[Bug target/39090] MIPS: wrong-code with 64-bit values and register asm constraints with o32 ABI.

[nemet at gcc dot gnu dot org]

------- Comment #1 from nemet at gcc dot gnu dot org  2009-02-03 18:36 -------
> Register $3 (v1) returns with uninitialized garbage.  This is the high part of
> the 64 bit return value.
> 
> I am not sure what should happen here.  Really the "d" asm constraint should
> not match a 64 bit variable for the o32 ABI.

No, I think it should.  You just need to use high-part and low-part operand
codes to refer to the 32-bit parts:

unsigned long long bar(unsigned long long l) 
{ 
  unsigned long long rv; 
  asm volatile ("#fill %L0; #fill %M0" : "=d" (rv)); 
  return rv; 
} 
#APP
 # 4 "s.c" 1
        #fill $5; #fill $4
 # 0 "" 2
 #NO_APP
        move    $2,$4
        .set    noreorder
        .set    nomacro
        j       $31
        move    $3,$5
        .set    macro
        .set    reorder


-- 

nemet at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nemet at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39090