--- gcc/Makefile.in.jj	2023-06-06 20:02:35.581211930 +0200
+++ gcc/Makefile.in	2023-06-10 10:17:05.062270115 +0200
@@ -466,6 +466,7 @@ USER_H = $(srcdir)/ginclude/float.h \
 	 $(srcdir)/ginclude/stdnoreturn.h \
 	 $(srcdir)/ginclude/stdalign.h \
 	 $(srcdir)/ginclude/stdatomic.h \
+	 $(srcdir)/ginclude/stdckdint.h \
 	 $(EXTRA_HEADERS)
 
 USER_H_INC_NEXT_PRE = @user_headers_inc_next_pre@
--- gcc/ginclude/stdckdint.h.jj	2023-06-10 09:20:39.154053338 +0200
+++ gcc/ginclude/stdckdint.h	2023-06-12 18:09:06.429184992 +0200
@@ -0,0 +1,58 @@
+/* Copyright (C) 2023 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+/* ISO C23: 7.20 Checked Integer Arithmetic <stdckdint.h>.  */
+
+#ifndef _STDCKDINT_H
+#define _STDCKDINT_H
+
+#define __STDC_VERSION_STDCKDINT_H__ 202311L
+
+#if __STDC_VERSION__ >= 201112L
+# define __ckd_type_check_1(a, n) \
+  static_assert (_Generic (((__typeof_unqual__ (a)) 0),			      \
+			   char: 0,					      \
+			   default: __builtin_classify_type (__typeof__ (a))  \
+				    == 1),				      \
+		 "types used in " n " should be integral other than plain "   \
+		 "char, bool, bit-precise integer or enumerated type")
+# define __ckd_type_check(r, a, b, n) \
+  (__extension__ ({ __ckd_type_check_1 ((r)[0], n);			      \
+		    __ckd_type_check_1 (a, n);				      \
+		    __ckd_type_check_1 (b, n);				      \
+		    (r); }))
+#else
+# define __ckd_type_check(r, a, b, n) r
+#endif
+
+#define ckd_add(r, a, b) \
+  ((_Bool) __builtin_add_overflow (a, b,				      \
+				   __ckd_type_check (r, a, b, "ckd_add")))
+#define ckd_sub(r, a, b) \
+  ((_Bool) __builtin_sub_overflow (a, b,				      \
+				   __ckd_type_check (r, a, b, "ckd_sub")))
+#define ckd_mul(r, a, b) \
+  ((_Bool) __builtin_mul_overflow (a, b,				      \
+				   __ckd_type_check (r, a, b, "ckd_mul")))
+
+#endif	/* stdckdint.h */
--- gcc/testsuite/gcc.dg/stdckdint-1.c.jj	2023-06-10 10:04:23.547792318 +0200
+++ gcc/testsuite/gcc.dg/stdckdint-1.c	2023-06-10 10:50:29.748579415 +0200
@@ -0,0 +1,61 @@
+/* Test C23 Checked Integer Arithmetic macros in <stdckdint.h>.  */
+/* { dg-do run } */
+/* { dg-options "-std=c2x" } */
+
+#include <stdckdint.h>
+
+#if __STDC_VERSION_STDCKDINT_H__ != 202311L
+# error __STDC_VERSION_STDCKDINT_H__ not defined to 202311L
+#endif
+
+extern void abort (void);
+
+int
+main ()
+{
+  unsigned int a;
+  if (ckd_add (&a, 1, 2) || a != 3)
+    abort ();
+  if (ckd_add (&a, ~2U, 2) || a != ~0U)
+    abort ();
+  if (!ckd_add (&a, ~2U, 4) || a != 1)
+    abort ();
+  if (ckd_sub (&a, 42, 2) || a != 40)
+    abort ();
+  if (!ckd_sub (&a, 11, ~0ULL) || a != 12)
+    abort ();
+  if (ckd_mul (&a, 42, 16U) || a != 672)
+    abort ();
+  if (ckd_mul (&a, ~0UL, 0) || a != 0)
+    abort ();
+  if (ckd_mul (&a, 1, ~0U) || a != ~0U)
+    abort ();
+  if (ckd_mul (&a, ~0UL, 1) != (~0UL > ~0U) || a != ~0U)
+    abort ();
+  static_assert (_Generic (ckd_add (&a, 1, 1), bool: 1, default: 0));
+  static_assert (_Generic (ckd_sub (&a, 1, 1), bool: 1, default: 0));
+  static_assert (_Generic (ckd_mul (&a, 1, 1), bool: 1, default: 0));
+  signed char b;
+  if (ckd_add (&b, 8, 12) || b != 20)
+    abort ();
+  if (ckd_sub (&b, 8UL, 12ULL) || b != -4)
+    abort ();
+  if (ckd_mul (&b, 2, 3) || b != 6)
+    abort ();
+  unsigned char c;
+  if (ckd_add (&c, 8, 12) || c != 20)
+    abort ();
+  if (ckd_sub (&c, 8UL, 12ULL) != (-4ULL > (unsigned char) -4U)
+      || c != (unsigned char) -4U)
+    abort ();
+  if (ckd_mul (&c, 2, 3) || c != 6)
+    abort ();
+  long long d;
+  if (ckd_add (&d, ~0U, ~0U) != (~0U + 1ULL < ~0U)
+      || d != (long long) (2 * (unsigned long long) ~0U))
+    abort ();
+  if (ckd_sub (&d, 0, 0) || d != 0)
+    abort ();
+  if (ckd_mul (&d, 16, 1) || d != 16)
+    abort ();
+}
--- gcc/testsuite/gcc.dg/stdckdint-2.c.jj	2023-06-10 10:04:31.600681050 +0200
+++ gcc/testsuite/gcc.dg/stdckdint-2.c	2023-06-12 18:10:23.201127813 +0200
@@ -0,0 +1,53 @@
+/* Test C23 Checked Integer Arithmetic macros in <stdckdint.h>.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x" } */
+
+#include <stdckdint.h>
+
+int
+main ()
+{
+  char a;
+  bool b;
+  enum E { E1, E2 } c = E1;
+  int d;
+  ckd_add (&a, 1, 1);		/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&a, 1, 1);		/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&a, 1, 1);		/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&b, 1, 1);		/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+				/* { dg-error "has pointer to boolean type" "" { target *-*-* } .-1 } */
+  ckd_sub (&b, 1, 1);		/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+				/* { dg-error "has pointer to boolean type" "" { target *-*-* } .-1 } */
+  ckd_mul (&b, 1, 1);		/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+				/* { dg-error "has pointer to boolean type" "" { target *-*-* } .-1 } */
+  ckd_add (&c, 1, 1);		/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+				/* { dg-error "has pointer to enumerated type" "" { target *-*-* } .-1 } */
+  ckd_sub (&c, 1, 1);		/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+				/* { dg-error "has pointer to enumerated type" "" { target *-*-* } .-1 } */
+  ckd_mul (&c, 1, 1);		/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+				/* { dg-error "has pointer to enumerated type" "" { target *-*-* } .-1 } */
+  ckd_add (&d, (char) 1, 1);	/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, (char) 1, 1);	/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, (char) 1, 1);	/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, false, 1);	/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, false, 1);	/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, false, 1);	/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, true, 1);	/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, true, 1);	/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, true, 1);	/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, c, 1);		/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, c, 1);		/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, c, 1);		/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, 1, (char) 1);	/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, 1, (char) 1);	/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, 1, (char) 1);	/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, 1, false);	/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, 1, false);	/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, 1, false);	/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, 1, true);	/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, 1, true);	/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, 1, true);	/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_add (&d, 1, c);		/* { dg-error "types used in ckd_add should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_sub (&d, 1, c);		/* { dg-error "types used in ckd_sub should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+  ckd_mul (&d, 1, c);		/* { dg-error "types used in ckd_mul should be integral other than plain char, bool, bit-precise integer or enumerated type" } */
+}
