Maintaining TBAA information in stack coloring pass

Dear all,

While investigating recent failures in bootstrap on ppc64le buildbot, I found that the current stack coloring pass does not regard TBAA information when merging two allocas of different types (Actually there is a FIXME comment on handling of TBAA information in StackColoring.cpp)
Although the current failures are observed only on ppc64le, the cause of failures seems to be a platform-neutral issue and other platforms can suffer from similar problems.

I submitted a work-in-progress patch in Phabricator to resolve this issue.
Any suggestions or comments would be truly appreciated.


I’ll take a look. Stack coloring already has a hack that updates the (otherwise frozen) IR so that using BasicAA in the backend continues to work afterward. Dealing with this issue is also certainly necessary. Â -Hal