At some point, pass definitions were heavily macro-ized. Pass
descriptive names were added in two places. This is not only redundant
but a source of confusion. You could waste a lot of time grepping for
the wrong string. I removed all the getName() overrides which, at
around 90 passes, was a fairly significant amount of code bloat.
Any pass that we want to be able to invoke by name from a tool
(sil-opt) or pipeline plan *should* have unique type name, enum value,
commend-line string, and name string. I removed a comment about the
various inliner passes that contradicted that.
Side note: We should be consistent with the policy that a pass is
identified by its type. We have a couple passes, LICM and CSE, which
currently violate that convention.
We hit an assert in AllocStackHoisting that is only triggered in a release lto
build.
Clang forwards the read of parent basic block of 'AssignedLoc' in the next
statement:
auto *EntryBB = AssignedLoc->getFunction()->getEntryBlock(); // read AssignedLoc->ParentBB
AssignedLoc->removeFromParent(); // writes AssignedLoc->ParentBB
To this read:
EntryBB->push_front(AssignedLoc); // read AssignedLoc->ParentBB and assert if non-null, *should reload*
As a temporary workaround outline code to prevent the miscompile.
rdar://29982182
Hoist alloc_stack instructions of 'generic' or resilient type to the entry
block. At the same time also perform a very simple stack coloring analysis.
This does not use a true liveness-analysis yet but rather employs some simple
conservative checks to see whether the live ranges of two alloc_stacks might
interfere.
AllocStackHoisting is an IRGen SIL pass. This allows for using IRGen's type
lowering information. Furthermore, hoisting and merging the alloc_stack
instructions this late does not interfere with SIL optimizations because the
resulting SIL never gets serialized.
