In the format string for *scanf functions, the '%as', '%aS', and '%a[]'
modifiers behave differently depending on ISO C99 compatibility. When
_GNU_SOURCE is defined and -std=c89 is passed to the compiler, these
functions behave like ascanf, and the modifiers allocate memory for the
output. Otherwise, the ISO C99 compliant version of these functions is
used, and the modifiers consume a floating-point argument. This patch
adds the IEEE binary128 variant of ISO C99 compliant functions for the
third long double format on powerpc64le.
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Since commit
commit 03992356e6
Author: Zack Weinberg <zackw@panix.com>
Date: Sat Feb 10 11:58:35 2018 -0500
Use C99-compliant scanf under _GNU_SOURCE with modern compilers.
the selection of the GNU versions of scanf functions requires both
_GNU_SOURCE and -std=c89. This patch changes the tests in
ldbl-128ibm-compat so that they actually test the GNU versions (without
this change, the redirection to the ISO C99 version always happens, so
GNU versions of the new implementation (e.g. __scanfieee128) were left
untested).
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
The 'mode' argument to __vfscanf_internal allows the selection of the
long double format for all long double arguments requested by the format
string. Currently, there are two possibilities: long double with the
same format as double or long double as something else. The 'something
else' format varies between architectures, and on powerpc64le, it means
IBM Extended Precision format.
In preparation for the third option of long double format on
powerpc64le, this patch uses the new mode mask,
SCANF_LDBL_USES_FLOAT128, which tells __vfscanf_internal to call
__strtof128_internal, instead of __strtold_internal, and save the output
into a _Float128 variable.
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
