Diagnostic 15511: Not enough parameters of vector variant 'xxxx' of function 'xxxx' at position <val>

Cause:

This diagnostic is emitted by Intel(R) C++ Compiler 15.0 and above. This example uses User implemented vector variant of the function. Traditionally the vector variant of the user defined​ function is created by the compiler using __attribute__((vector)) with relevant clauses. Here the developer can provide target certain processors by providing the intrinsics implementation which targets those processor architecture. In this example, we create a vector variant of the scalar function MyMax() and target the vector variant for core i7 processor SSE4.2 architecture.

Examples:

#include <immintrin.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NN 1021

__declspec(noinline)

	float MyMax(float* a, float b)

	{

	  return *a + b;

	}

__declspec(vector_variant(implements(MyMax(float* a, float b)),

	                          vectorlength(4), processor(core_i7_sse4_2), mask))

	__m128 MyMaxVec(__m128i v_a1, __m128i v_a2,  __m128 v_b)

	{

	  return _mm_add_ps(_mm_cvtepi32_ps(v_a1), v_b);

	}
$ icpc test54.cc -c -qopt-report2 -qopt-report-phase=vec -qopt-report-file=stderr -xAVX

	error #15511: Not enough parameters of vector variant '_Z8MyMaxVec7__m128iS_6__m128' of function '_Z5MyMaxPff' at position 3.
 The correct prototype is: '__m128 _Z8MyMaxVec7__m128iS_6__m128(__m128i v0_0, __m128i v0_1, __m128 v1_0, __m128 m0_0)'.

	compilation aborted for test54.cc (code 1)
Resolution:


	Using __m128 data type instead will resolve this error and the vector variant of the function is generated.​