------- Comment #9 from dave at hiauly1 dot hia dot nrc dot ca 2006-12-14
19:55 -------
Subject: Re: FAIL: gcc.dg/builtins-57.c scan-tree-dump trunc
> trunc maybe available in the library, but gcc thinks it is not. Otherwise the
> testcase wouldn't fail - it tests for the transformation of floor (x) to trunc
> (x)
> if x is known to be positive.
If I understand correctly, the transformation only occurs when
TARGET_C99_FUNCTIONS is true. In the linux case, this depends on
OPTION_GLIBC. Can't figure out how OPTION_GLIBC gets defined...
It would be really nice if there was a way for a target to say
which C99 functions are implicitly available when it has a partial
set. Possibly, this code could be modified to add a target callback:
if (implicit_p)
implicit_built_in_decls[(int) fncode] = decl;
For example, something like:
if (implicit_p && targetm.implicit_built_in_p (fncode))
implicit_built_in_decls[(int) fncode] = decl;
Doing this might create a few problems for the libraries and testsuite,
but it should improve code optimization.
> Now if std=c99 does not help I can only make this a link-time testcase like
> (-ffinite-math-only to allow folding the FP comparison).
>
> That does work, right?
The test program works.
Dave
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30181
