1p-33 +asinh 0x1p-48 +asinh 0x1p-49 +asinh 0x1p-50 +asinh 0x1p-51 +asinh 0x1p-52 +asinh 0x1p-53 +asinh 0x1p-54 +asinh 0x1p-55 +asinh 0x1p-56 +asinh 0x1p-57 +asinh 0x1p-58 +asinh 0x1p-59 +asinh 0x1p-100 # Bug 16350: underflow exception may be missing. +asinh 0x1p-500 missing-underflow +asinh 0x1p-5000 missing-underflow asinh min missing-underflow asinh -min missing-underflow asinh min_subnorm missing-underflow diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps index 0977557..3ba23a4 100644 --- a/sysdeps/i386/fpu/libm-test-ulps +++ b/sysdeps/i386/fpu/libm-test-ulps @@ -68,14 +68,14 @@ ldouble: 1 Function: "asinh_downward": double: 1 float: 1 -ildouble: 1 +ildouble: 3 ldouble: 3 Function: "asinh_towardzero": double: 1 float: 1 -ildouble: 1 -ldouble: 2 +ildouble: 3 +ldouble: 3 Function: "asinh_upward": double: 1 @@ -83,7 +83,7 @@ float: 1 idouble: 1 ifloat: 1 ildouble: 5 -ldouble: 2 +ldouble: 3 Function: "atan2": ildouble: 1 diff --git a/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c b/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c index 043b151..b76e114 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c @@ -44,15 +44,15 @@ long double __asinhl(long double x) EXTRACT_WORDS64 (hx, xhi); ix = hx&0x7fffffffffffffffLL; if(ix>=0x7ff0000000000000LL) return x+x; /* x is inf or NaN */ - if(ix< 0x3e20000000000000LL) { /* |x|<2**-29 */ + if(ix< 0x3c70000000000000LL) { /* |x|<2**-56 */ if(huge+x>one) return x; /* return x inexact except 0 */ } - if(ix>0x41b0000000000000LL) { /* |x| > 2**28 */ + if(ix>0x4370000000000000LL) { /* |x| > 2**56 */ w = __ieee754_logl(fabsl(x))+ln2; - } else if (ix>0x4000000000000000LL) { /* 2**28 > |x| > 2.0 */ + } else if (ix>0x4000000000000000LL) { /* 2**56 >= |x| > 2.0 */ t = fabs(x); w = __ieee754_logl(2.0*t+one/(__ieee754_sqrtl(x*x+one)+t)); - } else { /* 2.0 > |x| > 2**-29 */ + } else { /* 2.0 >= |x| >= 2**-56 */ t = x*x; w =__log1pl(fabsl(x)+t/(one+__ieee754_sqrtl(one+t))); } diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps index cd9e44f..7252929 100644 --- a/sysdeps/x86_64/fpu/libm-test-ulps +++ b/sysdeps/x86_64/fpu/libm-test-ulps @@ -86,33 +86,34 @@ ldouble: 1 Function: "asinh": double: 1 float: 1 +idouble: 1 ifloat: 1 ildouble: 1 ldouble: 1 Function: "asinh_downward": -double: 1 +double: 2 float: 2 -idouble: 1 -ifloat: 1 -ildouble: 1 +idouble: 2 +ifloat: 2 +ildouble: 3 ldouble: 3 Function: "asinh_towardzero": -double: 1 -float: 1 -idouble: 1 -ifloat: 1 -ildouble: 1 -ldouble: 2 +double: 2 +float: 2 +idouble: 2 +ifloat: 2 +ildouble: 3 +ldouble: 3 Function: "asinh_upward": double: 2 float: 1 -idouble: 1 +idouble: 2 ifloat: 1 -ildouble: 2 -ldouble: 2 +ildouble: 3 +ldouble: 3 Function: "atan2": float: 1