[PATCH], PR target/78597, Fix PowerPC fp-int-convert-{float128-ieee,float64x}

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

This patch fixes PR target/78597 on PowerPC.  The basic problem is conversion
between unsigned int and _Float128 fails for 0x80000000.  Both power{7,8} using
simulated IEEE 128-bit floating point and power9 using hardware IEEE 128-bit
failed in the same test.

I cut down the patches I had developed for 79038 that are waiting for GCC 8 to
open up to include the patches that fix the problem, but don't do additional
improvements (optimizing conversions between char/short and _Float128, and
optimizing converting _Float128 to int/short/char and storing the result).

This patch is a little on the big side, because I deleted the two functions
(convert_float128_to_int and (convert_int_to_float128) that were doing the
integer/_Float128 conversions, and instead implemented them directly.  I also
deleted the various insns that those two functions called.  It only affects
_Float128/__float128 conversions.

I have tested this on a little endian power8 system.  Bootstrap passes, and the
only changes in the test suite runs were the following tests now pass:

	gcc.dg/torture/fp-int-convert-float128-ieee.c
	gcc.dg/torture/fp-int-convert-float64x.c

I did not add any tests, because it was covered by existing tests.  Can I check
this into trunk?

2017-01-30  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/78597
	PR target/79038
	* config/rs6000/rs6000-protos.h (convert_float128_to_int): Delete,
	no longer used.
	(convert_int_to_float128): Likewise.
	* config/rs6000/rs6000.c (convert_float128_to_int): Likewise.
	(convert_int_to_float128): Likewise.
	* config/rs6000/rs6000.md (UNSPEC_IEEE128_MOVE): Likewise.
	(UNSPEC_IEEE128_CONVERT): Likewise.
	(floatsi<mode>2, FLOAT128 iterator): Bypass calling
	rs6000_expand_float128_convert if we have IEEE 128-bit hardware.
	Use local variables for IBM extended format.
	(fix_trunc<mode>si2, FLOAT128 iterator): Likewise.
	(fix_trunc<mode>si2_fprs): Likewise.
	(fixuns_trunc<IEEE128:mode><SDI:mode>2): Likewise.
	(floatuns<IEEE128:mode>2, IEEE128 iterator): Likewise.
	(fix<uns>_<mode>si2_hw): Rework the IEEE 128-bt hardware support
	to know that we can now have integers of all sizes in vector
	registers.
	(fix<uns>_<mode>di2_hw): Likewise.
	(float<uns>_<mode>si2_hw): Likewise.
	(fix_<mode>si2_hw): Likewise.
	(fixuns_<mode>si2_hw): Likewise.
	(float<uns>_<mode>di2_hw): Likewise.
	(float_<mode>di2_hw): Likewise.
	(float_<mode>si2_hw): Likewise.
	(floatuns_<mode>di2_hw): Likewise.
	(floatuns_<mode>si2_hw): Likewise.
	(xscvqp<su>wz_<mode>): Delete, no longer used.
	(xscvqp<su>dz_<mode>): Likewise.
	(xscv<su>dqp_<mode>): Likewise.
	(ieee128_mfvsrd_64bit): Likewise.
	(ieee128_mfvsrd_32bit): Likewise.
	(ieee128_mfvsrwz): Likewise.
	(ieee128_mtvsrw): Likewise.
	(ieee128_mtvsrd_64bit): Likewise.
	(ieee128_mtvsrd_32bit): Likewise.

-- 
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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