tree b6b915cf382f4fcfbc9e289688e4b419a253f1ca
parent 2a3d16feea3449f2c1bc1325a17a19e428185983
author Florian Hahn <flo@fhahn.com> 1557247647 +0000
committer Florian Hahn <flo@fhahn.com> 1557247647 +0000

[DAGCombiner] Avoid creating large tokenfactors in visitTokenFactor

When simplifying TokenFactors, we potentially iterate over all
operands of a large number of TokenFactors. This causes quadratic
compile times in some cases and the large token factors cause additional
scalability problems elsewhere.

This patch adds some limits to the number of nodes explored for the
cases mentioned above.

Reviewers: niravd, spatel, craig.topper

Reviewed By: niravd

Differential Revision: https://reviews.llvm.org/D61397

llvm-svn: 360171