sablevm-developer

[Sablevm-developer] Another small step on powerpc

[Mark W. <ma...@kl...>]

Hi,

I can now run Hello World out of the box without patching
FileIn/Outputstream and from the normal user classpath
(including from jar files)!

The problem is in native.c (and clearly marked as such...)

@@ -1241,7 +1241,10 @@
       case SVM_TYPE_BOOLEAN:
 	{
 	  /* don't forget about little/big endian alignment */
-	  params[0].jint = *((jboolean *) &result[0]);
+          if (&result[0] == 0)
+	    params[0].jint = 0;
+          else
+            params[0].jint = 1;
 	  frame->stack_size++;
 	}

There are more places in that file that seem to need adaption for
powerpc but this one fixed the FileDescriptor problem I was seeing.

Cheers,

Mark

Re: [Sablevm-developer] Another small step on powerpc

[Etienne M. G. <eti...@uq...>]

Hi Mark,

Interesting discovery.  Read comments below.

On Sun, Aug 25, 2002 at 08:52:43PM +0200, Mark Wielaard wrote:
> I can now run Hello World out of the box without patching
> FileIn/Outputstream and from the normal user classpath
> (including from jar files)!
> 
> The problem is in native.c (and clearly marked as such...)
> 
> @@ -1241,7 +1241,10 @@
>        case SVM_TYPE_BOOLEAN:
>  	{
>  	  /* don't forget about little/big endian alignment */
> -	  params[0].jint = *((jboolean *) &result[0]);

I don't see what's wrong in that code (maybe I'm blind too;-).  The
call to ffi_call() was given a pointer to a location to store the
result value.  The pointer (seen by ffi_call as (void *)) was
&result[0].  "Previously" ffi_prep_cif() told the ffi library that
this pointer would be a pointer to a "jboolean" variable to hold the
jboolean return value.  So, at first glance, this code seems correct,
to me.

Now, reading the /usr/share/doc/libffi2/README file, I noticed that
there are potential problems on the PPC.  These problems seemed
related to structures, not to primitive type values, though.

Maybe I am missing something?...  Probably doing PPC libffi tests
would be the right thing to do, but I do not have time, just now;-)

Thanks for your work!

Etienne
-- 
Etienne M. Gagnon                    http://www.info.uqam.ca/~egagnon/
SableVM:                                       http://www.sablevm.org/
SableCC:                                       http://www.sablecc.org/