Re: [PATCH], PR 68404 patch #3 (fix earlyclobber problem on power8 fusion)

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

After looking at Bernd Schmidt and Jakub Jelinek's suggestions, I came to
conclusion that earlyclobber was not needed in this case, and I removed it.  I
bootstrapped the compiler using profiledbootstrap and lto options and it
succeeded build and running make check.  Just to be sure, I also did a
profiledbootstrap with LTO and -O3 and it built fine.  Is it ok to install
these patches?

I decided to keep the changes to the testsuite explicitly passing the fusion
switches, rather than letting -mtune=power8/power9 set them, but I can be
persuaded to restore the 3 tests to the way they were before February 9th.

[gcc]
2016-02-11  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/68404
	* config/rs6000/predicates.md (fusion_gpr_addis): Revert
	2016-02-09 change.

	* config/rs6000/rs6000.md (fusion_gpr_load_<mode>): Remove
	earlyclobber from target.  Use wF constraint for fused memory
	address.
	(fusion_gpr_<P:mode>_<GPR_FUSION:mode>_load): Likewise.

[gcc/testsuites]
2016-02-11  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/68404
	* gcc.target/powerpc/fusion.c: Do not assume that -mtune=power8
	sets -mpower8-fusion or -mtune=power9 sets -mpower9-fusion.
	* gcc.target/powerpc/fusion2.c: Likewise.
	* gcc.target/powerpc/fusion3.c: Likewise.

Since gcc 5.0 also has the earlyclobber in the pattern, I would like to apply
the same change to gcc 5.x (after testing of course), even though we haven't
yet run into the problem with GCC 5.x.  Is this ok as well?

-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.vnet.ibm.com, phone: +1 (978) 899-4797

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