AVX - storing __256 vector back to the memory (void**) in C,

Question

I have the following code extract written in C,

  double* res;
  posix_memalign((void **)&res, 32, sizeof(double)*4);

  __m256 ymm0, ymm1, ymm2, ymm3;

  ymm0 = _mm256_load_pd(vector_a);
  ymm1 = _mm256_load_pd(vector_b);

  ymm2 = _mm256_mul_pd(ymm1, ymm2); 

  ymm3 = _mm256_store_pd((double*)res, ymm3); <--- problem line,

When I compile, I get the following error message,

 error: assigning to '__m256' from incompatible type 'void'
    ymm3 = _mm256_store_pd((double*)res, ymm3);

I thought casting it to double pointer for 'res' would solve the issue but with no luck..

can anyone please help?

compiler - clang 3.4 - x86 ubuntu

doqtor · Accepted Answer · 2015-06-06T08:36:20.323

2

_mm256_store_pd does not return anything. Remove assignment to ymm3: _mm256_store_pd((double*)res, ymm3);

Also you don't need to cast res as it is already double*

edited Jun 06 '15 at 08:36

answered Jun 06 '15 at 08:32

doqtor

8,414
2
20
36

oh...... how did it ever got in there. thanks!! now it works perfectly. probably need to get some sleep lol. – lukieleetronic Jun 06 '15 at 08:36
That was my first thought when I saw this :) You need to get more sleep :) – doqtor Jun 06 '15 at 08:37

AVX - storing __256 vector back to the memory (void**) in C,

1 Answers1