Add a combined_fn enum

[Richard Sandiford <richard dot sandiford at arm dot com>]

I'm working on a patch series that needs to be able to treat built-in
functions and internal functions in a similar way.  This patch adds a
new enum, combined_fn, that combines the two together.  It also adds
utility functions for seeing which combined_fn (if any) is called by
a given CALL_EXPR or gcall.

Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.
OK to install?

Thanks,
Richard


gcc/
	* tree-core.h (internal_fn): Move immediately after the definition
	of built_in_function.
	(combined_fn): New enum.
	* tree.h (as_combined_fn, builtin_fn_p, as_builtin_fn)
	(internal_fn_p, as_internal_fn): New functions.
	(get_call_combined_fn, combined_fn_name): Declare.
	* tree.c (get_call_combined_fn): New function.
	(combined_fn_name): Likewise.
	* gimple.h (gimple_call_combined_fn): Declare.
	* gimple.c (gimple_call_combined_fn): New function.

diff --git a/gcc/gimple.c b/gcc/gimple.c
index 4ce38da..de3520a 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -2530,6 +2530,27 @@ gimple_call_builtin_p (const gimple *stmt, enum built_in_function code)
   return false;
 }
 
+/* If CALL is a call to a combined_fn (i.e. an internal function or
+   a normal built-in function), return its code, otherwise return
+   CFN_LAST.  */
+
+combined_fn
+gimple_call_combined_fn (const gimple *stmt)
+{
+  if (const gcall *call = dyn_cast <const gcall *> (stmt))
+    {
+      if (gimple_call_internal_p (call))
+	return as_combined_fn (gimple_call_internal_fn (call));
+
+      tree fndecl = gimple_call_fndecl (stmt);
+      if (fndecl
+	  && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
+	  && gimple_builtin_call_types_compatible_p (stmt, fndecl))
+	return as_combined_fn (DECL_FUNCTION_CODE (fndecl));
+    }
+  return CFN_LAST;
+}
+
 /* Return true if STMT clobbers memory.  STMT is required to be a
    GIMPLE_ASM.  */
 
diff --git a/gcc/gimple.h b/gcc/gimple.h
index 781801b..13cfbce 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -1499,6 +1499,7 @@ extern tree gimple_signed_type (tree);
 extern alias_set_type gimple_get_alias_set (tree);
 extern bool gimple_ior_addresses_taken (bitmap, gimple *);
 extern bool gimple_builtin_call_types_compatible_p (const gimple *, tree);
+extern combined_fn gimple_call_combined_fn (const gimple *);
 extern bool gimple_call_builtin_p (const gimple *);
 extern bool gimple_call_builtin_p (const gimple *, enum built_in_class);
 extern bool gimple_call_builtin_p (const gimple *, enum built_in_function);
diff --git a/gcc/tree-core.h b/gcc/tree-core.h
index 954368f..afb53be 100644
--- a/gcc/tree-core.h
+++ b/gcc/tree-core.h
@@ -184,6 +184,35 @@ enum built_in_function {
   END_BUILTINS
 };
 
+/* Internal functions.  */
+enum internal_fn {
+#define DEF_INTERNAL_FN(CODE, FLAGS, FNSPEC) IFN_##CODE,
+#include "internal-fn.def"
+  IFN_LAST
+};
+
+/* An enum that combines target-independent built-in functions with
+   internal functions, so that they can be treated in a similar way.
+   The numbers for built-in functions are the same as for the
+   built_in_function enum.  The numbers for internal functions
+   start at END_BUITLINS.  */
+enum combined_fn {
+#define DEF_BUILTIN(ENUM, N, C, T, LT, B, F, NA, AT, IM, COND) \
+  CFN_##ENUM = int (ENUM),
+#include "builtins.def"
+
+#define DEF_BUILTIN(ENUM, N, C, T, LT, B, F, NA, AT, IM, COND)
+#define DEF_BUILTIN_CHKP(ENUM, N, C, T, LT, B, F, NA, AT, IM, COND) \
+  CFN_##ENUM##_CHKP = int (ENUM##_CHKP),
+#include "builtins.def"
+
+#define DEF_INTERNAL_FN(CODE, FLAGS, FNSPEC) \
+  CFN_##CODE = int (END_BUILTINS) + int (IFN_##CODE),
+#include "internal-fn.def"
+
+  CFN_LAST
+};
+
 /* Tree code classes.  Each tree_code has an associated code class
    represented by a TREE_CODE_CLASS.  */
 enum tree_code_class {
@@ -766,13 +795,6 @@ enum annot_expr_kind {
   annot_expr_kind_last
 };
 
-/* Internal functions.  */
-enum internal_fn {
-#define DEF_INTERNAL_FN(CODE, FLAGS, FNSPEC) IFN_##CODE,
-#include "internal-fn.def"
-  IFN_LAST
-};
-
 /*---------------------------------------------------------------------------
                                 Type definitions
 ---------------------------------------------------------------------------*/
diff --git a/gcc/tree.c b/gcc/tree.c
index 5b9a7bd..94c3a1a 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -9316,6 +9316,25 @@ get_callee_fndecl (const_tree call)
   return NULL_TREE;
 }
 
+/* If CALL_EXPR CALL calls a normal built-in function or an internal function,
+   return the associated function code, otherwise return CFN_LAST.  */
+
+combined_fn
+get_call_combined_fn (const_tree call)
+{
+  /* It's invalid to call this function with anything but a CALL_EXPR.  */
+  gcc_assert (TREE_CODE (call) == CALL_EXPR);
+
+  if (!CALL_EXPR_FN (call))
+    return as_combined_fn (CALL_EXPR_IFN (call));
+
+  tree fndecl = get_callee_fndecl (call);
+  if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+    return as_combined_fn (DECL_FUNCTION_CODE (fndecl));
+
+  return CFN_LAST;
+}
+
 #define TREE_MEM_USAGE_SPACES 40
 
 /* Print debugging information about tree nodes generated during the compile,
@@ -13805,5 +13824,18 @@ nonnull_arg_p (const_tree arg)
   return false;
 }
 
+/* Return the name of combined function FN, for debugging purposes.  */
+
+const char *
+combined_fn_name (combined_fn fn)
+{
+  if (builtin_fn_p (fn))
+    {
+      tree fndecl = builtin_decl_explicit (as_builtin_fn (fn));
+      return IDENTIFIER_POINTER (DECL_NAME (fndecl));
+    }
+  else
+    return internal_fn_name (as_internal_fn (fn));
+}
 
 #include "gt-tree.h"
diff --git a/gcc/tree.h b/gcc/tree.h
index 6768b3b..14b46a4 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -22,6 +22,58 @@ along with GCC; see the file COPYING3.  If not see
 
 #include "tree-core.h"
 
+/* Convert a target-independent built-in function code to a combined_fn.  */
+
+inline combined_fn
+as_combined_fn (built_in_function fn)
+{
+  return combined_fn (int (fn));
+}
+
+/* Convert an internal function code to a combined_fn.  */
+
+inline combined_fn
+as_combined_fn (internal_fn fn)
+{
+  return combined_fn (int (fn) + int (END_BUILTINS));
+}
+
+/* Return true if CODE is a target-independent built-in function.  */
+
+inline bool
+builtin_fn_p (combined_fn code)
+{
+  return int (code) < int (END_BUILTINS);
+}
+
+/* Return the target-independent built-in function represented by CODE.
+   Only valid if builtin_fn_p (CODE).  */
+
+inline built_in_function
+as_builtin_fn (combined_fn code)
+{
+  gcc_checking_assert (builtin_fn_p (code));
+  return built_in_function (int (code));
+}
+
+/* Return true if CODE is an internal function.  */
+
+inline bool
+internal_fn_p (combined_fn code)
+{
+  return int (code) >= int (END_BUILTINS);
+}
+
+/* Return the internal function represented by CODE.  Only valid if
+   internal_fn_p (CODE).  */
+
+inline internal_fn
+as_internal_fn (combined_fn code)
+{
+  gcc_checking_assert (internal_fn_p (code));
+  return internal_fn (int (code) - int (END_BUILTINS));
+}
+
 /* Macros for initializing `tree_contains_struct'.  */
 #define MARK_TS_BASE(C)					\
   do {							\
@@ -4431,6 +4483,7 @@ extern unsigned crc32_unsigned (unsigned, unsigned);
 extern void clean_symbol_name (char *);
 extern tree get_file_function_name (const char *);
 extern tree get_callee_fndecl (const_tree);
+extern combined_fn get_call_combined_fn (const_tree);
 extern int type_num_arguments (const_tree);
 extern bool associative_tree_code (enum tree_code);
 extern bool commutative_tree_code (enum tree_code);
@@ -4456,6 +4509,7 @@ extern tree lhd_gcc_personality (void);
 extern void assign_assembler_name_if_neeeded (tree);
 extern void warn_deprecated_use (tree, tree);
 extern void cache_integer_cst (tree);
+extern const char *combined_fn_name (combined_fn);
 
 /* Return the memory model from a host integer.  */
 static inline enum memmodel