change specific int128 -> generic intN
diff mbox

Message ID 201404142303.s3EN3ONP009938@greed.delorie.com
State New
Headers show

Commit Message

DJ Delorie April 14, 2014, 11:03 p.m. UTC
[this time with patch]

This patch replaces the current int128 support with a generic intN
support, which happens to provide int128 as well as up to three
additional intN types per target.  I will post a separate patch for
the msp430 backend demonstrating the use of this new feature for
__int20, as well as a third to fix some problems with PSImode in
general.

The general idea is that genmodes has a new macro INT_N() for
<tm>-modes.def, which gives the mode and precision to use for
target-specific intN types.  These types are always created, but the
parser will error with "unsupported" if the target does not support
that mode for that compile (i.e. because of command line switches,
etc).  There's an INT_N(TI,128) in the common sources.

If the target defines any types larger than "long long", those types
(like int128 before) will be used for type promotion, but types
smaller than "long long" will not, to avoid confusing the C type
promotion rules.  Otherwise, it's up to the source being compiled to
specific __intN types as desired.

The only non-automatic part of this is the table of pre-computed
constants in builtin_define_type_minmax() (c-family/c-cppbuiltin.c).
I've added the entries for int20 and int24 but each target will need
to expand the table as needed.

gcc/

	* machmode.h (int_n_data_t): New.
	(int_n_enabled_p): New.
	(int_n_data): New.
	* tree.c (int_n_enabled_p): New.
	(int_n_trees): New.
	(make_or_reuse_type): Check for all __intN types, not just
	__int128.
	(build_common_tree_nodes): Likewise.  Also fill in integer_typs[]
	entries.
	* tree.h (int128_integer_type_node): Remove.
	(int128_unsigned_type_node): Remove.
	(int_n_trees_t): New.
	(int_n_enabled_p): New.
	(int_n_trees): New.
	* toplev.c (standard_type_bitsize): New.
	(do_compile): Check which __intN types are enabled for the current
	run.
	* builtin-types.def (BT_INT128): Remove.
	(BT_UINT128): Remove.
	* machmode.def: Add macro to create __intN for all targets.
	* stor-layout.c (mode_for_size): Support __intN types.
	(smallest_mode_for_size): Likewise.
	* genmodes.c (struct mode_data): Add int_n field.
	(blank_mode): Likewise.
	(INT_N): New.
	(make_int_n): New.
	(emit_insn_modes_h): Count __intN entries and define
	NUM_INT_N_ENTS.
	(emit_mode_int_n): New.
	(emit_insn_modes_c): Call it.
	* gimple.c (gimple_signed_or_unsigned_type): Check for all __intN
	types, not just __int128.
	* tree-core.h (integer_type_kind): Remove __int128-specific
	entries, reserve spots for __intN entries.

gcc/c-family/

	* c-pretty-print.c (pp_c_integer_constant): Check for all __intN
	types, not just __int128.
	* c-cppbuiltin.c (c_cpp_builtins): Add builtins for all __intN
	types, not just __int128.
	* c-common.c (c_common_reswords): Remove __int128 special case.
	(c_common_type_for_size): Check for all __intN types, not just
	__int128.
	(c_common_type_for_mode): Likewise.
	(c_common_signed_or_unsigned_type): Likewise.
	(c_build_bitfield_integer_type): Likewise.
	(c_common_nodes_and_builtins): Likewise.
	(keyword_begins_type_specifier): Likewise.
	* c-common.h (rid): Remove RID_INT128 and add RID_INT_N_* for all
	__intN variants.

gcc/c/

	* c-parser.c (c_parse_init): Add RID entries for each __intN.
	(c_token_starts_typename): Check all __intN, not just __int128.
	(c_token_starts_declspecs): Likewise.
	(c_parser_declspecs): Likewise.
	(c_parser_attribute_any_word): Likewise.
	(c_parser_objc_selector): Likewise.
	* c-tree.h (c_typespec_keyword): cts_int128 -> cts_int_n.
	(struct c_declspecs): Add int_n_idx field to record *which* __intN
	is specified.
	* c-decl.c (declspecs_add_type): Check for all __intN, not just
	__int128.
	(finish_declspecs): Likewise.

gcc/cp/
	* typeck.c (cp_common_type): Check for all __intN types, not just
	__int128.
	* decl.c (grokdeclarator): Likewise.
	* rtti.c (emit_support_tinfos): Remove __int128-specific entries.
	* parser.c (cp_lexer_next_token_is_decl_specifier_keyword): Check
	for all __intN types, not just __int128.
	(cp_parser_simple_type_specifier): Likewise.
	* mangle.c (integer_type_codes): Remove int128-specific codes.
	* cp-tree.h (cp_decl_specifier_seq): Add int_n_idx to store which
	__intN was specified.
	* lex.c (init_reswords): Reserve all __intN keywords.

gcc/lto/
	* lto-lang.c (lto_build_c_type_nodes): Check intN types for
	size-type as well.
	(lto_init): Initialize all intN types, not just int128.

Comments

Marc Glisse April 15, 2014, 5:53 a.m. UTC | #1
On Mon, 14 Apr 2014, DJ Delorie wrote:

> 	* rtti.c (emit_support_tinfos): Remove __int128-specific entries.

Hello,

I wanted to check the interaction with:
http://gcc.gnu.org/ml/gcc-patches/2014-04/msg00618.html

but I don't see where you moved the __int128 typeinfo generation.
DJ Delorie April 15, 2014, 6:17 a.m. UTC | #2
I wasn't sure what to do with that array, since it was static and
couldn't have "empty" slots in them like the arrays in tree.h.  Also,
do we need to have *every* type in that list?  What's the rule for
whether a type gets installed there or not?  The comment says
"guaranteed to be in the runtime support" but does that mean "for this
particular build" (wrt multilibs) as not all intN types are guaranteed
(even the int128 types were not guaranteed to be supported before my
patch).  In other parts of the patch, just taking out the special case
for __int128 was sufficient to "do the right thing" for all __intN
types.

I can certainly put the intN types in there, but note that it would
mean regenerating the fundamentals[] array at runtime to include those
types which are supported at the time.

Do the entries in the array need to be in a particular order?
Marc Glisse April 17, 2014, 8:11 p.m. UTC | #3
On Tue, 15 Apr 2014, DJ Delorie wrote:

> I wasn't sure what to do with that array, since it was static and
> couldn't have "empty" slots in them like the arrays in tree.h.  Also,
> do we need to have *every* type in that list?  What's the rule for
> whether a type gets installed there or not?  The comment says
> "guaranteed to be in the runtime support" but does that mean "for this
> particular build" (wrt multilibs) as not all intN types are guaranteed
> (even the int128 types were not guaranteed to be supported before my
> patch).  In other parts of the patch, just taking out the special case
> for __int128 was sufficient to "do the right thing" for all __intN
> types.

You need someone who understands this better than me (ask Jason). To be 
able to throw/catch a type, you need some typeinfo symbols. The front-end 
generates that for classes when they are defined. For fundamental types, 
it assumes libsupc++ will provide it, and the function you are modifying 
is the one generating libsupc++ (I am surprised your patch didn't cause 
any failure on x64_64, at least in abi_check). We need to generate the 
typeinfo for __intN, either in libsupc++, or in each TU, and since both 
cases will require code, I assume libsupc++ is preferable.

> I can certainly put the intN types in there, but note that it would
> mean regenerating the fundamentals[] array at runtime to include those
> types which are supported at the time.

After the patch I linked, it should just mean calling the helper function 
on your new types, no need to touch the array.

> Do the entries in the array need to be in a particular order?

No, any random order would do.
DJ Delorie May 8, 2014, 11:34 p.m. UTC | #4
The libstdc++v3 headers have __int128 hard-coded all over the place.
Any suggestions on parameterizing those for the __intN types that are
actually supported by the target?
Marc Glisse May 9, 2014, 12:26 a.m. UTC | #5
On Thu, 8 May 2014, DJ Delorie wrote:

> The libstdc++v3 headers have __int128 hard-coded all over the place.
> Any suggestions on parameterizing those for the __intN types that are
> actually supported by the target?

(adding libstdc++@ in Cc:)

The first idea that comes to mind (so possibly not such a good one) is to 
provide predefined macros:
#define __EXTENDED_INTEGER_TYPE_1__ __int24
#define __EXTENDED_INTEGER_TYPE_2__ __int128
#undef __EXTENDED_INTEGER_TYPE_3__

Assuming that the formula sizeof(type)*char_bit==precision works for all 
types, it should be sufficient for the library (abs, type_traits and 
numeric_limits).
DJ Delorie May 9, 2014, 2:21 a.m. UTC | #6
> Assuming that the formula sizeof(type)*char_bit==precision works for all 

It doesn't.  THe MSP430 has __int20 for example.

Would it be acceptable for the compiler to always define a set of
macros for each of the intN types?  I would have thought that would be
discouraged, but it would be an easier way to handle it.
Marc Glisse May 9, 2014, 7:59 a.m. UTC | #7
On Thu, 8 May 2014, DJ Delorie wrote:

>> Assuming that the formula sizeof(type)*char_bit==precision works for all
>
> It doesn't.  THe MSP430 has __int20 for example.

Well, it wasn't a hard requirement, it is just that the library has to 
use a more complicated way to get the precision (use (unsigned TYPE)(-1) 
to get the unsigned max and compute the precision from that, probably).

> Would it be acceptable for the compiler to always define a set of
> macros for each of the intN types?

What set of macros do you have in mind?

> I would have thought that would be discouraged,

If we can't think of another way...
DJ Delorie May 9, 2014, 6:29 p.m. UTC | #8
> Well, it wasn't a hard requirement, it is just that the library has
> to use a more complicated way to get the precision (use (unsigned
> TYPE)(-1) to get the unsigned max and compute the precision from
> that, probably).

We could define macros for the precision too, and we already know max
and min values as macros, it's "just a matter of" exporting that info
to the C++ headers somehow.

> > Would it be acceptable for the compiler to always define a set of
> > macros for each of the intN types?
> 
> What set of macros do you have in mind?

In general, I meant.  They'd be predefined for pretty much every
compile, not just the C++ headers.

Patch
diff mbox

Index: machmode.h
===================================================================
--- machmode.h	(revision 209391)
+++ machmode.h	(working copy)
@@ -322,7 +322,19 @@  extern void init_adjust_machine_modes (v
 			 GET_MODE_PRECISION (MODE2))
 
 #define HWI_COMPUTABLE_MODE_P(MODE) \
   (SCALAR_INT_MODE_P (MODE) \
    && GET_MODE_PRECISION (MODE) <= HOST_BITS_PER_WIDE_INT)
 
+typedef struct {
+  /* These parts are initailized by genmodes output */
+  unsigned int bitsize;
+  enum machine_mode m;
+  /* RID_* is RID_INTN_BASE + index into this array */
+} int_n_data_t;
+
+/* This is also in tree.h.  genmodes.c guarantees the're sorted from
+   smallest bitsize to largest bitsize. */
+extern bool int_n_enabled_p[NUM_INT_N_ENTS];
+extern const int_n_data_t int_n_data[NUM_INT_N_ENTS];
+
 #endif /* not HAVE_MACHINE_MODES */
Index: c-family/c-pretty-print.c
===================================================================
--- c-family/c-pretty-print.c	(revision 209391)
+++ c-family/c-pretty-print.c	(working copy)
@@ -907,12 +907,14 @@  pp_c_string_literal (c_pretty_printer *p
 
 /* Pretty-print an INTEGER literal.  */
 
 static void
 pp_c_integer_constant (c_pretty_printer *pp, tree i)
 {
+  int idx;
+
   /* We are going to compare the type of I to other types using
      pointer comparison so we need to use its canonical type.  */
   tree type =
     TYPE_CANONICAL (TREE_TYPE (i))
     ? TYPE_CANONICAL (TREE_TYPE (i))
     : TREE_TYPE (i);
@@ -939,15 +941,23 @@  pp_c_integer_constant (c_pretty_printer 
     pp_character (pp, 'u');
   if (type == long_integer_type_node || type == long_unsigned_type_node)
     pp_character (pp, 'l');
   else if (type == long_long_integer_type_node
 	   || type == long_long_unsigned_type_node)
     pp_string (pp, "ll");
-  else if (type == int128_integer_type_node
-           || type == int128_unsigned_type_node)
-    pp_string (pp, "I128");
+  else for (idx = 0; idx < NUM_INT_N_ENTS; idx ++)
+    if (int_n_enabled_p[idx])
+      {
+	char buf[2+20];
+	if (type == int_n_trees[idx].signed_type
+	    || type == int_n_trees[idx].unsigned_type)
+	  {
+	    sprintf (buf, "I%d", int_n_data[idx].bitsize);
+	    pp_string (pp, buf);
+	  }
+      }
 }
 
 /* Print out a CHARACTER literal.  */
 
 static void
 pp_c_character_constant (c_pretty_printer *pp, tree c)
Index: c-family/c-cppbuiltin.c
===================================================================
--- c-family/c-cppbuiltin.c	(revision 209391)
+++ c-family/c-cppbuiltin.c	(working copy)
@@ -775,12 +775,14 @@  cpp_iec_559_complex_value (void)
 }
 
 /* Hook that registers front end and target-specific built-ins.  */
 void
 c_cpp_builtins (cpp_reader *pfile)
 {
+  int i;
+
   /* -undef turns off target-specific built-ins.  */
   if (flag_undef)
     return;
 
   define_language_independent_builtin_macros (pfile);
 
@@ -993,15 +995,20 @@  c_cpp_builtins (cpp_reader *pfile)
   else if (flag_stack_protect == 1)
     cpp_define (pfile, "__SSP__=1");
 
   if (flag_openmp)
     cpp_define (pfile, "_OPENMP=201307");
 
-  if (int128_integer_type_node != NULL_TREE)
-    builtin_define_type_sizeof ("__SIZEOF_INT128__",
-			        int128_integer_type_node);
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i])
+      {
+	char buf[15+20];
+	sprintf(buf, "__SIZEOF_INT%d__", int_n_data[i].bitsize);
+	builtin_define_type_sizeof (buf,
+				    int_n_trees[i].signed_type);
+      }
   builtin_define_type_sizeof ("__SIZEOF_WCHAR_T__", wchar_type_node);
   builtin_define_type_sizeof ("__SIZEOF_WINT_T__", wint_type_node);
   builtin_define_type_sizeof ("__SIZEOF_PTRDIFF_T__",
 			      unsigned_ptrdiff_type_node);
 
   /* A straightforward target hook doesn't work, because of problems
@@ -1227,18 +1234,21 @@  builtin_define_with_hex_fp_value (const 
 static const char *
 type_suffix (tree type)
 {
   static const char *const suffixes[] = { "", "U", "L", "UL", "LL", "ULL" };
   int unsigned_suffix;
   int is_long;
+  int tp = TYPE_PRECISION (type);
 
   if (type == long_long_integer_type_node
-      || type == long_long_unsigned_type_node)
+      || type == long_long_unsigned_type_node
+      || tp > TYPE_PRECISION (long_integer_type_node))
     is_long = 2;
   else if (type == long_integer_type_node
-	   || type == long_unsigned_type_node)
+	   || type == long_unsigned_type_node
+	   || tp > TYPE_PRECISION (integer_type_node))
     is_long = 1;
   else if (type == integer_type_node
 	   || type == unsigned_type_node
 	   || type == short_integer_type_node
 	   || type == short_unsigned_type_node
 	   || type == signed_char_type_node
@@ -1298,29 +1308,32 @@  builtin_define_type_minmax (const char *
   static const char *const values[]
     = { "127", "255",
 	"32767", "65535",
 	"2147483647", "4294967295",
 	"9223372036854775807", "18446744073709551615",
 	"170141183460469231731687303715884105727",
-	"340282366920938463463374607431768211455" };
+	"340282366920938463463374607431768211455",
+	"524287", "1048575",
+	"8388607", "16777215",
+  };
 
   const char *value, *suffix;
   char *buf;
   size_t idx;
 
   /* Pre-rendering the values mean we don't have to futz with printing a
-     multi-word decimal value.  There are also a very limited number of
-     precisions that we support, so it's really a waste of time.  */
+     multi-word decimal value.  */
   switch (TYPE_PRECISION (type))
     {
     case 8:	idx = 0; break;
     case 16:	idx = 2; break;
     case 32:	idx = 4; break;
     case 64:	idx = 6; break;
     case 128:	idx = 8; break;
-    default:    gcc_unreachable ();
+    case 20:    idx = 10; break;
+    default:	gcc_unreachable ();
     }
 
   value = values[idx + TYPE_UNSIGNED (type)];
   suffix = type_suffix (type);
 
   buf = (char *) alloca (strlen (max_macro) + 1 + strlen (value)
Index: c-family/c-common.c
===================================================================
--- c-family/c-common.c	(revision 209391)
+++ c-family/c-common.c	(working copy)
@@ -57,18 +57,16 @@  cpp_reader *parse_in;		/* Declared in c-
 
    INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
 
 	tree short_integer_type_node;
 	tree long_integer_type_node;
 	tree long_long_integer_type_node;
-	tree int128_integer_type_node;
 
 	tree short_unsigned_type_node;
 	tree long_unsigned_type_node;
 	tree long_long_unsigned_type_node;
-	tree int128_unsigned_type_node;
 
 	tree truthvalue_type_node;
 	tree truthvalue_false_node;
 	tree truthvalue_true_node;
 
 	tree ptrdiff_type_node;
@@ -460,13 +458,12 @@  const struct c_common_resword c_common_r
   { "__has_trivial_destructor", RID_HAS_TRIVIAL_DESTRUCTOR, D_CXXONLY },
   { "__has_virtual_destructor", RID_HAS_VIRTUAL_DESTRUCTOR, D_CXXONLY },
   { "__imag",		RID_IMAGPART,	0 },
   { "__imag__",		RID_IMAGPART,	0 },
   { "__inline",		RID_INLINE,	0 },
   { "__inline__",	RID_INLINE,	0 },
-  { "__int128",		RID_INT128,	0 },
   { "__is_abstract",	RID_IS_ABSTRACT, D_CXXONLY },
   { "__is_base_of",	RID_IS_BASE_OF, D_CXXONLY },
   { "__is_class",	RID_IS_CLASS,	D_CXXONLY },
   { "__is_convertible_to", RID_IS_CONVERTIBLE_TO, D_CXXONLY },
   { "__is_empty",	RID_IS_EMPTY,	D_CXXONLY },
   { "__is_enum",	RID_IS_ENUM,	D_CXXONLY },
@@ -3395,12 +3392,14 @@  check_case_bounds (tree type, tree orig_
 /* Return an integer type with BITS bits of precision,
    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
 
 tree
 c_common_type_for_size (unsigned int bits, int unsignedp)
 {
+  int i;
+
   if (bits == TYPE_PRECISION (integer_type_node))
     return unsignedp ? unsigned_type_node : integer_type_node;
 
   if (bits == TYPE_PRECISION (signed_char_type_node))
     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
 
@@ -3411,16 +3410,17 @@  c_common_type_for_size (unsigned int bit
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
 
   if (bits == TYPE_PRECISION (long_long_integer_type_node))
     return (unsignedp ? long_long_unsigned_type_node
 	    : long_long_integer_type_node);
 
-  if (int128_integer_type_node
-      && bits == TYPE_PRECISION (int128_integer_type_node))
-    return (unsignedp ? int128_unsigned_type_node
-	    : int128_integer_type_node);
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& bits == int_n_data[i].bitsize)
+      return (unsignedp ? int_n_trees[i].unsigned_type
+	      : int_n_trees[i].signed_type);
 
   if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
     return (unsignedp ? widest_unsigned_literal_type_node
 	    : widest_integer_literal_type_node);
 
   if (bits <= TYPE_PRECISION (intQI_type_node))
@@ -3478,12 +3478,13 @@  static GTY(()) tree registered_builtin_t
    then UNSIGNEDP selects between saturating and nonsaturating types.  */
 
 tree
 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
 {
   tree t;
+  int i;
 
   if (mode == TYPE_MODE (integer_type_node))
     return unsignedp ? unsigned_type_node : integer_type_node;
 
   if (mode == TYPE_MODE (signed_char_type_node))
     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
@@ -3494,15 +3495,17 @@  c_common_type_for_mode (enum machine_mod
   if (mode == TYPE_MODE (long_integer_type_node))
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
 
   if (mode == TYPE_MODE (long_long_integer_type_node))
     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
 
-  if (int128_integer_type_node
-      && mode == TYPE_MODE (int128_integer_type_node))
-    return unsignedp ? int128_unsigned_type_node : int128_integer_type_node;
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& mode == int_n_data[i].m)
+      return (unsignedp ? int_n_trees[i].unsigned_type
+	      : int_n_trees[i].signed_type);
 
   if (mode == TYPE_MODE (widest_integer_literal_type_node))
     return unsignedp ? widest_unsigned_literal_type_node
 		     : widest_integer_literal_type_node;
 
   if (mode == QImode)
@@ -3694,12 +3697,13 @@  c_common_signed_type (tree type)
    signed according to UNSIGNEDP.  */
 
 tree
 c_common_signed_or_unsigned_type (int unsignedp, tree type)
 {
   tree type1;
+  int i;
 
   /* This block of code emulates the behavior of the old
      c_common_unsigned_type. In particular, it returns
      long_unsigned_type_node if passed a long, even when a int would
      have the same size. This is necessary for warnings to work
      correctly in archs where sizeof(int) == sizeof(long) */
@@ -3712,16 +3716,20 @@  c_common_signed_or_unsigned_type (int un
   if (type1 == short_integer_type_node || type1 == short_unsigned_type_node)
     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
   if (type1 == long_integer_type_node || type1 == long_unsigned_type_node)
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
   if (type1 == long_long_integer_type_node || type1 == long_long_unsigned_type_node)
     return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
-  if (int128_integer_type_node
-      && (type1 == int128_integer_type_node
-	  || type1 == int128_unsigned_type_node))
-    return unsignedp ? int128_unsigned_type_node : int128_integer_type_node;
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& (type1 == int_n_trees[i].unsigned_type
+	    || type1 == int_n_trees[i].signed_type))
+      return (unsignedp ? int_n_trees[i].unsigned_type
+	      : int_n_trees[i].signed_type);
+
   if (type1 == widest_integer_literal_type_node || type1 == widest_unsigned_literal_type_node)
     return unsignedp ? widest_unsigned_literal_type_node : widest_integer_literal_type_node;
 #if HOST_BITS_PER_WIDE_INT >= 64
   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
 #endif
@@ -3830,15 +3838,20 @@  c_common_signed_or_unsigned_type (int un
     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
   if (TYPE_OK (long_integer_type_node))
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
   if (TYPE_OK (long_long_integer_type_node))
     return (unsignedp ? long_long_unsigned_type_node
 	    : long_long_integer_type_node);
-  if (int128_integer_type_node && TYPE_OK (int128_integer_type_node))
-    return (unsignedp ? int128_unsigned_type_node
-	    : int128_integer_type_node);
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& TYPE_MODE (type) == int_n_data[i].m
+	&& TYPE_PRECISION (type) == int_n_data[i].bitsize)
+      return (unsignedp ? int_n_trees[i].unsigned_type
+	      : int_n_trees[i].signed_type);
+
   if (TYPE_OK (widest_integer_literal_type_node))
     return (unsignedp ? widest_unsigned_literal_type_node
 	    : widest_integer_literal_type_node);
 
 #if HOST_BITS_PER_WIDE_INT >= 64
   if (TYPE_OK (intTI_type_node))
@@ -3859,12 +3872,14 @@  c_common_signed_or_unsigned_type (int un
 
 /* Build a bit-field integer type for the given WIDTH and UNSIGNEDP.  */
 
 tree
 c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp)
 {
+  int i;
+
   /* Extended integer types of the same width as a standard type have
      lesser rank, so those of the same width as int promote to int or
      unsigned int and are valid for printf formats expecting int or
      unsigned int.  To avoid such special cases, avoid creating
      extended integer types for bit-fields if a standard integer type
      is available.  */
@@ -3876,16 +3891,17 @@  c_build_bitfield_integer_type (unsigned 
     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
   if (width == TYPE_PRECISION (long_integer_type_node))
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
   if (width == TYPE_PRECISION (long_long_integer_type_node))
     return (unsignedp ? long_long_unsigned_type_node
 	    : long_long_integer_type_node);
-  if (int128_integer_type_node
-      && width == TYPE_PRECISION (int128_integer_type_node))
-    return (unsignedp ? int128_unsigned_type_node
-	    : int128_integer_type_node);
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& width == int_n_data[i].bitsize)
+      return (unsignedp ? int_n_trees[i].unsigned_type
+	      : int_n_trees[i].signed_type);
   return build_nonstandard_integer_type (width, unsignedp);
 }
 
 /* The C version of the register_builtin_type langhook.  */
 
 void
@@ -5292,12 +5308,13 @@  c_common_nodes_and_builtins (void)
   int char16_type_size;
   int char32_type_size;
   int wchar_type_size;
   tree array_domain_type;
   tree va_list_ref_type_node;
   tree va_list_arg_type_node;
+  int i;
 
   build_common_tree_nodes (flag_signed_char, flag_short_double);
 
   /* Define `int' and `char' first so that dbx will output them first.  */
   record_builtin_type (RID_INT, NULL, integer_type_node);
   record_builtin_type (RID_CHAR, "char", char_type_node);
@@ -5308,19 +5325,25 @@  c_common_nodes_and_builtins (void)
   if (c_dialect_cxx ())
     record_builtin_type (RID_SIGNED, NULL, integer_type_node);
   record_builtin_type (RID_LONG, "long int", long_integer_type_node);
   record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
   record_builtin_type (RID_MAX, "long unsigned int",
 		       long_unsigned_type_node);
-  if (int128_integer_type_node != NULL_TREE)
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
     {
-      record_builtin_type (RID_INT128, "__int128",
-			   int128_integer_type_node);
-      record_builtin_type (RID_MAX, "__int128 unsigned",
-			   int128_unsigned_type_node);
+      char name[25];
+
+      sprintf (name, "__int%d", int_n_data[i].bitsize);
+      record_builtin_type ((enum rid)(RID_FIRST_INT_N + i), xstrdup (name),
+			   int_n_trees[i].signed_type);
+      sprintf (name, "__int%d unsigned", int_n_data[i].bitsize);
+      record_builtin_type (RID_MAX, xstrdup (name),
+			   int_n_trees[i].unsigned_type);
     }
+
   if (c_dialect_cxx ())
     record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
   record_builtin_type (RID_MAX, "long long int",
 		       long_long_integer_type_node);
   record_builtin_type (RID_MAX, "long long unsigned int",
 		       long_long_unsigned_type_node);
@@ -5350,12 +5373,14 @@  c_common_nodes_and_builtins (void)
 					 TYPE_DECL, NULL_TREE,
 					 intSI_type_node));
   lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
 					 TYPE_DECL, NULL_TREE,
 					 intDI_type_node));
 #if HOST_BITS_PER_WIDE_INT >= 64
+  /* Note that this is different than the __int128 type that's part of
+     the generic __intN support.  */
   if (targetm.scalar_mode_supported_p (TImode))
     lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
 					   TYPE_DECL,
 					   get_identifier ("__int128_t"),
 					   intTI_type_node));
 #endif
@@ -11632,13 +11657,12 @@  keyword_begins_type_specifier (enum rid 
     case RID_AUTO_TYPE:
     case RID_INT:
     case RID_CHAR:
     case RID_FLOAT:
     case RID_DOUBLE:
     case RID_VOID:
-    case RID_INT128:
     case RID_UNSIGNED:
     case RID_LONG:
     case RID_SHORT:
     case RID_SIGNED:
     case RID_DFLOAT32:
     case RID_DFLOAT64:
@@ -11655,12 +11679,16 @@  keyword_begins_type_specifier (enum rid 
     case RID_STRUCT:
     case RID_CLASS:
     case RID_UNION:
     case RID_ENUM:
       return true;
     default:
+      if (keyword >= RID_FIRST_INT_N
+	  && keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
+	  && int_n_enabled_p[keyword-RID_FIRST_INT_N])
+	return true;
       return false;
     }
 }
 
 /* Return true if KEYWORD names a type qualifier.  */
 
Index: c-family/c-common.h
===================================================================
--- c-family/c-common.h	(revision 209391)
+++ c-family/c-common.h	(working copy)
@@ -88,13 +88,12 @@  enum rid
   /* C (reserved and imaginary types not implemented, so any use is a
      syntax error) */
   RID_IMAGINARY,
 
   /* C */
   RID_INT,     RID_CHAR,   RID_FLOAT,    RID_DOUBLE, RID_VOID,
-  RID_INT128,
   RID_ENUM,    RID_STRUCT, RID_UNION,    RID_IF,     RID_ELSE,
   RID_WHILE,   RID_DO,     RID_FOR,      RID_SWITCH, RID_CASE,
   RID_DEFAULT, RID_BREAK,  RID_CONTINUE, RID_RETURN, RID_GOTO,
   RID_SIZEOF,
 
   /* C extensions */
@@ -185,12 +184,29 @@  enum rid
   RID_ADDR_SPACE_14,
   RID_ADDR_SPACE_15,
 
   RID_FIRST_ADDR_SPACE = RID_ADDR_SPACE_0,
   RID_LAST_ADDR_SPACE = RID_ADDR_SPACE_15,
 
+  /* __intN_t keywords.  The _N_M here doesn't correspond to the intN
+     in the keyword; use the bitsize in int_n_t_data_t[M] for that.
+     For example, if int_n_t_data_t[0].bitsize is 13, then RID_INT_N_0
+     is for __int13_t.  */
+
+  /* Note that the range to use is RID_FIRST_INT_N through
+     RID_FIRST_INT_N + NUM_INT_N_ENTS - 1 and c-parser.c has a list of
+     all RID_INT_N_* in a case statement.  */
+
+  RID_INT_N_0,
+  RID_INT_N_1,
+  RID_INT_N_2,
+  RID_INT_N_3,
+
+  RID_FIRST_INT_N = RID_INT_N_0,
+  RID_LAST_INT_N = RID_INT_N_3,
+
   RID_MAX,
 
   RID_FIRST_MODIFIER = RID_STATIC,
   RID_LAST_MODIFIER = RID_ONEWAY,
 
   RID_FIRST_CXX0X = RID_CONSTEXPR,
Index: c/c-parser.c
===================================================================
--- c/c-parser.c	(revision 209391)
+++ c/c-parser.c	(working copy)
@@ -109,12 +109,22 @@  c_parse_init (void)
 
       id = get_identifier (c_common_reswords[i].word);
       C_SET_RID_CODE (id, c_common_reswords[i].rid);
       C_IS_RESERVED_WORD (id) = 1;
       ridpointers [(int) c_common_reswords[i].rid] = id;
     }
+
+  for (i = 0; i < NUM_INT_N_ENTS; i++)
+    {
+      /* We always create the symbols but they aren't always supported.  */
+      char name[50];
+      sprintf (name, "__int%d", int_n_data[i].bitsize);
+      id = get_identifier (xstrdup (name));
+      C_SET_RID_CODE (id, RID_FIRST_INT_N + i);
+      C_IS_RESERVED_WORD (id) = 1;
+    }
 }
 
 /* The C lexer intermediates between the lexer in cpplib and c-lex.c
    and the C parser.  Unlike the C++ lexer, the parser structure
    stores the lexer information instead of using a separate structure.
    Identifiers are separated into ordinary identifiers, type names,
@@ -484,13 +494,12 @@  c_token_starts_typename (c_token *token)
 	}
     case CPP_KEYWORD:
       switch (token->keyword)
 	{
 	case RID_UNSIGNED:
 	case RID_LONG:
-	case RID_INT128:
 	case RID_SHORT:
 	case RID_SIGNED:
 	case RID_COMPLEX:
 	case RID_INT:
 	case RID_CHAR:
 	case RID_FLOAT:
@@ -512,12 +521,16 @@  c_token_starts_typename (c_token *token)
 	case RID_FRACT:
 	case RID_ACCUM:
 	case RID_SAT:
 	case RID_AUTO_TYPE:
 	  return true;
 	default:
+	  if (token->keyword >= RID_FIRST_INT_N
+	      && token->keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
+	      && int_n_enabled_p[token->keyword - RID_FIRST_INT_N])
+	    return true;
 	  return false;
 	}
     case CPP_LESS:
       if (c_dialect_objc ())
 	return true;
       return false;
@@ -642,13 +655,12 @@  c_token_starts_declspecs (c_token *token
 	case RID_INLINE:
 	case RID_NORETURN:
 	case RID_AUTO:
 	case RID_THREAD:
 	case RID_UNSIGNED:
 	case RID_LONG:
-	case RID_INT128:
 	case RID_SHORT:
 	case RID_SIGNED:
 	case RID_COMPLEX:
 	case RID_INT:
 	case RID_CHAR:
 	case RID_FLOAT:
@@ -671,12 +683,16 @@  c_token_starts_declspecs (c_token *token
 	case RID_SAT:
 	case RID_ALIGNAS:
 	case RID_ATOMIC:
 	case RID_AUTO_TYPE:
 	  return true;
 	default:
+	  if (token->keyword >= RID_FIRST_INT_N
+	      && token->keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
+	      && int_n_enabled_p[token->keyword - RID_FIRST_INT_N])
+	    return true;
 	  return false;
 	}
     case CPP_LESS:
       if (c_dialect_objc ())
 	return true;
       return false;
@@ -2136,13 +2152,13 @@  c_parser_static_assert_declaration_no_se
    storage-class-specifier:
      __thread
 
    type-specifier:
      typeof-specifier
      __auto_type
-     __int128
+     __intN
      _Decimal32
      _Decimal64
      _Decimal128
      _Fract
      _Accum
      _Sat
@@ -2290,13 +2306,12 @@  c_parser_declspecs (c_parser *parser, st
 	case RID_AUTO_TYPE:
 	  if (!auto_type_ok)
 	    goto out;
 	  /* Fall through.  */
 	case RID_UNSIGNED:
 	case RID_LONG:
-	case RID_INT128:
 	case RID_SHORT:
 	case RID_SIGNED:
 	case RID_COMPLEX:
 	case RID_INT:
 	case RID_CHAR:
 	case RID_FLOAT:
@@ -2306,12 +2321,16 @@  c_parser_declspecs (c_parser *parser, st
 	case RID_DFLOAT64:
 	case RID_DFLOAT128:
 	case RID_BOOL:
 	case RID_FRACT:
 	case RID_ACCUM:
 	case RID_SAT:
+	case RID_INT_N_0:
+	case RID_INT_N_1:
+	case RID_INT_N_2:
+	case RID_INT_N_3:
 	  if (!typespec_ok)
 	    goto out;
 	  attrs_ok = true;
 	  seen_type = true;
 	  if (c_dialect_objc ())
 	    parser->objc_need_raw_identifier = true;
@@ -3726,13 +3745,12 @@  c_parser_attribute_any_word (c_parser *p
       bool ok;
       switch (c_parser_peek_token (parser)->keyword)
 	{
 	case RID_STATIC:
 	case RID_UNSIGNED:
 	case RID_LONG:
-	case RID_INT128:
 	case RID_CONST:
 	case RID_EXTERN:
 	case RID_REGISTER:
 	case RID_TYPEDEF:
 	case RID_SHORT:
 	case RID_INLINE:
@@ -3756,12 +3774,16 @@  c_parser_attribute_any_word (c_parser *p
 	case RID_ACCUM:
 	case RID_SAT:
 	case RID_TRANSACTION_ATOMIC:
 	case RID_TRANSACTION_CANCEL:
 	case RID_ATOMIC:
 	case RID_AUTO_TYPE:
+	case RID_INT_N_0:
+	case RID_INT_N_1:
+	case RID_INT_N_2:
+	case RID_INT_N_3:
 	  ok = true;
 	  break;
 	default:
 	  ok = false;
 	  break;
 	}
@@ -8897,13 +8919,12 @@  c_parser_objc_selector (c_parser *parser
     case RID_ASM:
     case RID_SIZEOF:
     case RID_TYPEOF:
     case RID_ALIGNOF:
     case RID_UNSIGNED:
     case RID_LONG:
-    case RID_INT128:
     case RID_CONST:
     case RID_SHORT:
     case RID_VOLATILE:
     case RID_SIGNED:
     case RID_RESTRICT:
     case RID_COMPLEX:
@@ -8918,12 +8939,16 @@  c_parser_objc_selector (c_parser *parser
     case RID_FLOAT:
     case RID_DOUBLE:
     case RID_VOID:
     case RID_BOOL:
     case RID_ATOMIC:
     case RID_AUTO_TYPE:
+    case RID_INT_N_0:
+    case RID_INT_N_1:
+    case RID_INT_N_2:
+    case RID_INT_N_3:
       c_parser_consume_token (parser);
       return value;
     default:
       return NULL_TREE;
     }
 }
Index: c/c-tree.h
===================================================================
--- c/c-tree.h	(revision 209391)
+++ c/c-tree.h	(working copy)
@@ -196,13 +196,13 @@  enum c_typespec_keyword {
   cts_none,
   cts_void,
   cts_bool,
   cts_char,
   cts_int,
   cts_float,
-  cts_int128,
+  cts_int_n,
   cts_double,
   cts_dfloat32,
   cts_dfloat64,
   cts_dfloat128,
   cts_fract,
   cts_accum,
@@ -263,12 +263,14 @@  struct c_declspecs {
      separately.  */
   tree attrs;
   /* The base-2 log of the greatest alignment required by an _Alignas
      specifier, in bytes, or -1 if no such specifiers with nonzero
      alignment.  */
   int align_log;
+  /* For the __intN declspec, this stores the index into the int_n_* arrays.  */
+  int int_n_idx;
   /* The storage class specifier, or csc_none if none.  */
   enum c_storage_class storage_class;
   /* Any type specifier keyword used such as "int", not reflecting
      modifiers such as "short", or cts_none if none.  */
   ENUM_BITFIELD (c_typespec_keyword) typespec_word : 8;
   /* The kind of type specifier if one has been seen, ctsk_none
Index: c/c-decl.c
===================================================================
--- c/c-decl.c	(revision 209391)
+++ c/c-decl.c	(working copy)
@@ -9147,16 +9147,17 @@  declspecs_add_type (location_t loc, stru
 			  ("both %<long%> and %<__auto_type%> in "
 			   "declaration specifiers"));
 	      else if (specs->typespec_word == cts_void)
 		error_at (loc,
 			  ("both %<long%> and %<void%> in "
 			   "declaration specifiers"));
-	      else if (specs->typespec_word == cts_int128)
+	      else if (specs->typespec_word == cts_int_n)
 		  error_at (loc,
-			    ("both %<long%> and %<__int128%> in "
-			     "declaration specifiers"));
+			    ("both %<long%> and %<__int%d%> in "
+			     "declaration specifiers"),
+			    int_n_data[specs->int_n_idx].bitsize);
 	      else if (specs->typespec_word == cts_bool)
 		error_at (loc,
 			  ("both %<long%> and %<_Bool%> in "
 			   "declaration specifiers"));
 	      else if (specs->typespec_word == cts_char)
 		error_at (loc,
@@ -9195,16 +9196,17 @@  declspecs_add_type (location_t loc, stru
 			  ("both %<short%> and %<__auto_type%> in "
 			   "declaration specifiers"));
 	      else if (specs->typespec_word == cts_void)
 		error_at (loc,
 			  ("both %<short%> and %<void%> in "
 			   "declaration specifiers"));
-	      else if (specs->typespec_word == cts_int128)
+	      else if (specs->typespec_word == cts_int_n)
 		error_at (loc,
-			  ("both %<short%> and %<__int128%> in "
-			   "declaration specifiers"));
+			  ("both %<short%> and %<__int%d%> in "
+			   "declaration specifiers"),
+			  int_n_data[specs->int_n_idx].bitsize);
 	      else if (specs->typespec_word == cts_bool)
 		error_at (loc,
 			  ("both %<short%> and %<_Bool%> in "
 			   "declaration specifiers"));
 	      else if (specs->typespec_word == cts_char)
 		error_at (loc,
@@ -9372,17 +9374,18 @@  declspecs_add_type (location_t loc, stru
 		}
 	      break;
 	    case RID_SAT:
 	      dupe = specs->saturating_p;
 	      pedwarn (loc, OPT_Wpedantic,
 		       "ISO C does not support saturating types");
-	      if (specs->typespec_word == cts_int128)
+	      if (specs->typespec_word == cts_int_n)
 	        {
 		  error_at (loc,
-			    ("both %<_Sat%> and %<__int128%> in "
-			     "declaration specifiers"));
+			    ("both %<_Sat%> and %<__int%d%> in "
+			     "declaration specifiers"),
+			    int_n_data[specs->int_n_idx].bitsize);
 	        }
 	      else if (specs->typespec_word == cts_auto_type)
 		error_at (loc,
 			  ("both %<_Sat%> and %<__auto_type%> in "
 			   "declaration specifiers"));
 	      else if (specs->typespec_word == cts_void)
@@ -9440,13 +9443,13 @@  declspecs_add_type (location_t loc, stru
 
 	  return specs;
 	}
       else
 	{
 	  /* "void", "_Bool", "char", "int", "float", "double", "_Decimal32",
-	     "__int128", "_Decimal64", "_Decimal128", "_Fract", "_Accum" or
+	     "__intN", "_Decimal64", "_Decimal128", "_Fract", "_Accum" or
 	     "__auto_type".  */
 	  if (specs->typespec_word != cts_none)
 	    {
 	      error_at (loc,
 			"two or more data types in declaration specifiers");
 	      return specs;
@@ -9481,37 +9484,44 @@  declspecs_add_type (location_t loc, stru
 	      else
 		{
 		  specs->typespec_word = cts_auto_type;
 		  specs->locations[cdw_typespec] = loc;
 		}
 	      return specs;
-	    case RID_INT128:
-	      if (int128_integer_type_node == NULL_TREE)
-		{
-		  error_at (loc, "%<__int128%> is not supported for this target");
-		  return specs;
-		}
+	    case RID_INT_N_0:
+	    case RID_INT_N_1:
+	    case RID_INT_N_2:
+	    case RID_INT_N_3:
+	      specs->int_n_idx = i - RID_INT_N_0;
 	      if (!in_system_header_at (input_location))
 		pedwarn (loc, OPT_Wpedantic,
-			 "ISO C does not support %<__int128%> type");
+			 "ISO C does not support %<__int%d%> types",
+			 int_n_data[specs->int_n_idx].bitsize);
 
 	      if (specs->long_p)
 		error_at (loc,
-			  ("both %<__int128%> and %<long%> in "
-			   "declaration specifiers"));
+			  ("both %<__int%d%> and %<long%> in "
+			   "declaration specifiers"),
+			  int_n_data[specs->int_n_idx].bitsize);
 	      else if (specs->saturating_p)
 		error_at (loc,
-			  ("both %<_Sat%> and %<__int128%> in "
-			   "declaration specifiers"));
+			  ("both %<_Sat%> and %<__int%d%> in "
+			   "declaration specifiers"),
+			  int_n_data[specs->int_n_idx].bitsize);
 	      else if (specs->short_p)
 		error_at (loc,
-			  ("both %<__int128%> and %<short%> in "
-			   "declaration specifiers"));
+			  ("both %<__int%d%> and %<short%> in "
+			   "declaration specifiers"),
+			  int_n_data[specs->int_n_idx].bitsize);
+	      else if (! int_n_enabled_p [specs->int_n_idx])
+		error_at (loc,
+			  "%<__int%d%> is not supported on this target",
+			  int_n_data[specs->int_n_idx].bitsize);
 	      else
 		{
-		  specs->typespec_word = cts_int128;
+		  specs->typespec_word = cts_int_n;
 		  specs->locations[cdw_typespec] = loc;
 		}
 	      return specs;
 	    case RID_VOID:
 	      if (specs->long_p)
 		error_at (loc,
@@ -10070,18 +10080,18 @@  finish_declspecs (struct c_declspecs *sp
 	{
 	  pedwarn (specs->locations[cdw_complex], OPT_Wpedantic,
 		   "ISO C does not support complex integer types");
 	  specs->type = build_complex_type (specs->type);
 	}
       break;
-    case cts_int128:
+    case cts_int_n:
       gcc_assert (!specs->long_p && !specs->short_p && !specs->long_long_p);
       gcc_assert (!(specs->signed_p && specs->unsigned_p));
       specs->type = (specs->unsigned_p
-		     ? int128_unsigned_type_node
-		     : int128_integer_type_node);
+		     ? int_n_trees[specs->int_n_idx].unsigned_type
+		     : int_n_trees[specs->int_n_idx].signed_type);
       if (specs->complex_p)
 	{
 	  pedwarn (specs->locations[cdw_complex], OPT_Wpedantic,
 		   "ISO C does not support complex integer types");
 	  specs->type = build_complex_type (specs->type);
 	}
Index: tree.c
===================================================================
--- tree.c	(revision 209391)
+++ tree.c	(working copy)
@@ -236,12 +236,15 @@  static unsigned int type_hash_list (cons
 static unsigned int attribute_hash_list (const_tree, hashval_t);
 static bool decls_same_for_odr (tree decl1, tree decl2);
 
 tree global_trees[TI_MAX];
 tree integer_types[itk_none];
 
+bool int_n_enabled_p[NUM_INT_N_ENTS];
+int_n_trees_t int_n_trees[NUM_INT_N_ENTS];
+
 unsigned char tree_contains_struct[MAX_TREE_CODES][64];
 
 /* Number of operands for each OpenMP clause.  */
 unsigned const char omp_clause_num_ops[] =
 {
   0, /* OMP_CLAUSE_ERROR  */
@@ -9436,26 +9439,31 @@  make_vector_type (tree innertype, int nu
   return t;
 }
 
 static tree
 make_or_reuse_type (unsigned size, int unsignedp)
 {
+  int i;
+
   if (size == INT_TYPE_SIZE)
     return unsignedp ? unsigned_type_node : integer_type_node;
   if (size == CHAR_TYPE_SIZE)
     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
   if (size == SHORT_TYPE_SIZE)
     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
   if (size == LONG_TYPE_SIZE)
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
   if (size == LONG_LONG_TYPE_SIZE)
     return (unsignedp ? long_long_unsigned_type_node
             : long_long_integer_type_node);
-  if (size == 128 && int128_integer_type_node)
-    return (unsignedp ? int128_unsigned_type_node
-            : int128_integer_type_node);
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (size == int_n_data[i].bitsize
+	&& int_n_enabled_p[i])
+      return (unsignedp ? int_n_trees[i].unsigned_type
+	      : int_n_trees[i].signed_type);
 
   if (unsignedp)
     return make_unsigned_type (size);
   else
     return make_signed_type (size);
 }
@@ -9565,12 +9573,14 @@  build_atomic_base (tree type, unsigned i
    SHORT_DOUBLE specifies whether double should be of the same precision
    as float.  */
 
 void
 build_common_tree_nodes (bool signed_char, bool short_double)
 {
+  int i;
+
   error_mark_node = make_node (ERROR_MARK);
   TREE_TYPE (error_mark_node) = error_mark_node;
 
   initialize_sizetypes ();
 
   /* Define both `signed char' and `unsigned char'.  */
@@ -9592,23 +9602,26 @@  build_common_tree_nodes (bool signed_cha
   integer_type_node = make_signed_type (INT_TYPE_SIZE);
   unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
   long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
   long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
   long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
   long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
-#if HOST_BITS_PER_WIDE_INT >= 64
-    /* TODO: This isn't correct, but as logic depends at the moment on
-       host's instead of target's wide-integer.
-       If there is a target not supporting TImode, but has an 128-bit
-       integer-scalar register, this target check needs to be adjusted. */
-    if (targetm.scalar_mode_supported_p (TImode))
-      {
-        int128_integer_type_node = make_signed_type (128);
-        int128_unsigned_type_node = make_unsigned_type (128);
-      }
-#endif
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    {
+      int_n_trees[i].signed_type = make_signed_type (int_n_data[i].bitsize);
+      int_n_trees[i].unsigned_type = make_unsigned_type (int_n_data[i].bitsize);
+      TYPE_SIZE (int_n_trees[i].signed_type) = bitsize_int (int_n_data[i].bitsize);
+      TYPE_SIZE (int_n_trees[i].unsigned_type) = bitsize_int (int_n_data[i].bitsize);
+
+      if (int_n_data[i].bitsize > LONG_LONG_TYPE_SIZE)
+	{
+	  integer_types[itk_intN_0 + i * 2] = int_n_trees[i].signed_type;
+	  integer_types[itk_unsigned_intN_0 + i * 2] = int_n_trees[i].unsigned_type;
+	}
+    }
 
   /* Define a boolean type.  This type only represents boolean values but
      may be larger than char depending on the value of BOOL_TYPE_SIZE.
      Front ends which want to override this size (i.e. Java) can redefine
      boolean_type_node before calling build_common_tree_nodes_2.  */
   boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
@@ -9623,13 +9636,30 @@  build_common_tree_nodes (bool signed_cha
     size_type_node = long_unsigned_type_node;
   else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0)
     size_type_node = long_long_unsigned_type_node;
   else if (strcmp (SIZE_TYPE, "short unsigned int") == 0)
     size_type_node = short_unsigned_type_node;
   else
-    gcc_unreachable ();
+    {
+      int i;
+
+      size_type_node = NULL_TREE;
+      for (i = 0; i < NUM_INT_N_ENTS; i++)
+	if (int_n_enabled_p[i])
+	  {
+	    char name[50];
+	    sprintf (name, "__int%d unsigned", int_n_data[i].bitsize);
+
+	    if (strcmp (name, SIZE_TYPE) == 0)
+	      {
+		size_type_node = int_n_trees[i].signed_type;
+	      }
+	  }
+      if (size_type_node == NULL_TREE)
+	gcc_unreachable ();
+    }
 
   /* Fill in the rest of the sized types.  Reuse existing type nodes
      when possible.  */
   intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 0);
   intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 0);
   intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 0);
Index: tree.h
===================================================================
--- tree.h	(revision 209391)
+++ tree.h	(working copy)
@@ -3382,14 +3382,12 @@  tree_operand_check_code (const_tree __t,
 #define integer_type_node		integer_types[itk_int]
 #define unsigned_type_node		integer_types[itk_unsigned_int]
 #define long_integer_type_node		integer_types[itk_long]
 #define long_unsigned_type_node		integer_types[itk_unsigned_long]
 #define long_long_integer_type_node	integer_types[itk_long_long]
 #define long_long_unsigned_type_node	integer_types[itk_unsigned_long_long]
-#define int128_integer_type_node	integer_types[itk_int128]
-#define int128_unsigned_type_node	integer_types[itk_unsigned_int128]
 
 #define NULL_TREE (tree) NULL
 
 /* True if NODE is an erroneous expression.  */
 
 #define error_operand_p(NODE)					\
@@ -4581,7 +4579,18 @@  extern unsigned int get_pointer_alignmen
 extern tree fold_call_stmt (gimple, bool);
 extern tree gimple_fold_builtin_snprintf_chk (gimple, tree, enum built_in_function);
 extern void set_builtin_user_assembler_name (tree decl, const char *asmspec);
 extern bool is_simple_builtin (tree);
 extern bool is_inexpensive_builtin (tree);
 
+
+typedef struct {
+  /* These parts are initialized at runtime */
+  tree signed_type;
+  tree unsigned_type;
+} int_n_trees_t;
+
+/* This is also in machmode.h */
+extern bool int_n_enabled_p[NUM_INT_N_ENTS];
+extern int_n_trees_t int_n_trees[NUM_INT_N_ENTS];
+
 #endif  /* GCC_TREE_H  */
Index: toplev.c
===================================================================
--- toplev.c	(revision 209391)
+++ toplev.c	(working copy)
@@ -1867,12 +1867,24 @@  finalize (bool no_backend)
     dump_profile_report ();
 
   /* Language-specific end of compilation actions.  */
   lang_hooks.finish ();
 }
 
+static bool
+standard_type_bitsize (int bitsize)
+{
+  if (bitsize == CHAR_TYPE_SIZE
+      || bitsize == SHORT_TYPE_SIZE
+      || bitsize == INT_TYPE_SIZE
+      || bitsize == LONG_TYPE_SIZE
+      || (bitsize == LONG_LONG_TYPE_SIZE && LONG_LONG_TYPE_SIZE < GET_MODE_BITSIZE (TImode)))
+    return true;
+  return false;
+}
+
 /* Initialize the compiler, and compile the input file.  */
 static void
 do_compile (void)
 {
   /* Initialize timing first.  The C front ends read the main file in
      the post_options hook, and C++ does file timings.  */
@@ -1882,19 +1894,32 @@  do_compile (void)
 
   process_options ();
 
   /* Don't do any more if an error has already occurred.  */
   if (!seen_error ())
     {
+      int i;
+
       timevar_start (TV_PHASE_SETUP);
 
       /* This must be run always, because it is needed to compute the FP
 	 predefined macros, such as __LDBL_MAX__, for targets using non
 	 default FP formats.  */
       init_adjust_machine_modes ();
 
+      /* This must happen after the backend has a chance to process
+	 command line options, but before the parsers are
+	 initialized.  */
+      for (i = 0; i < NUM_INT_N_ENTS; i ++)
+	if (targetm.scalar_mode_supported_p (int_n_data[i].m)
+	    && ! standard_type_bitsize (int_n_data[i].bitsize)
+	    && int_n_data[i].bitsize <= HOST_BITS_PER_WIDE_INT * 2)
+	  int_n_enabled_p[i] = true;
+	else
+	  int_n_enabled_p[i] = false;
+
       /* Set up the back-end if requested.  */
       if (!no_backend)
 	backend_init ();
 
       /* Language-dependent initialization.  Returns true on success.  */
       if (lang_dependent_init (main_input_filename))
Index: cp/typeck.c
===================================================================
--- cp/typeck.c	(revision 209391)
+++ cp/typeck.c	(working copy)
@@ -267,12 +267,13 @@  original_type (tree t)
 static tree
 cp_common_type (tree t1, tree t2)
 {
   enum tree_code code1 = TREE_CODE (t1);
   enum tree_code code2 = TREE_CODE (t2);
   tree attributes;
+  int i;
 
 
   /* In what follows, we slightly generalize the rules given in [expr] so
      as to deal with `long long' and `complex'.  First, merge the
      attributes.  */
   attributes = (*targetm.merge_type_attributes) (t1, t2);
@@ -361,22 +362,25 @@  cp_common_type (tree t1, tree t2)
 	{
 	  tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
 		    ? long_long_unsigned_type_node
 		    : long_long_integer_type_node);
 	  return build_type_attribute_variant (t, attributes);
 	}
-      if (int128_integer_type_node != NULL_TREE
-	  && (same_type_p (TYPE_MAIN_VARIANT (t1),
-			   int128_integer_type_node)
-	      || same_type_p (TYPE_MAIN_VARIANT (t2),
-			      int128_integer_type_node)))
+      for (i = 0; i < NUM_INT_N_ENTS; i ++)
 	{
-	  tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
-		    ? int128_unsigned_type_node
-		    : int128_integer_type_node);
-	  return build_type_attribute_variant (t, attributes);
+	  if (int_n_enabled_p [i]
+	      && (same_type_p (TYPE_MAIN_VARIANT (t1),
+			       int_n_trees[i].signed_type)
+		  || same_type_p (TYPE_MAIN_VARIANT (t2),
+				  int_n_trees[i].signed_type)))
+	    {
+	      tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
+			? int_n_trees[i].unsigned_type
+			: int_n_trees[i].signed_type);
+	      return build_type_attribute_variant (t, attributes);
+	    }
 	}
 
       /* Go through the same procedure, but for longs.  */
       if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
 	  || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
 	return build_type_attribute_variant (long_unsigned_type_node,
Index: cp/decl.c
===================================================================
--- cp/decl.c	(revision 209391)
+++ cp/decl.c	(working copy)
@@ -8713,13 +8713,13 @@  grokdeclarator (const cp_declarator *dec
 		enum decl_context decl_context,
 		int initialized,
 		tree* attrlist)
 {
   tree type = NULL_TREE;
   int longlong = 0;
-  int explicit_int128 = 0;
+  int explicit_intN = 0;
   int virtualp, explicitp, friendp, inlinep, staticp;
   int explicit_int = 0;
   int explicit_char = 0;
   int defaulted_int = 0;
 
   tree typedef_decl = NULL_TREE;
@@ -8784,13 +8784,13 @@  grokdeclarator (const cp_declarator *dec
 
   signed_p = decl_spec_seq_has_spec_p (declspecs, ds_signed);
   unsigned_p = decl_spec_seq_has_spec_p (declspecs, ds_unsigned);
   short_p = decl_spec_seq_has_spec_p (declspecs, ds_short);
   long_p = decl_spec_seq_has_spec_p (declspecs, ds_long);
   longlong = decl_spec_seq_has_spec_p (declspecs, ds_long_long);
-  explicit_int128 = declspecs->explicit_int128_p;
+  explicit_intN = declspecs->explicit_intN_p;
   thread_p = decl_spec_seq_has_spec_p (declspecs, ds_thread);
 
   if (decl_context == FUNCDEF)
     funcdef_flag = true, decl_context = NORMAL;
   else if (decl_context == MEMFUNCDEF)
     funcdef_flag = true, decl_context = FIELD;
@@ -9125,22 +9125,24 @@  grokdeclarator (const cp_declarator *dec
 
       type = integer_type_node;
     }
 
   ctype = NULL_TREE;
 
-  if (explicit_int128)
+  if (explicit_intN)
     {
-      if (int128_integer_type_node == NULL_TREE)
-	{
-	  error ("%<__int128%> is not supported by this target");
-	  explicit_int128 = false;
-	}
+      if (! int_n_enabled_p[declspecs->int_n_idx])
+       {
+         error ("%<__int%d%> is not supported by this target",
+		int_n_data[declspecs->int_n_idx].bitsize);
+         explicit_intN = false;
+       }
       else if (pedantic && ! in_system_header_at (input_location))
-	pedwarn (input_location, OPT_Wpedantic,
-		 "ISO C++ does not support %<__int128%> for %qs", name);
+       pedwarn (input_location, OPT_Wpedantic,
+                "ISO C++ does not support %<__int%d%> for %qs",
+		int_n_data[declspecs->int_n_idx].bitsize,  name);
     }
 
   /* Now process the modifiers that were specified
      and check for invalid combinations.  */
 
   /* Long double is a special combination.  */
@@ -9166,13 +9168,13 @@  grokdeclarator (const cp_declarator *dec
       else if (long_p && TREE_CODE (type) == REAL_TYPE)
 	error ("%<long%> invalid for %qs", name);
       else if (short_p && TREE_CODE (type) == REAL_TYPE)
 	error ("%<short%> invalid for %qs", name);
       else if ((long_p || short_p) && TREE_CODE (type) != INTEGER_TYPE)
 	error ("%<long%> or %<short%> invalid for %qs", name);
-      else if ((long_p || short_p || explicit_char || explicit_int) && explicit_int128)
+      else if ((long_p || short_p || explicit_char || explicit_int) && explicit_intN)
 	error ("%<long%>, %<int%>, %<short%>, or %<char%> invalid for %qs", name);
       else if ((long_p || short_p) && explicit_char)
 	error ("%<long%> or %<short%> specified with char for %qs", name);
       else if (long_p && short_p)
 	error ("%<long%> and %<short%> specified together for %qs", name);
       else if (type == char16_type_node || type == char32_type_node)
@@ -9182,13 +9184,13 @@  grokdeclarator (const cp_declarator *dec
 	  else if (short_p || long_p)
 	    error ("%<short%> or %<long%> invalid for %qs", name);
 	}
       else
 	{
 	  ok = 1;
-	  if (!explicit_int && !defaulted_int && !explicit_char && !explicit_int128 && pedantic)
+	  if (!explicit_int && !defaulted_int && !explicit_char && !explicit_intN && pedantic)
 	    {
 	      pedwarn (input_location, OPT_Wpedantic, 
 		       "long, short, signed or unsigned used invalidly for %qs",
 		       name);
 	      if (flag_pedantic_errors)
 		ok = 0;
@@ -9224,14 +9226,14 @@  grokdeclarator (const cp_declarator *dec
 	     `signed int' cannot be so controlled.  */
 	  && !(typedef_decl
 	       && C_TYPEDEF_EXPLICITLY_SIGNED (typedef_decl))
 	  && TREE_CODE (type) == INTEGER_TYPE
 	  && !same_type_p (TYPE_MAIN_VARIANT (type), wchar_type_node)))
     {
-      if (explicit_int128)
-	type = int128_unsigned_type_node;
+      if (explicit_intN)
+	type = int_n_trees[declspecs->int_n_idx].unsigned_type;
       else if (longlong)
 	type = long_long_unsigned_type_node;
       else if (long_p)
 	type = long_unsigned_type_node;
       else if (short_p)
 	type = short_unsigned_type_node;
@@ -9241,14 +9243,14 @@  grokdeclarator (const cp_declarator *dec
 	type = unsigned_type_for (type);
       else
 	type = unsigned_type_node;
     }
   else if (signed_p && type == char_type_node)
     type = signed_char_type_node;
-  else if (explicit_int128)
-    type = int128_integer_type_node;
+  else if (explicit_intN)
+    type = int_n_trees[declspecs->int_n_idx].signed_type;
   else if (longlong)
     type = long_long_integer_type_node;
   else if (long_p)
     type = long_integer_type_node;
   else if (short_p)
     type = short_integer_type_node;
@@ -9258,13 +9260,13 @@  grokdeclarator (const cp_declarator *dec
       if (TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
 	error ("complex invalid for %qs", name);
       /* If we just have "complex", it is equivalent to
 	 "complex double", but if any modifiers at all are specified it is
 	 the complex form of TYPE.  E.g, "complex short" is
 	 "complex short int".  */
-      else if (defaulted_int && ! longlong && ! explicit_int128
+      else if (defaulted_int && ! longlong && ! explicit_intN
 	       && ! (long_p || short_p || signed_p || unsigned_p))
 	type = complex_double_type_node;
       else if (type == integer_type_node)
 	type = complex_integer_type_node;
       else if (type == float_type_node)
 	type = complex_float_type_node;
Index: cp/rtti.c
===================================================================
--- cp/rtti.c	(revision 209391)
+++ cp/rtti.c	(working copy)
@@ -1483,13 +1483,13 @@  emit_support_tinfos (void)
     &wchar_type_node, &char16_type_node, &char32_type_node,
     &char_type_node, &signed_char_type_node, &unsigned_char_type_node,
     &short_integer_type_node, &short_unsigned_type_node,
     &integer_type_node, &unsigned_type_node,
     &long_integer_type_node, &long_unsigned_type_node,
     &long_long_integer_type_node, &long_long_unsigned_type_node,
-    &int128_integer_type_node, &int128_unsigned_type_node,
+    //    &int128_integer_type_node, &int128_unsigned_type_node,
     &float_type_node, &double_type_node, &long_double_type_node,
     &dfloat32_type_node, &dfloat64_type_node, &dfloat128_type_node,
     &nullptr_type_node,
     0
   };
   int ix;
Index: cp/parser.c
===================================================================
--- cp/parser.c	(revision 209391)
+++ cp/parser.c	(working copy)
@@ -936,13 +936,12 @@  cp_lexer_next_token_is_decl_specifier_ke
     case RID_CHAR32:
     case RID_WCHAR:
     case RID_BOOL:
     case RID_SHORT:
     case RID_INT:
     case RID_LONG:
-    case RID_INT128:
     case RID_SIGNED:
     case RID_UNSIGNED:
     case RID_FLOAT:
     case RID_DOUBLE:
     case RID_VOID:
       /* GNU extensions.  */ 
@@ -951,12 +950,16 @@  cp_lexer_next_token_is_decl_specifier_ke
       /* C++0x extensions.  */
     case RID_DECLTYPE:
     case RID_UNDERLYING_TYPE:
       return true;
 
     default:
+      if (token->keyword >= RID_FIRST_INT_N
+	  && token->keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
+	  && int_n_enabled_p[token->keyword - RID_FIRST_INT_N])
+	return true;
       return false;
     }
 }
 
 /* Returns TRUE iff the token T begins a decltype type.  */
 
@@ -14470,12 +14473,13 @@  static tree
 cp_parser_simple_type_specifier (cp_parser* parser,
 				 cp_decl_specifier_seq *decl_specs,
 				 cp_parser_flags flags)
 {
   tree type = NULL_TREE;
   cp_token *token;
+  int idx;
 
   /* Peek at the next token.  */
   token = cp_lexer_peek_token (parser->lexer);
 
   /* If we're looking at a keyword, things are easy.  */
   switch (token->keyword)
@@ -14503,18 +14507,25 @@  cp_parser_simple_type_specifier (cp_pars
       break;
     case RID_INT:
       if (decl_specs)
 	decl_specs->explicit_int_p = true;
       type = integer_type_node;
       break;
-    case RID_INT128:
-      if (!int128_integer_type_node)
+    case RID_INT_N_0:
+    case RID_INT_N_1:
+    case RID_INT_N_2:
+    case RID_INT_N_3:
+      idx = token->keyword - RID_INT_N_0;
+      if (! int_n_enabled_p [idx])
 	break;
       if (decl_specs)
-        decl_specs->explicit_int128_p = true;
-      type = int128_integer_type_node;
+	{
+	  decl_specs->explicit_intN_p = true;
+	  decl_specs->int_n_idx = idx;
+	}
+      type = int_n_trees [idx].signed_type;
       break;
     case RID_LONG:
       if (decl_specs)
 	set_and_check_decl_spec_loc (decl_specs, ds_long, token);
       type = long_integer_type_node;
       break;
Index: cp/mangle.c
===================================================================
--- cp/mangle.c	(revision 209391)
+++ cp/mangle.c	(working copy)
@@ -149,14 +149,12 @@  integer_type_codes[itk_none] =
   'i',  /* itk_int */
   'j',  /* itk_unsigned_int */
   'l',  /* itk_long */
   'm',  /* itk_unsigned_long */
   'x',  /* itk_long_long */
   'y',  /* itk_unsigned_long_long */
-  'n',  /* itk_int128 */
-  'o',  /* itk_unsigned_int128  */
 };
 
 static int decl_is_template_id (const tree, tree* const);
 
 /* Functions for handling substitutions.  */
 
Index: cp/cp-tree.h
===================================================================
--- cp/cp-tree.h	(revision 209391)
+++ cp/cp-tree.h	(working copy)
@@ -4840,12 +4840,14 @@  typedef struct cp_decl_specifier_seq {
   /* If non-NULL, a built-in type that the user attempted to redefine
      to some other type.  */
   tree redefined_builtin_type;
   /* The storage class specified -- or sc_none if no storage class was
      explicitly specified.  */
   cp_storage_class storage_class;
+  /* For the __intN declspec, this stores the index into the int_n_* arrays.  */
+  int int_n_idx;
   /* True iff TYPE_SPEC defines a class or enum.  */
   BOOL_BITFIELD type_definition_p : 1;
   /* True iff multiple types were (erroneously) specified for this
      decl-specifier-seq.  */
   BOOL_BITFIELD multiple_types_p : 1;
   /* True iff multiple storage classes were (erroneously) specified
@@ -4855,14 +4857,14 @@  typedef struct cp_decl_specifier_seq {
   /* True iff at least one decl-specifier was found.  */
   BOOL_BITFIELD any_specifiers_p : 1;
   /* True iff at least one type-specifier was found.  */
   BOOL_BITFIELD any_type_specifiers_p : 1;
   /* True iff "int" was explicitly provided.  */
   BOOL_BITFIELD explicit_int_p : 1;
-  /* True iff "__int128" was explicitly provided.  */
-  BOOL_BITFIELD explicit_int128_p : 1;
+  /* True iff "__intN" was explicitly provided.  */
+  BOOL_BITFIELD explicit_intN_p : 1;
   /* True iff "char" was explicitly provided.  */
   BOOL_BITFIELD explicit_char_p : 1;
   /* True iff ds_thread is set for __thread, not thread_local.  */
   BOOL_BITFIELD gnu_thread_keyword_p : 1;
 } cp_decl_specifier_seq;
 
Index: cp/lex.c
===================================================================
--- cp/lex.c	(revision 209391)
+++ cp/lex.c	(working copy)
@@ -190,12 +190,21 @@  init_reswords (void)
       id = get_identifier (c_common_reswords[i].word);
       C_SET_RID_CODE (id, c_common_reswords[i].rid);
       ridpointers [(int) c_common_reswords[i].rid] = id;
       if (! (c_common_reswords[i].disable & mask))
 	C_IS_RESERVED_WORD (id) = 1;
     }
+
+  for (i = 0; i < NUM_INT_N_ENTS; i++)
+    {
+      char name[50];
+      sprintf (name, "__int%d", int_n_data[i].bitsize);
+      id = get_identifier (name);
+      C_SET_RID_CODE (id, RID_FIRST_INT_N + i);
+      C_IS_RESERVED_WORD (id) = 1;
+    }
 }
 
 static void
 init_cp_pragma (void)
 {
   c_register_pragma (0, "vtable", handle_pragma_vtable);
Index: builtin-types.def
===================================================================
--- builtin-types.def	(revision 209391)
+++ builtin-types.def	(working copy)
@@ -70,14 +70,12 @@  DEF_PRIMITIVE_TYPE (BT_BOOL, boolean_typ
 DEF_PRIMITIVE_TYPE (BT_INT, integer_type_node)
 DEF_PRIMITIVE_TYPE (BT_UINT, unsigned_type_node)
 DEF_PRIMITIVE_TYPE (BT_LONG, long_integer_type_node)
 DEF_PRIMITIVE_TYPE (BT_ULONG, long_unsigned_type_node)
 DEF_PRIMITIVE_TYPE (BT_LONGLONG, long_long_integer_type_node)
 DEF_PRIMITIVE_TYPE (BT_ULONGLONG, long_long_unsigned_type_node)
-DEF_PRIMITIVE_TYPE (BT_INT128, int128_integer_type_node)
-DEF_PRIMITIVE_TYPE (BT_UINT128, int128_unsigned_type_node)
 DEF_PRIMITIVE_TYPE (BT_INTMAX, intmax_type_node)
 DEF_PRIMITIVE_TYPE (BT_UINTMAX, uintmax_type_node)
 DEF_PRIMITIVE_TYPE (BT_UINT16, uint16_type_node)
 DEF_PRIMITIVE_TYPE (BT_UINT32, uint32_type_node)
 DEF_PRIMITIVE_TYPE (BT_UINT64, uint64_type_node)
 DEF_PRIMITIVE_TYPE (BT_WORD, (*lang_hooks.types.type_for_mode) (word_mode, 1))
Index: machmode.def
===================================================================
--- machmode.def	(revision 209391)
+++ machmode.def	(working copy)
@@ -189,12 +189,19 @@  INT_MODE (HI, 2);
 INT_MODE (SI, 4);
 INT_MODE (DI, 8);
 INT_MODE (TI, 16);
 
 /* No partial integer modes are defined by default.  */
 
+/* The target normally defines any target-specific __intN types and
+   their modes, but __int128 for TImode is fairly common so define it
+   here.  The type will not be created unless the target supports
+   TImode.  */
+
+INT_N (TI, 128);
+
 /* Basic floating point modes.  SF and DF are the only modes provided
    by default.  The names QF, HF, XF, and TF are reserved for targets
    that need 1-word, 2-word, 80-bit, or 128-bit float types respectively.
 
    These are the IEEE mappings.  They can be overridden with
    RESET_FLOAT_FORMAT or at runtime (in TARGET_OPTION_OVERRIDE).  */
Index: stor-layout.c
===================================================================
--- stor-layout.c	(revision 209391)
+++ stor-layout.c	(working copy)
@@ -310,22 +310,30 @@  finalize_size_functions (void)
    than MAX_FIXED_MODE_SIZE will not be used.  */
 
 enum machine_mode
 mode_for_size (unsigned int size, enum mode_class mclass, int limit)
 {
   enum machine_mode mode;
+  int i;
 
   if (limit && size > MAX_FIXED_MODE_SIZE)
     return BLKmode;
 
   /* Get the first mode which has this size, in the specified class.  */
   for (mode = GET_CLASS_NARROWEST_MODE (mclass); mode != VOIDmode;
        mode = GET_MODE_WIDER_MODE (mode))
     if (GET_MODE_PRECISION (mode) == size)
       return mode;
 
+  if ((mclass == MODE_INT || mclass == MODE_PARTIAL_INT)
+      && mode == BLKmode)
+    for (i = 0; i < NUM_INT_N_ENTS; i ++)
+      if (int_n_data[i].bitsize == size
+	  && int_n_enabled_p[i])
+	return int_n_data[i].m;
+
   return BLKmode;
 }
 
 /* Similar, except passed a tree node.  */
 
 enum machine_mode
@@ -346,22 +354,33 @@  mode_for_size_tree (const_tree size, enu
 /* Similar, but never return BLKmode; return the narrowest mode that
    contains at least the requested number of value bits.  */
 
 enum machine_mode
 smallest_mode_for_size (unsigned int size, enum mode_class mclass)
 {
-  enum machine_mode mode;
+  enum machine_mode mode = VOIDmode;
+  int i;
 
   /* Get the first mode which has at least this size, in the
      specified class.  */
   for (mode = GET_CLASS_NARROWEST_MODE (mclass); mode != VOIDmode;
        mode = GET_MODE_WIDER_MODE (mode))
     if (GET_MODE_PRECISION (mode) >= size)
-      return mode;
+      break;
 
-  gcc_unreachable ();
+  if (mclass == MODE_INT || mclass == MODE_PARTIAL_INT)
+    for (i = 0; i < NUM_INT_N_ENTS; i ++)
+      if (int_n_data[i].bitsize >= size
+	  && int_n_data[i].bitsize < GET_MODE_PRECISION (mode)
+	  && int_n_enabled_p[i])
+	mode = int_n_data[i].m;
+
+  if (mode == VOIDmode)
+    gcc_unreachable ();
+
+  return mode;
 }
 
 /* Find an integer mode of the exact same size, or BLKmode on failure.  */
 
 enum machine_mode
 int_mode_for_mode (enum machine_mode mode)
@@ -1687,12 +1706,13 @@  finalize_type_size (tree type)
        sizetype, so we force a conversion.  */
     TYPE_SIZE_UNIT (type)
       = fold_convert (sizetype,
 		      size_binop (FLOOR_DIV_EXPR, TYPE_SIZE (type),
 				  bitsize_unit_node));
 
+  /* DJ - this may break partial-int types.  */
   if (TYPE_SIZE (type) != 0)
     {
       TYPE_SIZE (type) = round_up (TYPE_SIZE (type), TYPE_ALIGN (type));
       TYPE_SIZE_UNIT (type)
 	= round_up (TYPE_SIZE_UNIT (type), TYPE_ALIGN_UNIT (type));
     }
@@ -2056,13 +2076,13 @@  layout_type (tree type)
 
     case BOOLEAN_TYPE:
     case INTEGER_TYPE:
     case ENUMERAL_TYPE:
       SET_TYPE_MODE (type,
 		     smallest_mode_for_size (TYPE_PRECISION (type), MODE_INT));
-      TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type)));
+      TYPE_SIZE (type) = bitsize_int (GET_MODE_PRECISION (TYPE_MODE (type)));
       TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type)));
       break;
 
     case REAL_TYPE:
       SET_TYPE_MODE (type,
 		     mode_for_size (TYPE_PRECISION (type), MODE_FLOAT, 0));
@@ -2157,13 +2177,13 @@  layout_type (tree type)
 	    mode = targetm.addr_space.address_mode (as);
 	  }
 
 	TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (mode));
 	TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (mode));
 	TYPE_UNSIGNED (type) = 1;
-	TYPE_PRECISION (type) = GET_MODE_BITSIZE (mode);
+	TYPE_PRECISION (type) = GET_MODE_PRECISION (mode);
       }
       break;
 
     case ARRAY_TYPE:
       {
 	tree index = TYPE_DOMAIN (type);
@@ -2452,16 +2472,33 @@  initialize_sizetypes (void)
     precision = LONG_TYPE_SIZE;
   else if (strcmp (SIZETYPE, "long long unsigned int") == 0)
     precision = LONG_LONG_TYPE_SIZE;
   else if (strcmp (SIZETYPE, "short unsigned int") == 0)
     precision = SHORT_TYPE_SIZE;
   else
-    gcc_unreachable ();
+    {
+      int i;
+
+      precision = -1;
+      for (i = 0; i < NUM_INT_N_ENTS; i++)
+	if (int_n_enabled_p[i])
+	  {
+	    char name[50];
+	    sprintf (name, "__int%d unsigned", int_n_data[i].bitsize);
+
+	    if (strcmp (name, SIZETYPE) == 0)
+	      {
+		precision = int_n_data[i].bitsize;
+	      }
+	  }
+      if (precision == -1)
+	gcc_unreachable ();
+    }
 
   bprecision
-    = MIN (precision + BITS_PER_UNIT_LOG + 1, MAX_FIXED_MODE_SIZE);
+    = MIN (precision, MAX_FIXED_MODE_SIZE);
   bprecision
     = GET_MODE_PRECISION (smallest_mode_for_size (bprecision, MODE_INT));
   if (bprecision > HOST_BITS_PER_DOUBLE_INT)
     bprecision = HOST_BITS_PER_DOUBLE_INT;
 
   /* Create stubs for sizetype and bitsizetype so we can create constants.  */
Index: genmodes.c
===================================================================
--- genmodes.c	(revision 209391)
+++ genmodes.c	(working copy)
@@ -69,23 +69,25 @@  struct mode_data
 
   const char *file;		/* file and line of definition, */
   unsigned int line;		/* for error reporting */
   unsigned int counter;		/* Rank ordering of modes */
   unsigned int ibit;		/* the number of integral bits */
   unsigned int fbit;		/* the number of fractional bits */
+
+  unsigned int int_n;		/* If nonzero, then __int<INT_N> will be defined */
 };
 
 static struct mode_data *modes[MAX_MODE_CLASS];
 static unsigned int n_modes[MAX_MODE_CLASS];
 static struct mode_data *void_mode;
 
 static const struct mode_data blank_mode = {
   0, "<unknown>", MAX_MODE_CLASS,
   -1U, -1U, -1U, -1U,
   0, 0, 0, 0, 0,
-  "<unknown>", 0, 0, 0, 0
+  "<unknown>", 0, 0, 0, 0, 0
 };
 
 static htab_t modes_by_name;
 
 /* Data structure for recording target-specified runtime adjustments
    to a particular mode.  We support varying the byte size, the
@@ -627,12 +629,40 @@  reset_float_format (const char *name, co
       error ("%s:%d: mode \"%s\" is not a FLOAT class", file, line, name);
       return;
     }
   m->format = format;
 }
 
+/* __intN support.  */
+#define INT_N(M,PREC)				\
+  make_int_n (#M, PREC, __FILE__, __LINE__)
+static void ATTRIBUTE_UNUSED
+make_int_n (const char *m, int bitsize,
+            const char *file, unsigned int line)
+{
+  struct mode_data *component = find_mode (m);
+  if (!component)
+    {
+      error ("%s:%d: no mode \"%s\"", file, line, m);
+      return;
+    }
+  if (component->cl != MODE_INT
+      && component->cl != MODE_PARTIAL_INT)
+    {
+      error ("%s:%d: mode \"%s\" is not class INT or PARTIAL_INT", file, line, m);
+      return;
+    }
+  if (component->int_n != 0)
+    {
+      error ("%s:%d: mode \"%s\" already has an intN", file, line, m);
+      return;
+    }
+
+  component->int_n = bitsize;
+}
+
 /* Partial integer modes are specified by relation to a full integer
    mode.  */
 #define PARTIAL_INT_MODE(M,PREC,NAME)				\
   make_partial_integer_mode (#M, #NAME, PREC, __FILE__, __LINE__)
 static void ATTRIBUTE_UNUSED
 make_partial_integer_mode (const char *base, const char *name,
@@ -906,12 +936,13 @@  emit_max_int (void)
 
 static void
 emit_insn_modes_h (void)
 {
   int c;
   struct mode_data *m, *first, *last;
+  int n_int_n_ents = 0;
 
   printf ("/* Generated automatically from machmode.def%s%s\n",
 	   HAVE_EXTRA_MODES ? " and " : "",
 	   EXTRA_MODES_FILE);
 
   puts ("\
@@ -966,12 +997,19 @@  enum machine_mode\n{");
 #if 0 /* disabled for backward compatibility, temporary */
   printf ("#define CONST_REAL_FORMAT_FOR_MODE%s\n", adj_format ? "" :" const");
 #endif
   printf ("#define CONST_MODE_IBIT%s\n", adj_ibit ? "" : " const");
   printf ("#define CONST_MODE_FBIT%s\n", adj_fbit ? "" : " const");
   emit_max_int ();
+
+  for_all_modes (c, m)
+    if (m->int_n)
+      n_int_n_ents ++;
+
+  printf ("#define NUM_INT_N_ENTS %d\n", n_int_n_ents);
+
   puts ("\
 \n\
 #endif /* insn-modes.h */");
 }
 
 static void
@@ -1409,12 +1447,59 @@  emit_mode_fbit (void)
   for_all_modes (c, m)
     tagged_printf ("%u", m->fbit, m->name);
 
   print_closer ();
 }
 
+/* Emit __intN for all modes.  */
+
+static void
+emit_mode_int_n (void)
+{
+  int c;
+  struct mode_data *m;
+  struct mode_data **mode_sort;
+  int n_modes = 0;
+  int i, j;
+
+  print_decl ("int_n_data_t", "int_n_data", "");
+
+  n_modes = 0;
+  for_all_modes (c, m)
+    if (m->int_n)
+      n_modes ++;
+  mode_sort = XALLOCAVEC (struct mode_data *, n_modes);
+
+  n_modes = 0;
+  for_all_modes (c, m)
+    if (m->int_n)
+      mode_sort[n_modes++] = m;
+
+  /* Yes, this is a bubblesort, but there are at most four (and
+     usually only 1-2) entries to sort.  */
+  for (i = 0; i<n_modes - 1; i++)
+    for (j = i + 1; j < n_modes; j++)
+      if (mode_sort[i]->int_n > mode_sort[j]->int_n)
+	{
+	  m = mode_sort[i];
+	  mode_sort[i] = mode_sort[j];
+	  mode_sort[j] = m;
+	}
+
+  for (i = 0; i < n_modes; i ++)
+    {
+      m = mode_sort[i];
+      printf(" {\n");
+      tagged_printf ("%u", m->int_n, m->name);
+      printf ("%smode,", m->name);
+      printf(" },\n");
+    }
+
+  print_closer ();
+}
+
 
 static void
 emit_insn_modes_c (void)
 {
   emit_insn_modes_c_header ();
   emit_mode_name ();
@@ -1428,12 +1513,13 @@  emit_insn_modes_c (void)
   emit_mode_base_align ();
   emit_class_narrowest_mode ();
   emit_real_format_for_mode ();
   emit_mode_adjustments ();
   emit_mode_ibit ();
   emit_mode_fbit ();
+  emit_mode_int_n ();
 }
 
 static void
 emit_min_insn_modes_c (void)
 {
   emit_min_insn_modes_c_header ();
Index: lto/lto-lang.c
===================================================================
--- lto/lto-lang.c	(revision 209391)
+++ lto/lto-lang.c	(working copy)
@@ -1140,23 +1140,44 @@  lto_build_c_type_nodes (void)
     {
       intmax_type_node = long_long_integer_type_node;
       uintmax_type_node = long_long_unsigned_type_node;
       signed_size_type_node = long_long_integer_type_node;
     }
   else
-    gcc_unreachable ();
+    {
+      int i;
+
+      signed_size_type_node = NULL_TREE;
+      for (i = 0; i < NUM_INT_N_ENTS; i++)
+	if (int_n_enabled_p[i])
+	  {
+	    char name[50];
+	    sprintf (name, "__int%d unsigned", int_n_data[i].bitsize);
+
+	    if (strcmp (name, SIZE_TYPE) == 0)
+	      {
+		intmax_type_node = int_n_trees[i].signed_type;
+		uintmax_type_node = int_n_trees[i].unsigned_type;
+		signed_size_type_node = int_n_trees[i].signed_type;
+	      }
+	  }
+      if (signed_size_type_node == NULL_TREE)
+	gcc_unreachable ();
+    }
 
   wint_type_node = unsigned_type_node;
   pid_type_node = integer_type_node;
 }
 
 /* Perform LTO-specific initialization.  */
 
 static bool
 lto_init (void)
 {
+  int i;
+
   /* We need to generate LTO if running in WPA mode.  */
   flag_generate_lto = (flag_wpa != NULL);
 
   /* Create the basic integer types.  */
   build_common_tree_nodes (flag_signed_char, flag_short_double);
 
@@ -1222,14 +1243,19 @@  lto_init (void)
   NAME_TYPE (long_double_type_node, "long double");
   NAME_TYPE (void_type_node, "void");
   NAME_TYPE (boolean_type_node, "bool");
   NAME_TYPE (complex_float_type_node, "complex float");
   NAME_TYPE (complex_double_type_node, "complex double");
   NAME_TYPE (complex_long_double_type_node, "complex long double");
-  if (int128_integer_type_node)
-    NAME_TYPE (int128_integer_type_node, "__int128");
+  for (i = 0; i < NUM_INT_N_ENTS; i++)
+    if (int_n_enabled_p[i])
+      {
+	char name[50];
+	sprintf (name, "__int%d", int_n_data[i].bitsize);
+	NAME_TYPE (int_n_trees[i].signed_type, name);
+      }
 #undef NAME_TYPE
 
   /* Initialize LTO-specific data structures.  */
   in_lto_p = true;
 
   return true;
Index: gimple.c
===================================================================
--- gimple.c	(revision 209391)
+++ gimple.c	(working copy)
@@ -2096,12 +2096,13 @@  gimple_compare_field_offset (tree f1, tr
    signed according to UNSIGNEDP.  */
 
 static tree
 gimple_signed_or_unsigned_type (bool unsignedp, tree type)
 {
   tree type1;
+  int i;
 
   type1 = TYPE_MAIN_VARIANT (type);
   if (type1 == signed_char_type_node
       || type1 == char_type_node
       || type1 == unsigned_char_type_node)
     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
@@ -2113,16 +2114,21 @@  gimple_signed_or_unsigned_type (bool uns
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
   if (type1 == long_long_integer_type_node
       || type1 == long_long_unsigned_type_node)
     return unsignedp
            ? long_long_unsigned_type_node
 	   : long_long_integer_type_node;
-  if (int128_integer_type_node && (type1 == int128_integer_type_node || type1 == int128_unsigned_type_node))
-    return unsignedp
-           ? int128_unsigned_type_node
-	   : int128_integer_type_node;
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& (type1 == int_n_trees[i].unsigned_type
+	    || type1 == int_n_trees[i].signed_type))
+	return unsignedp
+	  ? int_n_trees[i].unsigned_type
+	  : int_n_trees[i].signed_type;
+
 #if HOST_BITS_PER_WIDE_INT >= 64
   if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
 #endif
   if (type1 == intDI_type_node || type1 == unsigned_intDI_type_node)
     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
@@ -2229,16 +2235,20 @@  gimple_signed_or_unsigned_type (bool uns
   if (TYPE_OK (long_integer_type_node))
     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
   if (TYPE_OK (long_long_integer_type_node))
     return (unsignedp
 	    ? long_long_unsigned_type_node
 	    : long_long_integer_type_node);
-  if (int128_integer_type_node && TYPE_OK (int128_integer_type_node))
-    return (unsignedp
-	    ? int128_unsigned_type_node
-	    : int128_integer_type_node);
+
+  for (i = 0; i < NUM_INT_N_ENTS; i ++)
+    if (int_n_enabled_p[i]
+	&& TYPE_MODE (type) == int_n_data[i].m
+	&& TYPE_PRECISION (type) == int_n_data[i].bitsize)
+	return unsignedp
+	  ? int_n_trees[i].unsigned_type
+	  : int_n_trees[i].signed_type;
 
 #if HOST_BITS_PER_WIDE_INT >= 64
   if (TYPE_OK (intTI_type_node))
     return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
 #endif
   if (TYPE_OK (intDI_type_node))
Index: tree-core.h
===================================================================
--- tree-core.h	(revision 209391)
+++ tree-core.h	(working copy)
@@ -560,14 +560,22 @@  enum integer_type_kind {
   itk_int,
   itk_unsigned_int,
   itk_long,
   itk_unsigned_long,
   itk_long_long,
   itk_unsigned_long_long,
-  itk_int128,
-  itk_unsigned_int128,
+
+  itk_intN_0,
+  itk_unsigned_intN_0,
+  itk_intN_1,
+  itk_unsigned_intN_1,
+  itk_intN_2,
+  itk_unsigned_intN_2,
+  itk_intN_3,
+  itk_unsigned_intN_3,
+
   itk_none
 };
 
 /* A pointer-to-function member type looks like:
 
      struct {