diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 6f9e4241e47..c94b7d720a4 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,16 @@
+2009-05-29  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/40019
+	* trans-types.c (gfc_build_uint_type): Make nonstatic.
+	* trans.h (gfor_fndecl_clz128, gfor_fndecl_ctz128): New prototypes.
+	* trans-types.h (gfc_build_uint_type): Add prototype.
+	* trans-decl.c (gfc_build_intrinsic_function_decls): Build
+	gfor_fndecl_clz128 and gfor_fndecl_ctz128.
+	* trans-intrinsic.c (gfc_conv_intrinsic_leadz,
+	gfc_conv_intrinsic_trailz): Call the right builtins or library
+	functions, and cast arguments to unsigned types first.
+	* simplify.c (gfc_simplify_leadz): Deal with negative arguments.
+
 2009-05-27  Ian Lance Taylor  <iant@google.com>
 
 	* Make-lang.in (gfortran$(exeext)): Change $(COMPILER) to
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 4dd114b532f..51a3c5198e5 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -2579,10 +2579,13 @@ gfc_simplify_leadz (gfc_expr *e)
   bs = gfc_integer_kinds[i].bit_size;
   if (mpz_cmp_si (e->value.integer, 0) == 0)
     lz = bs;
+  else if (mpz_cmp_si (e->value.integer, 0) < 0)
+    lz = 0;
   else
     lz = bs - mpz_sizeinbase (e->value.integer, 2);
 
-  result = gfc_constant_result (BT_INTEGER, gfc_default_integer_kind, &e->where);
+  result = gfc_constant_result (BT_INTEGER, gfc_default_integer_kind,
+				&e->where);
   mpz_set_ui (result->value.integer, lz);
 
   return result;
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index ba85eddeb8a..a036aebd172 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -145,6 +145,8 @@ tree gfor_fndecl_convert_char4_to_char1;
 tree gfor_fndecl_size0;
 tree gfor_fndecl_size1;
 tree gfor_fndecl_iargc;
+tree gfor_fndecl_clz128;
+tree gfor_fndecl_ctz128;
 
 /* Intrinsic functions implemented in Fortran.  */
 tree gfor_fndecl_sc_kind;
@@ -2570,6 +2572,19 @@ gfc_build_intrinsic_function_decls (void)
     gfc_build_library_function_decl (get_identifier (PREFIX ("iargc")),
 				     gfc_int4_type_node,
 				     0);
+
+  if (gfc_type_for_size (128, true))
+    {
+      tree uint128 = gfc_type_for_size (128, true);
+
+      gfor_fndecl_clz128 =
+	gfc_build_library_function_decl (get_identifier (PREFIX ("clz128")),
+					 integer_type_node, 1, uint128);
+
+      gfor_fndecl_ctz128 =
+	gfc_build_library_function_decl (get_identifier (PREFIX ("ctz128")),
+					 integer_type_node, 1, uint128);
+    }
 }
 
 
diff --git a/gcc/fortran/trans-intrinsic.c b/gcc/fortran/trans-intrinsic.c
index 33cc7f569a3..c1409578610 100644
--- a/gcc/fortran/trans-intrinsic.c
+++ b/gcc/fortran/trans-intrinsic.c
@@ -2710,53 +2710,51 @@ gfc_conv_intrinsic_leadz (gfc_se * se, gfc_expr * expr)
   tree leadz;
   tree bit_size;
   tree tmp;
-  int arg_kind;
-  int i, n, s;
+  tree func;
+  int s, argsize;
 
   gfc_conv_intrinsic_function_args (se, expr, &arg, 1);
+  argsize = TYPE_PRECISION (TREE_TYPE (arg));
 
   /* Which variant of __builtin_clz* should we call?  */
-  arg_kind = expr->value.function.actual->expr->ts.kind;
-  i = gfc_validate_kind (BT_INTEGER, arg_kind, false);
-  switch (arg_kind)
+  if (argsize <= INT_TYPE_SIZE)
     {
-      case 1:
-      case 2:
-      case 4:
-        arg_type = unsigned_type_node;
-	n = BUILT_IN_CLZ;
-	break;
-
-      case 8:
-        arg_type = long_unsigned_type_node;
-	n = BUILT_IN_CLZL;
-	break;
-
-      case 16:
-        arg_type = long_long_unsigned_type_node;
-	n = BUILT_IN_CLZLL;
-	break;
-
-      default:
-        gcc_unreachable ();
+      arg_type = unsigned_type_node;
+      func = built_in_decls[BUILT_IN_CLZ];
+    }
+  else if (argsize <= LONG_TYPE_SIZE)
+    {
+      arg_type = long_unsigned_type_node;
+      func = built_in_decls[BUILT_IN_CLZL];
+    }
+  else if (argsize <= LONG_LONG_TYPE_SIZE)
+    {
+      arg_type = long_long_unsigned_type_node;
+      func = built_in_decls[BUILT_IN_CLZLL];
+    }
+  else
+    {
+      gcc_assert (argsize == 128);
+      arg_type = gfc_build_uint_type (argsize);
+      func = gfor_fndecl_clz128;
     }
 
-  /* Convert the actual argument to the proper argument type for the built-in
+  /* Convert the actual argument twice: first, to the unsigned type of the
+     same size; then, to the proper argument type for the built-in
      function.  But the return type is of the default INTEGER kind.  */
+  arg = fold_convert (gfc_build_uint_type (argsize), arg);
   arg = fold_convert (arg_type, arg);
   result_type = gfc_get_int_type (gfc_default_integer_kind);
 
   /* Compute LEADZ for the case i .ne. 0.  */
-  s = TYPE_PRECISION (arg_type) - gfc_integer_kinds[i].bit_size;
-  tmp = fold_convert (result_type, build_call_expr (built_in_decls[n], 1, arg));
+  s = TYPE_PRECISION (arg_type) - argsize;
+  tmp = fold_convert (result_type, build_call_expr (func, 1, arg));
   leadz = fold_build2 (MINUS_EXPR, result_type,
 		       tmp, build_int_cst (result_type, s));
 
   /* Build BIT_SIZE.  */
-  bit_size = build_int_cst (result_type, gfc_integer_kinds[i].bit_size);
+  bit_size = build_int_cst (result_type, argsize);
 
-  /* ??? For some combinations of targets and integer kinds, the condition
-	 can be avoided if CLZ_DEFINED_VALUE_AT_ZERO is used.  Later.  */
   cond = fold_build2 (EQ_EXPR, boolean_type_node,
 		      arg, build_int_cst (arg_type, 0));
   se->expr = fold_build3 (COND_EXPR, result_type, cond, bit_size, leadz);
@@ -2777,50 +2775,48 @@ gfc_conv_intrinsic_trailz (gfc_se * se, gfc_expr *expr)
   tree result_type;
   tree trailz;
   tree bit_size;
-  int arg_kind;
-  int i, n;
+  tree func;
+  int argsize;
 
   gfc_conv_intrinsic_function_args (se, expr, &arg, 1);
+  argsize = TYPE_PRECISION (TREE_TYPE (arg));
 
-  /* Which variant of __builtin_clz* should we call?  */
-  arg_kind = expr->value.function.actual->expr->ts.kind;
-  i = gfc_validate_kind (BT_INTEGER, arg_kind, false);
-  switch (expr->ts.kind)
+  /* Which variant of __builtin_ctz* should we call?  */
+  if (argsize <= INT_TYPE_SIZE)
     {
-      case 1:
-      case 2:
-      case 4:
-        arg_type = unsigned_type_node;
-	n = BUILT_IN_CTZ;
-	break;
-
-      case 8:
-        arg_type = long_unsigned_type_node;
-	n = BUILT_IN_CTZL;
-	break;
-
-      case 16:
-        arg_type = long_long_unsigned_type_node;
-	n = BUILT_IN_CTZLL;
-	break;
-
-      default:
-        gcc_unreachable ();
+      arg_type = unsigned_type_node;
+      func = built_in_decls[BUILT_IN_CTZ];
+    }
+  else if (argsize <= LONG_TYPE_SIZE)
+    {
+      arg_type = long_unsigned_type_node;
+      func = built_in_decls[BUILT_IN_CTZL];
+    }
+  else if (argsize <= LONG_LONG_TYPE_SIZE)
+    {
+      arg_type = long_long_unsigned_type_node;
+      func = built_in_decls[BUILT_IN_CTZLL];
+    }
+  else
+    {
+      gcc_assert (argsize == 128);
+      arg_type = gfc_build_uint_type (argsize);
+      func = gfor_fndecl_ctz128;
     }
 
-  /* Convert the actual argument to the proper argument type for the built-in
+  /* Convert the actual argument twice: first, to the unsigned type of the
+     same size; then, to the proper argument type for the built-in
      function.  But the return type is of the default INTEGER kind.  */
+  arg = fold_convert (gfc_build_uint_type (argsize), arg);
   arg = fold_convert (arg_type, arg);
   result_type = gfc_get_int_type (gfc_default_integer_kind);
 
   /* Compute TRAILZ for the case i .ne. 0.  */
-  trailz = fold_convert (result_type, build_call_expr (built_in_decls[n], 1, arg));
+  trailz = fold_convert (result_type, build_call_expr (func, 1, arg));
 
   /* Build BIT_SIZE.  */
-  bit_size = build_int_cst (result_type, gfc_integer_kinds[i].bit_size);
+  bit_size = build_int_cst (result_type, argsize);
 
-  /* ??? For some combinations of targets and integer kinds, the condition
-	 can be avoided if CTZ_DEFINED_VALUE_AT_ZERO is used.  Later.  */
   cond = fold_build2 (EQ_EXPR, boolean_type_node,
 		      arg, build_int_cst (arg_type, 0));
   se->expr = fold_build3 (COND_EXPR, result_type, cond, bit_size, trailz);
diff --git a/gcc/fortran/trans-types.c b/gcc/fortran/trans-types.c
index e945fcbf7b5..0c439937125 100644
--- a/gcc/fortran/trans-types.c
+++ b/gcc/fortran/trans-types.c
@@ -686,7 +686,7 @@ gfc_build_int_type (gfc_integer_info *info)
   return make_signed_type (mode_precision);
 }
 
-static tree
+tree
 gfc_build_uint_type (int size)
 {
   if (size == CHAR_TYPE_SIZE)
diff --git a/gcc/fortran/trans-types.h b/gcc/fortran/trans-types.h
index c3e51a11c8e..283d57772a0 100644
--- a/gcc/fortran/trans-types.h
+++ b/gcc/fortran/trans-types.h
@@ -68,6 +68,7 @@ tree gfc_get_function_type (gfc_symbol *);
 
 tree gfc_type_for_size (unsigned, int);
 tree gfc_type_for_mode (enum machine_mode, int);
+tree gfc_build_uint_type (int);
 
 tree gfc_get_element_type (tree);
 tree gfc_get_array_type_bounds (tree, int, tree *, tree *, int,
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index 4846af245fd..906896985d1 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -590,6 +590,8 @@ extern GTY(()) tree gfor_fndecl_convert_char4_to_char1;
 extern GTY(()) tree gfor_fndecl_size0;
 extern GTY(()) tree gfor_fndecl_size1;
 extern GTY(()) tree gfor_fndecl_iargc;
+extern GTY(()) tree gfor_fndecl_clz128;
+extern GTY(()) tree gfor_fndecl_ctz128;
 
 /* Implemented in Fortran.  */
 extern GTY(()) tree gfor_fndecl_sc_kind;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7479c1a74ea..214cf74523e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2009-05-29  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/40019
+	* gfortran.dg/leadz_trailz_1.f90: New test.
+	* gfortran.dg/leadz_trailz_2.f90: New test.
+
 2009-05-29  Martin Jambor  <mjambor@suse.cz>
 
 	* gfortran.dg/pr25923.f90: XFAIL warning expectation.
diff --git a/gcc/testsuite/gfortran.dg/leadz_trailz_1.f90 b/gcc/testsuite/gfortran.dg/leadz_trailz_1.f90
new file mode 100644
index 00000000000..a0cd1979225
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/leadz_trailz_1.f90
@@ -0,0 +1,133 @@
+! { dg-do run }
+
+  integer(kind=1) :: i1
+  integer(kind=2) :: i2
+  integer(kind=4) :: i4
+  integer(kind=8) :: i8
+
+  i1 = -1
+  i2 = -1
+  i4 = -1
+  i8 = -1
+
+  if (leadz(i1) /= 0) call abort
+  if (leadz(i2) /= 0) call abort
+  if (leadz(i4) /= 0) call abort
+  if (leadz(i8) /= 0) call abort
+
+  if (trailz(i1) /= 0) call abort
+  if (trailz(i2) /= 0) call abort
+  if (trailz(i4) /= 0) call abort
+  if (trailz(i8) /= 0) call abort
+
+  if (leadz(-1_1) /= 0) call abort
+  if (leadz(-1_2) /= 0) call abort
+  if (leadz(-1_4) /= 0) call abort
+  if (leadz(-1_8) /= 0) call abort
+
+  if (trailz(-1_1) /= 0) call abort
+  if (trailz(-1_2) /= 0) call abort
+  if (trailz(-1_4) /= 0) call abort
+  if (trailz(-1_8) /= 0) call abort
+
+  i1 = -64
+  i2 = -64
+  i4 = -64
+  i8 = -64
+
+  if (leadz(i1) /= 0) call abort
+  if (leadz(i2) /= 0) call abort
+  if (leadz(i4) /= 0) call abort
+  if (leadz(i8) /= 0) call abort
+
+  if (trailz(i1) /= 6) call abort
+  if (trailz(i2) /= 6) call abort
+  if (trailz(i4) /= 6) call abort
+  if (trailz(i8) /= 6) call abort
+
+  if (leadz(-64_1) /= 0) call abort
+  if (leadz(-64_2) /= 0) call abort
+  if (leadz(-64_4) /= 0) call abort
+  if (leadz(-64_8) /= 0) call abort
+
+  if (trailz(-64_1) /= 6) call abort
+  if (trailz(-64_2) /= 6) call abort
+  if (trailz(-64_4) /= 6) call abort
+  if (trailz(-64_8) /= 6) call abort
+
+  i1 = -108
+  i2 = -108
+  i4 = -108
+  i8 = -108
+
+  if (leadz(i1) /= 0) call abort
+  if (leadz(i2) /= 0) call abort
+  if (leadz(i4) /= 0) call abort
+  if (leadz(i8) /= 0) call abort
+
+  if (trailz(i1) /= 2) call abort
+  if (trailz(i2) /= 2) call abort
+  if (trailz(i4) /= 2) call abort
+  if (trailz(i8) /= 2) call abort
+
+  if (leadz(-108_1) /= 0) call abort
+  if (leadz(-108_2) /= 0) call abort
+  if (leadz(-108_4) /= 0) call abort
+  if (leadz(-108_8) /= 0) call abort
+
+  if (trailz(-108_1) /= 2) call abort
+  if (trailz(-108_2) /= 2) call abort
+  if (trailz(-108_4) /= 2) call abort
+  if (trailz(-108_8) /= 2) call abort
+
+  i1 = 1
+  i2 = 1
+  i4 = 1
+  i8 = 1
+
+  if (leadz(i1) /= bit_size(i1) - 1) call abort
+  if (leadz(i2) /= bit_size(i2) - 1) call abort
+  if (leadz(i4) /= bit_size(i4) - 1) call abort
+  if (leadz(i8) /= bit_size(i8) - 1) call abort
+
+  if (trailz(i1) /= 0) call abort
+  if (trailz(i2) /= 0) call abort
+  if (trailz(i4) /= 0) call abort
+  if (trailz(i8) /= 0) call abort
+
+  if (leadz(1_1) /= bit_size(1_1) - 1) call abort
+  if (leadz(1_2) /= bit_size(1_2) - 1) call abort
+  if (leadz(1_4) /= bit_size(1_4) - 1) call abort
+  if (leadz(1_8) /= bit_size(1_8) - 1) call abort
+
+  if (trailz(1_1) /= 0) call abort
+  if (trailz(1_2) /= 0) call abort
+  if (trailz(1_4) /= 0) call abort
+  if (trailz(1_8) /= 0) call abort
+
+  i1 = 64
+  i2 = 64
+  i4 = 64
+  i8 = 64
+
+  if (leadz(i1) /= 1) call abort
+  if (leadz(i2) /= 9) call abort
+  if (leadz(i4) /= 25) call abort
+  if (leadz(i8) /= 57) call abort
+
+  if (trailz(i1) /= 6) call abort
+  if (trailz(i2) /= 6) call abort
+  if (trailz(i4) /= 6) call abort
+  if (trailz(i8) /= 6) call abort
+
+  if (leadz(64_1) /= 1) call abort
+  if (leadz(64_2) /= 9) call abort
+  if (leadz(64_4) /= 25) call abort
+  if (leadz(64_8) /= 57) call abort
+
+  if (trailz(64_1) /= 6) call abort
+  if (trailz(64_2) /= 6) call abort
+  if (trailz(64_4) /= 6) call abort
+  if (trailz(64_8) /= 6) call abort
+
+end
diff --git a/gcc/testsuite/gfortran.dg/leadz_trailz_2.f90 b/gcc/testsuite/gfortran.dg/leadz_trailz_2.f90
new file mode 100644
index 00000000000..08701d8a537
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/leadz_trailz_2.f90
@@ -0,0 +1,36 @@
+! { dg-do run }
+! { dg-require-effective-target fortran_large_int }
+
+  integer(kind=16) :: i16
+
+  i16 = -1
+  if (leadz(i16) /= 0) call abort
+  if (trailz(i16) /= 0) call abort
+  if (leadz(-1_16) /= 0) call abort
+  if (trailz(-1_16) /= 0) call abort
+
+  i16 = -64
+  if (leadz(i16) /= 0) call abort
+  if (trailz(i16) /= 6) call abort
+  if (leadz(-64_16) /= 0) call abort
+  if (trailz(-64_16) /= 6) call abort
+
+  i16 = -108
+  if (leadz(i16) /= 0) call abort
+  if (trailz(i16) /= 2) call abort
+  if (leadz(-108_16) /= 0) call abort
+  if (trailz(-108_16) /= 2) call abort
+
+  i16 = 1
+  if (leadz(i16) /= bit_size(i16) - 1) call abort
+  if (trailz(i16) /= 0) call abort
+  if (leadz(1_16) /= bit_size(1_16) - 1) call abort
+  if (trailz(1_16) /= 0) call abort
+
+  i16 = 64
+  if (leadz(i16) /= 121) call abort
+  if (trailz(i16) /= 6) call abort
+  if (leadz(64_16) /= 121) call abort
+  if (trailz(64_16) /= 6) call abort
+
+end
diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 7519578da6b..2d27d0321bf 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,11 @@
+2009-05-29  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/40019
+	* intrinsics/bit_intrinsics.c: New file.
+	* gfortran.map (GFORTRAN_1.2): New list.
+	* Makefile.am: Add intrinsics/bit_intrinsics.c.
+	* Makefile.in: Regenerate.
+
 2009-05-29  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	PR libfortran/40190
diff --git a/libgfortran/Makefile.am b/libgfortran/Makefile.am
index ce73ff22e51..f5f92dfb432 100644
--- a/libgfortran/Makefile.am
+++ b/libgfortran/Makefile.am
@@ -62,6 +62,7 @@ intrinsics/associated.c \
 intrinsics/abort.c \
 intrinsics/access.c \
 intrinsics/args.c \
+intrinsics/bit_intrinsics.c \
 intrinsics/c99_functions.c \
 intrinsics/chdir.c \
 intrinsics/chmod.c \
diff --git a/libgfortran/Makefile.in b/libgfortran/Makefile.in
index 8d356d5f3b8..ce2b5a21cb1 100644
--- a/libgfortran/Makefile.in
+++ b/libgfortran/Makefile.in
@@ -416,9 +416,9 @@ am__libgfortran_la_SOURCES_DIST = runtime/backtrace.c \
 	io/size_from_kind.c io/transfer.c io/unit.c io/unix.c \
 	io/write.c io/fbuf.c intrinsics/associated.c \
 	intrinsics/abort.c intrinsics/access.c intrinsics/args.c \
-	intrinsics/c99_functions.c intrinsics/chdir.c \
-	intrinsics/chmod.c intrinsics/clock.c intrinsics/cpu_time.c \
-	intrinsics/cshift0.c intrinsics/ctime.c \
+	intrinsics/bit_intrinsics.c intrinsics/c99_functions.c \
+	intrinsics/chdir.c intrinsics/chmod.c intrinsics/clock.c \
+	intrinsics/cpu_time.c intrinsics/cshift0.c intrinsics/ctime.c \
 	intrinsics/date_and_time.c intrinsics/dtime.c intrinsics/env.c \
 	intrinsics/eoshift0.c intrinsics/eoshift2.c \
 	intrinsics/erfc_scaled.c intrinsics/etime.c intrinsics/exit.c \
@@ -711,9 +711,9 @@ am__objects_35 = close.lo file_pos.lo format.lo inquire.lo \
 	intrinsics.lo list_read.lo lock.lo open.lo read.lo \
 	size_from_kind.lo transfer.lo unit.lo unix.lo write.lo fbuf.lo
 am__objects_36 = associated.lo abort.lo access.lo args.lo \
-	c99_functions.lo chdir.lo chmod.lo clock.lo cpu_time.lo \
-	cshift0.lo ctime.lo date_and_time.lo dtime.lo env.lo \
-	eoshift0.lo eoshift2.lo erfc_scaled.lo etime.lo exit.lo \
+	bit_intrinsics.lo c99_functions.lo chdir.lo chmod.lo clock.lo \
+	cpu_time.lo cshift0.lo ctime.lo date_and_time.lo dtime.lo \
+	env.lo eoshift0.lo eoshift2.lo erfc_scaled.lo etime.lo exit.lo \
 	fnum.lo gerror.lo getcwd.lo getlog.lo getXid.lo hostnm.lo \
 	ierrno.lo ishftc.lo iso_c_generated_procs.lo iso_c_binding.lo \
 	kill.lo link.lo malloc.lo mvbits.lo move_alloc.lo \
@@ -990,6 +990,7 @@ intrinsics/associated.c \
 intrinsics/abort.c \
 intrinsics/access.c \
 intrinsics/args.c \
+intrinsics/bit_intrinsics.c \
 intrinsics/c99_functions.c \
 intrinsics/chdir.c \
 intrinsics/chmod.c \
@@ -1804,6 +1805,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/args.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/associated.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/backtrace.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/bit_intrinsics.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/c99_functions.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/chdir.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/chmod.Plo@am__quote@
@@ -5322,6 +5324,13 @@ args.lo: intrinsics/args.c
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(LIBTOOL) --tag=CC --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o args.lo `test -f 'intrinsics/args.c' || echo '$(srcdir)/'`intrinsics/args.c
 
+bit_intrinsics.lo: intrinsics/bit_intrinsics.c
+@am__fastdepCC_TRUE@	if $(LIBTOOL) --tag=CC --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT bit_intrinsics.lo -MD -MP -MF "$(DEPDIR)/bit_intrinsics.Tpo" -c -o bit_intrinsics.lo `test -f 'intrinsics/bit_intrinsics.c' || echo '$(srcdir)/'`intrinsics/bit_intrinsics.c; \
+@am__fastdepCC_TRUE@	then mv -f "$(DEPDIR)/bit_intrinsics.Tpo" "$(DEPDIR)/bit_intrinsics.Plo"; else rm -f "$(DEPDIR)/bit_intrinsics.Tpo"; exit 1; fi
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='intrinsics/bit_intrinsics.c' object='bit_intrinsics.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(LIBTOOL) --tag=CC --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o bit_intrinsics.lo `test -f 'intrinsics/bit_intrinsics.c' || echo '$(srcdir)/'`intrinsics/bit_intrinsics.c
+
 c99_functions.lo: intrinsics/c99_functions.c
 @am__fastdepCC_TRUE@	if $(LIBTOOL) --tag=CC --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT c99_functions.lo -MD -MP -MF "$(DEPDIR)/c99_functions.Tpo" -c -o c99_functions.lo `test -f 'intrinsics/c99_functions.c' || echo '$(srcdir)/'`intrinsics/c99_functions.c; \
 @am__fastdepCC_TRUE@	then mv -f "$(DEPDIR)/c99_functions.Tpo" "$(DEPDIR)/c99_functions.Plo"; else rm -f "$(DEPDIR)/c99_functions.Tpo"; exit 1; fi
diff --git a/libgfortran/gfortran.map b/libgfortran/gfortran.map
index 93973d5b338..c8de09cf055 100644
--- a/libgfortran/gfortran.map
+++ b/libgfortran/gfortran.map
@@ -1090,6 +1090,13 @@ GFORTRAN_1.1 {
     _gfortran_unpack1_char4;
 } GFORTRAN_1.0; 
 
+
+GFORTRAN_1.2 {
+  global:
+    _gfortran_clz128;
+    _gfortran_ctz128;
+} GFORTRAN_1.1; 
+
 F2C_1.0 {
   global:
     _gfortran_f2c_specific__abs_c4;
diff --git a/libgfortran/intrinsics/bit_intrinsics.c b/libgfortran/intrinsics/bit_intrinsics.c
new file mode 100644
index 00000000000..92f5f039be6
--- /dev/null
+++ b/libgfortran/intrinsics/bit_intrinsics.c
@@ -0,0 +1,138 @@
+/* Implementation of the bit intrinsics not implemented as GCC builtins.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+This file is part of the GNU Fortran runtime library (libgfortran).
+
+Libgfortran 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 of the License, or (at your option) any later version.
+
+Libgfortran 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/>.  */
+
+#include "libgfortran.h"
+
+
+#ifdef HAVE_GFC_INTEGER_16
+extern int clz128 (GFC_INTEGER_16);
+export_proto(clz128);
+
+int
+clz128 (GFC_INTEGER_16 x)
+{
+  int res = 127;
+
+  // We can't write 0xFFFFFFFFFFFFFFFF0000000000000000, so we work around it
+  if (x & ((__uint128_t) 0xFFFFFFFFFFFFFFFF << 64))
+    {
+      res -= 64;
+      x >>= 64;
+    }
+
+  if (x & 0xFFFFFFFF00000000)
+    {
+      res -= 32;
+      x >>= 32;
+    }
+
+  if (x & 0xFFFF0000)
+    {
+      res -= 16;
+      x >>= 16;
+    }
+
+  if (x & 0xFF00)
+    {
+      res -= 8;
+      x >>= 8;
+    }
+
+  if (x & 0xF0)
+    {
+      res -= 4;
+      x >>= 4;
+    }
+
+  if (x & 0xC)
+    {
+      res -= 2;
+      x >>= 2;
+    }
+
+  if (x & 0x2)
+    {
+      res -= 1;
+      x >>= 1;
+    }
+
+  return res;
+}
+#endif
+
+
+#ifdef HAVE_GFC_INTEGER_16
+extern int ctz128 (GFC_INTEGER_16);
+export_proto(ctz128);
+
+int
+ctz128 (GFC_INTEGER_16 x)
+{
+  int res = 0;
+
+  if ((x & 0xFFFFFFFFFFFFFFFF) == 0)
+    {
+      res += 64;
+      x >>= 64;
+    }
+
+  if ((x & 0xFFFFFFFF) == 0)
+    {
+      res += 32;
+      x >>= 32;
+    }
+
+  if ((x & 0xFFFF) == 0)
+    {
+      res += 16;
+      x >>= 16;
+    }
+
+  if ((x & 0xFF) == 0)
+    {
+      res += 8;
+      x >>= 8;
+    }
+
+  if ((x & 0xF) == 0)
+    {
+      res += 4;
+      x >>= 4;
+    }
+
+  if ((x & 0x3) == 0)
+    {
+      res += 2;
+      x >>= 2;
+    }
+
+  if ((x & 0x1) == 0)
+    {
+      res += 1;
+      x >>= 1;
+    }
+
+  return res;
+}
+#endif