Hello!

This is the third version of BMI2 support that includes generation of
mulx, rorx, <shift>x part. This patch includes all comments on
previous version, splits all insn post-reload, uses "enable" attribute
and avoids new register modifiers. As a compromise (see previous
posts), the mulx insn is now split post-reload into pattern that
separates outputs (so, post-reload passes can do their job more
effectively), with the hope that someday other DWI patterns will be
rewritten in the same way.

2011-08-21  Uros Bizjak  <ubizjak@gmail.com>

	* config/i386/i386.md (type): Add imulx, ishiftx and rotatex.
	(length_immediate): Handle imulx, ishiftx and rotatex.
	(imm_disp): Ditto.
	(isa): Add bmi2.
	(enabled): Handle bmi2.
	(w): New mode attribute.

	(*mul<mode><dwi>3): Split from *<u>mul<mode><dwi>3.
	(*umul<mode><dwi>3): Ditto.  Add imulx BMI2 alternative.
	(*bmi2_umulditi3_1): New insn pattern.
	(*bmi2_umulsidi3_1): Ditto.
	(*umul<mode><dwi>3 splitter): New splitter to avoid flags dependency.

	(*bmi2_ashl<mode>3_1): New insn pattern.
	(*ashl<mode>3_1): Add ishiftx BMI2 alternative.
	(*ashl<mode>3_1 splitter): New splitter to avoid flags dependency.
	(*bmi2_ashlsi3_1_zext): New insn pattern.
	(*ashlsi3_1_zext): Add ishiftx BMI2 alternative.
	(*ashlsi3_1_zext splitter): New splitter to avoid flags dependency.

	(*bmi2_<shiftrt_insn><mode>3_1): New insn pattern.
	(*<shiftrt_insn><mode>3_1): Add ishiftx BMI2 alternative.
	(*<shiftrt_insn><mode>3_1 splitter): New splitter to avoid
	flags dependency.
	(*bmi2_<shiftrt_insn>si3_1_zext): New insn pattern.
	(*<shiftrt_insn>si3_1_zext): Add ishiftx BMI2 alternative.
	(*<shiftrt_insn>si3_1_zext splitter): New splitter to avoid
	flags dependency.

	(*bmi2_rorx<mode>3_1): New insn pattern.
	(*<rotate_insn><mode>3_1): Add rotatex BMI2 alternative.
	(*rotate<mode>3_1 splitter): New splitter to avoid flags dependency.
	(*rotatert<mode>3_1 splitter): Ditto.
	(*bmi2_rorxsi3_1_zext): New insn pattern.
	(*<rotate_insn>si3_1_zext): Add rotatex BMI2 alternative.
	(*rotatesi3_1_zext  splitter): New splitter to avoid flags dependency.
	(*rotatertsi3_1_zext splitter): Ditto.

The patch was bootstrapped and fully tested on x86_64-pc-linux-gnu
{,-m32}. Kirill, please add other stuff, re-test it on simulator and
re-post complete patch with (fixed) testcases.

Uros.