From a92ac9f494b2a7d59a1f54ba79c569a35a6da005 Mon Sep 17 00:00:00 2001 From: "Paul E. Murphy" Date: Fri, 7 Feb 2020 14:07:01 -0600 Subject: [PATCH] ldbl-128ibm: make ieee754.h work with IEEE 128 long double Instead of attempting something more creative, just copy the small struct from ldbl-128 and enable it when IEEE long double is present, and update the ibm long double variant if supported. Likewise, provide a shadow copy of math_ldbl.h to prevent the ibm128 specific long double header from poisoning unrelated files due to it's usage in math_private.h. Reviewed-by: Tulio Magno Quites Machado Filho --- .../ieee754/ldbl-128ibm-compat/math_ldbl.h | 30 ++++++++ sysdeps/ieee754/ldbl-128ibm/ieee754.h | 68 ++++++++++++++++++- 2 files changed, 96 insertions(+), 2 deletions(-) create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h b/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h new file mode 100644 index 0000000000..352617e178 --- /dev/null +++ b/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h @@ -0,0 +1,30 @@ +/* Manipulation of the bit representation of 'long double' quantities. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _MATH_LDBL_H_IBM128_COMPAT +#define _MATH_LDBL_H_IBM128_COMPAT 1 + +#include + +/* Trampoline in the ldbl-128ibm headers if building against the + old abi. Otherwise, we have nothing to add. */ +#if __LONG_DOUBLE_USES_FLOAT128 == 0 +#include_next +#endif + +#endif /* _MATH_LDBL_H_IBM128_COMPAT */ diff --git a/sysdeps/ieee754/ldbl-128ibm/ieee754.h b/sysdeps/ieee754/ldbl-128ibm/ieee754.h index 87c64fc316..fe4892d84f 100644 --- a/sysdeps/ieee754/ldbl-128ibm/ieee754.h +++ b/sysdeps/ieee754/ldbl-128ibm/ieee754.h @@ -21,6 +21,7 @@ #include #include +#include __BEGIN_DECLS @@ -111,6 +112,65 @@ union ieee754_double #define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */ +#if __LONG_DOUBLE_USES_FLOAT128 == 1 +/* long double is IEEE 128 bit */ +union ieee854_long_double + { + long double d; + + /* This is the IEEE 854 quad-precision format. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:15; + /* Together these comprise the mantissa. */ + unsigned int mantissa0:16; + unsigned int mantissa1:32; + unsigned int mantissa2:32; + unsigned int mantissa3:32; +#endif /* Big endian. */ +#if __BYTE_ORDER == __LITTLE_ENDIAN + /* Together these comprise the mantissa. */ + unsigned int mantissa3:32; + unsigned int mantissa2:32; + unsigned int mantissa1:32; + unsigned int mantissa0:16; + unsigned int exponent:15; + unsigned int negative:1; +#endif /* Little endian. */ + } ieee; + + /* This format makes it easier to see if a NaN is a signalling NaN. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:15; + unsigned int quiet_nan:1; + /* Together these comprise the mantissa. */ + unsigned int mantissa0:15; + unsigned int mantissa1:32; + unsigned int mantissa2:32; + unsigned int mantissa3:32; +#else + /* Together these comprise the mantissa. */ + unsigned int mantissa3:32; + unsigned int mantissa2:32; + unsigned int mantissa1:32; + unsigned int mantissa0:15; + unsigned int quiet_nan:1; + unsigned int exponent:15; + unsigned int negative:1; +#endif + } ieee_nan; + }; + +#define IEEE854_LONG_DOUBLE_BIAS 0x3fff /* Added to exponent. */ +#endif + + +#if __LONG_DOUBLE_USES_FLOAT128 == 0 || __GNUC_PREREQ (7, 0) /* IBM extended format for long double. Each long double is made up of two IEEE doubles. The value of the @@ -121,12 +181,16 @@ union ieee754_double -0.0. No other requirements are made; so, for example, 1.0 may be represented as (1.0, +0.0) or (1.0, -0.0), and the low part of a NaN is don't-care. */ - union ibm_extended_long_double { - long double ld; +# if __LONG_DOUBLE_USES_FLOAT128 == 1 && __GNUC_PREREQ (7, 0) + __ibm128 ld; +# else + long double ld; +# endif union ieee754_double d[2]; }; +#endif __END_DECLS