[Bug tree-optimization/56787] [4.8/4.9 Regression] Vectorization fails because of CLOBBER statements

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56787



Jakub Jelinek <jakub at gcc dot gnu.org> changed:



           What    |Removed                     |Added

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                 CC|                            |jakub at gcc dot gnu.org



--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-02 
14:50:18 UTC ---

Somewhat reduced testcase:

inline void

bar (const float s[5], float z[3][5])

{

  float a = s[0], b = s[1], c = s[2], d = s[3], e = s[4];

  float f = 1.0f / a;

  float u = f * b, v = f * c, w = f * d;

  float p = 0.4f * (e - 0.5f * (b * u + c * v + d * w));

  z[0][3] = b * w;

  z[1][3] = c * w;

  z[2][3] = d * w + p;

}



void

foo (unsigned long n, const float *__restrict u0,

     const float *__restrict u1, const float *__restrict u2,

     const float *__restrict u3, const float *__restrict u4,

     const float *__restrict s0, const float *__restrict s1,

     const float *__restrict s2, float *__restrict t3,

     float *__restrict t4)

{

  unsigned long i;

  for (i = 0; i < n; i++)

    {

      float u[5], f[3][5];

      u[0] = u0[i]; u[1] = u1[i]; u[2] = u2[i]; u[3] = u3[i]; u[4] = u4[i];

      bar (u, f);

      t3[i] = s0[i] * f[0][3] + s1[i] * f[1][3] + s2[i] * f[2][3];

    }

}