Re: test-float fails on regular PowerPC, too.

[Bruno Haible]

Hi,

Andreas Metzler wrote on 2011-09-05:
> > > test-float fails on PowerPC (not PowerPC64), too. This causes
> [...]
> > Does the test failure go away if you change in lib/float.in.h the
> > condition
> 
> >     (defined _ARCH_PPC || defined _POWER) && defined _AIX
> 
> > to
> 
> >     (defined _ARCH_PPC || defined _POWER || defined __ppc__ || defined 
> > __powerpc__)
> 
> > and adjust m4/float_h.m4 to set FLOAT_H=float.h and REPLACE_FLOAT_LDBL=1
> > (like it is done for AIX)?
> 
> Like I tried in the attached patched? - No did not help.

I got access to a Linux/PowerPC machine now, and verified that
  1) the only problem on this platform is with LDBL_MAX; all other math.h
     related tests pass.
  2) the patch below fixes the test failure.


2011-09-29  Bruno Haible  <address@hidden>

        float: Fix LDBL_MAX value on Linux/PowerPC.
        * m4/float_h.m4 (gl_FLOAT_H): Set FLOAT_H and REPLACE_FLOAT_LDBL also
        on Linux/PowerPC.
        * lib/float.in.h (LDBL_MAX): Redefine also on Linux/PowerPC.
        * lib/float.c (gl_LDBL_MAX): Also define on Linux/PowerPC.
        * doc/posix-headers/float.texi: Mention Linux/PowerPC as an affected
        platform.
        Reported by Andreas Metzler <address@hidden>.

--- doc/posix-headers/float.texi.orig   Fri Sep 30 03:52:12 2011
+++ doc/posix-headers/float.texi        Fri Sep 30 03:52:05 2011
@@ -14,8 +14,9 @@
 @samp{double}.
 On FreeBSD/x86 6.4, they represent the incorrect 53-bit precision assumptions
 in the compiler, not the real 64-bit precision at runtime.
-On AIX 7.1 with GCC 4.2 and on IRIX 6.5, they don't reflect the
-``double double'' representation of @code{long double} correctly.
+On Linux/PowerPC with GCC 4.4, on AIX 7.1 with GCC 4.2, and on IRIX 6.5,
+they don't reflect the ``double double'' representation of @code{long double}
+correctly.
 @end itemize
 
 Portability problems not fixed by Gnulib:
--- lib/float.c.orig    Fri Sep 30 03:52:12 2011
+++ lib/float.c Thu Sep 29 23:02:37 2011
@@ -20,7 +20,7 @@
 /* Specification.  */
 #include <float.h>
 
-#if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 
106) && defined __GNUC__
+#if (defined _ARCH_PPC || defined _POWER) && (defined _AIX || defined 
__linux__) && (LDBL_MANT_DIG == 106) && defined __GNUC__
 const union gl_long_double_union gl_LDBL_MAX =
   { { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL } };
 #elif defined __i386__
--- lib/float.in.h.orig Fri Sep 30 03:52:12 2011
+++ lib/float.in.h      Fri Sep 30 03:50:52 2011
@@ -109,7 +109,8 @@
 #endif
 
 /* On AIX 7.1 with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX are
-   wrong.  */
+   wrong.
+   On Linux/PowerPC with gcc 4.4, the value of LDBL_MAX is wrong.  */
 #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 
106) && defined __GNUC__
 # undef LDBL_MIN_EXP
 # define LDBL_MIN_EXP DBL_MIN_EXP
@@ -117,6 +118,8 @@
 # define LDBL_MIN_10_EXP DBL_MIN_10_EXP
 # undef LDBL_MIN
 # define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 
2^-1022 */
+#endif
+#if (defined _ARCH_PPC || defined _POWER) && (defined _AIX || defined 
__linux__) && (LDBL_MANT_DIG == 106) && defined __GNUC__
 # undef LDBL_MAX
 /* LDBL_MAX is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xFFFFFFFF 
}.
    It is not easy to define:
--- m4/float_h.m4.orig  Fri Sep 30 03:52:12 2011
+++ m4/float_h.m4       Thu Sep 29 22:58:14 2011
@@ -1,4 +1,4 @@
-# float_h.m4 serial 7
+# float_h.m4 serial 8
 dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -33,9 +33,16 @@
           ;;
       esac
       ;;
+    linux*)
+      case "$host_cpu" in
+        powerpc*)
+          FLOAT_H=float.h
+          ;;
+      esac
+      ;;
   esac
   case "$host_os" in
-    aix* | freebsd*)
+    aix* | freebsd* | linux*)
       if test -n "$FLOAT_H"; then
         REPLACE_FLOAT_LDBL=1
       fi

-- 
In memoriam Cheb Hasni <http://en.wikipedia.org/wiki/Cheb_Hasni>