[PATCH] PR 53487 - Fix isel on powerpc to work again

[Michael Meissner <meissner at linux dot vnet dot ibm dot com>]

This patch fixes PR 53487, so that -misel will no longer cause an unknown insn
error.  Andrew Pinksi's changes on May 4th, 2012, changed to use the
mov<mode>cc pattern instead of the cstore<mode>4 in some cases, when a target
machine defines both patterns.  The cstore<mode>4 pattern had checks in it to
prevent ISELs involving floating point compares from being generated, but
mov<mode>cc did not.  In addition, building Spec showed that going through
mov<mode>cc also needed to make sure a comparison against a negative integer
constant like cstore<mode>4 also had.

I have bootstrapped the compiler (using BOOT_CFLAGS='-g -O2 -mcpu=power7
-misel) and there were no regressions in the test suite against an unpatched
compiler.  I have also built the Spec 2006 suite with isel, and it generated no
errors.  Is this patch ok to apply?

[gcc]
2012-06-04  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/53487
	* config/rs6000/rs6000.c (rs6000_generate_compare): If we are
	doing an unsigned compare, make sure the second argument is not a
	negative constant.
	(rs6000_emit_cmove): Don't allow floating point comparisons when
	generating ISEL moves.

[gcc/testsuite]
2012-06-04  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* gcc.target/powerpc/pr53487.c: New test.

-- 
Michael Meissner, IBM
5 Technology Place Drive, M/S 2757, Westford, MA 01886-3141, USA
meissner@linux.vnet.ibm.com	fax +1 (978) 399-6899

Attachment: bug-53487.patch01b
Description: Text document