Commit Graph

3 Commits

Author SHA1 Message Date
Teresa Johnson 9766fd64fb [ThinLTO] Add per-module indexes to combined index consistently
Summary:
Without this change we only add module paths to the combined index when
there is a module hash or at least one global value. Make this more
consistent by adding the module to the index whenever there is a summary
section, and it is a per-module summary (had a MODULE_CODE_SOURCE_FILENAME
record).

Since we will no longer add module paths lazily, add a new interface to get
the module info from the index that asserts it is already added.

Fixes PR37899.

Reviewers: Vlad, pcc

Subscribers: mehdi_amini, inglorion, steven_wu, llvm-commits

Differential Revision: https://reviews.llvm.org/D48511

llvm-svn: 335567
2018-06-26 01:32:58 +00:00
Vitaly Buka a5376f393e [LTO] Make processing of combined module more consistent
Summary:
1. Use stream 0 only for combined module. Previously if combined module was not
processes ThinLTO used the stream for own output. However small changes in input,
could trigger combined module  and shuffle outputs making life of llvm::LTO harder.

2. Always process combined module and write output to stream 0. Processing empty
combined module is cheap and allows llvm::LTO users to avoid implementing processing
which is already done in llvm::LTO.

Subscribers: mehdi_amini, inglorion, eraman, hiraditya

Differential Revision: https://reviews.llvm.org/D41267

llvm-svn: 320905
2017-12-16 02:10:00 +00:00
Peter Collingbourne fa58f7528e LTO: Mark undefined module asm symbols as used.
Marking them as used causes them to be considered visible outside of LTO. This
prevents the symbols from being internalized or discarded, either by GlobalDCE
or by summary-based dead stripping in ThinLTO.

This change makes it unnecessary to add these symbols to llvm.compiler.used
in the backend, as the symbols are kept alive by virtue of being external,
so remove the backend code that handles that.

Fixes PR32798.

Differential Revision: https://reviews.llvm.org/D32544

llvm-svn: 301438
2017-04-26 17:53:39 +00:00