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[p5sagit/p5-mst-13.2.git] / README.tru64

diff --git a/README.tru64 b/README.tru64
index c551a36..ce2181a 100644 (file)
--- a/README.tru64
+++ b/README.tru64
@@ -15,11 +15,13 @@ is compiled and/or runs.
 =head2 Compiling Perl 5 on Tru64
 
 The recommended compiler to use in Tru64 is the native C compiler.
-The native compiler produces much faster code (the speed difference is
-noticeable: several dozen percentages) and also more correct code: if you
-are considering using the GNU C compiler you should use the gcc 2.95.3
-release since older gcc releases are known to produce buggy code when
-compiling Perl.
+The native compiler produces much faster code (the speed difference
+is noticeable: several dozen percentages) and also more correct code:
+if you are considering using the GNU C compiler you should use the
+gcc 2.95.3 since all older gcc releases are known to produce broken
+code when compiling Perl.  One manifestation of this brokenness is
+the lib/sdbm test dumping core; another is the op/regexp dumping core
+(depending on the GCC release).
 
 =head2 Using Large Files with Perl on Tru64
 
@@ -40,6 +42,20 @@ example the regular expressions are not thread-safe.  The bugs are
 very hard to fix are and therefore the 5.005 threads model is still
 classified as an experimental feature.
 
+=head2 Long Doubles on Tru64
+
+You cannot Configure Perl to use long doubles unless you have at least
+Tru64 V5.0, the long double support simply wasn't functional before
+that.
+
+At the time of this writing, there's a bug in the Tru64 libc printing
+of long doubles when not using "e" notation.  The values are correct
+and usable, but you only get a limited number of digits displayed
+unless you force the issue by using C<printf "%.33e",$num> or the like.
+For Tru64 versions V5.0A through V5.1A, a patch is expected sometime after
+perl 5.8.0 is released.  If your libc has not yet been patched, you'll get
+a warning from Configure when selecting long doubles.
+
 =head2 64-bit Perl on Tru64
 
 In Tru64 Perl's integers are automatically 64-bit wide, there is
@@ -51,7 +67,7 @@ in INSTALL.  Similarly, there is no need for -Duse64bitall.
 When compiling Perl in Tru64 you may (depending on the compiler
 release) see two warnings like this
 
-    cc: Warning: util.c, line 3797: In this statement, floating-point overflow occurs in evaluating the expression "1.8e308". (floatoverfl)
+    cc: Warning: numeric.c, line 104: In this statement, floating-point overflow occurs in evaluating the expression "1.8e308". (floatoverfl)
         return HUGE_VAL;
     -----------^