Allow adding of arbitrary code to benchmark tests

This allows us to define custom functions in C code files and
benchmark scenarios rather than just functions.  The main current use
of this is to separate the slow and fast path benchmarks for math
functions.

ChangeLog

@@ -1,3 +1,8 @@
+2013-03-21  Siddhesh Poyarekar  <siddhesh@redhat.com>
+
+	* Rules ($(objpfx)bench-%.c): Include code from a C source
+	file.
+
 2013-03-21  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #15287]

Rules

@@ -210,8 +210,12 @@ $(binaries-bench): %: %.o \
 	$(+link)
 
 $(objpfx)bench-%.c: %-inputs bench-skeleton.c
+	{ if [ -n "$($*-INCLUDE)" ]; then \
+	  cat $($*-INCLUDE); \
+	fi; \
 	$(..)scripts/bench.pl $(patsubst %-inputs,%,$<) \
-	  $($*-ITER) $($*-ARGLIST) $($*-RET) > $@
+	  $($*-ITER) $($*-ARGLIST) $($*-RET); } > $@-tmp
+	mv -f $@-tmp $@
 
 
 .PHONY: distclean realclean subdir_distclean subdir_realclean \