Commit Graph

15 Commits

Author SHA1 Message Date
Hans Wennborg c6e5c4654b Don't use $ as suffix for symbol names in ThinLTOBitcodeWriter and other places
Using $ breaks demangling of the symbols. For example,

$ c++filt _Z3foov\$123
_Z3foov$123

This causes problems for developers who would like to see nice stack traces
etc., but also for automatic crash tracking systems which try to organize
crashes based on the stack traces.

Instead, use the period as suffix separator, since Itanium demanglers normally
ignore such suffixes:

$ c++filt _Z3foov.123
foo() [clone .123]

This is already done in some places; try to do it everywhere.

Differential revision: https://reviews.llvm.org/D97484
2021-03-29 13:03:52 +02:00
evgeny 6d2032e259 [WPD] Provide a way to prevent functions from being devirtualized
Differential revision: https://reviews.llvm.org/D75617
2020-03-09 14:05:15 +03:00
Teresa Johnson 2f63d549f1 Restore "[LTO/WPD] Enable aggressive WPD under LTO option"
This restores 59733525d3 (D71913), along
with bot fix 19c76989bb.

The bot failure should be fixed by D73418, committed as
af954e441a.

I also added a fix for non-x86 bot failures by requiring x86 in new test
lld/test/ELF/lto/devirt_vcall_vis_public.ll.
2020-01-27 07:55:05 -08:00
Teresa Johnson 90e630a95e Revert "[LTO/WPD] Enable aggressive WPD under LTO option"
This reverts commit 59733525d3.

There is a windows sanitizer bot failure in one of the cfi tests
that I will need some time to figure out:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/57155/steps/stage%201%20check/logs/stdio
2020-01-23 17:29:24 -08:00
Teresa Johnson 59733525d3 [LTO/WPD] Enable aggressive WPD under LTO option
Summary:
Third part in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html

This patch adds type test metadata under -fwhole-program-vtables,
even for classes without hidden visibility. It then changes WPD to skip
devirtualization for a virtual function call when any of the compatible
vtables has public vcall visibility.

Additionally, internal LLVM options as well as lld and gold-plugin
options are added which enable upgrading all public vcall visibility
to linkage unit (hidden) visibility during LTO. This enables the more
aggressive WPD to kick in based on LTO time knowledge of the visibility
guarantees.

Support was added to all flavors of LTO WPD (regular, hybrid and
index-only), and to both the new and old LTO APIs.

Unfortunately it was not simple to split the first and second parts of
this part of the change (the unconditional emission of type tests and
the upgrading of the vcall visiblity) as I needed a way to upgrade the
public visibility on legacy WPD llvm assembly tests that don't include
linkage unit vcall visibility specifiers, to avoid a lot of test churn.

I also added a mechanism to LowerTypeTests that allows dropping type
test assume sequences we now aggressively insert when we invoke
distributed ThinLTO backends with null indexes, which is used in testing
mode, and which doesn't invoke the normal ThinLTO backend pipeline.

Depends on D71907 and D71911.

Reviewers: pcc, evgeny777, steven_wu, espindola

Subscribers: emaste, Prazek, inglorion, arichardson, hiraditya, MaskRay, dexonsmith, dang, davidxl, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71913
2020-01-23 16:09:44 -08:00
Amy Huang 7b1d793713 Reland "Change the X86 datalayout to add three address spaces
for 32 bit signed, 32 bit unsigned, and 64 bit pointers."
This reverts 57076d3199.

Original review at https://reviews.llvm.org/D64931.
Review for added fix at https://reviews.llvm.org/D66843.

llvm-svn: 371568
2019-09-10 23:15:38 +00:00
Vlad Tsyrklevich 57076d3199 Revert "Change the X86 datalayout to add three address spaces for 32 bit signed,"
This reverts commit r370083 because it caused check-lld failures on
sanitizer-x86_64-linux-fast.

llvm-svn: 370142
2019-08-28 01:08:54 +00:00
Amy Huang 1299945b81 Change the X86 datalayout to add three address spaces for 32 bit signed,
32 bit unsigned, and 64 bit pointers.

llvm-svn: 370083
2019-08-27 17:46:53 +00:00
Teresa Johnson d2df54e6a5 [ThinLTO] Implement index-based WPD
This patch adds support to the WholeProgramDevirt pass to perform
index-based WPD, which is invoked from ThinLTO during the thin link.

The ThinLTO backend (WPD import phase) behaves the same regardless of
whether the WPD decisions were made with the index-based or (the
existing) IR-based analysis.

Depends on D54815.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, arphaman, dang, llvm-commits

Differential Revision: https://reviews.llvm.org/D55153

llvm-svn: 367679
2019-08-02 13:10:52 +00:00
Teresa Johnson ba5a72ff8d [ThinLTO] Reenable test with workaround for known failure
Reenable the testing disabled in r364978 with the same workaround used
for this failure in the cfi-devirt.ll test. The known issue is PR39436,
and the workaround is to add -verify-machineinstrs=0.

llvm-svn: 364997
2019-07-03 02:14:47 +00:00
Teresa Johnson 45fa289eb1 [ThinLTO] Work around existing failure exposed by new test
When adding summary entries for index-based WPD (r364960), an added
test also included some additional testing of the existing hybrid
Thin/Regular LTO WPD (test/ThinLTO/X86/devirt.ll). That part of the
test is producing a failure on the llvm-clang-x86_64-expensive-checks-win
bot:

*** Bad machine code: Explicit definition marked as use ***
- function:    __typeid__ZTS1A_0_branch_funnel
- basic block: %bb.0  (0x81d4c58)
- instruction: ICALL_BRANCH_FUNNEL %0:gr64, @0, 16, @_ZN1B1fEi, 48, @_ZN1C1fEi
- operand 0:   %0:gr64
LLVM ERROR: Found 1 machine code errors.

This is functionality unrelated to the summary entries added with my
patch, so I am disabling this part of the new test until it is
addressed. I'll continue to investigate the failure.

llvm-svn: 364978
2019-07-02 23:28:28 +00:00
Teresa Johnson 54c7907f52 [ThinLTO] Dump input on failure in devirt test
To help track down bug exposed by llvm-clang-x86_64-expensive-checks-win
bot.

llvm-svn: 364973
2019-07-02 22:06:02 +00:00
Teresa Johnson a700436323 [ThinLTO] Add summary entries for index-based WPD
Summary:
If LTOUnit splitting is disabled, the module summary analysis computes
the summary information necessary to perform single implementation
devirtualization during the thin link with the index and no IR. The
information collected from the regular LTO IR in the current hybrid WPD
algorithm is summarized, including:
1) For vtable definitions, record the function pointers and their offset
within the vtable initializer (subsumes the information collected from
IR by tryFindVirtualCallTargets).
2) A record for each type metadata summarizing the vtable definitions
decorated with that metadata (subsumes the TypeIdentiferMap collected
from IR).

Also added are the necessary bitcode records, and the corresponding
assembly support.

The follow-on index-based WPD patch is D55153.

Depends on D53890.

Reviewers: pcc

Subscribers: mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits

Differential Revision: https://reviews.llvm.org/D54815

llvm-svn: 364960
2019-07-02 19:38:02 +00:00
Teresa Johnson 8d86f1ba47 Revert "[ThinLTO] Add summary entries for index-based WPD"
Mistaken commit of something still under review!

This reverts commit r351453.

llvm-svn: 351455
2019-01-17 16:05:04 +00:00
Teresa Johnson 4fcf3b1621 [ThinLTO] Add summary entries for index-based WPD
Summary:
If LTOUnit splitting is disabled, the module summary analysis computes
the summary information necessary to perform single implementation
devirtualization during the thin link with the index and no IR. The
information collected from the regular LTO IR in the current hybrid WPD
algorithm is summarized, including:
1) For vtable definitions, record the function pointers and their offset
within the vtable initializer (subsumes the information collected from
IR by tryFindVirtualCallTargets).
2) A record for each type metadata summarizing the vtable definitions
decorated with that metadata (subsumes the TypeIdentiferMap collected
from IR).

Also added are the necessary bitcode records, and the corresponding
assembly support.

The index-based WPD will be sent as a follow-on.

Depends on D53890.

Reviewers: pcc

Subscribers: mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits

Differential Revision: https://reviews.llvm.org/D54815

llvm-svn: 351453
2019-01-17 15:49:03 +00:00