Implement more rtx vector folds on variable-length vectors

This patch extends the tree-level folding of variable-length vectors
so that it can also be used on rtxes.  The first step is to move
the tree_vector_builder new_unary/binary_operator routines to the
parent vector_builder class (which in turn means adding a new
template parameter).  The second step is to make simplify-rtx.c
use a direct rtx analogue of the VECTOR_CST handling in fold-const.c.

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* vector-builder.h (vector_builder): Add a shape template parameter.
	(vector_builder::new_unary_operation): New function, generalizing
	the old tree_vector_builder function.
	(vector_builder::new_binary_operation): Likewise.
	(vector_builder::binary_encoded_nelts): Likewise.
	* int-vector-builder.h (int_vector_builder): Update template
	parameters to vector_builder.
	(int_vector_builder::shape_nelts): New function.
	* rtx-vector-builder.h (rtx_vector_builder): Update template
	parameters to vector_builder.
	(rtx_vector_builder::shape_nelts): New function.
	(rtx_vector_builder::nelts_of): Likewise.
	(rtx_vector_builder::npatterns_of): Likewise.
	(rtx_vector_builder::nelts_per_pattern_of): Likewise.
	* tree-vector-builder.h (tree_vector_builder): Update template
	parameters to vector_builder.
	(tree_vector_builder::shape_nelts): New function.
	(tree_vector_builder::nelts_of): Likewise.
	(tree_vector_builder::npatterns_of): Likewise.
	(tree_vector_builder::nelts_per_pattern_of): Likewise.
	* tree-vector-builder.c (tree_vector_builder::new_unary_operation)
	(tree_vector_builder::new_binary_operation): Delete.
	(tree_vector_builder::binary_encoded_nelts): Likewise.
	* simplify-rtx.c: Include rtx-vector-builder.h.
	(distributes_over_addition_p): New function.
	(simplify_const_unary_operation)
	(simplify_const_binary_operation): Generalize handling of vector
	constants to include variable-length vectors.
	(test_vector_ops_series): Add more tests.

From-SVN: r273867

1 files changed, 0 insertions, 97 deletions

diff --git a/gcc/tree-vector-builder.c b/gcc/tree-vector-builder.c
index f31dc13..d02fb95 100644
--- a/gcc/tree-vector-builder.c
+++ b/gcc/tree-vector-builder.c
@@ -24,103 +24,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "fold-const.h"
 #include "tree-vector-builder.h"
 
-/* Try to start building a new vector of type TYPE that holds the result of
-   a unary operation on VECTOR_CST T.  ALLOW_STEPPED_P is true if the
-   operation can handle stepped encodings directly, without having to
-   expand the full sequence.
-
-   Return true if the operation is possible, which it always is when
-   ALLOW_STEPPED_P is true.  Leave the builder unchanged otherwise.  */
-
-bool
-tree_vector_builder::new_unary_operation (tree type, tree t,
-					  bool allow_stepped_p)
-{
-  poly_uint64 full_nelts = TYPE_VECTOR_SUBPARTS (type);
-  gcc_assert (known_eq (full_nelts, TYPE_VECTOR_SUBPARTS (TREE_TYPE (t))));
-  unsigned int npatterns = VECTOR_CST_NPATTERNS (t);
-  unsigned int nelts_per_pattern = VECTOR_CST_NELTS_PER_PATTERN (t);
-  if (!allow_stepped_p && nelts_per_pattern > 2)
-    {
-      if (!full_nelts.is_constant ())
-	return false;
-      npatterns = full_nelts.to_constant ();
-      nelts_per_pattern = 1;
-    }
-  new_vector (type, npatterns, nelts_per_pattern);
-  return true;
-}
-
-/* Try to start building a new vector of type TYPE that holds the result of
-   a binary operation on VECTOR_CSTs T1 and T2.  ALLOW_STEPPED_P is true if
-   the operation can handle stepped encodings directly, without having to
-   expand the full sequence.
-
-   Return true if the operation is possible.  Leave the builder unchanged
-   otherwise.  */
-
-bool
-tree_vector_builder::new_binary_operation (tree type, tree t1, tree t2,
-					   bool allow_stepped_p)
-{
-  poly_uint64 full_nelts = TYPE_VECTOR_SUBPARTS (type);
-  gcc_assert (known_eq (full_nelts, TYPE_VECTOR_SUBPARTS (TREE_TYPE (t1)))
-	      && known_eq (full_nelts, TYPE_VECTOR_SUBPARTS (TREE_TYPE (t2))));
-  /* Conceptually we split the patterns in T1 and T2 until we have
-     an equal number for both.  Each split pattern requires the same
-     number of elements per pattern as the original.  E.g. splitting:
-
-       { 1, 2, 3, ... }
-
-     into two gives:
-
-       { 1, 3, 5, ... }
-       { 2, 4, 6, ... }
-
-     while splitting:
-
-       { 1, 0, ... }
-
-     into two gives:
-
-       { 1, 0, ... }
-       { 0, 0, ... }.  */
-  unsigned int npatterns = least_common_multiple (VECTOR_CST_NPATTERNS (t1),
-						  VECTOR_CST_NPATTERNS (t2));
-  unsigned int nelts_per_pattern = MAX (VECTOR_CST_NELTS_PER_PATTERN (t1),
-					VECTOR_CST_NELTS_PER_PATTERN (t2));
-  if (!allow_stepped_p && nelts_per_pattern > 2)
-    {
-      if (!full_nelts.is_constant ())
-	return false;
-      npatterns = full_nelts.to_constant ();
-      nelts_per_pattern = 1;
-    }
-  new_vector (type, npatterns, nelts_per_pattern);
-  return true;
-}
-
-/* Return the number of elements that the caller needs to operate on in
-   order to handle a binary operation on VECTOR_CSTs T1 and T2.  This static
-   function is used instead of new_binary_operation if the result of the
-   operation is not a VECTOR_CST.  */
-
-unsigned int
-tree_vector_builder::binary_encoded_nelts (tree t1, tree t2)
-{
-  poly_uint64 nelts = TYPE_VECTOR_SUBPARTS (TREE_TYPE (t1));
-  gcc_assert (known_eq (nelts, TYPE_VECTOR_SUBPARTS (TREE_TYPE (t2))));
-  /* See new_binary_operation for details.  */
-  unsigned int npatterns = least_common_multiple (VECTOR_CST_NPATTERNS (t1),
-						  VECTOR_CST_NPATTERNS (t2));
-  unsigned int nelts_per_pattern = MAX (VECTOR_CST_NELTS_PER_PATTERN (t1),
-					VECTOR_CST_NELTS_PER_PATTERN (t2));
-  unsigned HOST_WIDE_INT const_nelts;
-  if (nelts.is_constant (&const_nelts))
-    return MIN (npatterns * nelts_per_pattern, const_nelts);
-  return npatterns * nelts_per_pattern;
-}
-
 /* Return a vector element with the value BASE + FACTOR * STEP.  */
 
 tree