[PATCH], PR 77670, Fix PowerPC ISA 3.0 -mpower9-minmax code generation

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

There are some instructions in PowerPC ISA 3.0 that are not currently enabled
by default when you use -mcpu=power9.  These instructions are currently added
with the -mpower9-minmax switch.

I recently built Spec 2006 with the current trunk compiler, and I discovered
that three of the benchmarks (gamess, povray, and soplex) do not build when you
use the -mpower9-minmiax option.

In particular, ISA 3.0 adds 3 new instructions: XSCMPEQDP, XSCMPGEDP, and
XSCMPGTDP that are similar to the vector instructions in that they set the
scalar part of the vector register to all 0's or all 1's so that the XXSEL
instruction can be used to do a floating point conditional move.

The code did not provide an inverted operation that moves the registers if the
condition is false instead of true.  I added the an insn splitter for the
inverted operation to fix the problem.

In testing it, I discovered that when I implemented the XXSEL operation for
scalar, I had the registers backwards.  I provided a fix for this as well.

I rebuilt Spec 2016, and it all builds now.  I also tested a small program on
the simulator and it generated the correct output.

Since this is in ISA 3.0 code only, I did not do the full bootstrap and make
check sequence.  I can do this if you prefer.

Is the patch ok to put into the trunk?

2016-09-20  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/77670
	* config/rs6000/predicates.md (invert_fpmask_comparison_operator):
	New predicate that matches the ISA 3.0 XSCMP{EQ,GT,GE}DP
	instructions when you want to invert the test.
	* config/rs6000/rs6000.md (fpmask<mode>): Use the arguments in the
	correct order for XXSEL.
	(mov<SFDF:mode><SFDF2:mode>cc_invert_p9): Define the inverted test
	for using XSCMP{EQ,GT,GE}DP.

-- 
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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