New upstream version 1.9

[debian/gzip] / lib / fpucw.h

diff --git a/lib/fpucw.h b/lib/fpucw.h
index a6226afcf8579e7a1e323e40158d76e1632f4cfb..0c04800885715c6ad7f189eb8f4f5f39579c80e6 100644 (file)
--- a/lib/fpucw.h
+++ b/lib/fpucw.h
@@ -1,5 +1,5 @@
-/* Manipulating the FPU control word.
-   Copyright (C) 2007-2008 Free Software Foundation, Inc.
+/* Manipulating the FPU control word.  -*- coding: utf-8 -*-
+   Copyright (C) 2007-2018 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2007.
 
    This program is free software: you can redistribute it and/or modify
@@ -13,7 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef _FPUCW_H
 #define _FPUCW_H
@@ -30,17 +30,18 @@
 
    On some platforms, such as NetBSD, the default precision is set to
    "double precision".  This means that 'long double' instructions will operate
-   only as 'double', i.e. lead wrong results.
+   only as 'double', i.e. lead to wrong results.  Similarly on FreeBSD 6.4, at
+   least for the division of 'long double' numbers.
 
    The FPU control word is under control of the application, i.e. it is
    not required to be set either way by the ABI.  (In fact, the i386 ABI
-   http://refspecs.freestandards.org/elf/abi386-4.pdf page 3-12 = page 38
+   https://www.linux-mips.org/pub/linux/mips/doc/ABI/abi386-4.pdf page 3-12 = page 38
    is not clear about it.  But in any case, gcc treats the control word
    like a "preserved" register: it emits code that assumes that the control
    word is preserved across calls, and it restores the control word at the
    end of functions that modify it.)
 
-   See Vincent Lefèvre's page http://www.vinc17.org/research/extended.en.html
+   See Vincent Lefèvre's page https://www.vinc17.net/research/extended.en.html
    for a good explanation.
    See http://www.uwsg.iu.edu/hypermail/linux/kernel/0103.0/0453.html for
    some argumentation which setting should be the default.  */
@@ -70,19 +71,19 @@ typedef unsigned short fpucw_t; /* glibc calls this fpu_control_t */
 # define FPU_PC_EXTENDED 0x300  /* glibc calls this _FPU_EXTENDED */
 
 # define GET_FPUCW() \
-  ({ fpucw_t _cw;                                              \
-     __asm__ __volatile__ ("fnstcw %0" : "=m" (*&_cw));                \
-     _cw;                                                      \
+  ({ fpucw_t _cw;                                               \
+     __asm__ __volatile__ ("fnstcw %0" : "=m" (*&_cw));         \
+     _cw;                                                       \
    })
 # define SET_FPUCW(word) \
-  (void)({ fpucw_t _ncw = (word);                              \
-           __asm__ __volatile__ ("fldcw %0" : : "m" (*&_ncw)); \
+  (void)({ fpucw_t _ncw = (word);                               \
+           __asm__ __volatile__ ("fldcw %0" : : "m" (*&_ncw));  \
          })
 
 # define DECL_LONG_DOUBLE_ROUNDING \
   fpucw_t oldcw;
 # define BEGIN_LONG_DOUBLE_ROUNDING() \
-  (void)(oldcw = GET_FPUCW (),                                 \
+  (void)(oldcw = GET_FPUCW (),                                  \
          SET_FPUCW ((oldcw & ~FPU_PC_MASK) | FPU_PC_EXTENDED))
 # define END_LONG_DOUBLE_ROUNDING() \
   SET_FPUCW (oldcw)