diff mbox series

[v19,37/40] c++: Implement __is_signed built-in trait

Message ID 20231013223957.1634024-38-kmatsui@gcc.gnu.org
State Unresolved
Headers
Series Optimize type traits performance |

Checks

Context Check Description
snail/gcc-patch-check warning Git am fail log

Commit Message

Ken Matsui Oct. 13, 2023, 10:37 p.m. UTC 
  This patch implements built-in trait for std::is_signed.

gcc/cp/ChangeLog:

	* cp-trait.def: Define __is_signed.
	* cp-trait.gperf: Reflect cp-trait.def change.
	* cp-trait.h: Likewise.
	* constraint.cc (diagnose_trait_expr): Handle CPTK_IS_SIGNED.
	* semantics.cc (trait_expr_value): Likewise.
	(finish_trait_expr): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/has-builtin-1.C: Test existence of __is_signed.
	* g++.dg/ext/is_signed.C: New test.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
 gcc/cp/constraint.cc                     |   3 +
 gcc/cp/cp-trait.def                      |   1 +
 gcc/cp/cp-trait.gperf                    |   1 +
 gcc/cp/cp-trait.h                        | 211 ++++++++++++-----------
 gcc/cp/semantics.cc                      |   4 +
 gcc/testsuite/g++.dg/ext/has-builtin-1.C |   3 +
 gcc/testsuite/g++.dg/ext/is_signed.C     |  47 +++++
 7 files changed, 165 insertions(+), 105 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/is_signed.C
diff mbox series

Patch

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index c28dad702c3..b161c9b2c9e 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3802,6 +3802,9 @@  diagnose_trait_expr (tree expr, tree args)
     case CPTK_IS_SAME:
       inform (loc, "  %qT is not the same as %qT", t1, t2);
       break;
+    case CPTK_IS_SIGNED:
+      inform (loc, "  %qT is not a signed type", t1);
+      break;
     case CPTK_IS_SCOPED_ENUM:
       inform (loc, "  %qT is not a scoped enum", t1);
       break;
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 0603b4a230f..b0faa4c8937 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -86,6 +86,7 @@  DEFTRAIT_EXPR (IS_POINTER, "__is_pointer", 1)
 DEFTRAIT_EXPR (IS_POLYMORPHIC, "__is_polymorphic", 1)
 DEFTRAIT_EXPR (IS_REFERENCE, "__is_reference", 1)
 DEFTRAIT_EXPR (IS_SAME, "__is_same", 2)
+DEFTRAIT_EXPR (IS_SIGNED, "__is_signed", 1)
 DEFTRAIT_EXPR (IS_SCOPED_ENUM, "__is_scoped_enum", 1)
 DEFTRAIT_EXPR (IS_STD_LAYOUT, "__is_standard_layout", 1)
 DEFTRAIT_EXPR (IS_TRIVIAL, "__is_trivial", 1)
diff --git a/gcc/cp/cp-trait.gperf b/gcc/cp/cp-trait.gperf
index 90d05bca5c1..de0ba162e7a 100644
--- a/gcc/cp/cp-trait.gperf
+++ b/gcc/cp/cp-trait.gperf
@@ -66,6 +66,7 @@  struct cp_trait {
 "__is_polymorphic", CPTK_IS_POLYMORPHIC, 1, false
 "__is_reference", CPTK_IS_REFERENCE, 1, false
 "__is_same", CPTK_IS_SAME, 2, false
+"__is_signed", CPTK_IS_SIGNED, 1, false
 "__is_scoped_enum", CPTK_IS_SCOPED_ENUM, 1, false
 "__is_standard_layout", CPTK_IS_STD_LAYOUT, 1, false
 "__is_trivial", CPTK_IS_TRIVIAL, 1, false
diff --git a/gcc/cp/cp-trait.h b/gcc/cp/cp-trait.h
index 75ab2b5edfa..6d1078de2fe 100644
--- a/gcc/cp/cp-trait.h
+++ b/gcc/cp/cp-trait.h
@@ -54,7 +54,7 @@  struct cp_trait {
   short arity;
   bool type;
 };
-/* maximum key range = 129, duplicates = 0 */
+/* maximum key range = 119, duplicates = 0 */
 
 class cp_trait_lookup
 {
@@ -69,32 +69,32 @@  cp_trait_lookup::hash (const char *str, size_t len)
 {
   static const unsigned char asso_values[] =
     {
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136,  20, 136,  45,  35,  40,
-       60,   0,  55,   0, 136,   0, 136, 136,  10,  15,
-       35,   0,  10, 136,  10,  15,   5,  15,   0, 136,
-      136,  20, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136, 136, 136, 136, 136,
-      136, 136, 136, 136, 136, 136
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126,  20, 126,  40,  45,  50,
+       55,   0,   5,  15, 126,   0, 126, 126,  35,  10,
+       35,   0,  10, 126,  30,   5,   5,  16,  30, 126,
+      126,  10, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
+      126, 126, 126, 126, 126, 126
     };
   unsigned int hval = len;
 
@@ -116,149 +116,150 @@  cp_trait_lookup::find (const char *str, size_t len)
 {
   enum
     {
-      TOTAL_KEYWORDS = 60,
+      TOTAL_KEYWORDS = 61,
       MIN_WORD_LENGTH = 7,
       MAX_WORD_LENGTH = 37,
       MIN_HASH_VALUE = 7,
-      MAX_HASH_VALUE = 135
+      MAX_HASH_VALUE = 125
     };
 
   static const struct cp_trait wordlist[] =
     {
-#line 88 "../../gcc/cp/cp-trait.gperf"
+#line 89 "../../gcc/cp/cp-trait.gperf"
       {"__bases", CPTK_BASES, 1, true},
-#line 81 "../../gcc/cp/cp-trait.gperf"
-      {"__remove_cv", CPTK_REMOVE_CV, 1, true},
 #line 82 "../../gcc/cp/cp-trait.gperf"
-      {"__remove_cvref", CPTK_REMOVE_CVREF, 1, true},
+      {"__remove_cv", CPTK_REMOVE_CV, 1, true},
 #line 83 "../../gcc/cp/cp-trait.gperf"
+      {"__remove_cvref", CPTK_REMOVE_CVREF, 1, true},
+#line 84 "../../gcc/cp/cp-trait.gperf"
       {"__remove_pointer", CPTK_REMOVE_POINTER, 1, true},
-#line 71 "../../gcc/cp/cp-trait.gperf"
+#line 72 "../../gcc/cp/cp-trait.gperf"
       {"__is_trivial", CPTK_IS_TRIVIAL, 1, false},
-#line 84 "../../gcc/cp/cp-trait.gperf"
+#line 85 "../../gcc/cp/cp-trait.gperf"
       {"__remove_reference", CPTK_REMOVE_REFERENCE, 1, true},
-#line 89 "../../gcc/cp/cp-trait.gperf"
+#line 90 "../../gcc/cp/cp-trait.gperf"
       {"__direct_bases", CPTK_DIRECT_BASES, 1, true},
 #line 51 "../../gcc/cp/cp-trait.gperf"
       {"__is_empty", CPTK_IS_EMPTY, 1, false},
+#line 70 "../../gcc/cp/cp-trait.gperf"
+      {"__is_scoped_enum", CPTK_IS_SCOPED_ENUM, 1, false},
 #line 65 "../../gcc/cp/cp-trait.gperf"
       {"__is_pointer", CPTK_IS_POINTER, 1, false},
-#line 78 "../../gcc/cp/cp-trait.gperf"
-      {"__is_volatile", CPTK_IS_VOLATILE, 1, false},
+#line 68 "../../gcc/cp/cp-trait.gperf"
+      {"__is_same", CPTK_IS_SAME, 2, false},
 #line 52 "../../gcc/cp/cp-trait.gperf"
       {"__is_enum", CPTK_IS_ENUM, 1, false},
-#line 76 "../../gcc/cp/cp-trait.gperf"
+#line 77 "../../gcc/cp/cp-trait.gperf"
       {"__is_union", CPTK_IS_UNION, 1, false},
-#line 86 "../../gcc/cp/cp-trait.gperf"
-      {"__underlying_type", CPTK_UNDERLYING_TYPE, 1, true},
-#line 74 "../../gcc/cp/cp-trait.gperf"
+#line 30 "../../gcc/cp/cp-trait.gperf"
+      {"__is_same_as", CPTK_IS_SAME, 2, false},
+#line 75 "../../gcc/cp/cp-trait.gperf"
       {"__is_trivially_copyable", CPTK_IS_TRIVIALLY_COPYABLE, 1, false},
-#line 85 "../../gcc/cp/cp-trait.gperf"
+#line 86 "../../gcc/cp/cp-trait.gperf"
       {"__type_pack_element", CPTK_TYPE_PACK_ELEMENT, -1, true},
-#line 72 "../../gcc/cp/cp-trait.gperf"
+#line 73 "../../gcc/cp/cp-trait.gperf"
       {"__is_trivially_assignable", CPTK_IS_TRIVIALLY_ASSIGNABLE, 2, false},
 #line 69 "../../gcc/cp/cp-trait.gperf"
-      {"__is_scoped_enum", CPTK_IS_SCOPED_ENUM, 1, false},
-#line 56 "../../gcc/cp/cp-trait.gperf"
-      {"__is_literal_type", CPTK_IS_LITERAL_TYPE, 1, false},
-#line 73 "../../gcc/cp/cp-trait.gperf"
+      {"__is_signed", CPTK_IS_SIGNED, 1, false},
+#line 74 "../../gcc/cp/cp-trait.gperf"
       {"__is_trivially_constructible", CPTK_IS_TRIVIALLY_CONSTRUCTIBLE, -1, false},
-#line 80 "../../gcc/cp/cp-trait.gperf"
+#line 78 "../../gcc/cp/cp-trait.gperf"
+      {"__is_unsigned", CPTK_IS_UNSIGNED, 1, false},
+#line 81 "../../gcc/cp/cp-trait.gperf"
       {"__reference_converts_from_temporary", CPTK_REF_CONVERTS_FROM_TEMPORARY, 2, false},
-#line 66 "../../gcc/cp/cp-trait.gperf"
-      {"__is_polymorphic", CPTK_IS_POLYMORPHIC, 1, false},
-#line 79 "../../gcc/cp/cp-trait.gperf"
+#line 80 "../../gcc/cp/cp-trait.gperf"
       {"__reference_constructs_from_temporary", CPTK_REF_CONSTRUCTS_FROM_TEMPORARY, 2, false},
 #line 33 "../../gcc/cp/cp-trait.gperf"
       {"__has_nothrow_copy", CPTK_HAS_NOTHROW_COPY, 1, false},
-#line 68 "../../gcc/cp/cp-trait.gperf"
-      {"__is_same", CPTK_IS_SAME, 2, false},
+#line 59 "../../gcc/cp/cp-trait.gperf"
+      {"__is_member_pointer", CPTK_IS_MEMBER_POINTER, 1, false},
 #line 31 "../../gcc/cp/cp-trait.gperf"
       {"__has_nothrow_assign", CPTK_HAS_NOTHROW_ASSIGN, 1, false},
-#line 30 "../../gcc/cp/cp-trait.gperf"
-      {"__is_same_as", CPTK_IS_SAME, 2, false},
-#line 77 "../../gcc/cp/cp-trait.gperf"
-      {"__is_unsigned", CPTK_IS_UNSIGNED, 1, false},
 #line 39 "../../gcc/cp/cp-trait.gperf"
       {"__has_virtual_destructor", CPTK_HAS_VIRTUAL_DESTRUCTOR, 1, false},
 #line 32 "../../gcc/cp/cp-trait.gperf"
       {"__has_nothrow_constructor", CPTK_HAS_NOTHROW_CONSTRUCTOR, 1, false},
-#line 63 "../../gcc/cp/cp-trait.gperf"
-      {"__is_pointer_interconvertible_base_of", CPTK_IS_POINTER_INTERCONVERTIBLE_BASE_OF, 2, false},
-#line 36 "../../gcc/cp/cp-trait.gperf"
-      {"__has_trivial_copy", CPTK_HAS_TRIVIAL_COPY, 1, false},
-#line 59 "../../gcc/cp/cp-trait.gperf"
-      {"__is_member_pointer", CPTK_IS_MEMBER_POINTER, 1, false},
-#line 34 "../../gcc/cp/cp-trait.gperf"
-      {"__has_trivial_assign", CPTK_HAS_TRIVIAL_ASSIGN, 1, false},
-#line 55 "../../gcc/cp/cp-trait.gperf"
-      {"__is_layout_compatible", CPTK_IS_LAYOUT_COMPATIBLE, 2, false},
-#line 37 "../../gcc/cp/cp-trait.gperf"
-      {"__has_trivial_destructor", CPTK_HAS_TRIVIAL_DESTRUCTOR, 1, false},
-#line 35 "../../gcc/cp/cp-trait.gperf"
-      {"__has_trivial_constructor", CPTK_HAS_TRIVIAL_CONSTRUCTOR, 1, false},
 #line 58 "../../gcc/cp/cp-trait.gperf"
       {"__is_member_object_pointer", CPTK_IS_MEMBER_OBJECT_POINTER, 1, false},
+#line 63 "../../gcc/cp/cp-trait.gperf"
+      {"__is_pointer_interconvertible_base_of", CPTK_IS_POINTER_INTERCONVERTIBLE_BASE_OF, 2, false},
 #line 57 "../../gcc/cp/cp-trait.gperf"
       {"__is_member_function_pointer", CPTK_IS_MEMBER_FUNCTION_POINTER, 1, false},
-#line 41 "../../gcc/cp/cp-trait.gperf"
-      {"__is_aggregate", CPTK_IS_AGGREGATE, 1, false},
+#line 67 "../../gcc/cp/cp-trait.gperf"
+      {"__is_reference", CPTK_IS_REFERENCE, 1, false},
+#line 53 "../../gcc/cp/cp-trait.gperf"
+      {"__is_final", CPTK_IS_FINAL, 1, false},
+#line 87 "../../gcc/cp/cp-trait.gperf"
+      {"__underlying_type", CPTK_UNDERLYING_TYPE, 1, true},
+#line 54 "../../gcc/cp/cp-trait.gperf"
+      {"__is_function", CPTK_IS_FUNCTION, 1, false},
 #line 42 "../../gcc/cp/cp-trait.gperf"
       {"__is_arithmetic", CPTK_IS_ARITHMETIC, 1, false},
+#line 56 "../../gcc/cp/cp-trait.gperf"
+      {"__is_literal_type", CPTK_IS_LITERAL_TYPE, 1, false},
+#line 40 "../../gcc/cp/cp-trait.gperf"
+      {"__is_abstract", CPTK_IS_ABSTRACT, 1, false},
+#line 44 "../../gcc/cp/cp-trait.gperf"
+      {"__is_assignable", CPTK_IS_ASSIGNABLE, 2, false},
+#line 66 "../../gcc/cp/cp-trait.gperf"
+      {"__is_polymorphic", CPTK_IS_POLYMORPHIC, 1, false},
 #line 45 "../../gcc/cp/cp-trait.gperf"
       {"__is_base_of", CPTK_IS_BASE_OF, 2, false},
 #line 60 "../../gcc/cp/cp-trait.gperf"
       {"__is_nothrow_assignable", CPTK_IS_NOTHROW_ASSIGNABLE, 2, false},
 #line 62 "../../gcc/cp/cp-trait.gperf"
       {"__is_nothrow_convertible", CPTK_IS_NOTHROW_CONVERTIBLE, 2, false},
-#line 43 "../../gcc/cp/cp-trait.gperf"
-      {"__is_array", CPTK_IS_ARRAY, 1, false},
+#line 71 "../../gcc/cp/cp-trait.gperf"
+      {"__is_standard_layout", CPTK_IS_STD_LAYOUT, 1, false},
 #line 61 "../../gcc/cp/cp-trait.gperf"
       {"__is_nothrow_constructible", CPTK_IS_NOTHROW_CONSTRUCTIBLE, -1, false},
+#line 55 "../../gcc/cp/cp-trait.gperf"
+      {"__is_layout_compatible", CPTK_IS_LAYOUT_COMPATIBLE, 2, false},
+#line 36 "../../gcc/cp/cp-trait.gperf"
+      {"__has_trivial_copy", CPTK_HAS_TRIVIAL_COPY, 1, false},
+#line 41 "../../gcc/cp/cp-trait.gperf"
+      {"__is_aggregate", CPTK_IS_AGGREGATE, 1, false},
+#line 34 "../../gcc/cp/cp-trait.gperf"
+      {"__has_trivial_assign", CPTK_HAS_TRIVIAL_ASSIGN, 1, false},
+#line 64 "../../gcc/cp/cp-trait.gperf"
+      {"__is_pod", CPTK_IS_POD, 1, false},
+#line 37 "../../gcc/cp/cp-trait.gperf"
+      {"__has_trivial_destructor", CPTK_HAS_TRIVIAL_DESTRUCTOR, 1, false},
+#line 35 "../../gcc/cp/cp-trait.gperf"
+      {"__has_trivial_constructor", CPTK_HAS_TRIVIAL_CONSTRUCTOR, 1, false},
+#line 79 "../../gcc/cp/cp-trait.gperf"
+      {"__is_volatile", CPTK_IS_VOLATILE, 1, false},
 #line 46 "../../gcc/cp/cp-trait.gperf"
       {"__is_bounded_array", CPTK_IS_BOUNDED_ARRAY, 1, false},
-#line 75 "../../gcc/cp/cp-trait.gperf"
+#line 43 "../../gcc/cp/cp-trait.gperf"
+      {"__is_array", CPTK_IS_ARRAY, 1, false},
+#line 76 "../../gcc/cp/cp-trait.gperf"
       {"__is_unbounded_array", CPTK_IS_UNBOUNDED_ARRAY, 1, false},
-#line 40 "../../gcc/cp/cp-trait.gperf"
-      {"__is_abstract", CPTK_IS_ABSTRACT, 1, false},
-#line 44 "../../gcc/cp/cp-trait.gperf"
-      {"__is_assignable", CPTK_IS_ASSIGNABLE, 2, false},
-#line 64 "../../gcc/cp/cp-trait.gperf"
-      {"__is_pod", CPTK_IS_POD, 1, false},
-#line 67 "../../gcc/cp/cp-trait.gperf"
-      {"__is_reference", CPTK_IS_REFERENCE, 1, false},
-#line 70 "../../gcc/cp/cp-trait.gperf"
-      {"__is_standard_layout", CPTK_IS_STD_LAYOUT, 1, false},
-#line 48 "../../gcc/cp/cp-trait.gperf"
-      {"__is_const", CPTK_IS_CONST, 1, false},
 #line 38 "../../gcc/cp/cp-trait.gperf"
       {"__has_unique_object_representations", CPTK_HAS_UNIQUE_OBJ_REPRESENTATIONS, 1, false},
+#line 48 "../../gcc/cp/cp-trait.gperf"
+      {"__is_const", CPTK_IS_CONST, 1, false},
+#line 47 "../../gcc/cp/cp-trait.gperf"
+      {"__is_class", CPTK_IS_CLASS, 1, false},
 #line 50 "../../gcc/cp/cp-trait.gperf"
       {"__is_convertible", CPTK_IS_CONVERTIBLE, 2, false},
 #line 49 "../../gcc/cp/cp-trait.gperf"
       {"__is_constructible", CPTK_IS_CONSTRUCTIBLE, -1, false},
-#line 47 "../../gcc/cp/cp-trait.gperf"
-      {"__is_class", CPTK_IS_CLASS, 1, false},
-#line 53 "../../gcc/cp/cp-trait.gperf"
-      {"__is_final", CPTK_IS_FINAL, 1, false},
-#line 54 "../../gcc/cp/cp-trait.gperf"
-      {"__is_function", CPTK_IS_FUNCTION, 1, false},
-#line 87 "../../gcc/cp/cp-trait.gperf"
+#line 88 "../../gcc/cp/cp-trait.gperf"
       {"__is_deducible ", CPTK_IS_DEDUCIBLE, 2, false}
     };
 
   static const signed char lookup[] =
     {
       -1, -1, -1, -1, -1, -1, -1,  0, -1, -1, -1,  1, -1, -1,
-       2, -1,  3,  4,  5,  6,  7, -1,  8,  9, 10, 11, -1, 12,
-      13, 14, 15, 16, 17, 18, -1, 19, 20, 21, 22, 23, 24, -1,
-      25, 26, 27, 28, -1, 29, 30, 31, 32, -1, 33, -1, 34, 35,
-      36, -1, 37, 38, 39, -1, 40, 41, 42, 43, 44, -1, 45, -1,
-      46, -1, -1, 47, -1, 48, -1, -1, 49, 50, 51, -1, -1, -1,
-      -1, 52, -1, -1, -1, -1, 53, 54, -1, 55, -1, 56, -1, -1,
-      -1, -1, 57, -1, -1, 58, -1, -1, -1, -1, -1, -1, -1, -1,
-      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-      -1, -1, -1, -1, -1, -1, -1, -1, -1, 59
+       2, -1,  3,  4,  5,  6,  7,  8,  9, -1, 10, 11, 12, 13,
+      14, 15, 16, 17, -1, 18, 19, 20, -1, 21, 22, 23, 24, -1,
+      -1, -1, 25, 26, 27, 28, 29, 30, 31, -1, 32, 33, -1, 34,
+      -1, 35, 36, -1, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46,
+      47, -1, -1, 48, 49, 50, -1, -1, 51, 52, 53, 54, -1, -1,
+      -1, -1, -1, -1, -1, -1, 55, -1, -1, -1, -1, 56, -1, -1,
+      -1, -1, 57, 58, -1, 59, -1, -1, -1, -1, -1, -1, -1, -1,
+      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 60
     };
 
   if (len <= MAX_WORD_LENGTH && len >= MIN_WORD_LENGTH)
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 14387821b85..5e6b2ca37ac 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12226,6 +12226,9 @@  trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_SAME:
       return same_type_p (type1, type2);
 
+    case CPTK_IS_SIGNED:
+      return ARITHMETIC_TYPE_P (type1) && TYPE_SIGN (type1) == SIGNED;
+
     case CPTK_IS_SCOPED_ENUM:
       return SCOPED_ENUM_P (type1);
 
@@ -12425,6 +12428,7 @@  finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_POINTER:
     case CPTK_IS_REFERENCE:
     case CPTK_IS_SAME:
+    case CPTK_IS_SIGNED:
     case CPTK_IS_SCOPED_ENUM:
     case CPTK_IS_UNBOUNDED_ARRAY:
     case CPTK_IS_UNION:
diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index 3d380f94b06..aaf7254df4b 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -140,6 +140,9 @@ 
 #if !__has_builtin (__is_same_as)
 # error "__has_builtin (__is_same_as) failed"
 #endif
+#if !__has_builtin (__is_signed)
+# error "__has_builtin (__is_signed) failed"
+#endif
 #if !__has_builtin (__is_scoped_enum)
 # error "__has_builtin (__is_scoped_enum) failed"
 #endif
diff --git a/gcc/testsuite/g++.dg/ext/is_signed.C b/gcc/testsuite/g++.dg/ext/is_signed.C
new file mode 100644
index 00000000000..a04b548105d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_signed.C
@@ -0,0 +1,47 @@ 
+// { dg-do compile { target c++11 } }
+
+#include <testsuite_tr1.h>
+
+using namespace __gnu_test;
+
+#define SA(X) static_assert((X),#X)
+#define SA_TEST_CATEGORY(TRAIT, X, expect) \
+  SA(TRAIT(X) == expect);                  \
+  SA(TRAIT(const X) == expect);            \
+  SA(TRAIT(volatile X) == expect);         \
+  SA(TRAIT(const volatile X) == expect)
+
+SA_TEST_CATEGORY(__is_signed, void, false);
+
+SA_TEST_CATEGORY(__is_signed, bool, bool(-1) < bool(0));
+SA_TEST_CATEGORY(__is_signed, char, char(-1) < char(0));
+SA_TEST_CATEGORY(__is_signed, signed char, true);
+SA_TEST_CATEGORY(__is_signed, unsigned char, false);
+SA_TEST_CATEGORY(__is_signed, wchar_t, wchar_t(-1) < wchar_t(0));
+SA_TEST_CATEGORY(__is_signed, short, true);
+SA_TEST_CATEGORY(__is_signed, unsigned short, false);
+SA_TEST_CATEGORY(__is_signed, int, true);
+SA_TEST_CATEGORY(__is_signed, unsigned int, false);
+SA_TEST_CATEGORY(__is_signed, long, true);
+SA_TEST_CATEGORY(__is_signed, unsigned long, false);
+SA_TEST_CATEGORY(__is_signed, long long, true);
+SA_TEST_CATEGORY(__is_signed, unsigned long long, false);
+
+SA_TEST_CATEGORY(__is_signed, float, true);
+SA_TEST_CATEGORY(__is_signed, double, true);
+SA_TEST_CATEGORY(__is_signed, long double, true);
+
+#ifndef __STRICT_ANSI__
+// GNU Extensions.
+#ifdef __SIZEOF_INT128__
+SA_TEST_CATEGORY(__is_signed, __int128, true);
+SA_TEST_CATEGORY(__is_signed, unsigned __int128, false);
+#endif
+
+#ifdef _GLIBCXX_USE_FLOAT128
+SA_TEST_CATEGORY(__is_signed, __float128, true);
+#endif
+#endif
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_signed, ClassType, false);