Prepare vfscanf to use __strtof128_internal

On powerpc64le, long double can currently take two formats: the same as
double (-mlong-double-64) or IBM Extended Precision (default with
-mlong-double-128 or explicitly with -mabi=ibmlongdouble).  The internal
implementation of scanf-like functions is aware of these possibilites
and, based on the format in use, properly calls __strtold_internal or
__strtod_internal, saving the return to a variable of type double or
long double.

When library support for TS 18661-3 was added to glibc, a new function,
__strtof128_internal, was added to enable reading of floating-point
values with IEEE binary128 format into the _Float128 type.  Now that
powerpc64le is getting support for its third long double format, and
taking into account that this format is the same as the format of
_Float128, this patch extends __vfscanf_internal and __vfwscanf_internal
to call __strtof128_internal or __wcstof128_internal when appropriate.
The result gets saved into a variable of _Float128 type.

Tested for powerpc64le.

1 files changed, 12 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 998f4c153f..c6ad912b11 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2018-12-07  Gabriel F. T. Gomes  <gabriel@inconstante.eti.br>
+
+	* libio/libioP.h (SCANF_LDBL_USES_FLOAT128): New macro to be
+	used as a mask for the mode argument of __vfscanf_internal and
+	__vfwscanf_internal.
+	* stdio-common/vfscanf-internal.c
+	[defined COMPILE_WSCANF && __HAVE_FLOAT128_UNLIKE_LDBL]
+	(__strtof128_internal): Define to __wcstof128_internal.
+	[__HAVE_FLOAT128_UNLIKE_LDBL] (__vfscanf_internal): Call
+	__strtof128_internal or __wcstof128_internal when the format of
+	long double is the same as _Float128.
+
 2018-12-05  Samuel Thibault  <samuel.thibault@ens-lyon.org>
 
 	* include/unistd.h (__confstr): Add prototype and hidden prototype.