Commit Graph

5 Commits

Author SHA1 Message Date
Teresa Johnson 02e98331c0 [ThinLTO] Use valueid instead of bitcode offsets in combined index file
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
2016-04-27 13:28:35 +00:00
Mehdi Amini 8fe6936e18 Add a version field in the bitcode for the summary
Differential Revision: http://reviews.llvm.org/D19456

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267318
2016-04-24 03:18:11 +00:00
Mehdi Amini 02fa65209c Relax test using CHECK-DAG instead of CHECK-NEXT
It seems we still have some ordering issue in the combined index
emission, but I can't figure out why right now.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267306
2016-04-24 00:25:15 +00:00
Mehdi Amini 363d83f808 Fix test stability (was sensitive to the path)
This is a fixup for r267304.
The test was sensitive to the path in a subtle way:
the index in memory is sorted by GUID, which are hashes
that include the source filename for local globals.
Teresa recently added a directive at the IR level, so
we can specify it here to make the test independent of
the path.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267305
2016-04-24 00:03:57 +00:00
Mehdi Amini ae64eafd31 Store and emit original name in combined index
Summary:
As discussed in D18298, some local globals can't
be renamed/promoted (because they have a section, or because
they are referenced from inline assembly).
To be able to detect naming collision, we need to keep around
the "GUID" using their original name without taking the linkage
into account.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19454

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267304
2016-04-23 23:38:17 +00:00