On 10/14/24 14:37, Jonathan Wakely wrote:
>
>
> On Mon, 14 Oct 2024 at 14:36, Kyrylo Tkachov <ktkac...@nvidia.com> wrote:
>>
>>
>>
>>> On 14 Oct 2024, at 15:28, Ricardo Jesus <r...@nvidia.com> wrote:
>>>
>>> External email: Use caution opening links or attachments
>>>
>>>
>>> This patch modifies the implementation of the vectorized mersenne
>>> twister random number generator to use __builtin_shufflevector instead
>>> of __builtin_shuffle. This makes it (almost) compatible with Clang.
>>>
>>> To make the implementation fully compatible with Clang, Clang will need
>>> to support internal Neon types like __Uint8x16_t and __Uint32x4_t, which
>>> currently it does not. This looks like an oversight in Clang and so will
>>> be addressed separately.
>>>
>>> I see no codegen change with this patch.
>>
>> FWIW the change looks ok to me from an aarch64 perspective.
>> The only potential problem could have been a compile error so as long as the
>> CI buildbots are happy I think this would be safe to take.
>
> OK thanks for looking. I'll wait to see that CI is green (thanks for
> resubmitting it, Ricardo!) and then push it.
>
Hi Jonathan,
When you have a chance, could you please check if the CI is looking good?
Thanks very much!
Ricardo
>
>> Thanks,
>> Kyrill
>>
>>>
>>> Bootstrapped and tested on aarch64-none-linux-gnu.
>>>
>>> Signed-off-by: Ricardo Jesus <r...@nvidia.com>
>>>
>>> 2024-09-05 Ricardo Jesus <r...@nvidia.com>
>>>
>>> * config/cpu/aarch64/opt/ext/opt_random.h (__VEXT): Replace uses
>>> of __builtin_shuffle with __builtin_shufflevector.
>>> (__aarch64_lsl_128): Move shift amount to a template parameter.
>>> (__aarch64_lsr_128): Move shift amount to a template parameter.
>>> (__aarch64_recursion): Update call sites of __aarch64_lsl_128
>>> and __aarch64_lsr_128.
>>> ---
>>> .../config/cpu/aarch64/opt/ext/opt_random.h | 28 +++++++++++--------
>>> 1 file changed, 16 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/libstdc++-v3/config/cpu/aarch64/opt/ext/opt_random.h
>>> b/libstdc++-v3/config/cpu/aarch64/opt/ext/opt_random.h
>>> index 7f756d1572f..7eb816abcd0 100644
>>> --- a/libstdc++-v3/config/cpu/aarch64/opt/ext/opt_random.h
>>> +++ b/libstdc++-v3/config/cpu/aarch64/opt/ext/opt_random.h
>>> @@ -35,13 +35,13 @@
>>> #ifdef __ARM_NEON
>>>
>>> #ifdef __ARM_BIG_ENDIAN
>>> -# define __VEXT(_A,_B,_C) __builtin_shuffle (_A, _B, (__Uint8x16_t) \
>>> - {16-_C, 17-_C, 18-_C, 19-_C, 20-_C, 21-_C, 22-_C, 23-_C, \
>>> - 24-_C, 25-_C, 26-_C, 27-_C, 28-_C, 29-_C, 30-_C, 31-_C})
>>> +# define __VEXT(_A,_B,_C) __builtin_shufflevector (_A, _B, \
>>> + 16-_C, 17-_C, 18-_C, 19-_C, 20-_C, 21-_C, 22-_C, 23-_C, \
>>> + 24-_C, 25-_C, 26-_C, 27-_C, 28-_C, 29-_C, 30-_C, 31-_C)
>>> #else
>>> -# define __VEXT(_A,_B,_C) __builtin_shuffle (_B, _A, (__Uint8x16_t) \
>>> - {_C, _C+1, _C+2, _C+3, _C+4, _C+5, _C+6, _C+7, \
>>> - _C+8, _C+9, _C+10, _C+11, _C+12, _C+13, _C+14, _C+15})
>>> +# define __VEXT(_A,_B,_C) __builtin_shufflevector (_B, _A, \
>>> + _C, _C+1, _C+2, _C+3, _C+4, _C+5, _C+6, _C+7, \
>>> + _C+8, _C+9, _C+10, _C+11, _C+12, _C+13, _C+14, _C+15)
>>> #endif
>>>
>>> #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
>>> @@ -52,9 +52,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>> namespace {
>>> // Logical Shift right 128-bits by c * 8 bits
>>>
>>> - __extension__ extern __inline __Uint32x4_t
>>> + __extension__
>>> + template<int __c>
>>> + extern __inline __Uint32x4_t
>>> __attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
>>> - __aarch64_lsr_128 (__Uint8x16_t __a, __const int __c)
>>> + __aarch64_lsr_128 (__Uint8x16_t __a)
>>> {
>>> const __Uint8x16_t __zero = {0, 0, 0, 0, 0, 0, 0, 0,
>>> 0, 0, 0, 0, 0, 0, 0, 0};
>>> @@ -64,9 +66,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>>
>>> // Logical Shift left 128-bits by c * 8 bits
>>>
>>> - __extension__ extern __inline __Uint32x4_t
>>> + __extension__
>>> + template<int __c>
>>> + extern __inline __Uint32x4_t
>>> __attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
>>> - __aarch64_lsl_128 (__Uint8x16_t __a, __const int __c)
>>> + __aarch64_lsl_128 (__Uint8x16_t __a)
>>> {
>>> const __Uint8x16_t __zero = {0, 0, 0, 0, 0, 0, 0, 0,
>>> 0, 0, 0, 0, 0, 0, 0, 0};
>>> @@ -82,14 +86,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>> __Uint32x4_t __e)
>>> {
>>> __Uint32x4_t __y = (__b >> __sr1);
>>> - __Uint32x4_t __z = __aarch64_lsr_128 ((__Uint8x16_t) __c, __sr2);
>>> + __Uint32x4_t __z = __aarch64_lsr_128<__sr2> ((__Uint8x16_t) __c);
>>>
>>> __Uint32x4_t __v = __d << __sl1;
>>>
>>> __z = __z ^ __a;
>>> __z = __z ^ __v;
>>>
>>> - __Uint32x4_t __x = __aarch64_lsl_128 ((__Uint8x16_t) __a, __sl2);
>>> + __Uint32x4_t __x = __aarch64_lsl_128<__sl2> ((__Uint8x16_t) __a);
>>>
>>> __y = __y & __e;
>>> __z = __z ^ __x;
>>> --
>>> 2.44.0
>>>
>>
>
