[PATCH GCC][1/3]Simplify (A + CST cmp A -> CST cmp zero) for undefined overflow type

[Bin Cheng]

Hi,
This is a rework of patch set at https://gcc.gnu.org/ml/gcc-patches/2017-06/msg01036.html
and https://gcc.gnu.org/ml/gcc-patches/2017-06/msg01037.html.  The patch set improves niters
bound analysis for split loop.  Instead of feeding bound computation to generic folder, this
patch simplifies (A + CST cmp A  ->  CST cmp zero) for types with undefined overflow behavior.
Bootstrap and test for patch set on x86_64 and AArch64.  Comments?

Thanks,
bin
2017-10-16  Bin Cheng  <bin.cheng@arm.com>

	* match.pd (A + CST cmp A  ->  CST cmp zero): New simplification
	for undefined overflow types in (A + CST CMP A  ->  A CMP' CST').
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-simplify-AopCst-cmp-A-20171006.txt.patch
Type: text/x-patch
Size: 1806 bytes
Desc: 0001-simplify-AopCst-cmp-A-20171006.txt.patch
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20171019/412c6dd7/attachment.bin>