From 737df6e61771e330559a152be1653b173012172b Mon Sep 17 00:00:00 2001 From: Tobias Burnus Date: Wed, 31 Oct 2012 16:46:59 +0100 Subject: [PATCH] complex.c (csqrtq): NaN and INF fixes. 2012-10-31 Tobias Burnus Joseph Myers David S. Miller Ulrich Drepper Marek Polacek : Petr Baudis * math/complex.c (csqrtq): NaN and INF fixes. * math/sqrtq.c (sqrt): NaN, INF and < 0 fixes. * math/expm1q.c (expm1q): Changes from GLIBC. Use expq for large parameters. Fix errno for boundary conditions. * math/finiteq.c (finiteq): Add comment. * math/fmaq.c (fmaq): Changes from GLIBC. Fix missing underflows and bad results for some subnormal results. Fix sign of inexact zero return. Fix sign of exact zero return. Ensure additions are not scheduled after fetestexcept. * math/jnq.c (jnq): Changes from GLIBC. Set up errno properly for ynq. Fix jnq precision. * math/nearbyintq.c (nearbyintq): Changes from GLIBC. Do not manipulate bits before adding and subtracting TWO112[sx]. * math/rintq.c (rintq): Ditto. * math/scalbnq.c (scalbnq): Changes from GLIBC. Fix integer overflow. Co-Authored-By: David S. Miller Co-Authored-By: Joseph Myers Co-Authored-By: Ulrich Drepper From-SVN: r193037 --- libquadmath/ChangeLog | 24 ++++++++++++++++++++++++ libquadmath/math/complex.c | 10 +++++++++- libquadmath/math/expm1q.c | 11 ++++++++++- libquadmath/math/finiteq.c | 5 +++++ libquadmath/math/fmaq.c | 36 ++++++++++++++++++++---------------- libquadmath/math/jnq.c | 19 ++++++++++++++++--- libquadmath/math/nearbyintq.c | 25 +++---------------------- libquadmath/math/rintq.c | 35 +++++++++++++---------------------- libquadmath/math/scalblnq.c | 15 ++++++++++++--- libquadmath/math/scalbnq.c | 16 +++++++++++++--- libquadmath/math/sqrtq.c | 9 ++++++--- 11 files changed, 131 insertions(+), 74 deletions(-) diff --git a/libquadmath/ChangeLog b/libquadmath/ChangeLog index dd37cd3..37cc5a2 100644 --- a/libquadmath/ChangeLog +++ b/libquadmath/ChangeLog @@ -1,3 +1,27 @@ +2012-10-31 Tobias Burnus + Joseph Myers + David S. Miller + Ulrich Drepper + Marek Polacek : + Petr Baudis + + * math/complex.c (csqrtq): NaN and INF fixes. + * math/sqrtq.c (sqrt): NaN, INF and < 0 fixes. + * math/expm1q.c (expm1q): Changes from GLIBC. Use expq for + large parameters. Fix errno for boundary conditions. + * math/finiteq.c (finiteq): Add comment. + * math/fmaq.c (fmaq): Changes from GLIBC. Fix missing underflows + and bad results for some subnormal results. Fix sign of inexact + zero return. Fix sign of exact zero return. + Ensure additions are not scheduled after fetestexcept. + * math/jnq.c (jnq): Changes from GLIBC. Set up errno properly + for ynq. Fix jnq precision. + * math/nearbyintq.c (nearbyintq): Changes from GLIBC. Do not + manipulate bits before adding and subtracting TWO112[sx]. + * math/rintq.c (rintq): Ditto. + * math/scalbnq.c (scalbnq): Changes from GLIBC. Fix integer + overflow. + 2012-09-14 David Edelsohn * configure: Regenerated. diff --git a/libquadmath/math/complex.c b/libquadmath/math/complex.c index f67448a..9953f52 100644 --- a/libquadmath/math/complex.c +++ b/libquadmath/math/complex.c @@ -177,7 +177,11 @@ csqrtq (__complex128 z) if (im == 0) { - if (re < 0) + if (isnanq (re)) + { + COMPLEX_ASSIGN (v, -re, -re); + } + else if (re < 0) { COMPLEX_ASSIGN (v, 0, copysignq (sqrtq (-re), im)); } @@ -186,6 +190,10 @@ csqrtq (__complex128 z) COMPLEX_ASSIGN (v, fabsq (sqrtq (re)), copysignq (0, im)); } } + else if (isinfq (im)) + { + COMPLEX_ASSIGN (v, fabsq (im), im); + } else if (re == 0) { __float128 r = sqrtq (0.5 * fabsq (im)); diff --git a/libquadmath/math/expm1q.c b/libquadmath/math/expm1q.c index 510c98f..8cfdd8e 100644 --- a/libquadmath/math/expm1q.c +++ b/libquadmath/math/expm1q.c @@ -53,6 +53,7 @@ +#include #include "quadmath-imp.h" /* exp(x) - 1 = x + 0.5 x^2 + x^3 P(x)/Q(x) @@ -100,6 +101,11 @@ expm1q (__float128 x) ix = u.words32.w0; sign = ix & 0x80000000; ix &= 0x7fffffff; + if (!sign && ix >= 0x40060000) + { + /* If num is positive and exp >= 6 use plain exp. */ + return expq (x); + } if (ix >= 0x7fff0000) { /* Infinity. */ @@ -120,7 +126,10 @@ expm1q (__float128 x) /* Overflow. */ if (x > maxlog) - return (HUGE_VALQ * HUGE_VALQ); + { + errno = ERANGE; + return (HUGE_VALQ * HUGE_VALQ); + } /* Minimum value. */ if (x < minarg) diff --git a/libquadmath/math/finiteq.c b/libquadmath/math/finiteq.c index f22e9d7..663c928 100644 --- a/libquadmath/math/finiteq.c +++ b/libquadmath/math/finiteq.c @@ -15,6 +15,11 @@ #include "quadmath-imp.h" +/* + * finiteq(x) returns 1 is x is finite, else 0; + * no branching! + */ + int finiteq (const __float128 x) { diff --git a/libquadmath/math/fmaq.c b/libquadmath/math/fmaq.c index 126b0a2..23e3188 100644 --- a/libquadmath/math/fmaq.c +++ b/libquadmath/math/fmaq.c @@ -1,5 +1,5 @@ /* Compute x * y + z as ternary operation. - Copyright (C) 2010 Free Software Foundation, Inc. + Copyright (C) 2010-2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jakub Jelinek , 2010. @@ -57,6 +57,11 @@ fmaq (__float128 x, __float128 y, __float128 z) && u.ieee.exponent != 0x7fff && v.ieee.exponent != 0x7fff) return (z + x) + y; + /* If z is zero and x are y are nonzero, compute the result + as x * y to avoid the wrong sign of a zero result if x * y + underflows to 0. */ + if (z == 0 && x != 0 && y != 0) + return x * y; /* If x or y or z is Inf/NaN, or if fma will certainly overflow, or if x * y is less than half of FLT128_DENORM_MIN, compute as x * y + z. */ @@ -136,6 +141,11 @@ fmaq (__float128 x, __float128 y, __float128 z) y = v.value; z = w.value; } + + /* Ensure correct sign of exact 0 + 0. */ + if (__builtin_expect ((x == 0 || y == 0) && z == 0, 0)) + return x * y + z; + /* Multiplication m1 + m2 = x * y using Dekker's algorithm. */ #define C ((1LL << (FLT128_MANT_DIG + 1) / 2) + 1) __float128 x1 = x * C; @@ -191,7 +201,7 @@ fmaq (__float128 x, __float128 y, __float128 z) #endif v.value = a1 + u.value; /* Ensure the addition is not scheduled after fetestexcept call. */ - asm volatile ("" : : "m" (v)); + asm volatile ("" : : "m" (v.value)); #ifdef USE_FENV_H int j = fetestexcept (FE_INEXACT) != 0; feupdateenv (&env); @@ -220,20 +230,14 @@ fmaq (__float128 x, __float128 y, __float128 z) { /* v.ieee.mant_low & 2 is LSB bit of the result before rounding, v.ieee.mant_low & 1 is the round bit and j is our sticky - bit. In round-to-nearest 001 rounds down like 00, - 011 rounds up, even though 01 rounds down (thus we need - to adjust), 101 rounds down like 10 and 111 rounds up - like 11. */ - if ((v.ieee.mant_low & 3) == 1) - { - v.value *= 0x1p-226Q; - if (v.ieee.negative) - return v.value - 0x1p-16494Q /* __FLT128_DENORM_MIN__ */; - else - return v.value + 0x1p-16494Q /* __FLT128_DENORM_MIN__ */; - } - else - return v.value * 0x1p-226Q; + bit. */ + w.value = 0.0Q; + w.ieee.mant_low = ((v.ieee.mant_low & 3) << 1) | j; + w.ieee.negative = v.ieee.negative; + v.ieee.mant_low &= ~3U; + v.value *= 0x1p-226L; + w.value *= 0x1p-2L; + return v.value + w.value; } v.ieee.mant_low |= j; return v.value * 0x1p-226Q; diff --git a/libquadmath/math/jnq.c b/libquadmath/math/jnq.c index d82947a..56a1836 100644 --- a/libquadmath/math/jnq.c +++ b/libquadmath/math/jnq.c @@ -11,9 +11,9 @@ /* Modifications for 128-bit long double are Copyright (C) 2001 Stephen L. Moshier - and are incorporated herein by permission of the author. The author + and are incorporated herein by permission of the author. The author reserves the right to distribute this material elsewhere under different - copying permissions. These modifications are distributed here under + copying permissions. These modifications are distributed here under the following terms: This library is free software; you can redistribute it and/or @@ -56,6 +56,7 @@ * */ +#include #include "quadmath-imp.h" static const __float128 @@ -273,7 +274,16 @@ jnq (int n, __float128 x) } } } - b = (t * j0q (x) / b); + /* j0() and j1() suffer enormous loss of precision at and + * near zero; however, we know that their zero points never + * coincide, so just choose the one further away from zero. + */ + z = j0q (x); + w = j1q (x); + if (fabsq (z) >= fabsq (w)) + b = (t * z / b); + else + b = (t * w / a); } } if (sgn == 1) @@ -374,6 +384,9 @@ ynq (int n, __float128 x) a = temp; } } + /* If B is +-Inf, set up errno accordingly. */ + if (! finiteq (b)) + errno = ERANGE; if (sign > 0) return b; else diff --git a/libquadmath/math/nearbyintq.c b/libquadmath/math/nearbyintq.c index 8e92c5a..2071248 100644 --- a/libquadmath/math/nearbyintq.c +++ b/libquadmath/math/nearbyintq.c @@ -44,18 +44,13 @@ nearbyintq(__float128 x) fenv_t env; #endif int64_t i0,j0,sx; - uint64_t i,i1; + uint64_t i1; __float128 w,t; GET_FLT128_WORDS64(i0,i1,x); sx = (((uint64_t)i0)>>63); j0 = ((i0>>48)&0x7fff)-0x3fff; - if(j0<48) { + if(j0<112) { if(j0<0) { - if(((i0&0x7fffffffffffffffLL)|i1)==0) return x; - i1 |= (i0&0x0000ffffffffffffLL); - i0 &= 0xffffe00000000000ULL; - i0 |= ((i1|-i1)>>16)&0x0000800000000000LL; - SET_FLT128_MSW64(x,i0); #ifdef USE_FENV_H feholdexcept (&env); #endif @@ -67,25 +62,11 @@ nearbyintq(__float128 x) GET_FLT128_MSW64(i0,t); SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63)); return t; - } else { - i = (0x0000ffffffffffffLL)>>j0; - if(((i0&i)|i1)==0) return x; /* x is integral */ - i>>=1; - if(((i0&i)|i1)!=0) { - if(j0==47) i1 = 0x4000000000000000ULL; else - i0 = (i0&(~i))|((0x0000200000000000LL)>>j0); - } } - } else if (j0>111) { + } else { if(j0==0x4000) return x+x; /* inf or NaN */ else return x; /* x is integral */ - } else { - i = -1ULL>>(j0-48); - if((i1&i)==0) return x; /* x is integral */ - i>>=1; - if((i1&i)!=0) i1 = (i1&(~i))|((0x4000000000000000LL)>>(j0-48)); } - SET_FLT128_WORDS64(x,i0,i1); #ifdef USE_FENV_H feholdexcept (&env); #endif diff --git a/libquadmath/math/rintq.c b/libquadmath/math/rintq.c index fe7a591..8a93fdb 100644 --- a/libquadmath/math/rintq.c +++ b/libquadmath/math/rintq.c @@ -13,6 +13,16 @@ * ==================================================== */ +/* + * rintq(x) + * Return x rounded to integral value according to the prevailing + * rounding mode. + * Method: + * Using floating addition. + * Exception: + * Inexact flag raised if x not equal to rintq(x). + */ + #include "quadmath-imp.h" static const __float128 @@ -25,42 +35,23 @@ __float128 rintq (__float128 x) { int64_t i0,j0,sx; - uint64_t i,i1; + uint64_t i1; __float128 w,t; GET_FLT128_WORDS64(i0,i1,x); sx = (((uint64_t)i0)>>63); j0 = ((i0>>48)&0x7fff)-0x3fff; - if(j0<48) { + if(j0<112) { if(j0<0) { - if(((i0&0x7fffffffffffffffLL)|i1)==0) return x; - i1 |= (i0&0x0000ffffffffffffLL); - i0 &= 0xffffe00000000000ULL; - i0 |= ((i1|-i1)>>16)&0x0000800000000000LL; - SET_FLT128_MSW64(x,i0); w = TWO112[sx]+x; t = w-TWO112[sx]; GET_FLT128_MSW64(i0,t); SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63)); return t; - } else { - i = (0x0000ffffffffffffLL)>>j0; - if(((i0&i)|i1)==0) return x; /* x is integral */ - i>>=1; - if(((i0&i)|i1)!=0) { - if(j0==47) i1 = 0x4000000000000000ULL; else - i0 = (i0&(~i))|((0x0000200000000000LL)>>j0); - } } - } else if (j0>111) { + } else { if(j0==0x4000) return x+x; /* inf or NaN */ else return x; /* x is integral */ - } else { - i = -1ULL>>(j0-48); - if((i1&i)==0) return x; /* x is integral */ - i>>=1; - if((i1&i)!=0) i1 = (i1&(~i))|((0x4000000000000000LL)>>(j0-48)); } - SET_FLT128_WORDS64(x,i0,i1); w = TWO112[sx]+x; return w-TWO112[sx]; } diff --git a/libquadmath/math/scalblnq.c b/libquadmath/math/scalblnq.c index 75997f6..b233225 100644 --- a/libquadmath/math/scalblnq.c +++ b/libquadmath/math/scalblnq.c @@ -13,6 +13,13 @@ * ==================================================== */ +/* + * scalblnq (_float128 x, long int n) + * scalblnq(x,n) returns x* 2**n computed by exponent + * manipulation rather than by actually performing an + * exponentiation or a multiplication. + */ + #include "quadmath-imp.h" static const __float128 @@ -34,10 +41,12 @@ scalblnq (__float128 x, long int n) k = ((hx>>48)&0x7fff) - 114; } if (k==0x7fff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0x7ffe) - return huge*copysignq(huge,x); /* overflow */ if (n< -50000) return tiny*copysignq(tiny,x); /*underflow*/ + if (n> 50000 || k+n > 0x7ffe) + return huge*copysignq(huge,x); /* overflow */ + /* Now k and n are bounded we know that k = k+n does not + overflow. */ + k = k+n; if (k > 0) /* normal result */ {SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); return x;} if (k <= -114) diff --git a/libquadmath/math/scalbnq.c b/libquadmath/math/scalbnq.c index b7049a7..f0852ee 100644 --- a/libquadmath/math/scalbnq.c +++ b/libquadmath/math/scalbnq.c @@ -13,6 +13,14 @@ * ==================================================== */ + +/* + * scalbnq (__float128 x, int n) + * scalbnq(x,n) returns x* 2**n computed by exponent + * manipulation rather than by actually performing an + * exponentiation or a multiplication. + */ + #include "quadmath-imp.h" static const __float128 @@ -34,10 +42,12 @@ scalbnq (__float128 x, int n) k = ((hx>>48)&0x7fff) - 114; } if (k==0x7fff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0x7ffe) - return huge*copysignq(huge,x); /* overflow */ if (n< -50000) return tiny*copysignq(tiny,x); /*underflow*/ + if (n> 50000 || k+n > 0x7ffe) + return huge*copysignq(huge,x); /* overflow */ + /* Now k and n are bounded we know that k = k+n does not + overflow. */ + k = k+n; if (k > 0) /* normal result */ {SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); return x;} if (k <= -114) diff --git a/libquadmath/math/sqrtq.c b/libquadmath/math/sqrtq.c index 6ed4605..f63c0d1 100644 --- a/libquadmath/math/sqrtq.c +++ b/libquadmath/math/sqrtq.c @@ -8,14 +8,17 @@ sqrtq (const __float128 x) __float128 y; int exp; - if (x == 0) + if (isnanq (x) || (isinfq (x) && x > 0)) return x; - if (isnanq (x)) + if (x == 0) return x; if (x < 0) - return nanq (""); + { + /* Return NaN with invalid signal. */ + return (x - x) / (x - x); + } if (x <= DBL_MAX && x >= DBL_MIN) { -- 2.7.4