This patch modifies the indirect call promotion utilities by exposing and using
an unconditional call promotion interface. The unconditional promotion
interface (i.e., call promotion without creating an if-then-else) can be used
if it's known that an indirect call has only one possible callee. The existing
conditional promotion interface uses this unconditional interface to promote an
indirect call after it has been versioned and placed within the "then" block.
A consequence of unconditional promotion is that the fix-up operations for phi
nodes in the normal destination of invoke instructions are changed. This is
necessary because the existing implementation assumed that an invoke had been
versioned, creating a "merge" block where a return value bitcast could be
placed. In the new implementation, the edge between a promoted invoke's parent
block and its normal destination is split if needed to add a bitcast for the
return value. If the invoke is also versioned, the phi node merging the return
value of the promoted and original invoke instructions is placed in the "merge"
block.
Differential Revision: https://reviews.llvm.org/D40751
llvm-svn: 321210
Summary: Currently, ICP checks the count against a fixed value to see if it is hot enough to be promoted. This does not work for SamplePGO because sampled count may be much smaller. This patch uses PSI to check if the count is hot enough to be promoted.
Reviewers: davidxl, tejohnson, eraman
Reviewed By: davidxl
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D36341
llvm-svn: 310416
This patch implements the transformation that promotes indirect calls to
conditional direct calls when the indirect-call value profile meta-data is
available.
Differential Revision: http://reviews.llvm.org/D17864
llvm-svn: 267815
Matthew Simpson