[Bug target/63250] Complex fp16 arithmetic uses nonexistent libgcc functions

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63250

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Fri, 16 Jan 2015, ramana at gcc dot gnu.org wrote:

> > Remove LIBGCC2_LONG_DOUBLE_TYPE_SIZE target macro.
> > 
> > This patch removes the target macro LIBGCC2_LONG_DOUBLE_TYPE_SIZE.
> 
> Joseph, how does this patch go towards "fixing" this issue as it doesn't even
> touch the ARM backend ?

The patch *references* this issue in the write-up (I now use git-style 
commit messages with a summary line and full patch write-up as sent to 
gcc-patches, rather than just the ChangeLog entries):

* If other cases of excess precision are supported in future, the code
  for defining __LIBGCC_*_EXCESS_PRECISION__ may need updating.
  Although the most likely such cases might not actually involve
  excess precision for any mode used in libgcc - FLT_EVAL_METHOD being
  32 to do _Float16 arithmetic on _Float32 should have the effect of
  _Complex _Float16 arithmetic using __mulsc3 and __divsc3, rather
  than currently nonexistent __mulhc3 and __divhc3 as in bug 63250 for
  ARM.