rs6000, add argument to function find_instance

The function find_instance assumes it is called to check a built-in with
only two arguments.  This patch extends the function by adding a parameter
specifying the number of built-in arguments to check.

Note, this patch was supposed to have been applied before commit:

  commit b51795c832cf6e724d61919eb18a383223b76694
  Author: Carl Love <cel@us.ibm.com>
  Date:   Wed Jul 26 11:31:53 2023 -0400

      rs6000, fix vec_replace_unaligned built-in arguments
       ...

gcc/ChangeLog:
	* config/rs6000/rs6000-c.cc (find_instance): Add new parameter that
	specifies the number of built-in arguments to check.
	(altivec_resolve_overloaded_builtin): Update calls to find_instance
	to pass the number of built-in arguments to be checked.

1 files changed, 25 insertions, 14 deletions

diff --git a/gcc/config/rs6000/rs6000-c.cc b/gcc/config/rs6000/rs6000-c.cc
index 00476f9..65be0ac 100644
--- a/gcc/config/rs6000/rs6000-c.cc
+++ b/gcc/config/rs6000/rs6000-c.cc
@@ -1668,18 +1668,19 @@ resolve_vec_step (resolution *res, vec<tree, va_gc> *arglist, unsigned nargs)
 /* Look for a matching instance in a chain of instances.  INSTANCE points to
    the chain of instances; INSTANCE_CODE is the code identifying the specific
    built-in being searched for; FCODE is the overloaded function code; TYPES
-   contains an array of two types that must match the types of the instance's
-   parameters; and ARGS contains an array of two arguments to be passed to
-   the instance.  If found, resolve the built-in and return it, unless the
-   built-in is not supported in context.  In that case, set
-   UNSUPPORTED_BUILTIN to true.  If we don't match, return error_mark_node
-   and leave UNSUPPORTED_BUILTIN alone.  */
+   contains an array of NARGS types that must match the types of the
+   instance's parameters; ARGS contains an array of NARGS arguments to be
+   passed to the instance; and NARGS is the number of built-in arguments to
+   check.  If found, resolve the built-in and return it, unless the built-in
+   is not supported in context.  In that case, set UNSUPPORTED_BUILTIN to
+   true.  If we don't match, return error_mark_node and leave
+   UNSUPPORTED_BUILTIN alone.  */
 
 tree
 find_instance (bool *unsupported_builtin, ovlddata **instance,
 	       rs6000_gen_builtins instance_code,
 	       rs6000_gen_builtins fcode,
-	       tree *types, tree *args)
+	       tree *types, tree *args, int nargs)
 {
   while (*instance && (*instance)->bifid != instance_code)
     *instance = (*instance)->next;
@@ -1691,17 +1692,27 @@ find_instance (bool *unsupported_builtin, ovlddata **instance,
   if (!inst->fntype)
     return error_mark_node;
   tree fntype = rs6000_builtin_info[inst->bifid].fntype;
-  tree parmtype0 = TREE_VALUE (TYPE_ARG_TYPES (fntype));
-  tree parmtype1 = TREE_VALUE (TREE_CHAIN (TYPE_ARG_TYPES (fntype)));
+  tree argtype = TYPE_ARG_TYPES (fntype);
+  bool args_compatible = true;
 
-  if (rs6000_builtin_type_compatible (types[0], parmtype0)
-      && rs6000_builtin_type_compatible (types[1], parmtype1))
+  for (int i = 0; i < nargs; i++)
+    {
+      tree parmtype = TREE_VALUE (argtype);
+      if (!rs6000_builtin_type_compatible (types[i], parmtype))
+	{
+	  args_compatible = false;
+	  break;
+	}
+      argtype = TREE_CHAIN (argtype);
+    }
+
+  if (args_compatible)
     {
       if (rs6000_builtin_decl (inst->bifid, false) != error_mark_node
 	  && rs6000_builtin_is_supported (inst->bifid))
 	{
 	  tree ret_type = TREE_TYPE (inst->fntype);
-	  return altivec_build_resolved_builtin (args, 2, fntype, ret_type,
+	  return altivec_build_resolved_builtin (args, nargs, fntype, ret_type,
 						 inst->bifid, fcode);
 	}
       else
@@ -1921,7 +1932,7 @@ altivec_resolve_overloaded_builtin (location_t loc, tree fndecl,
 	  instance_code = RS6000_BIF_CMPB_32;
 
 	tree call = find_instance (&unsupported_builtin, &instance,
-				   instance_code, fcode, types, args);
+				   instance_code, fcode, types, args, nargs);
 	if (call != error_mark_node)
 	  return call;
 	break;
@@ -1981,7 +1992,7 @@ altivec_resolve_overloaded_builtin (location_t loc, tree fndecl,
 	  break;
 
 	tree call = find_instance (&unsupported_builtin, &instance,
-				   instance_code, fcode, types, args);
+				   instance_code, fcode, types, args, nargs);
 	if (call != error_mark_node)
 	  return call;
 	break;