4 Commits

Author	SHA1	Message	Date
QingShan Zhang	3906ae387f	[DAGCombine] Check the uses of negated floating constant and remove the hack ... PowerPC hits an assertion due to somewhat the same reason as https://reviews.llvm.org/D70975. Though there are already some hack, it still failed with some case, when the operand 0 is NOT a const fp, it is another fma that with const fp. And that const fp is negated which result in multi-uses. A better fix is to check the uses of the negated const fp. If there are already use of its negated value, we will have benefit as no extra Node is added. Differential revision: https://reviews.llvm.org/D75501	2020-03-05 03:42:50 +00:00
QingShan Zhang	d48ac7d54d	[DAGCombine] Fold the (fma -x, y, -z) to -(fma x, y, z) ... This is a positive combination as long as the NEG is NOT free, as we are reducing the number of NEG from two to one. Differential Revision: https://reviews.llvm.org/D72312	2020-01-09 04:33:46 +00:00
QingShan Zhang	44f78f368c	[NFC][Test] Add the option -enable-no-signed-zeros-fp-math for test ... fma-combine.ll	2020-01-08 06:48:51 +00:00
QingShan Zhang	d877229b5b	[NFC][Test] Add a test to verify the DAGCombine of fma	2020-01-07 03:13:39 +00:00