glibc/sysdeps/s390/bits
Marius Hillenbrand f88242af19 S390: Derive float_t from FLT_EVAL_METHOD
float_t supposedly represents the type that is used to evaluate float
expressions internally. While the isa supports single-precision float
operations, the port of glibc to s390 incorrectly deferred to the
generic definitions which, back then, tied float_t to double. gcc by
default evaluates float in single precision, so that scenario violates
the C standard (sections 5.2.4.2.2 and 7.12 in C11/C17). With
-fexcess-precision=standard, gcc evaluates float in double precision,
which aligns with the standard yet at the cost of added conversion
instructions.

With this patch, we drop the s390-specific definition of float_t and
defer to the default behavior, which aligns float_t with the
compiler-defined FLT_EVAL_METHOD in a standard-compliant way.

Checked on s390x-linux-gnu with 31-bit and 64-bit builds.
2020-12-09 16:26:46 +01:00
..
endianness.h Split up endian.h to minimize exposure of BYTE_ORDER. 2019-10-01 14:54:46 -07:00
link.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
setjmp.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00