On Wed, 24 May 2023, Richard Biener via Gcc-patches wrote:
> I’d have to check the ISAs what they actually do here - it of course depends
> on RTL semantics as well but as you say those are not strictly defined here
> either.
Plus, we can add the following executable test to the testsuite:
#include <stdint.h>
#define CHECK(TYPE, WIDTH, OP, COUNT, INVERT) \
{ \
typedef TYPE vec __attribute__((vector_size(WIDTH))); \
\
static volatile vec zero; \
vec tmp = (zero-2) OP (COUNT); \
vec ref = INVERT zero; \
if (__builtin_memcmp(&tmp, &ref, sizeof tmp)) \
__builtin_abort(); \
}
int main(void)
{
CHECK( uint8_t, 16, <<, 8, )
CHECK( uint8_t, 16, <<, 31, )
CHECK( uint8_t, 16, >>, 8, )
CHECK( uint8_t, 16, >>, 31, )
CHECK( int8_t, 16, <<, 8, )
CHECK( int8_t, 16, <<, 31, )
CHECK( int8_t, 16, >>, 8, ~)
CHECK( int8_t, 16, >>, 31, ~)
CHECK(uint16_t, 16, <<, 16, )
CHECK(uint16_t, 16, <<, 31, )
CHECK(uint16_t, 16, >>, 16, )
CHECK(uint16_t, 16, >>, 31, )
CHECK( int16_t, 16, <<, 16, )
CHECK( int16_t, 16, <<, 31, )
CHECK( int16_t, 16, >>, 16, ~)
CHECK( int16_t, 16, >>, 31, ~)
// Per-lane-variable shifts:
CHECK( uint8_t, 16, <<, zero+8, )
CHECK( uint8_t, 16, <<, zero+31, )
CHECK( uint8_t, 16, >>, zero+8, )
CHECK( uint8_t, 16, >>, zero+31, )
CHECK( int8_t, 16, <<, zero+8, )
CHECK( int8_t, 16, <<, zero+31, )
CHECK( int8_t, 16, >>, zero+8, ~)
CHECK( int8_t, 16, >>, zero+31, ~)
CHECK(uint16_t, 16, <<, zero+16, )
CHECK(uint16_t, 16, <<, zero+31, )
CHECK(uint16_t, 16, >>, zero+16, )
CHECK(uint16_t, 16, >>, zero+31, )
CHECK( int16_t, 16, <<, zero+16, )
CHECK( int16_t, 16, <<, zero+31, )
CHECK( int16_t, 16, >>, zero+16, ~)
CHECK( int16_t, 16, >>, zero+31, ~)
// Repeat for WIDTH=32 and WIDTH=64
}
Alexander
