160 Commits

Author SHA1 Message Date
Fangrui Song
1b162fabe8 [Support] Change SetVector's default template parameter to SmallVector<*, 0>
Similar to D156016 for MapVector.

This brings back commit fae7b98c221b5b28797f7b56b656b6b819d99f27 with a
fix to llvm/unittests/Support/ThreadPool.cpp's `_WIN32` code path.
2023-07-25 13:13:35 -07:00
Simon Pilgrim
3d83912c0c Revert rGfae7b98c221b5b28797f7b56b656b6b819d99f27 "[Support] Change SetVector's default template parameter to SmallVector<*, 0>"
This is failing on Windows MSVC builds:
llvm\unittests\Support\ThreadPool.cpp(380): error C2440: 'return': cannot convert from 'Vector' to 'std::vector<llvm::BitVector,std::allocator<llvm::BitVector>>'
        with
        [
            Vector=llvm::SmallVector<llvm::BitVector,0>
        ]
2023-07-25 10:22:08 +01:00
Fangrui Song
fae7b98c22 [Support] Change SetVector's default template parameter to SmallVector<*, 0>
Similar to D156016 for MapVector.
2023-07-25 00:39:17 -07:00
Fangrui Song
fb2a971c01 [Support] Change MapVector's default template parameter to SmallVector<*, 0>
SmallVector<*, 0> is often a better replacement for std::vector :
both the object size and the code size are smaller.
(SmallMapVector uses SmallVector as well, but it is not common.)

clang size decreases by 0.0226%.
instructions:u decreases 0.037% when compiling a sqlite3 amalgram.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D156016
2023-07-24 22:04:03 -07:00
Matthew Voss
a1ca3af31e [llvm] A Unified LTO Bitcode Frontend
Here's a high level summary of the changes in this patch. For more
information on rational, see the RFC.
(https://discourse.llvm.org/t/rfc-a-unified-lto-bitcode-frontend/61774).

  - Add config parameter to LTO backend, specifying which LTO mode is
    desired when using unified LTO.
  - Add unified LTO flag to the summary index for efficiency. Unified
    LTO modules can be detected without parsing the module.
  - Make sure that the ModuleID is generated by incorporating more types
    of symbols.

Differential Revision: https://reviews.llvm.org/D123803
2023-07-05 14:53:14 -07:00
Arnold Schwaighofer
98eb8abff6 Add a type_checked_load_relative to support relative function pointer tables
This adds a type_checked_load_relative intrinsic whose semantics it is to
load a relative function pointer.

A relative function pointer is a pointer to a 32bit value that when
added to its address yields the address of the function.

Differential Revision: https://reviews.llvm.org/D143204
2023-06-29 08:33:45 -07:00
Teresa Johnson
cfad2d3a3d [MemProf] Context disambiguation cloning pass [patch 4/4]
Applies ThinLTO cloning decisions made during the thin link and
recorded in the summary index to the IR during the ThinLTO backend.

Depends on D141077.

Differential Revision: https://reviews.llvm.org/D149117
2023-05-05 16:26:32 -07:00
Teresa Johnson
3adc6e0308 [ThinLTO] Remove BlockCount for non partial sample profile builds
As pointed out in
https://discourse.llvm.org/t/undeterministic-thin-index-file/69985, the
block count added to distributed ThinLTO index files breaks incremental
builds on ThinLTO - if any linked file has a different number of BBs,
then the accumulated sum placed in the index files will change, causing
all ThinLTO backend compiles to be redone.

The block count is only used for scaling of partial sample profiles, and
was added in D80403 for D79831.

This patch simply removes this field from the index files of non partial
sample profile compiles, which is NFC on the output of the compiler.

We subsequently need to see if this can be removed for partial sample
profiles without signficant performance loss, or redesigned in a way
that does not destroy caching.

Differential Revision: https://reviews.llvm.org/D148746
2023-04-20 11:45:15 -07:00
Leonard Chan
474f5efebe Revert "[llvm] Teach whole program devirtualization about relative vtables"
This reverts commit db288184765c0b4010060ebea1f6de3ac1f66445.

Reverting since it broke our lto builders reported by fxbug.dev/123807.
2023-03-26 01:53:13 +00:00
Leonard Chan
db28818476 [llvm] Teach whole program devirtualization about relative vtables
Prior to this patch, WPD was not acting on relative-vtables in C++. This
involves teaching WPD about these things:

- llvm.load.relative which is how relative-vtables are indexed (instead of GEP)
- dso_local_equivalent which is used in the vtable itself when taking the
  offset between a virtual function and vtable
- Update llvm/test/ThinLTO/X86/devirt.ll to use opaque pointers and add
  equivalent tests for RV

Differential Revision: https://reviews.llvm.org/D134320
2023-02-23 22:18:43 +00:00
Teresa Johnson
8045ba8948 [ThinLTO/WPD] Handle function alias in vtable correctly
We were not summarizing a function alias in the vtable, leading to
incorrect WPD in some cases, and missing WPD in others.

Specifically, we would end up ignoring function aliases as they aren't
summarized, so we could incorrectly devirtualize if there was a single
other non-alias function in a compatible vtable. And if there was only
one implementation, but it was an alias, we would not be able to
identify and perform the single implementation devirtualization.

Handling the alias summary correctly also required fixing the handling
in mustBeUnreachableFunction, so that it is not incorrectly ignored.

Regular LTO is conservatively correct because it will skip
devirtualizing when any pointer within a vtable is not a function.
However, it needs additional work to be able to take advantage of
function alias within the vtable that is in fact the only
implementation. For that reason, the Regular LTO testing in the second
test case is currently disabled, and will be enabled along with a follow
on enhancement fix for Regular LTO WPD.

Differential Revision: https://reviews.llvm.org/D144209
2023-02-16 18:20:12 -08:00
Fangrui Song
f199f97c72 ModuleSummaryAnalysis: Internalize some cl::opt 2022-11-23 17:33:34 -08:00
Teresa Johnson
9eacbba290 Restore "[MemProf] ThinLTO summary support" with more fixes
This restores commit 98ed423361de2f9dc0113a31be2aa04524489ca9 and
follow on fix 00c22351ba697dbddb4b5bf0ad94e4bcea4b316b, which were
reverted in 5d938eb6f79b16f55266dd23d5df831f552ea082 due to an
MSVC bot failure. I've included a fix for that failure.

Differential Revision: https://reviews.llvm.org/D135714
2022-11-16 09:42:41 -08:00
Jeremy Morse
5d938eb6f7 Revert "Restore "[MemProf] ThinLTO summary support" with fixes"
This reverts commit 00c22351ba697dbddb4b5bf0ad94e4bcea4b316b.
This reverts commit 98ed423361de2f9dc0113a31be2aa04524489ca9.

Seemingly MSVC has some kind of issue with this patch, in terms of linking:

  https://lab.llvm.org/buildbot/#/builders/123/builds/14137

I'll post more detail on D135714 momentarily.
2022-11-16 11:21:02 +00:00
Teresa Johnson
98ed423361 Restore "[MemProf] ThinLTO summary support" with fixes
This restores 47459455009db4790ffc3765a2ec0f8b4934c2a4, which was
reverted in commit 452a14efc84edf808d1e2953dad2c694972b312f, along with
fixes for a couple of bot failures.
2022-11-15 08:55:17 -08:00
Teresa Johnson
452a14efc8 Revert "[MemProf] ThinLTO summary support"
This reverts commit 47459455009db4790ffc3765a2ec0f8b4934c2a4.

Revert while I try to fix a couple of non-Linux build failures.
2022-11-15 07:39:40 -08:00
Teresa Johnson
4745945500 [MemProf] ThinLTO summary support
Implements the ThinLTO summary support for memprof related metadata.

This includes support for the assembly format, and for building the
summary from IR during ModuleSummaryAnalysis.

To reduce space in both the bitcode format and the in memory index,
we do 2 things:
1. We keep a single vector of all uniq stack id hashes, and record the
   index into this vector in the callsite and allocation memprof
   summaries.
2. When building the combined index during the LTO link, the callsite
   and allocation memprof summaries are only kept on the FunctionSummary
   of the prevailing copy.

Differential Revision: https://reviews.llvm.org/D135714
2022-11-15 06:45:12 -08:00
Fangrui Song
77bf0df376 Revert "[opt][clang] Enable using -module-summary/-flto=thin with -S/-emit-llvm"
This reverts commit bf8381a8bce28fc69857645cc7e84a72317e693e.

There is a layering violation: LLVMAnalysis depends on LLVMCore, so
LLVMCore should not include LLVMAnalysis header
llvm/Analysis/ModuleSummaryAnalysis.h
2022-11-14 15:51:03 -08:00
Alexander Shaposhnikov
bf8381a8bc [opt][clang] Enable using -module-summary/-flto=thin with -S/-emit-llvm
Enable using -module-summary with -S
(similarly to what currently can be achieved with opt <input> -o - | llvm-dis).
This is a recommit of ef9e62469.

Test plan: ninja check-all

Differential revision: https://reviews.llvm.org/D137768
2022-11-14 23:24:08 +00:00
Nikita Popov
eb470e67c1 [ModuleSummaryAnalysis] Use helper methods to check readnone/readonly (NFC)
This makes sure that this code continue working when switching to
the memory attribute.

A caveat here is that onlyReadsMemory() will also true for readnone.
To be conservative, I'm explicitly excluding that case here.
2022-10-21 12:18:57 +02:00
Arthur Eubanks
2eade1dba4 [WPD] Use new llvm.public.type.test intrinsic for potentially publicly visible classes
Turning on opaque pointers has uncovered an issue with WPD where we currently pattern match away `assume(type.test)` in WPD so that a later LTT doesn't resolve the type test to undef and introduce an `assume(false)`. The pattern matching can fail in cases where we transform two `assume(type.test)`s into `assume(phi(type.test.1, type.test.2))`.

Currently we create `assume(type.test)` for all virtual calls that might be devirtualized. This is to support `-Wl,--lto-whole-program-visibility`.

To prevent this, all virtual calls that may not be in the same LTO module instead use a new `llvm.public.type.test` intrinsic in place of the `llvm.type.test`. Then when we know if `-Wl,--lto-whole-program-visibility` is passed or not, we can either replace all `llvm.public.type.test` with `llvm.type.test`, or replace all `llvm.public.type.test` with `true`. This prevents WPD from trying to pattern match away `assume(type.test)` for public virtual calls when failing the pattern matching will result in miscompiles.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D128955
2022-07-26 08:01:08 -07:00
Schrodinger ZHU Yifan
304027206c [ThinLTO] Support aliased GlobalIFunc
Fixes https://github.com/llvm/llvm-project/issues/56290: when an ifunc is
aliased in LTO, clang will attempt to create an alias summary; however, as ifunc
is not included in the module summary, doing so will lead to crash.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D129009
2022-07-20 15:30:38 -07:00
Kazu Hirata
601b3a13de [Analysis] Qualify auto variables in for loops (NFC) 2022-07-16 23:26:34 -07:00
Kazu Hirata
7a47ee51a1 [llvm] Don't use Optional::getValue (NFC) 2022-06-20 22:45:45 -07:00
Jez Ng
dd29597e10 [LTO] Initialize canAutoHide() using canBeOmittedFromSymbolTable()
Per discussion on
https://reviews.llvm.org/D59709#inline-1148734, this seems like the
right course of action. `canBeOmittedFromSymbolTable()` subsumes and
generalizes the previous logic. In addition to handling `linkonce_odr`
`unnamed_addr` globals, we now also internalize `linkonce_odr` +
`local_unnamed_addr` constants.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D120173
2022-03-03 19:04:11 -05:00
serge-sans-paille
71c3a5519d Cleanup includes: LLVMAnalysis
Number of lines output by preprocessor:
before: 1065940348
after:  1065307662

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D120659
2022-03-01 18:01:54 +01:00
Fangrui Song
cf9e61a9bb [LTO][WPD] Simplify mustBeUnreachableFunction and test after D115492
An well-formed IR function definition must have an entry basic block and
a well-formed IR basic block must have one terminator so the emptiness
check can be simplified.
Also simplify the test a bit.

Reviewed By: luna

Differential Revision: https://reviews.llvm.org/D115780
2021-12-15 15:43:35 -08:00
Mingming Liu
09a704c5ef [LTO] Ignore unreachable virtual functions in WPD in hybrid LTO.
Differential Revision: https://reviews.llvm.org/D115492
2021-12-14 20:18:04 +00:00
Itay Bookstein
40ec1c0f16 [IR][NFC] Rename getBaseObject to getAliaseeObject
To better reflect the meaning of the now-disambiguated {GlobalValue,
GlobalAlias}::getBaseObject after breaking off GlobalIFunc::getResolverFunction
(D109792), the function is renamed to getAliaseeObject.
2021-10-06 19:33:10 -07:00
modimo
20faf78919 [ThinLTO] Add noRecurse and noUnwind thinlink function attribute propagation
Thinlink provides an opportunity to propagate function attributes across modules, enabling additional propagation opportunities.

This change propagates (currently default off, turn on with `disable-thinlto-funcattrs=1`) noRecurse and noUnwind based off of function summaries of the prevailing functions in bottom-up call-graph order. Testing on clang self-build:
1. There's a 35-40% increase in noUnwind functions due to the additional propagation opportunities.
2. Throughput is measured at 10-15% increase in thinlink time which itself is 1.5% of E2E link time.

Implementation-wise this adds the following summary function attributes:
1. noUnwind: function is noUnwind
2. mayThrow: function contains a non-call instruction that `Instruction::mayThrow` returns true on (e.g. windows SEH instructions)
3. hasUnknownCall: function contains calls that don't make it into the summary call-graph thus should not be propagated from (e.g. indirect for now, could add no-opt functions as well)

Testing:
Clang self-build passes and 2nd stage build passes check-all
ninja check-all with newly added tests passing

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D36850
2021-09-27 12:28:07 -07:00
Hongtao Yu
c5fafc1e73 [CSSPGO] Tweakes to lower pseudo probe runtime overhead
A couple tweaks to

1. allow more thinlto importing by excluding probe intrinsics from IR size in module summary

2. Allow general default attributes (nofree nosync nounwind) for pseudo probe intrinsic. Without those attributes, pseudo probes will be basically treated as unknown calls which will in turn block their containing functions from annotated with those attributes.

Reviewed By: wenlei

Differential Revision: https://reviews.llvm.org/D109976
2021-09-17 12:28:09 -07:00
Arthur Eubanks
92ce6db9ee [NFC] Rename AttributeList::hasFnAttribute() -> hasFnAttr()
This is more consistent with similar methods.
2021-08-13 11:09:18 -07:00
Wenlei He
1a8087adaf [ThinLTO] Disallow importing for functions with indir branch to block address
We don't allowing inlining for functions with blockaddress with uses other than strictly callbr. This is because if the blockaddress escapes the function via a global variable, inlining may lead to an invalid cross-function reference.

We check against such cases during inlining, however the check can fail for ThinLTO post-link because CFG simplification can incorrectly removes blocks based on wrong block reachability.

When we import a function with blockaddress taken in a global variable but without importing that variable, we won't go through value mapping to reflect the real address-taken-ness of the cloned blocks. For the imported clone, this leads to blocks reachable from indirect branch through global variable being incorrectly treated as unreachable and removed by SimplifyCFG.

Since inlining for such cases shouldn't be allowed in the first place, I'm marking them as ineligible for importing during pre-link to save the problem of missing address-taken-ness of imported clone as well as bad DCE and inlining.

Differential Revision: https://reviews.llvm.org/D106930
2021-07-28 18:02:48 -07:00
Nico Weber
ba7a92c01e [Support] Don't include VirtualFileSystem.h in CommandLine.h
CommandLine.h is indirectly included in ~50% of TUs when building
clang, and VirtualFileSystem.h is large.

(Already remarked by jhenderson on D70769.)

No behavior change.

Differential Revision: https://reviews.llvm.org/D100957
2021-04-21 10:19:01 -04:00
Philip Reames
908215b346 Use AssumeInst in a few more places [nfc]
Follow up to a6d2a8d6f5.  These were found by simply grepping for "::assume", and are the subset of that result which looked cleaner to me using the isa/dyn_cast patterns.
2021-04-06 13:18:53 -07:00
Fangrui Song
e6a104465d [ModuleSummaryAnalysis] Avoid duplicate elements in Worklist. NFC 2021-03-06 14:19:22 -08:00
Fangrui Song
ef312951fd collectUsedGlobalVariables: migrate SmallPtrSetImpl overload to SmallVecImpl overload after D97128
And delete the SmallPtrSetImpl overload.

While here, decrease inline element counts from 8 to 4. See D97128 for the choice.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D97257
2021-02-23 16:09:06 -08:00
Kazu Hirata
896d0e1a2a [Analysis] Use range-based for loops (NFC) 2021-02-22 20:17:18 -08:00
Fangrui Song
54fb3ca96e [ThinLTO] Add Visibility bits to GlobalValueSummary::GVFlags
Imported functions and variable get the visibility from the module supplying the
definition.  However, non-imported definitions do not get the visibility from
(ELF) the most constraining visibility among all modules (Mach-O) the visibility
of the prevailing definition.

This patch

* adds visibility bits to GlobalValueSummary::GVFlags
* computes the result visibility and propagates it to all definitions

Protected/hidden can imply dso_local which can enable some optimizations (this
is stronger than GVFlags::DSOLocal because the implied dso_local can be
leveraged for ELF -shared while default visibility dso_local has to be cleared
for ELF -shared).

Note: we don't have summaries for declarations, so for ELF if a declaration has
the most constraining visibility, the result visibility may not be that one.

Differential Revision: https://reviews.llvm.org/D92900
2021-01-27 10:43:51 -08:00
Kazu Hirata
23b0ab2acb [llvm] Use the default value of drop_begin (NFC) 2021-01-18 10:16:36 -08:00
Kazu Hirata
2efcbe24a7 [llvm] Use llvm::drop_begin (NFC) 2021-01-14 20:30:33 -08:00
Vitaly Buka
fc4fd89852 [StackSafety] Use ValueInfo in ParamAccess::Call
This avoid GUID lookup in Index.findSummaryInModule.
Follow up for D81242.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D85269
2020-08-14 12:42:44 -07:00
Vitaly Buka
5b1c70a48d [StackSafety] Pass summary into codegen
Summary:
The patch wraps ThinLTO index into immutable
pass which can be used by StackSafety analysis.

Reviewers: eugenis, pcc

Reviewed By: eugenis

Subscribers: hiraditya, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80985
2020-06-10 21:02:54 -07:00
Vitaly Buka
4666953ce2 [StackSafety] Add info into function summary
Summary:
This patch adds optional field into function summary,
implements asm and bitcode serialization. YAML
serialization is omitted and can be added later if
needed.

This patch includes this information into summary only
if module contains at least one sanitize_memtag function.
In a near future MTE is the user of the analysis.
Later if needed we can provede more direct control
on when information is included into summary.

Reviewers: eugenis

Subscribers: hiraditya, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80908
2020-06-10 02:43:28 -07:00
Hiroshi Yamauchi
a7fa35a629 [ThinLTO] Compute the basic block count across modules.
Summary:
Count the per-module number of basic blocks when the module summary is computed
and sum them up during Thin LTO indexing.

This is used to estimate the working set size under the partial sample PGO.

This is split off of D79831.

Reviewers: davidxl, espindola

Subscribers: emaste, inglorion, hiraditya, MaskRay, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80403
2020-05-28 10:33:05 -07:00
Craig Topper
a58b62b4a2 [IR] Replace all uses of CallBase::getCalledValue() with getCalledOperand().
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().

I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.

Differential Revision: https://reviews.llvm.org/D78882
2020-04-27 22:17:03 -07:00
Mircea Trofin
cb56e9b923 [llvm][NFC] Use CallBase instead of Instruction in ProfileSummaryInfo
Summary:
getProfileCount requires the parameter be a valid CallBase, and its uses
reflect that.

Reviewers: dblaikie, craig.topper, wmi

Subscribers: eraman, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78940
2020-04-27 20:47:52 -07:00
Mircea Trofin
cea6f4d5f8 [llvm][NFC][CallSite] Remove CallSite from TypeMetadataUtils & related
Reviewers: craig.topper, dblaikie

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78666
2020-04-23 08:23:16 -07:00
Mehdi Amini
384ca190ae Revert "Move ModuleSummaryAnalysis from libAnalysis to libObject to break the dependency from Analysis to Object"
This reverts commit 10df1563d608323a3144afc5f6038ecb81869b92.

Some buildbots are broken.
2020-04-14 00:27:08 +00:00
Mehdi Amini
10df1563d6 Move ModuleSummaryAnalysis from libAnalysis to libObject to break the dependency from Analysis to Object
ModuleSummaryAnalysis is the only file in libAnalysis that brings a
dependency on the CodeGen layer from libAnalysis, moving it breaks this
dependency.

Differential Revision: https://reviews.llvm.org/D77994
2020-04-13 23:12:11 +00:00