Enache Adrian wrote:
>  On Mon, Nov 24, 2003 a.d., Yitzchak Scott-Thoennes wrote:
>  > If NV is long double, Gconvert is supposed to take long doubles if
>  > Configure can figure out how (e.g. qgcvt or sprintf "%.*llg").  If
>  > sprintf is not used, it is possible that whatever is used end up
>  > converting differently than sprintf would have.  Would this explain
>  > the results here?  What is perl -V:d_Gconvert?
>  
>  No Gconvert is just fine. (it's qgcvt() here).
>  The bug is:
>  
>  1. classical cast & punch.
>  	 Gconvert((double)nv, digits, 0, ebuf);
>     nv is a long double, and Gconvert takes a long double argument too.
>  
>  2. the new %.g special case avoids all the stuff in sv.c:9227 and
>     below, which is setting the correct size to use.
>  
>  I don't see how to fix 2) in the new patch :-)

/me neither. I've thus applied the fix below : (but better tuits welcome)

Change 21800 by rgs@rgs-home on 2003/11/28 22:38:40

        Fix a regression introduced by change #21694 on sprintf()
        with long doubles, by disabling the specific optimisation
        path in this case ; remove a unnecessary cast ; add a new
        test file for miscellaneous sprintf() test that don't fit
        in the t/op/sprintf.t framework.

Affected files ...

... //depot/perl/MANIFEST#1110 edit
... //depot/perl/sv.c#697 edit
... //depot/perl/t/op/sprintf2.t#1 add

Differences ...

==== //depot/perl/MANIFEST#1110 (text) ====

@@ -2796,6 +2796,7 @@
 t/op/splice.t                  See if splice works
 t/op/split.t                   See if split works
 t/op/sprintf.t                 See if sprintf works
+t/op/sprintf2.t                        See if sprintf works
 t/op/srand.t                   See if srand works
 t/op/stash.t                   See if %:: stashes work
 t/op/stat.t                    See if stat works

==== //depot/perl/sv.c#697 (text) ====

@@ -8630,6 +8630,7 @@
        }
     }
 
+#ifndef USE_LONG_DOUBLE
     /* special-case "%.<number> [gf]" */
     if ( patlen <= 5 && pat[0] == '%' && pat[1] == '.'
         && (pat[patlen-1] == 'g' || pat[patlen-1] == 'f') ) {
@@ -8650,7 +8651,7 @@
                return;
            if (*pp == 'g') {
                if (digits < sizeof(ebuf) - NV_DIG - 10) { /* 0, point, slack */
-                   Gconvert((double)nv, digits, 0, ebuf);
+                   Gconvert(nv, digits, 0, ebuf);
                    sv_catpv(sv, ebuf);
                    if (*ebuf)  /* May return an empty string for digits==0 */
                        return;
@@ -8665,6 +8666,7 @@
            }
        }
     }
+#endif /* !USE_LONG_DOUBLE */
 
     if (!args && svix < svmax && DO_UTF8(*svargs))
        has_utf8 = TRUE;
@@ -9359,7 +9361,7 @@
            if ( !(width || left || plus || alt) && fill != '0'
                 && has_precis && intsize != 'q' ) {    /* Shortcuts */
                if ( c == 'g') {
-                   Gconvert((double)nv, precis, 0, PL_efloatbuf);
+                   Gconvert(nv, precis, 0, PL_efloatbuf);
                    if (*PL_efloatbuf)  /* May return an empty string for digits==0 */
                        goto float_converted;
                } else if ( c == 'f' && !precis) {