Bump to m4 1.4.19

[platform/upstream/m4.git] / lib / fpucw.h

diff --git a/lib/fpucw.h b/lib/fpucw.h
index 07403bf..f6ed550 100644 (file)
--- a/lib/fpucw.h
+++ b/lib/fpucw.h
@@ -1,5 +1,5 @@
-/* Manipulating the FPU control word.
-   Copyright (C) 2007-2011 Free Software Foundation, Inc.
+/* Manipulating the FPU control word.  -*- coding: utf-8 -*-
+   Copyright (C) 2007-2021 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
@@ -30,19 +30,20 @@
 
    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
+   See https://web.archive.org/web/20060905133417/http://www.uwsg.iu.edu/hypermail/linux/kernel/0103.0/0453.html
    some argumentation which setting should be the default.  */
 
 /* This header file provides the following facilities:
@@ -60,8 +61,8 @@
                                     'long double' safe operation precision
  */
 
-/* Inline assembler like this works only with GNU C.  */
-#if (defined __i386__ || defined __x86_64__) && defined __GNUC__
+/* Inline assembler like this works only with GNU C and clang.  */
+#if (defined __i386__ || defined __x86_64__) && (defined __GNUC__ || defined __clang__)
 
 typedef unsigned short fpucw_t; /* glibc calls this fpu_control_t */
 
@@ -69,12 +70,12 @@ typedef unsigned short fpucw_t; /* glibc calls this fpu_control_t */
 # define FPU_PC_DOUBLE 0x200    /* glibc calls this _FPU_DOUBLE */
 # define FPU_PC_EXTENDED 0x300  /* glibc calls this _FPU_EXTENDED */
 
-# define GET_FPUCW() \
+# define GET_FPUCW() __extension__ \
   ({ fpucw_t _cw;                                               \
      __asm__ __volatile__ ("fnstcw %0" : "=m" (*&_cw));         \
      _cw;                                                       \
    })
-# define SET_FPUCW(word) \
+# define SET_FPUCW(word) __extension__ \
   (void)({ fpucw_t _ncw = (word);                               \
            __asm__ __volatile__ ("fldcw %0" : : "m" (*&_ncw));  \
          })