[rfc] fix umul_ppmm() in our libgcc

[Adrian Chadd]

The error is unsupported constraints. '=h' (hi register) is
unsupported as of some GCC > 4.2.1.



-a


On 15 June 2015 at 10:15, Stanislav Sedov <stas at freebsd.org> wrote:
>
>> On Jun 13, 2015, at 3:41 PM, Adrian Chadd <adrian at freebsd.org> wrote:
>>
>> Hi,
>>
>> our libgcc in -base is very .. old. It chokes when compiling for
>> mips32. This patch seems to do the right thing.
>>
>> Does anyone have any positive/negative feedback?
>>
>> Thanks,
>>
>>
>> -adrian
>>
>>
>> Index: contrib/gcc/longlong.h
>> ===================================================================
>> --- contrib/gcc/longlong.h      (revision 284090)
>> +++ contrib/gcc/longlong.h      (working copy)
>> @@ -584,11 +584,11 @@
>>
>> #if defined (__mips__) && W_TYPE_SIZE == 32
>> #define umul_ppmm(w1, w0, u, v) \
>> -  __asm__ ("multu %2,%3"                                               \
>> -          : "=l" ((USItype) (w0)),                                     \
>> -            "=h" ((USItype) (w1))                                      \
>> -          : "d" ((USItype) (u)),                                       \
>> -            "d" ((USItype) (v)))
>> +       do {                                                            \
>> +        UDItype __ll = (UDItype)(u) * (v);                             \
>> +        w1 = __ll >> 32;                                               \
>> +        w0 = __ll;                                                     \
>> +       } while (0)
>> #define UMUL_TIME 10
>> #define UDIV_TIME 100
>> #endif /* __mips__ */
>
> This looks right to me in terms of functionality, but what is wrong
> with the original code (multu)?  That one seems correct as well.
>
> What error do you see when compiling it?
>
> --
> ST4096-RIPE
>
>
>