Fix PR88784, middle end is missing some optimizations about unsigned

Fix PR88784, middle end is missing some optimizations about unsigned

2019-09-16  Li Jia He  <helijia@linux.ibm.com>
	    Qi Feng  <ffengqi@linux.ibm.com>

	PR middle-end/88784
	* match.pd (x >  y  &&  x != XXX_MIN): Optimize into 'x > y'.
	(x >  y  &&  x == XXX_MIN): Optimize into 'false'.
	(x <= y  &&  x == XXX_MIN): Optimize into 'x == XXX_MIN'.
	(x <  y  &&  x != XXX_MAX): Optimize into 'x < y'.
	(x <  y  &&  x == XXX_MAX): Optimize into 'false'.
	(x >= y  &&  x == XXX_MAX): Optimize into 'x == XXX_MAX'.
	(x >  y  ||  x != XXX_MIN): Optimize into 'x != XXX_MIN'.
	(x <= y  ||  x != XXX_MIN): Optimize into 'true'.
	(x <= y  ||  x == XXX_MIN): Optimize into 'x <= y'.
	(x <  y  ||  x != XXX_MAX): Optimize into 'x != XXX_MAX'.
	(x >= y  ||  x != XXX_MAX): Optimize into 'true'.
	(x >= y  ||  x == XXX_MAX): Optimize into 'x >= y'.
2019-09-16  Li Jia He  <helijia@linux.ibm.com>
	    Qi Feng  <ffengqi@linux.ibm.com>

	PR middle-end/88784
	* gcc.dg/pr88784-1.c: New testcase.
	* gcc.dg/pr88784-2.c: New testcase.
	* gcc.dg/pr88784-3.c: New testcase.
	* gcc.dg/pr88784-4.c: New testcase.
	* gcc.dg/pr88784-5.c: New testcase.
	* gcc.dg/pr88784-6.c: New testcase.
	* gcc.dg/pr88784-7.c: New testcase.
	* gcc.dg/pr88784-8.c: New testcase.
	* gcc.dg/pr88784-9.c: New testcase.
	* gcc.dg/pr88784-10.c: New testcase.
	* gcc.dg/pr88784-11.c: New testcase.
	* gcc.dg/pr88784-12.c: New testcase.

Co-Authored-By: Qi Feng <ffengqi@linux.ibm.com>
From-SVN: r275749