https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123149
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #4)
> Looks like the subreg is getting in the way to detecting this as a rotate.
But 64 is not recognized either.
With say
```
__m128i rot1_64(__m128i v) {
return _mm_xor_si128(_mm_slli_epi64(v, 5), _mm_srli_epi64(v, 64-5));
}
```
Combine gets:
```
Trying 8, 6 -> 10:
8: r106:V2DI=r104:V2DI<<0x5
REG_DEAD r104:V2DI
6: r105:V2DI=r104:V2DI 0>>0x3b
10: r108:V2DI=r105:V2DI^r106:V2DI
REG_DEAD r106:V2DI
REG_DEAD r105:V2DI
Failed to match this instruction:
(set (reg:V2DI 108 [ _3 ])
(rotate:V2DI (reg/v:V2DI 104 [ v ])
(const_int 5 [0x5])))
```
which is not recognized even though it should be as:
vprolq $5, %xmm0, %xmm0
