This adds support for a HasTailCall flag on function call edges in the
ThinLTO summary. It is intended for use in aiding discovery of missing
frames from tail calls in profiled call stacks for MemProf of profiled
binaries that did not disable tail call elimination. A follow on change
will add the use of this new flag during MemProf context disambiguation.

The new flag is encoded in the bitcode along with either the hotness
flag from the profile, or the relative block frequency under the
-write-relbf-to-summary flag when there is no profile data.
Because we now will always have some additional call edge information, I
have removed the non-profile function summary record format, and we
simply encode the tail call flag along with a hotness type of none when
there is no profile information or relative block frequency. The change
of record format and name caused most of the test case changes.

I have added explicit testing of generation of the new tail call flag
into the bitcode and IR assembly format as part of the changes to
llvm/test/Bitcode/thinlto-function-summary-refgraph.ll. I have also
added round trip testing through assembly and bitcode to
llvm/test/Assembler/thinlto-summary.ll.

While updating clang tests for having clang set dso_local I noticed
that:

- There are *a lot* of tests to update.
- Many of the updates are redundant.

They are redundant because a GV is "obviously dso_local". This patch
starts formalizing that a bit by requiring that internal and private
GVs be dso_local too. Since they all are, we don't have to print
dso_local to the textual representation, making it a bit more compact
and easier to read.

llvm-svn: 322317

Summary:
This adds a new summary flag NotEligibleToImport that subsumes
several existing flags (NoRename, HasInlineAsmMaybeReferencingInternal
and IsNotViableToInline). It also subsumes the checking of references
on the summary that was being done during the thin link by
eligibleForImport() for each candidate. It is much more efficient to
do that checking once during the per-module summary build and record
it in the summary.

Reviewers: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28169

llvm-svn: 291108

Summary:
With the removal of support for lazy parsing of combined index summary
records (e.g. r267344), we no longer need to include the summary record
bitcode offset in the VST entries for definitions. Change the combined
index format to be similar to the per-module index format in using value
ids to cross-reference from the summary record to the VST entry (rather
than the summary record bitcode offset to cross-reference in the other
direction).

The visible changes are:
1) Add the value id to the combined summary records
2) Remove the summary offset from the combined VST records, which has
the following effects:
- No longer need the VST_CODE_COMBINED_GVDEFENTRY record, as all
  combined index VST entries now only contain the value id and
  corresponding GUID.
- No longer have duplicate VST entries in the case where there are
  multiple definitions of a symbol (e.g. weak/linkonce), as they all
  have the same value id and GUID.

An implication of #2 above is that in order to hook up an alias to the
correct aliasee based on the value id of the aliasee recorded in the
combined index alias record, we need to scan the entries in the index
for that GUID to find the one from the same module (i.e. the case where
there are multiple entries for the aliasee). But the reader no longer
has to maintain a special map to hook up the alias/aliasee.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19481

llvm-svn: 267712

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19405

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267329