With large parts from Jim Wilson:

	PR target/43902
	* tree-pretty-print.c (dump_generic_node, op_code_prio): Add
	WIDEN_MULT_PLUS_EXPR and WIDEN_MULT_MINUS_EXPR.
	* optabs.c (optab_for_tree_code): Likewise.
	(expand_widen_pattern_expr): Likewise.
	* tree-ssa-math-opts.c (convert_mult_to_widen): New function, broken
	out of execute_optimize_widening_mul.
	(convert_plusminus_to_widen): New function.
	(execute_optimize_widening_mul): Use the two new functions.
	* expr.c (expand_expr_real_2): Add support for GIMPLE_TERNARY_RHS.
	Remove code to generate widening multiply-accumulate.  Add support
	for WIDEN_MULT_PLUS_EXPR and WIDEN_MULT_MINUS_EXPR.
	* gimple-pretty-print.c (dump_ternary_rhs): New function.
	(dump_gimple_assign): Call it when appropriate.
	* tree.def (WIDEN_MULT_PLUS_EXPR, WIDEN_MULT_MINUS_EXPR): New codes.
	* cfgexpand.c (gimple_assign_rhs_to_tree): Likewise.
	(expand_gimple_stmt_1): Likewise.
	(expand_debug_expr): Support WIDEN_MULT_PLUS_EXPR and
	WIDEN_MULT_MINUS_EXPR.
	* tree-ssa-operands.c (get_expr_operands): Likewise.
	* tree-inline.c (estimate_operator_cost): Likewise.
	* gimple.c (extract_ops_from_tree_1): Renamed from
	extract_ops_from_tree.  Add new arg for a third operand; fill it.
	(gimple_build_assign_stat): Support operations with three operands.
	(gimple_build_assign_with_ops_stat): Likewise.
	(gimple_assign_set_rhs_from_tree): Likewise.
	(gimple_assign_set_rhs_with_ops_1): Renamed from
	gimple_assign_set_rhs_with_ops.  Add new arg for a third operand.
	(get_gimple_rhs_num_ops): Support GIMPLE_TERNARY_RHS.
	(get_gimple_rhs_num_ops): Handle WIDEN_MULT_PLUS_EXPR and
	WIDEN_MULT_MINUS_EXPR.
	* gimple.h (enum gimple_rhs_class): Add GIMPLE_TERNARY_RHS.
	(extract_ops_from_tree_1): Adjust declaration.
	(gimple_assign_set_rhs_with_ops_1): Likewise.
	(gimple_build_assign_with_ops): Pass NULL for last operand.
	(gimple_build_assign_with_ops3): New macro.
	(gimple_assign_rhs3, gimple_assign_rhs3_ptr, gimple_assign_set_rhs3,
	gimple_assign_set_rhs_with_ops, extract_ops_from_tree): New inline
	functions.
	* tree-cfg.c (verify_gimple_assign_ternary): New static function.
	(verify_gimple_assign): Call it.
	* doc/gimple.texi (Manipulating operands): Document GIMPLE_TERNARY_RHS.
	(Tuple specific accessors, subsection GIMPLE_ASSIGN): Document new
	functions for dealing with three-operand statements.
	* tree.c (commutative_ternary_tree_code): New function.
	* tree.h (commutative_ternary_tree_code): Declare it.
	* tree-vrp.c (gimple_assign_nonnegative_warnv_p): Return false for ternary
	statements.
	(gimple_assign_nonzero_warnv_p): Likewise.
	* tree-ssa-sccvn.c (stmt_has_constants): Handle GIMPLE_TERNARY_RHS.
	* tree-ssa-ccp.c (get_rhs_assign_op_for_ccp): New static function.
	(ccp_fold): Use it.  Handle GIMPLE_TERNARY_RHS.
	* tree-ssa-dom.c (enum expr_kind): Add EXPR_TERNARY.
	(struct hashtable_expr): New member ternary in the union.
	(initialize_hash_element): Handle GIMPLE_TERNARY_RHS.
	(hashable_expr_equal_p): Fix indentation.  Handle EXPR_TERNARY.
	(iterative_hash_hashable_expr): Likewise.
	(print_expr_hash_elt): Handle EXPR_TERNARY.
	* gimple-fold.c (fold_gimple_assign): Handle GIMPLE_TERNARY_RHS.
	* tree-ssa-threadedge.c (fold_assignment_stmt): Remove useless break
	statements.  Handle GIMPLE_TERNARY_RHS.

testsuite/
	PR target/43902
	* gcc.target/mips/madd-9.c: New test.

From-SVN: r161366

1 files changed, 27 insertions, 0 deletions

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 3479d07..a37b4a3 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -986,6 +986,33 @@ fold_gimple_assign (gimple_stmt_iterator *si)
         }
       break;
 
+    case GIMPLE_TERNARY_RHS:
+      result = fold_ternary_loc (loc, subcode,
+				 TREE_TYPE (gimple_assign_lhs (stmt)),
+				 gimple_assign_rhs1 (stmt),
+				 gimple_assign_rhs2 (stmt),
+				 gimple_assign_rhs3 (stmt));
+
+      if (result)
+        {
+          STRIP_USELESS_TYPE_CONVERSION (result);
+          if (valid_gimple_rhs_p (result))
+	    return result;
+
+	  /* Fold might have produced non-GIMPLE, so if we trust it blindly
+	     we lose canonicalization opportunities.  Do not go again
+	     through fold here though, or the same non-GIMPLE will be
+	     produced.  */
+          if (commutative_ternary_tree_code (subcode)
+              && tree_swap_operands_p (gimple_assign_rhs1 (stmt),
+                                       gimple_assign_rhs2 (stmt), false))
+            return build3 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)),
+			   gimple_assign_rhs2 (stmt),
+			   gimple_assign_rhs1 (stmt),
+			   gimple_assign_rhs3 (stmt));
+        }
+      break;
+
     case GIMPLE_INVALID_RHS:
       gcc_unreachable ();
     }