SSE test/sample code from Game Engine Architecture by Jason Gregory

SSETest.cpp

#include <cstdio>
#include <xmmintrin.h>

__m128 addWithAssembly(const __m128 a, const __m128 b)
{
	__asm addps xmm0, xmm1
}

__m128 addWithIntrinsics(const __m128 a, const __m128 b)
{
	return _mm_add_ps(a, b);
}


void testSSE()
{
	__declspec(align(16)) float A[4]; 
	__declspec(align(16)) float B[4] = { 8.0f, 6.0f, 4.0f, 2.0f };
	__declspec(align(16)) float C[4];
	__declspec(align(16)) float D[4];

	__m128 a = _mm_set_ps(2.0f, 4.0f, 6.0f, 8.0f);
	__m128 b = _mm_load_ps(&B[0]);

	__m128 c = addWithAssembly(a, b);
	__m128 d = addWithIntrinsics(a, b);

	_mm_store_ps(&A[0], a);
	_mm_store_ps(&B[0], b);
	_mm_store_ps(&C[0], c);
	_mm_store_ps(&D[0], d);

	printf("a = %g %g %g %g\n", A[0], A[1], A[2], A[3]);
	printf("b = %g %g %g %g\n", B[0], B[1], B[2], B[3]);
	printf("c = %g %g %g %g\n", C[0], C[1], C[2], C[3]);
	printf("a = %g %g %g %g\n", D[0], D[1], D[2], D[3]);
}

int main()
{
	testSSE();

	return 0;
}