middle-end/105049 - fix uniform_vector_p and vector CTOR gimplification

We have

  return VIEW_CONVERT_EXPR<U>( VEC_PERM_EXPR < {<<< Unknown tree: compound_literal_expr
        V D.1984 = { 0 }; >>>, { 0 }} , {<<< Unknown tree: compound_literal_expr
        V D.1985 = { 0 }; >>>, { 0 }} , { 0, 0 } >  & {(short int) SAVE_EXPR <c>, (short int) SAVE_EXPR <c>});

where we gimplify the init CTORs to

  _1 = {{ 0 }, { 0 }};
  _2 = {{ 0 }, { 0 }};

instead of to vector constants.  That later runs into a bug in
uniform_vector_p which doesn't handle CTORs of vector elements
correctly.

The following adjusts uniform_vector_p to handle CTORs of vector
elements.

2022-03-25  Richard Biener  <rguenther@suse.de>

	PR middle-end/105049
	* tree.cc (uniform_vector_p): Recurse for VECTOR_CST or
	CONSTRUCTOR first elements.

	* gcc.dg/pr105049.c: New testcase.
This commit is contained in:
Richard Biener 2022-03-25 08:43:45 +01:00
parent 711c7f079b
commit 0b0fc52b04
2 changed files with 14 additions and 0 deletions

View File

@ -0,0 +1,12 @@
/* { dg-do compile } */
/* { dg-options "-O -fno-tree-forwprop" } */
typedef short __attribute__((__vector_size__ (sizeof(short)))) V;
typedef short __attribute__((__vector_size__ (2*sizeof(short)))) U;
char c;
U
foo (void)
{
return __builtin_shufflevector ((V){}, (V){}, 0, 0) & c;
}

View File

@ -10266,6 +10266,8 @@ uniform_vector_p (const_tree vec)
if (i != nelts)
return NULL_TREE;
if (TREE_CODE (first) == CONSTRUCTOR || TREE_CODE (first) == VECTOR_CST)
return uniform_vector_p (first);
return first;
}