[PATCH]middle-end Fix PR103007, add missing check on complex fms detection.

[Richard Biener]

On Mon, 1 Nov 2021, Tamar Christina wrote:

> Hi All,
> 
> The complex FMS detection is missing a check on if the nodes of the VEC_PERM
> has the amount of children we expect before it recurses.
> 
> This check is there on MUL and FMA but was missing for FMS, due to this the
> compiler goes on further than it should and hits an assert.
> 
> Bootstrapped Regtested on aarch64-none-linux-gnu, x86_64-pc-linux-gnu
> and no issues.
> 
> Ok for master?

OK.

Thanks,
Richard.

> Thanks,
> Tamar
> 
> gcc/ChangeLog:
> 
> 	PR tree-optimizations/103007
> 	* tree-vect-slp-patterns.c (complex_fms_pattern::matches): Add elem
> 	check.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR tree-optimizations/103007
> 	* g++.dg/pr103007.C: New test.
> 
> --- inline copy of patch -- 
> diff --git a/gcc/testsuite/g++.dg/pr103007.C b/gcc/testsuite/g++.dg/pr103007.C
> new file mode 100644
> index 0000000000000000000000000000000000000000..1631a85080039f29b83c97d2f62c66be9eac109f
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr103007.C
> @@ -0,0 +1,19 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-O3" } */
> +
> +typedef float MushMeshVector[4];
> +struct MushMeshQuaternionPair {
> +  void VectorRotate(MushMeshVector &);
> +  MushMeshVector m_first;
> +  MushMeshVector m_second;
> +};
> +void 
> +MushMeshQuaternionPair::
> +VectorRotate(MushMeshVector &ioVec)  {
> +  ioVec[2] = (2 - m_first[1] + m_first[3] * 0);
> +  ioVec[3] = (m_first[3] + m_first[1] - m_first[2] * 0);
> +  float c = ioVec[2], d = ioVec[3];
> +  ioVec[2] = (0 - d * m_second[1]);
> +  ioVec[3] = (2 - c * m_second[1]);
> +}
> +
> diff --git a/gcc/tree-vect-slp-patterns.c b/gcc/tree-vect-slp-patterns.c
> index 6b37e9bac6f3f86a51d1a532a4c570a37af76eac..5e64a9bc417ab6b855e8791fd482dba23287f467 100644
> --- a/gcc/tree-vect-slp-patterns.c
> +++ b/gcc/tree-vect-slp-patterns.c
> @@ -1250,13 +1250,17 @@ complex_fms_pattern::matches (complex_operation_t op,
>  
>    auto childs = SLP_TREE_CHILDREN (nodes[0]);
>    auto l0node = SLP_TREE_CHILDREN (childs[0]);
> -  auto l1node = SLP_TREE_CHILDREN (childs[1]);
>  
>    /* Now operand2+4 may lead to another expression.  */
>    auto_vec<slp_tree> left_op, right_op;
>    left_op.safe_splice (SLP_TREE_CHILDREN (l0node[1]));
>    right_op.safe_splice (SLP_TREE_CHILDREN (nodes[1]));
>  
> +  /* If these nodes don't have any children then they're
> +     not ones we're interested in.  */
> +  if (left_op.length () != 2 || right_op.length () != 2)
> +    return IFN_LAST;
> +
>    bool is_neg = vect_normalize_conj_loc (left_op);
>  
>    bool conj_first_operand = false;
> 
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)