for correct propagation/update of liveness information within subexpressions
of Block-Level expressions. Test case provided by Nuno Lopes.
llvm-svn: 44225
the StmtIterator referring to the initializers of a chain of Decls was equal
to the "end" iterator. The particular bug manifested when an iterator was
created on a chain of decls with no initializers.
Thanks to Nuno Lopes for reporting this bug and providing a patch.
llvm-svn: 44220
http://llvm.org/viewvc/llvm-project?rev=44199&view=rev
This patch completely broke serialization due to an invariant I assumed but
did not hold. The assumed invariant was that all pointer IDs emitted by a call
to BatchEmitOwnedPtrs would be consecutive. This is only the case if there has
been no forward references to an owned pointer (and hence already registered
with the Serializer object).
llvm-svn: 44203
Deserialize::ReadDiffPtrID to read and emit bools instead of unsigned
integers. This should result in a nice space optimization once we have
"auto-abbreviation" generation in place.
llvm-svn: 44200
SerializedPtrID, followed by the *differences* in IDs. The big idea is that
most IDs will be just be 1 off from the previous (either that or NULL, which
we encode as a difference if 0), so this will greatly reduce the encoding
space for extra IDs to just 1 bit per pointer.
So far this optimization reduces serialization of Carbon.h by only 1%, but
we aren't using any abbreviations now in the Bitcode file to properly take
advantage of this optimization.
llvm-svn: 44199
When a live interval is being spilled, rather than creating short, non-spillable
intervals for every def / use, split the interval at BB boundaries. That is, for
every BB where the live interval is defined or used, create a new interval that
covers all the defs and uses in the BB.
This is designed to eliminate one common problem: multiple reloads of the same
value in a single basic block. Note, it does *not* decrease the number of spills
since no copies are inserted so the split intervals are *connected* through
spill and reloads (or rematerialization). The newly created intervals can be
spilled again, in that case, since it does not span multiple basic blocks, it's
spilled in the usual manner. However, it can reuse the same stack slot as the
previously split interval.
This is currently controlled by -split-intervals-at-bb.
llvm-svn: 44198
Some FunctionDecls do not appear at the top-level or are owned by a DeclStmt.
In calls to implicitly defined functions, a FunctionDecl is created, but only
the DeclRefExprs reference them. Since an implicitly defined function may be
called multiple times, there is no clear ownership model for such objects.
Temporary solution: when serializing out DeclRefExprs, emit an ownership bit
for the Decl. This bit is determined by querying the serializer to see if the
Decl has already been serialized. If it hasn't, emit the Decl as an owned
pointer.
I repeat: this is a hack. This should be fixed.
llvm-svn: 44176
Chris Lattner