c, c++: Add new value for vector types for __builtin_classify_type

While filing a clang request to return 18 on _BitInts for
__builtin_classify_type instead of -1 they return currently, I've
noticed that we return -1 for vector types.  Initially I wanted to change
behavior just for __builtin_classify_type (type) form, as that is new in
GCC 14 and we've returned for 20+ years -1 for __builtin_classify_type
on vector expressions, but I was convinved otherwise, so this changes
the behavior even for that and now returns 19.

2023-11-20  Jakub Jelinek  <jakub@redhat.com>

gcc/
	* typeclass.h (enum type_class): Add vector_type_class.
	* builtins.cc (type_to_class): Return vector_type_class for
	VECTOR_TYPE.
	* doc/extend.texi (__builtin_classify_type): Mention bit-precise
	integer types and vector types.
gcc/testsuite/
	* c-c++-common/builtin-classify-type-1.c (main): Add tests for vector
	types.

4 files changed, 19 insertions, 6 deletions

diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index 5ece0d2..a489ef1 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -1859,6 +1859,7 @@ type_to_class (tree type)
     case LANG_TYPE:	   return lang_type_class;
     case OPAQUE_TYPE:      return opaque_type_class;
     case BITINT_TYPE:	   return bitint_type_class;
+    case VECTOR_TYPE:	   return vector_type_class;
     default:		   return no_type_class;
     }
 }
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 3169acd..9474e93 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -14746,11 +14746,11 @@ The @code{__builtin_classify_type} returns a small integer with a category
 of @var{arg} argument's type, like void type, integer type, enumeral type,
 boolean type, pointer type, reference type, offset type, real type, complex
 type, function type, method type, record type, union type, array type,
-string type, etc.  When the argument is an expression, for
-backwards compatibility reason the argument is promoted like arguments
-passed to @code{...} in varargs function, so some classes are never returned
-in certain languages.  Alternatively, the argument of the built-in
-function can be a typename, such as the @code{typeof} specifier.
+string type, bit-precise integer type, vector type, etc.  When the argument
+is an expression, for backwards compatibility reason the argument is promoted
+like arguments passed to @code{...} in varargs function, so some classes are
+never returned in certain languages.  Alternatively, the argument of the
+built-in function can be a typename, such as the @code{typeof} specifier.
 
 @smallexample
 int a[2];
diff --git a/gcc/testsuite/c-c++-common/builtin-classify-type-1.c b/gcc/testsuite/c-c++-common/builtin-classify-type-1.c
index a41dbe1..f90f2d9 100644
--- a/gcc/testsuite/c-c++-common/builtin-classify-type-1.c
+++ b/gcc/testsuite/c-c++-common/builtin-classify-type-1.c
@@ -22,6 +22,10 @@ main ()
   const char *p = (const char *) 0;
   float f = 0.0;
   _Complex double c = 0.0;
+  typedef int VI __attribute__((vector_size (4 * sizeof (int))));
+  typedef float VF __attribute__((vector_size (4 * sizeof (int))));
+  VI vi = { 0, 0, 0, 0 };
+  VF vf = { 0.0f, 0.0f, 0.0f, 0.0f };
 #ifdef __cplusplus
   struct T { void foo (); };
   int &r = a[0];
@@ -43,6 +47,8 @@ main ()
   static_assert (__builtin_classify_type (struct S) == 12, "");
   static_assert (__builtin_classify_type (union U) == 13, "");
   static_assert (__builtin_classify_type (int [2]) == 14, "");
+  static_assert (__builtin_classify_type (VI) == 19, "");
+  static_assert (__builtin_classify_type (VF) == 19, "");
   static_assert (__builtin_classify_type (__typeof__ (a[0])) == 1, "");
   static_assert (__builtin_classify_type (__typeof__ (e)) == 3, "");
   static_assert (__builtin_classify_type (__typeof__ (b)) == 4, "");
@@ -57,6 +63,8 @@ main ()
   static_assert (__builtin_classify_type (__typeof__ (s)) == 12, "");
   static_assert (__builtin_classify_type (__typeof__ (u)) == 13, "");
   static_assert (__builtin_classify_type (__typeof__ (a)) == 14, "");
+  static_assert (__builtin_classify_type (__typeof__ (vi)) == 19, "");
+  static_assert (__builtin_classify_type (__typeof__ (vf)) == 19, "");
 #ifndef __cplusplus
   static_assert (__builtin_classify_type (a[0]) == 1, "");
   static_assert (__builtin_classify_type (e) == 1, "");
@@ -102,4 +110,8 @@ main ()
     abort ();
   if (__builtin_classify_type (a) != 5)
     abort ();
+  if (__builtin_classify_type (vi) != 19)
+    abort ();
+  if (__builtin_classify_type (vf) != 19)
+    abort ();
 }
diff --git a/gcc/typeclass.h b/gcc/typeclass.h
index 4b162e1..2723c65 100644
--- a/gcc/typeclass.h
+++ b/gcc/typeclass.h
@@ -38,7 +38,7 @@ enum type_class
   record_type_class, union_type_class,
   array_type_class, string_type_class,
   lang_type_class, opaque_type_class,
-  bitint_type_class
+  bitint_type_class, vector_type_class
 };
 
 #endif /* GCC_TYPECLASS_H */