[Patch,libffi] Add MIPS64 soft-float support to libffi.

[David Daney]

Anthony Green wrote:
> David Daney wrote:
>> libffi is lacking support for the mips64 soft-float ABIs.  In addition 
>> be being annoying in and of itself, it also causes libjava failures.
>>
>> The patch adds soft-float support for both n32 and n64 ABIs.  Quite a 
>> bit of code had to be touched as the rules for passing structures 
>> containing floating point elements are a slightly complex.
>>
>> While working on the patch I noticed that we were failing a bunch if 
>> pointer passing test cases that where recently added.  It turns out 
>> that the original closure support for returning pointers was incorrect 
>> and this was unmasked by the new test cases.  I wrapped fixes for this 
>> into the patch as well (Yes, I know it is technically a no-no).  The 
>> change to ffi_java_raw_to_rvalue() is needed with with the fixed 
>> closure pointer return.
>>
>> I would like to add that I think there is still incorrect handling for 
>> values of most types on big-endian systems in java_raw_api.c, but 
>> since the java interpreter only uses a couple of types, the 
>> problematical cases are never used.
>>
>> The end result is that all libffi tests except for some long double 
>> things now pass at -O0.  There are a couple of floating point failures 
>> with optimization turned on, but they look like they may be issues 
>> with  libgcc's soft-float support.  The long double FAILures seem to 
>> be due to lack of support in my glibc's printf.
>>
>>
>> Tested on mips64-unknown-linux-gnu soft-float with both n32 and n64 
>> ABIs with no regressions.  Currently testing mips64-unknown-linux-gnu 
>> hard-float n32 and n64.
>>
>> OK to commit given the hard-float testing is good?
> Thanks David.  Please commit once you've confirmed good test results.  
> I'll move the patch to the libffi repository once I see your commit.
> 

Now committed (r151726).  Sorry for the delay, but my O2 is not the 
fastest machine and I was too lazy to put a hard float filesystem on my 
fast machines.

David Daney