[971031]: Fix for broken hypot funct. on m88k-motorola-sysv3

[manfred at s-direktnet dot de]

On Wed, 5 November 1997, 07:43:39, manfred@s-direktnet.de wrote:

    These are my results for egcs-971031 on m88k-motorola-sysv3 (aka delta88) using
    
      [snip]

       [10]: fixincludes patch for a m88k-motorola-sysv3 from <manfred@s-direktnet.de>
    	 - will send it soon.
    
      [snip]

Here   it comes.  The  problem  that's  fixed is  caused   by a stupid
`optimization' in the `hypot' function of Motorola's libm.a.

   DESCRIPTION
     hypot(x,y) returns

          sqrt(x*x + y*y)

If either x or y is 0, hypot simply returns the other value regardless
of any sign.  This, of course, causes pretty  much failures during the
libstdc++ tests, because the lib itself uses hypot frequently.

hypot  (0.0, -1.0)   e.g.   returns   -1.0,  not  1.0  as   one  would
expect. Since I cannot fix the library (nor  can I request a fixed one
from Motorola because my customers insist on the particular OS version
we're  using here), I provide   a `fake_hypot' function  in the  fixed
`math.h' file which takes care of this bug:

  #ifdef __STDC__
  static __inline__ double fake_hypot (double x, double y)
  #else
  static __inline__ double fake_hypot (x, y)
          double x, y;
  #endif
  {
          return fabs (hypot (x, y));
  }
  #define hypot   fake_hypot


Another  fix is  for  the strlen, etc.   functions, which  are defined
differently depending on _POSIX_SOURCE;  fixincludes fails to fix this
one.


Wed Nov  5 13:31:40 1997  Manfred Hollstein  <manfred@s-direktnet.de>

	* fixincludes (str{len,spn,cspn} return value): Handle different
	layout on sysV88.
	(hypot): Provide a fake for hypot which is broken on m88k-motorola-sysv3.

diff --context --recursive --show-c-function -x *.o -x *.info* -x *.html* -x *.elc -x *.dvi -x *.orig -x *~ -x version.el egcs-971031.orig/gcc/fixincludes egcs-971031/gcc/fixincludes
*** egcs-971031.orig/gcc/fixincludes	Tue Sep  2 20:38:30 1997
- --- egcs-971031/gcc/fixincludes	Mon Nov  3 12:44:33 1997
*************** INPUT=${2-${INPUT-/usr/include}}
*** 12,17 ****
- --- 12,25 ----
  # Directory in which to store the results.
  LIB=${1?"fixincludes: output directory not specified"}
  
+ # Define what target system we're fixing.
+ if test -r ./Makefile; then
+ 	target_canonical="`sed -n -e 's,^target[ 	]*=[ 	]*\(.*\)$,\1,p' < Makefile`"
+ 	test -z "${target_canonical}" && target_canonical=unknown
+ else
+ 	target_canonical=unknown
+ fi
+ 
  # Define PWDCMD as a command to use to get the working dir
  # in the form that we want.
  PWDCMD=pwd
*************** fi
*** 1982,1987 ****
- --- 1990,1996 ----
  # Correct the return type for strlen in string.h on Lynx.
  # Correct the argument type for ffs in string.h on Alpha OSF/1 V2.0.
  # Add missing const for strdup on OSF/1 V3.0.
+ # On sysV88 layout is slightly different.
  file=string.h
  if [ -r $file ] && [ ! -r ${LIB}/$file ]; then
    cp $file ${LIB}/$file >/dev/null 2>&1 || echo "Can't copy $file"
*************** if [ -r ${LIB}/$file ]; then
*** 2000,2005 ****
- --- 2009,2016 ----
        -e 's/^\(	strncmp()\),\n\(	strlen(),\)$/\1;\
  extern unsigned int\
  \2/'\
+       -e '/^extern int$/N'\
+       -e 's/^extern int\(\n	strlen(),\)/extern size_t\1/' \
      ${LIB}/$file > ${LIB}/${file}.sed
    rm -f ${LIB}/$file; mv ${LIB}/${file}.sed ${LIB}/$file
    if cmp $file ${LIB}/$file >/dev/null 2>&1; then
*************** do
*** 2284,2289 ****
- --- 2295,2335 ----
      fi
    fi
  done
+ 
+ # libm.a on m88k-motorola-sysv3 contains a stupid optimization for function
+ # hypot(), which returns the second argument without even looking at its value
+ # if the other is 0.0
+ file=math.h
+ if [ $target_canonical = m88k-motorola-sysv3 ]; then
+   if [ -r $file ] && [ ! -r ${LIB}/$file ]; then
+     cp $file ${LIB}/$file >/dev/null 2>&1 || echo "Can't copy $file"
+     chmod +w ${LIB}/$file 2>/dev/null
+     chmod a+r ${LIB}/$file 2>/dev/null
+   fi
+ 
+   if [ -r ${LIB}/$file ]; then
+     echo Fixing $file, hypot definition
+     sed -e '/^extern double hypot();$/a\
+ \/* Workaround a stupid Motorola optimization if one\
+    of x or y is 0.0 and the other is negative!  *\/\
+ #ifdef __STDC__\
+ static __inline__ double fake_hypot (double x, double y)\
+ #else\
+ static __inline__ double fake_hypot (x, y)\
+ 	double x, y;\
+ #endif\
+ {\
+ 	return fabs (hypot (x, y));\
+ }\
+ #define hypot	fake_hypot
+ ' \
+       ${LIB}/$file > ${LIB}/${file}.sed
+     rm -f ${LIB}/$file; mv ${LIB}/${file}.sed ${LIB}/$file
+     if cmp $file ${LIB}/$file >/dev/null 2>&1; then
+       rm -f ${LIB}/$file
+     fi
+   fi
+ fi
  
  # math.h on SunOS 4 puts the declaration of matherr before the definition
  # of struct exception, so the prototype (added by fixproto) causes havoc.