This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Fix vector/scalar to vecto/vector conversion (PR92515)


r278235 broke conversions of vector/scalar shifts into vector/vector
shifts on targets that only provide the latter.  We need to record
whether a conversion is required in that case too.

Also, the old useless_type_conversion_p condition seemed unnecessarily
strong, since the shift amount can have a different signedness from
the shifted value and its vector type is never assumed to be identical
to vectype.  The patch therefore uses tree_nop_conversion_p instead.

Tested on aarch64-linux-gnu and spot-checked on powerpc64-linux-gnu.
OK to install?

Richard


2019-11-15  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR tree-optimization/92515
	* tree-vect-stmts.c (vectorizable_shift): Record incompatible op1
	types when converting a vector/scalar shift into a vector/vector one,
	using tree_nop_conversion_p instead of useless_type_conversion_p.
	Move the conversion code to the transform block.

Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c	2019-11-14 15:31:21.616704454 +0000
+++ gcc/tree-vect-stmts.c	2019-11-15 12:54:19.281608678 +0000
@@ -5750,21 +5750,9 @@ vectorizable_shift (stmt_vec_info stmt_i
                  the rhs being int, instead of the same type as the lhs,
                  so make sure the scalar is the right type if we are
 		 dealing with vectors of long long/long/short/char.  */
-              if (dt[1] == vect_constant_def)
-		{
-		  if (!slp_node)
-		    op1 = fold_convert (TREE_TYPE (vectype), op1);
-		}
-	      else if (!useless_type_conversion_p (TREE_TYPE (vectype),
-						   TREE_TYPE (op1)))
-		{
-		  if (vec_stmt && !slp_node)
-		    {
-		      op1 = fold_convert (TREE_TYPE (vectype), op1);
-		      op1 = vect_init_vector (stmt_info, op1,
-					      TREE_TYPE (vectype), NULL);
-		    }
-		}
+	      incompatible_op1_vectype_p
+		= !tree_nop_conversion_p (TREE_TYPE (vectype),
+					  TREE_TYPE (op1));
             }
         }
     }
@@ -5819,6 +5807,14 @@ vectorizable_shift (stmt_vec_info stmt_i
     dump_printf_loc (MSG_NOTE, vect_location,
                      "transform binary/unary operation.\n");
 
+  if (incompatible_op1_vectype_p && !slp_node)
+    {
+      op1 = fold_convert (TREE_TYPE (vectype), op1);
+      if (dt[1] != vect_constant_def)
+	op1 = vect_init_vector (stmt_info, op1,
+				TREE_TYPE (vectype), NULL);
+    }
+
   /* Handle def.  */
   vec_dest = vect_create_destination_var (scalar_dest, vectype);
 


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]