The documentation for -fcx-limited-range states:
@item -fcx-limited-range
@opindex fcx-limited-range
When enabled, this option states that a range reduction step is not
needed when performing complex division. The default is
@option{-fno-cx-limited-range}, but is enabled by @option{-ffast-math}.
This option controls the default setting of the ISO C99
@code{CX_LIMITED_RANGE} pragma. Nevertheless, the option applies to
all languages.
However, -fcx-limited-range (and the CX_LIMITED_RANGE pragma) affect
multiplication and absolute value as well as division, since it's not only
range reduction but also handling of FP exceptions. See Section 7.3.4 and Annex
G in the C99 standard (assuming the FCD is close to the actual standard).
At least for multiplication, it seems the actual code is correct, i.e. a call
to mulsc in libgcc is done without -fcx-limited-range, so I guess it's only the
documentation that needs to be updated.
--
Summary: Documentation incorrect for -fcx-limited-range
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jb at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35162
