5 files changed, 14 insertions, 0 deletions
diff --git a/cc.h b/cc.h
index 6cf3f94..80cf344 100644
--- a/cc.h
+++ b/cc.h
@@ -239,6 +239,7 @@ enum builtinkind {
 	BUILTININFF,
 	BUILTINNANF,
 	BUILTINOFFSETOF,
+	BUILTINTYPESCOMPATIBLEP,
 	BUILTINVAARG,
 	BUILTINVACOPY,
 	BUILTINVAEND,
diff --git a/expr.c b/expr.c
index 28585c9..5c3e688 100644
--- a/expr.c
+++ b/expr.c
@@ -442,6 +442,11 @@ builtinfunc(struct scope *s, enum builtinkind kind)
 		e = mkconstexpr(&typeulong, offset);
 		free(name);
 		break;
+	case BUILTINTYPESCOMPATIBLEP:
+		t = typename(s, NULL);
+		expect(TCOMMA, "after type name");
+		e = mkconstexpr(&typeint, typecompatible(t, typename(s, NULL)));
+		break;
 	case BUILTINVAARG:
 		e = mkexpr(EXPRBUILTIN, NULL);
 		e->builtin.kind = BUILTINVAARG;
diff --git a/scope.c b/scope.c
index 1dc9f5c..f7207d1 100644
--- a/scope.c
+++ b/scope.c
@@ -20,6 +20,8 @@ scopeinit(void)
 		{"__builtin_inff",       {.kind = DECLBUILTIN, .builtin = BUILTININFF}},
 		{"__builtin_nanf",       {.kind = DECLBUILTIN, .builtin = BUILTINNANF}},
 		{"__builtin_offsetof",   {.kind = DECLBUILTIN, .builtin = BUILTINOFFSETOF}},
+		{"__builtin_types_compatible_p",
+			{.kind = DECLBUILTIN, .builtin = BUILTINTYPESCOMPATIBLEP}},
 		{"__builtin_va_arg",     {.kind = DECLBUILTIN, .builtin = BUILTINVAARG}},
 		{"__builtin_va_copy",    {.kind = DECLBUILTIN, .builtin = BUILTINVACOPY}},
 		{"__builtin_va_end",     {.kind = DECLBUILTIN, .builtin = BUILTINVAEND}},
diff --git a/test/builtin-types-compatible-p.c b/test/builtin-types-compatible-p.c
new file mode 100644
index 0000000..23631ce
--- /dev/null
+++ b/test/builtin-types-compatible-p.c
@@ -0,0 +1,3 @@
+int x = __builtin_types_compatible_p(unsigned, enum {A});
+int y = __builtin_types_compatible_p(const int, int);  /* qualifiers are ignored */
+int z = __builtin_types_compatible_p(int *, unsigned *);
diff --git a/test/builtin-types-compatible-p.qbe b/test/builtin-types-compatible-p.qbe
new file mode 100644
index 0000000..cae3e60
--- /dev/null
+++ b/test/builtin-types-compatible-p.qbe
@@ -0,0 +1,3 @@
+export data $x = align 4 { w 1, }
+export data $y = align 4 { w 1, }
+export data $z = align 4 { w 0, }