[PATCH v2 2/9] float128: Add conversion from float128 to mpn

["Gabriel F. T. Gomes" <gftg at linux dot vnet dot ibm dot com>]

Changes since v1:

  - Removed the [unrelated] change to sys/param.h.  Now gmp-impl.h
    includes sys/param.h instead of redefining MAX/MIN.
  - Added an inclusion of bits/floatn.h to include/gmp.h.  It was mistakenly
    added in the next commit in the series.
  - Removed the macro __FLOAT128_OVERRIDE in favor of a redefinition of
    __mpn_extract_long_double to __mpn_extract_float128 in float128_private.h.

-- 8< --
Reuse the code for __mpn_extract_long_double to implement
__mpn_extract_float128.

2017-05-15  Gabriel F. T. Gomes  <gftg@linux.vnet.ibm.com>

	* include/gmp.h: Include bits/floatn.h
	(__mpn_extract_float128): Declare when __HAVE_DISTINCT_FLOAT128 is 1.
	* stdlib/gmp-impl.h: Also check if alloca is not defined before
	including stack-alloc.h.  It could have been defined by other header
	which not necessarily defines HAVE_ALLOCA.
	* sysdeps/ieee754/float128/Makefile: New file.
	* sysdeps/ieee754/float128/float1282mpn.c: New file.
	* sysdeps/ieee754/float128/float128_private.h: Include gmp.h before
	redefining __mpn_extract_long_double to __mpn_extract_float128, then
	redefine __mpn_extract_long_double to __mpn_extract_float128.
	* sysdeps/ieee754/ldbl-128/ldbl2mpn.c: Replace long double with
	_Float128 to allow float128_private.h overrides.
---
 include/gmp.h                               |  8 ++++++++
 stdlib/gmp-impl.h                           |  3 ++-
 sysdeps/ieee754/float128/Makefile           |  3 +++
 sysdeps/ieee754/float128/float1282mpn.c     | 20 ++++++++++++++++++++
 sysdeps/ieee754/float128/float128_private.h |  2 ++
 sysdeps/ieee754/ldbl-128/ldbl2mpn.c         |  3 ++-
 6 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/ieee754/float128/Makefile
 create mode 100644 sysdeps/ieee754/float128/float1282mpn.c

diff --git a/include/gmp.h b/include/gmp.h
index b741670..e6f635e 100644
--- a/include/gmp.h
+++ b/include/gmp.h
@@ -6,6 +6,8 @@
 
 #include <stdlib/gmp.h>
 
+#include <bits/floatn.h>
+
 /* Now define the internal interfaces.  */
 extern mp_size_t __mpn_extract_double (mp_ptr res_ptr, mp_size_t size,
 				       int *expt, int *is_neg,
@@ -15,6 +17,12 @@ extern mp_size_t __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
 					    int *expt, int *is_neg,
 					    long double value);
 
+#if __HAVE_DISTINCT_FLOAT128
+extern mp_size_t __mpn_extract_float128 (mp_ptr res_ptr, mp_size_t size,
+					 int *expt, int *is_neg,
+					 _Float128 value);
+#endif
+
 extern float __mpn_construct_float (mp_srcptr frac_ptr, int expt, int sign);
 
 extern double __mpn_construct_double (mp_srcptr frac_ptr, int expt,
diff --git a/stdlib/gmp-impl.h b/stdlib/gmp-impl.h
index 89693c4..42d3e4a 100644
--- a/stdlib/gmp-impl.h
+++ b/stdlib/gmp-impl.h
@@ -47,7 +47,8 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, see
 #endif
 #endif
 
-#if ! defined (HAVE_ALLOCA) || defined (USE_STACK_ALLOC)
+#if (! defined (alloca) && ! defined (HAVE_ALLOCA)) \
+    || defined (USE_STACK_ALLOC)
 #include "stack-alloc.h"
 #else
 #define TMP_DECL(m)
diff --git a/sysdeps/ieee754/float128/Makefile b/sysdeps/ieee754/float128/Makefile
new file mode 100644
index 0000000..6a7b0e0
--- /dev/null
+++ b/sysdeps/ieee754/float128/Makefile
@@ -0,0 +1,3 @@
+ifeq ($(subdir),stdlib)
+routines += float1282mpn
+endif
diff --git a/sysdeps/ieee754/float128/float1282mpn.c b/sysdeps/ieee754/float128/float1282mpn.c
new file mode 100644
index 0000000..f012ccf
--- /dev/null
+++ b/sysdeps/ieee754/float128/float1282mpn.c
@@ -0,0 +1,20 @@
+/* Convert a _Float128 type to multiprecision.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <float128_private.h>
+#include "../ldbl-128/ldbl2mpn.c"
diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
index 894e6ac..1e00853 100644
--- a/sysdeps/ieee754/float128/float128_private.h
+++ b/sysdeps/ieee754/float128/float128_private.h
@@ -17,6 +17,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 /* This must be included before the function renames below.  */
+#include <gmp.h>
 #include <math.h>
 #undef HUGE_VALL
 #define HUGE_VALL HUGE_VAL_F128
@@ -291,6 +292,7 @@
 #define __kernel_tanl __kernel_tanf128
 #define __lgamma_negl __lgamma_negf128
 #define __lgamma_productl __lgamma_productf128
+#define __mpn_extract_long_double __mpn_extract_float128
 #define __sincosl_table __sincosf128_table
 #define mul_splitl mul_splitf128
 
diff --git a/sysdeps/ieee754/ldbl-128/ldbl2mpn.c b/sysdeps/ieee754/ldbl-128/ldbl2mpn.c
index 71a6f04..1c79a5d 100644
--- a/sysdeps/ieee754/ldbl-128/ldbl2mpn.c
+++ b/sysdeps/ieee754/ldbl-128/ldbl2mpn.c
@@ -21,6 +21,7 @@
 #include <ieee754.h>
 #include <float.h>
 #include <math.h>
+#include <math_private.h>
 #include <stdlib.h>
 
 /* Convert a `long double' in IEEE854 quad-precision format to a
@@ -31,7 +32,7 @@
 mp_size_t
 __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
 			   int *expt, int *is_neg,
-			   long double value)
+			   _Float128 value)
 {
   union ieee854_long_double u;
   u.d = value;
-- 
2.4.11