Make less use of get_same_sized_vectype

Some callers of get_same_sized_vectype were dealing with operands that
are constant or defined externally, and so have no STMT_VINFO_VECTYPE
available.  Under the current model, using get_same_sized_vectype for
that case is equivalent to using get_vectype_for_scalar_type, since
get_vectype_for_scalar_type always returns vectors of the same size,
once a size is fixed.

Using get_vectype_for_scalar_type is arguably more obvious though:
if we're using the same scalar type as we would for internal
definitions, we should use the same vector type too.  (Constant and
external definitions sometimes let us change the original scalar type
to a "nicer" scalar type, but that isn't what's happening here.)

This is a prerequisite to supporting multiple vector sizes in the same
vec_info.

2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vect-stmts.c (vectorizable_call): If an operand is
	constant or external, use get_vectype_for_scalar_type
	rather than get_same_sized_vectype to get its vector type.
	(vectorizable_conversion, vectorizable_shift): Likewise.
	(vectorizable_operation): Likewise.

From-SVN: r278238

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bd9eeecea9e31aed07544aacd74d1ae779987a6b..28baebee3b76f0ed909538c7bef088937630c67e 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>
+
+       * tree-vect-stmts.c (vectorizable_call): If an operand is
+       constant or external, use get_vectype_for_scalar_type
+       rather than get_same_sized_vectype to get its vector type.
+       (vectorizable_conversion, vectorizable_shift): Likewise.
+       (vectorizable_operation): Likewise.
+
 2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>
 
        * tree-vectorizer.h (vec_info::vector_size): Replace with...

diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 43b2b0fa84e516f3880259e46e16a75bdb6d5e59..b7fff7822773d1c3917add8c27da3c11738cb9ae 100644 (file)
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -3295,10 +3295,10 @@ vectorizable_call (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
          return false;
        }
     }
-  /* If all arguments are external or constant defs use a vector type with
-     the same size as the output vector type.  */
+  /* If all arguments are external or constant defs, infer the vector type
+     from the scalar type.  */
   if (!vectype_in)
-    vectype_in = get_same_sized_vectype (rhs_type, vectype_out);
+    vectype_in = get_vectype_for_scalar_type (vinfo, rhs_type);
   if (vec_stmt)
     gcc_assert (vectype_in);
   if (!vectype_in)
@@ -4787,10 +4787,10 @@ vectorizable_conversion (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
        }
     }
 
-  /* If op0 is an external or constant defs use a vector type of
-     the same size as the output vector type.  */
+  /* If op0 is an external or constant def, infer the vector type
+     from the scalar type.  */
   if (!vectype_in)
-    vectype_in = get_same_sized_vectype (rhs_type, vectype_out);
+    vectype_in = get_vectype_for_scalar_type (vinfo, rhs_type);
   if (vec_stmt)
     gcc_assert (vectype_in);
   if (!vectype_in)
@@ -5586,10 +5586,10 @@ vectorizable_shift (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
                          "use not simple.\n");
       return false;
     }
-  /* If op0 is an external or constant def use a vector type with
-     the same size as the output vector type.  */
+  /* If op0 is an external or constant def, infer the vector type
+     from the scalar type.  */
   if (!vectype)
-    vectype = get_same_sized_vectype (TREE_TYPE (op0), vectype_out);
+    vectype = get_vectype_for_scalar_type (vinfo, TREE_TYPE (op0));
   if (vec_stmt)
     gcc_assert (vectype);
   if (!vectype)
@@ -5688,7 +5688,7 @@ vectorizable_shift (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
                          "vector/vector shift/rotate found.\n");
 
       if (!op1_vectype)
-       op1_vectype = get_same_sized_vectype (TREE_TYPE (op1), vectype_out);
+       op1_vectype = get_vectype_for_scalar_type (vinfo, TREE_TYPE (op1));
       incompatible_op1_vectype_p
        = (op1_vectype == NULL_TREE
           || maybe_ne (TYPE_VECTOR_SUBPARTS (op1_vectype),
@@ -6019,8 +6019,8 @@ vectorizable_operation (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
                          "use not simple.\n");
       return false;
     }
-  /* If op0 is an external or constant def use a vector type with
-     the same size as the output vector type.  */
+  /* If op0 is an external or constant def, infer the vector type
+     from the scalar type.  */
   if (!vectype)
     {
       /* For boolean type we cannot determine vectype by
@@ -6040,7 +6040,7 @@ vectorizable_operation (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
          vectype = vectype_out;
        }
       else
-       vectype = get_same_sized_vectype (TREE_TYPE (op0), vectype_out);
+       vectype = get_vectype_for_scalar_type (vinfo, TREE_TYPE (op0));
     }
   if (vec_stmt)
     gcc_assert (vectype);