New Makefile target `regen-ulps'.

The wiki "Regeneration" page has this to say about update ULPs.

"The libm-test-ulps files are semiautomatically updated. To
update an ulps baseline, run each of the failing tests (test-float,
 test-double, etc.) with -u; this will generate a file called ULPs;
concatenate each of those files with the existing libm-test-ulps
file, after removing any entries for particularly huge numbers of
ulps that you do not want to mark as expected. Then run
gen-libm-test.pl -n -u FILE where FILE is the concatenated file
produced in the previous step. This generates a file called
NewUlps which is the new sorted version of libm-test-ulps."

The same information is listed in math/README.libm-test, and is a
lot of manual work that you often want to run over-and-over again
while working on a particular test.

The `regen-ulps' convenience target does this automatically for
developers.

We strictly assume the source tree is readonly and add a
new --output-dir option to libm-test.inc to allow for writing
out ULPs to $(objpfx).

When run the new target does the following:
* Starts with the baseline ULPs file.
* Runs each of the libm math tests with -u.
* Adds new changes seen with -u to the baseline.
* Sorts and prepares the test output with gen-libm-test.pl.
* Leaves math/NewUlps in your build tree to copy to your source
  tree, cleanup, and checkin.

The math test documentation in math/README.libm-test is updated
document the new Makefile target.

---

2013-04-06  Carlos O'Donell  <carlos@redhat.com>

	* Makefile.in (regen-ulps): New target.
	* math/Makefile [ifneq (no,$(PERL)]: Declare regen-ulps with .PHONY.
	[ifneq (no,$(PERL)] (run-regen-ulps): New variable.
	[ifneq (no,$(PERL)] (regen-ulps): New target.
	[ifeq (no,$(PERL)] (regen-ulps): New target.
	* math/libm-test.inc (ulps_file_name): Define.
	(output_dir): New variable.
	(options): Add "output-dir" option.
	(parse_opt): Handle 'o' case.
	(main): If output_dir is non-NULL use it as a prefix
	otherwise use "".
	* math/README.libm-test: Update `How can I generate "libm-test-ulps"?'

1 files changed, 27 insertions, 0 deletions

diff --git a/math/Makefile b/math/Makefile
index f396ba206a..ee5b58239e 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -150,6 +150,33 @@ extra-objs += libieee.a ieee-math.o
 
 include ../Rules
 
+ifneq (no,$(PERL))
+# Run the math programs to automatically generate ULPs files.
+.PHONY: regen-ulps
+
+run-regen-ulps = $(test-wrapper-env) \
+	    GCONV_PATH=$(common-objpfx)iconvdata LC_ALL=C \
+	    $($*-ENV) $(run-via-rtld-prefix) $${run}
+
+regen-ulps: $(addprefix $(objpfx),$(libm-tests))
+	rm -f $(objpfx)ULPs; rm -f $(objpfx)NewUlps; \
+	cp $(ulps-file) $(objpfx)libm-test-ulps; \
+	for run in $^; do \
+	  echo "Regenerating ULPs for $${run}"; \
+	  $(run-regen-ulps) -u -o $(objpfx); \
+	  cat $(objpfx)ULPs >> $(objpfx)libm-test-ulps; \
+	  rm $(objpfx)ULPs; \
+	done; \
+	$(PERL) gen-libm-test.pl -o $(objpfx) -n -u $(objpfx)libm-test-ulps; \
+	echo "Automatic regeneration of ULPs complete."; \
+	echo "Difference between the current baseline and the new baseline is:";\
+	diff -urN $(ulps-file) $(objpfx)NewUlps; \
+	echo "Copy $(objpfx)NewUlps to $(ulps-file) (relative to source)."
+else
+regen-ulps:
+	@echo "Automatic regeneration of ULPs requires perl."; \
+	exit 1;
+endif
 
 # The generated sysd-rules file defines rules like this for sources
 # coming from sysdeps/ directories.  These rules find the generic sources.