[kaffe] Re: The problem of "Double.c and buggy strtod" is settled

[Ito Kazumitsu]

In message "Re: [kaffe] Re: The problem of "Double.c and buggy strtod" is settled"
    on 03/06/06, Ito Kazumitsu <ito.kazumitsu at hitachi-cable.co.jp> writes:

> Seeing the source,  I found that the libiberty-strtod.c used atof.
> The atof of Linux 2.0.38 uses its own __strtod_internal.
> 
> As long as __strtod_internal is used,  you cannot expect a good
> result.

I am afraid it is quite difficult to keep __strtod_internal
from being called.

So I tried the attached replace/strtod.c and changed Double.c
like this:

--- libraries/clib/native/Double.c.orig	Fri Apr 12 21:56:11 2002
+++ libraries/clib/native/Double.c	Fri Jun  6 18:41:03 2003
@@ -23,6 +23,7 @@
 #include "files.h"
 #include "java_lang_Double.h"
 #include <native.h>
+extern double my_strtod();
 
 /*
  * Convert a "normal" double to a string with the supplied precision.
@@ -130,7 +131,7 @@
 #endif
 
 	/* Parse value; check for empty parse */
-	value = strtod(buf, &endbuf);
+	value = my_strtod(buf, &endbuf);
 	if (endbuf == buf) {
 		msg = startbuf;		/* this is what JDK 1.1.6 does */
 		goto bail;


The result was satisfactory but "make test" showed "FAIL: DoublePrint.java".
But diff test/regression/DoublePrint.out test/regression/DoublePrint.fail
is only this:

10c10
<   4.9E-324
---
>   4.9406564584125E-324

I think this difference is ignoreable.

And my replace/strtod.c follows.  It is based on the idea
that the need for parsing "4.9406564584124654418e-324"
except for the compiling of Double.java must be rare.

$ cat replace/strtod.c
#include <stdlib.h>

#define JAVA_DOUBLE_MIN_STR "4.9406564584124654418e-324"
#define JAVA_DOUBLE_MIN 4.9406564584124654418e-324

double
my_strtod (str, ptr)
     char *str;
     char **ptr;
{
     char *q;
     char *r;
     int m;
     int l;
     double d;
     if (*str == JAVA_DOUBLE_MIN_STR[0]) {
        q = str;
        r = JAVA_DOUBLE_MIN_STR;
        m = 1;
        l = 0;
        while (*r) {
           if (*q++ != *r++) {
              m = 0;
              break;
           }
           l++;
        }
        if (m) {
           d = JAVA_DOUBLE_MIN;
           if (ptr != NULL) {
              *ptr = str + l;
           }
        }
        else {
           d = strtod (str, ptr);
        }
     }
     else {
        d = strtod (str, ptr);
     }
     return d;
}