r249718 | ast | 2015-10-08 11:52:40 -0700 (Thu, 08 Oct 2015) | 16 lines
[bpf] Do not expand UNDEF SDNode during insn selection lowering
o Before this patch, BPF backend will expand UNDEF node to i64 constant 0. o For second pass of dag combiner, legalizer will run through each to-be-processed dag node. o If any new SDNode is generated and has an undef operand, dag combiner will put undef node, newly-generated constant-0 node, and any node which uses these nodes in the working list. o During this process, it is possible undef operand is generated again, and this will form an infinite loop for dag combiner pass2. o This patch allows UNDEF to be a legal type.
Signed-off-by: Yonghong Song <firstname.lastname@example.org>