Compiler Warning (level 1) C4391
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Compiler Warning (level 1) C4391

Error Message

'signature' : incorrect return type for intrinsic function, expected 'type'

A function declaration for a compiler intrinsic had the wrong return type. The resulting image may not run correctly.

To fix this warning, either correct the declaration or delete the declaration and simply #include the appropriate header file.

The following sample generates C4391:

// C4391.cpp
// compile with: /W1
// processor: x86
// uncomment the following line and delete the line that
// generated the warning to resolve
// #include "xmmintrin.h"

#ifdef  __cplusplus
extern "C" {

extern void _mm_load_ss(float *p);   // C4391

#ifdef  __cplusplus

int main()
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