Question

I’m trying to play around with SSE intrinsics. I have made a test program that just adds two vectors with four 16 bit elements together.

#include <xmmintrin.h>
#include <iostream>
using namespace std;

void test_vec_add(){
  const int length = 4;
  float product[128*4]  __attribute__ ((aligned(16)));
  _m128 x = _mm_set_ps(1.0f,2.0f,3.0f,4.0f);
  _m128 y = _mm_set_ps(1.0f,2.0f,3.0f,4.0f);
  _m128 z = _mm_add_ps(x,y);
  _mm_store_ps(product,z);
}
int main(){
  test_vec_add();
}

I’m compiling this code with

g++ -msse3 test_sse.cpp

However, I’m getting the following complication error

test_sse.cpp: In function ‘void test_vec_add()’:
test_sse.cpp:7:3: error: ‘_m128’ was not declared in this scope
test_sse.cpp:7:9: error: expected ‘;’ before ‘x’
test_sse.cpp:8:9: error: expected ‘;’ before ‘y’
test_sse.cpp:9:9: error: expected ‘;’ before ‘z’
test_sse.cpp:10:24: error: ‘z’ was not declared in this scope
test_sse.cpp: In function ‘int main()’:
test_sse.cpp:15:20: error: ‘test_vec_add’ was not declared in this scope

Its probably a really goofy mistake, but I can’t put my finger on where it is. Any help would be greatly appreciated.

Answer 1

It’s a simple typo.

The types such as __m128 begins with two underscores. The functions such as _mm_store_ps do begin with only one underscore.