[Bug tree-optimization/98176] Loop invariant memory could not be hoisted when nonpure_call in loop body

[wwwhhhyyy333 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98176

--- Comment #2 from Hongyu Wang <wwwhhhyyy333 at gmail dot com> ---
>> I doubt the call is the issue btw.

The aliasing could be removed by 

float foo(int *x, int n, float tx)   
{
        float ret[n];

        #pragma omp simd
        for (int i = 0; i < n; i++)
        {
            float s, c;                    

            s = c = tx * x[i];

            ret[0] += s*c;
        }

        return ret[0];
}

This is successfully vectorized, and the dump from lim2 has:

Moving statement
ret.1__I_lsm.7 = (*ret.1_18)[0];

But for 

float foo(int *x, int n, float tx)   
{
        float ret[n];

        #pragma omp simd
        for (int i = 0; i < n; i++)
        {
            float s, c;                    

            sincosf( tx * x[i] , &s, &c );

            ret[0] += s*c;
        }

        return ret[0];
}

It still could not be vectorized. I did initial debugging and see
tree-ssa-loop-im.c has

if (nonpure_call_p (stmt))
  {                                        
     maybe_never = true; 
     outermost = NULL;                      
  }

So no store-motion chance for any future statement in such block.

As a comparison, this could also be vectorized with simd clone:

float foo(int *x, int n, float tx)   
{
        float ret[n];

        #pragma omp simd
        for (int i = 0; i < n; i++)
        {
            float s, c;                    

            s = c = sinf( tx * x[i]);

            ret[0] += s*c;
        }

        return ret[0];
}