Commit Graph

12 Commits

Author SHA1 Message Date
Bjorn Pettersson 3f8027fb67 [test] Update some test cases to use -passes when specifying the pipeline
This updates transform test cases for
  ADCE
  AddDiscriminators
  AggressiveInstCombine
  AlignmentFromAssumptions
  ArgumentPromotion
  BDCE
  CalledValuePropagation
  DCE
  Reg2Mem
  WholeProgramDevirt
to use the -passes syntax when specifying the pipeline.

Given that LLVM_ENABLE_NEW_PASS_MANAGER isn't set to off (which is
a deprecated feature) the updated test cases already used the new
pass manager, but they were using the legacy syntax when specifying
the passes to run. This patch can be seen as a step toward deprecating
that interface.

This patch also removes some redundant RUN lines. Here I am
referring to test cases that had multiple RUN lines verifying both
the legacy "-passname" syntax and the new "-passes=passname" syntax.
Since we switched the default pass manager to "new PM" both RUN lines
have verified the new PM version of the pass (more or less wasting
time running the same test twice), unless LLVM_ENABLE_NEW_PASS_MANAGER
is set to "off". It is assumed that it is enough to run these tests
with the new pass manager now.

Differential Revision: https://reviews.llvm.org/D108472
2021-09-29 21:51:08 +02:00
Arthur Eubanks 460dda071e [WholeProgramDevirt][NewPM] Add NPM testing path to match legacy pass
The legacy pass's default constructor sets UseCommandLine = true and
goes down a separate testing route. Match that in the NPM pass.

This fixes all tests in llvm/test/Transforms/WholeProgramDevirt under NPM.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D88588
2020-09-30 17:27:37 -07:00
Bob Haarman cc5c58889e [WPD] Avoid noalias assumptions in unique return value optimization
Summary:
Changes the type of the @__typeid_.*_unique_member imports we generate
for unique return value optimization from i8 to [0 x i8]. This
prevents assuming that these imports do not alias, such as when
two unique return values occur in the same vtable.

Fixes PR45393.

Reviewers: tejohnson, pcc

Reviewed By: pcc

Subscribers: aganea, hiraditya, rnk, george.burgess.iv, dblaikie, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77421
2020-04-16 14:49:51 -07:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Peter Collingbourne 2974856ad4 Use branch funnels for virtual calls when retpoline mitigation is enabled.
The retpoline mitigation for variant 2 of CVE-2017-5715 inhibits the
branch predictor, and as a result it can lead to a measurable loss of
performance. We can reduce the performance impact of retpolined virtual
calls by replacing them with a special construct known as a branch
funnel, which is an instruction sequence that implements virtual calls
to a set of known targets using a binary tree of direct branches. This
allows the processor to speculately execute valid implementations of the
virtual function without allowing for speculative execution of of calls
to arbitrary addresses.

This patch extends the whole-program devirtualization pass to replace
certain virtual calls with calls to branch funnels, which are
represented using a new llvm.icall.jumptable intrinsic. It also extends
the LowerTypeTests pass to recognize the new intrinsic, generate code
for the branch funnels (x86_64 only for now) and lay out virtual tables
as required for each branch funnel.

The implementation supports full LTO as well as ThinLTO, and extends the
ThinLTO summary format used for whole-program devirtualization to
support branch funnels.

For more details see RFC:
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120672.html

Differential Revision: https://reviews.llvm.org/D42453

llvm-svn: 327163
2018-03-09 19:11:44 +00:00
Peter Collingbourne b15a35e604 WholeProgramDevirt: Add import/export support for targets without absolute symbol constants.
Not all targets support the use of absolute symbols to export
constants. In particular, ARM has a wide variety of constant encodings
that cannot currently be relocated by linkers. So instead of exporting
the constants using symbols, export them directly in the summary.
The values of the constants are left as zeroes on targets that support
symbolic exports.

This may result in more cache misses when targeting those architectures
as a result of arbitrary changes in constant values, but this seems
somewhat unavoidable for now.

Differential Revision: https://reviews.llvm.org/D37407

llvm-svn: 312967
2017-09-11 22:34:42 +00:00
Peter Collingbourne 001052a067 WholeProgramDevirt: Create bitcast to i8* at each virtual call site.
We can't reuse the llvm.assume instruction's bitcast because it may not
dominate every user of the vtable pointer.

Differential Revision: https://reviews.llvm.org/D36994

llvm-svn: 311491
2017-08-22 21:41:19 +00:00
Peter Collingbourne 14dcf02fcb WholeProgramDevirt: Implement export/import support for VCP.
Differential Revision: https://reviews.llvm.org/D30017

llvm-svn: 297503
2017-03-10 20:13:58 +00:00
Peter Collingbourne 59675ba0f8 WholeProgramDevirt: Implement export/import support for unique ret val opt.
Differential Revision: https://reviews.llvm.org/D29917

llvm-svn: 297502
2017-03-10 20:09:11 +00:00
Peter Collingbourne 0152c8156b WholeProgramDevirt: Implement importing for uniform ret val opt.
Differential Revision: https://reviews.llvm.org/D29854

llvm-svn: 297350
2017-03-09 01:11:15 +00:00
Peter Collingbourne 6d284fab20 WholeProgramDevirt: Implement importing for single-impl devirtualization.
Differential Revision: https://reviews.llvm.org/D29844

llvm-svn: 297333
2017-03-09 00:21:25 +00:00