Accept output arguments to benchmark functions

This patch adds the ability to accept output arguments to functions
being benchmarked, by nesting the argument type in <> in the args
directive.  It includes the sincos implementation as an example, where
the function would have the following args directive:

  ## args: double:<double *>:<double *>

This simply adds a definition for a static variable whose pointer gets
passed into the function, so it's not yet possible to pass something
more complicated like a pre-allocated string or array.  That would be
a good feature to add if a function needs it.

The values in the input file will map only to the input arguments.  So
if I had a directive like this for a function foo:

  ## args: int:<int *>:int:<int *>

and I have a value list like this:

1, 2
3, 4
5, 6

then the function calls generated would be:

foo (1, &out1, 2, &out2);
foo (3, &out1, 4, &out2);
foo (5, &out1, 6, &out2);

1 files changed, 6 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index c34668bb6d..dc38e5278b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2013-12-05  Siddhesh Poyarekar  <siddhesh@redhat.com>
 
+	* benchtests/README: Add note about output arguments.
+	* benchtests/bench-sincos.c: Remove file.
+	* benchtests/sincos-inputs: New file.
+	* scripts/bench.pl: Identify output arguments and define
+	static variables for them.
+
 	* debug/stpncpy_chk.c (__stpncpy_chk): Remove unused variables.
 
 	[BZ #15941]