881 Commits

Author SHA1 Message Date
serge-sans-paille
38818b60c5
Move from llvm::makeArrayRef to ArrayRef deduction guides - llvm/ part
Use deduction guides instead of helper functions.

The only non-automatic changes have been:

1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).

Per reviewers' comment, some useless makeArrayRef have been removed in the process.

This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.

Differential Revision: https://reviews.llvm.org/D140955
2023-01-05 14:11:08 +01:00
Archibald Elliott
f09cf34d00 [Support] Move TargetParsers to new component
This is a fairly large changeset, but it can be broken into a few
pieces:
- `llvm/Support/*TargetParser*` are all moved from the LLVM Support
  component into a new LLVM Component called "TargetParser". This
  potentially enables using tablegen to maintain this information, as
  is shown in https://reviews.llvm.org/D137517. This cannot currently
  be done, as llvm-tblgen relies on LLVM's Support component.
- This also moves two files from Support which use and depend on
  information in the TargetParser:
  - `llvm/Support/Host.{h,cpp}` which contains functions for inspecting
    the current Host machine for info about it, primarily to support
    getting the host triple, but also for `-mcpu=native` support in e.g.
    Clang. This is fairly tightly intertwined with the information in
    `X86TargetParser.h`, so keeping them in the same component makes
    sense.
  - `llvm/ADT/Triple.h` and `llvm/Support/Triple.cpp`, which contains
    the target triple parser and representation. This is very intertwined
    with the Arm target parser, because the arm architecture version
    appears in canonical triples on arm platforms.
- I moved the relevant unittests to their own directory.

And so, we end up with a single component that has all the information
about the following, which to me seems like a unified component:
- Triples that LLVM Knows about
- Architecture names and CPUs that LLVM knows about
- CPU detection logic for LLVM

Given this, I have also moved `RISCVISAInfo.h` into this component, as
it seems to me to be part of that same set of functionality.

If you get link errors in your components after this patch, you likely
need to add TargetParser into LLVM_LINK_COMPONENTS in CMake.

Differential Revision: https://reviews.llvm.org/D137838
2022-12-20 11:05:50 +00:00
Krzysztof Parzyszek
3c255f679c Process: convert Optional to std::optional
This applies to GetEnv and FindInEnvPath.
2022-12-06 09:56:14 -08:00
Fangrui Song
4e62072ca1 [Passes] llvm::Optional => std::optional 2022-12-04 20:44:52 +00:00
Fangrui Song
7d43c3ba51 IR: HotnessThreshold llvm::Optional => std::optional 2022-12-04 19:06:47 +00:00
Fangrui Song
bac974278c CodeGen/CommandFlags: Convert Optional to std::optional 2022-12-03 18:38:12 +00:00
Krzysztof Parzyszek
8c7c20f033 Convert Optional<CodeModel> to std::optional<CodeModel> 2022-12-03 12:08:47 -06:00
Kazu Hirata
aadaaface2 [llvm] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02 21:11:44 -08:00
Qiongsi Wu
3faab85c12 [AIX][LTO] Enabling Context Sensitive PGO Options
This patch enables context sensitive PGO (CSPGO) for LTO on AIX. Two parts are involved:

  # Frontend logic is added so libLTO can understand the CSPGO related options.
  # Two options are added to the backend so that the LTOCodeGenerator can understand the CSPGO related options and make use of them.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D138854
2022-11-30 10:22:26 -05:00
Wael Yehia
d4cb39287c [AIX][LTO] Properly respect LDR_CNTRL and set MAXDATA32 to 0xA0000000@DSA.
Reviewed By: rzurob

Differential Revision: https://reviews.llvm.org/D138944
2022-11-29 22:15:59 +00:00
Bjorn Pettersson
99c47d9e31 Remove TargetMachine::adjustPassManager
Since opt no longer supports to run default (O0/O1/O2/O3/Os/Oz)
pipelines using the legacy PM, there are no in-tree uses of
TargetMachine::adjustPassManager remaining. This patch removes the
no longer used adjustPassManager functions.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D137796
2022-11-28 10:24:16 +01:00
Kazu Hirata
b68a38a960 [LTO] Use std::optional in LTO.cpp (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-11-26 15:29:30 -08:00
Qiongsi Wu
573ff0f7d2 [AIX][LTO] Teaching lto-aix-system-assembler Relative Path and Tilde Resolution
The `lto-aix-system-assembler` currently only understands absolute path. This patch teaches the option so that it can resolve relative paths and tilde.

Reviewed By: w2yehia

Differential Revision: https://reviews.llvm.org/D138729
2022-11-25 15:34:25 -05:00
Evgeniy Brevnov
721f975d35 Use PassGate from LLVMContext if any otherwise global one
Differential Revision: https://reviews.llvm.org/D137149
2022-11-25 15:13:04 +07:00
Fangrui Song
5f759beaae [LTO] Move cl::opt inside llvm:: after D53294 2022-11-23 23:22:26 -08:00
Zequan Wu
84be92d26f Reland "[LTO][COFF] Use bitcode file names in lto native object file names."
This reverts commit 34108082947c964ae9bbfcd9808f2fd31c0d672f with fixes.
2022-11-22 13:46:42 -08:00
Roman Lebedev
3410808294
Revert "Reland "[LTO][COFF] Use bitcode file names in lto native object file names.""
Breaks build of LLVMgold here:
```
/repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1108:19: error: no matching function for call to 'localCache'
    Cache = check(localCache("ThinLTO", "Thin", options::cache_dir, AddBuffer));
                  ^~~~~~~~~~
/repositories/llvm-project/llvm/include/llvm/Support/Caching.h:72:21: note: candidate function not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1102:20)' to 'llvm::AddBufferFn' (aka 'function<void (unsigned int, const llvm::Twine &, std::unique_ptr<MemoryBuffer>)>') for 4th argument
Expected<FileCache> localCache(
                    ^
/repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1110:18: error: no viable conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'llvm::AddStreamFn' (aka 'function<Expected<std::unique_ptr<CachedFileStream>> (unsigned int, const llvm::Twine &)>')
  check(Lto->run(AddStream, Cache));
                 ^~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:375:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'std::nullptr_t' for 1st argument
      function(nullptr_t) noexcept
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:386:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'const std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream>> (unsigned int, const llvm::Twine &)> &' for 1st argument
      function(const function& __x)
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:404:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream>> (unsigned int, const llvm::Twine &)> &&' for 1st argument
      function(function&& __x) noexcept
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:435:2: note: candidate template ignored: requirement '_Callable<(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &, (lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20), std::__invoke_result<(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &, unsigned int, const llvm::Twine &>>::value' was not satisfied [with _Functor = (lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &]
        function(_Functor&& __f)
        ^
/repositories/llvm-project/llvm/include/llvm/LTO/LTO.h:278:25: note: passing argument to parameter 'AddStream' here
  Error run(AddStreamFn AddStream, FileCache Cache = nullptr);
                        ^

```

This reverts commit 387620aa8cea33174b6c1fb80c1af713fee732ac.
2022-11-23 00:40:12 +03:00
Zequan Wu
387620aa8c Reland "[LTO][COFF] Use bitcode file names in lto native object file names."
This reverts commit eef5405f74ae208e3e2eb7daacecac923d7338f2.
2022-11-22 11:26:18 -08:00
Zequan Wu
eef5405f74 Revert "[LTO][COFF] Use bitcode file names in lto native object file names."
This reverts commit 531ed6d5aa65f41c6dfe2e74905d5c6c88fc95a7.
2022-11-22 10:55:05 -08:00
Zequan Wu
531ed6d5aa [LTO][COFF] Use bitcode file names in lto native object file names.
Currently the lto native object files have names like main.exe.lto.1.obj. In
PDB, those names are used as names for each compiland. Microsoft’s tool
SizeBench uses those names to present to users the size of each object files.
So, names like main.exe.lto.1.obj is not user friendly.

This patch makes the lto native object file names more readable by using
the bitcode file names as part of the file names. For example, if the input
bitcode file has path like "path/to/foo.obj", its corresponding lto native
object file path would be "path/to/main.exe.lto.foo.obj". Since the lto native
object file name only bothers PDB, this patch only changes the lld-linker's
behavior.

Reviewed By: tejohnson, MaskRay, #lld-macho

Differential Revision: https://reviews.llvm.org/D137217
2022-11-22 10:19:58 -08:00
Fangrui Song
12050a3fb7 [LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally
For a local linkage GlobalObject in a non-prevailing COMDAT, it remains defined while its
leader has been made available_externally. This violates the COMDAT rule that
its members must be retained or discarded as a unit.

To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)

This fixes two problems.

(a) `__cxx_global_var_init` in a non-prevailing COMDAT group used to
linger around (unreferenced, hence benign), and is now correctly discarded.
```
int foo();
inline int v = foo();
```

(b) Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.

```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
#include "c.h"
int main() {
  bar();
  foo();
}
eof
cat > m2.cc <<'eof'
#include "c.h"
__attribute__((noinline)) void bar() {
  foo();
}
eof

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
```

If a GlobalAlias references a GlobalValue which is just changed to
available_externally, change the GlobalAlias as well (e.g. C5/D5 comdats due to
cc1 -mconstructor-aliases). The GlobalAlias may be referenced by other
available_externally functions, so it cannot easily be removed.

Depends on D137441: we use available_externally to mark a GlobalAlias in a
non-prevailing COMDAT, similar to how we handle GlobalVariable/Function.
GlobalAlias may refer to a ConstantExpr, not changing GlobalAlias to
GlobalVariable gives flexibility for future extensions (the use case is niche.
For simplicity we don't handle it yet). In addition, available_externally
GlobalAlias is the most straightforward implementation and retains the aliasee
information to help optimizers.

See windows-vftable.ll: Windows vftable uses an alias pointing to a
private constant where the alias is the COMDAT leader. The COMDAT use case
is skeptical and ThinLTO does not discard the alias in the non-prevailing COMDAT.
This patch retains the behavior.

See new tests ctor-dtor-alias2.ll: depending on whether the complete object
destructor emitted, when ctor/dtor aliases are used, we may see D0/D2 COMDATs in
one TU and D0/D1/D2 in a D5 COMDAT in another TU.
Allow such a mix-and-match with `if (GO->getComdat()->getName() == GO->getName()) NonPrevailingComdats.insert(GO->getComdat());`

GlobalAlias handling in ThinLTO is still weird, but this patch should hopefully
improve the situation for at least all cases I can think of.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D135427
2022-11-16 22:13:22 -08:00
Fangrui Song
2c239da691 Revert D135427 "[LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally"
This reverts commit 8901635423cbea4324059a5127657126d2e00ce1.

This change broke the following example and we need to check `if (GO->getComdat()->getName() == GO->getName())`
before `NonPrevailingComdats.insert(GO->getComdat());`
Revert for clarify.

```
// a.cc
template <typename T>
struct A final { virtual ~A() {} };
extern "C" void aa() { A<int> a; }
// b.cc
template <typename T>
struct A final { virtual ~A() {} };
template struct A<int>;
extern "C" void bb(A<int> *a) { delete a; }

clang -c -fpic -O0 -flto=thin a.cc && ld.lld -shared a.o b.o
```
2022-11-16 21:43:50 -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
Ying Yi
ca875cb4fe [ThinLTO] a ThinLTO warning is added if cache_size_bytes or cache_size_files is too small for the current link job. The warning recommends the user to consider adjusting --thinlto-cache-policy.
A specific case for ThinLTO cache pruning is that the current build is huge, and the cache wasn't big enough to hold the intermediate object files of that build. So in doing that build, a file would be cached, and later in that same build it would be evicted. This was significantly decreasing the effectiveness of the cache. By giving this warning, the user could identify the required cache size/files and improve ThinLTO link speed.

Differential Revision: https://reviews.llvm.org/D135590
2022-11-14 12:27:29 +00:00
Fangrui Song
8901635423 [LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally
For a local linkage GlobalObject in a non-prevailing COMDAT, it remains defined while its
leader has been made available_externally. This violates the COMDAT rule that
its members must be retained or discarded as a unit.

To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)

This fixes two problems.

(a) `__cxx_global_var_init` in a non-prevailing COMDAT group used to
linger around (unreferenced, hence benign), and is now correctly discarded.
```
int foo();
inline int v = foo();
```

(b) Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.

```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
#include "c.h"
int main() {
  bar();
  foo();
}
eof
cat > m2.cc <<'eof'
#include "c.h"
__attribute__((noinline)) void bar() {
  foo();
}
eof

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
```

If a GlobalAlias references a GlobalValue which is just changed to
available_externally, change the GlobalAlias as well (e.g. C5/D5 comdats due to
cc1 -mconstructor-aliases). The GlobalAlias may be referenced by other
available_externally functions, so it cannot easily be removed.

Depends on D137441: we use available_externally to mark a GlobalAlias in a
non-prevailing COMDAT, similar to how we handle GlobalVariable/Function.
GlobalAlias may refer to a ConstantExpr, not changing GlobalAlias to
GlobalVariable gives flexibility for future extensions (the use case is niche.
For simplicity we don't handle it yet). In addition, available_externally
GlobalAlias is the most straightforward implementation and retains the aliasee
information to help optimizers.

See windows-vftable.ll: Windows vftable uses an alias pointing to a
private constant where the alias is the COMDAT leader. The COMDAT use case
is skeptical and ThinLTO does not discard the alias in the non-prevailing COMDAT.
This patch retains the behavior.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D135427
2022-11-10 21:54:43 -08:00
Alan Zhao
885e6105b4 Revert "[LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally"
This reverts commit 89ddcff1d2d6e9f4de78f3a563a8b1987bf7ea8f.

Reason: This breaks bootstrapping builds of LLVM on Windows using
ThinLTO; see https://crbug.com/1382839
2022-11-10 17:48:18 -08:00
Fangrui Song
89ddcff1d2 [LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally
For a local linkage GlobalObject in a non-prevailing COMDAT, it remains defined while its
leader has been made available_externally. This violates the COMDAT rule that
its members must be retained or discarded as a unit.

To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)

This fixes two problems.

(a) `__cxx_global_var_init` in a non-prevailing COMDAT group used to
linger around (unreferenced, hence benign), and is now correctly discarded.
```
int foo();
inline int v = foo();
```

(b) Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.

```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
#include "c.h"
int main() {
  bar();
  foo();
}
eof
cat > m2.cc <<'eof'
#include "c.h"
__attribute__((noinline)) void bar() {
  foo();
}
eof

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
```

If a GlobalAlias references a GlobalValue which is just changed to
available_externally, change the GlobalAlias as well (e.g. C5/D5 comdats due to
cc1 -mconstructor-aliases). The GlobalAlias may be referenced by other
available_externally functions, so it cannot easily be removed.

Depends on D137441: we use available_externally to mark a GlobalAlias in a
non-prevailing COMDAT, similar to how we handle GlobalVariable/Function.
GlobalAlias may refer to a ConstantExpr, not changing GlobalAlias to
GlobalVariable gives flexibility for future extensions (the use case is niche.
For simplicity we don't handle it yet). In addition, available_externally
GlobalAlias is the most straightforward implementation and retains the aliasee
information to help optimizers.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D135427
2022-11-07 10:07:10 -08:00
Fangrui Song
c80b12d352 Revert D135427 "[LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally"
This reverts commit 8ef3fd8d59ba0100bc6e83350ab1e978536aa531.

I mentioned that GlobalAlias was not handled. It turns out GlobalAlias has to be handled in the same patch (as opposed to in a follow-up),
as otherwise clang codegen of C5/D5 constructor/destructor would regress (https://reviews.llvm.org/D135427#3869003).
2022-10-19 11:24:12 -07:00
serge-sans-paille
232e0a011e
[lto] Do not try to internalize symbols with escaped name
Because of LLVM mangling escape sequence (through '\01' prefix), it is possible
for a single symbols two have two different IR representations.

For instance, consider @symbol and @"\01_symbol". On OSX, because of the system
mangling rules, these two IR names point are converted in the same final symbol
upon linkage.

LTO doesn't model this behavior, which may result in symbols being incorrectly
internalized (if all reference use the escaping sequence while the definition
doesn't).

The proper approach is probably to use the mangled name to compute GUID to
avoid the dual representation, but we can also avoid discarding symbols that are
bound to two different IR names. This is an approximation, but it's less
intrusive on the codebase.

Fix #57864

Differential Revision: https://reviews.llvm.org/D135710
2022-10-14 22:34:17 +02:00
Fangrui Song
8ef3fd8d59 [LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally
For a local linkage GlobalObject in a non-prevailing COMDAT, it remains defined while its
leader has been made available_externally. This violates the COMDAT rule that
its members must be retained or discarded as a unit.

To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)

This fixes two problems.

(a) `__cxx_global_var_init` in a non-prevailing COMDAT group used to
linger around (unreferenced, hence benign), and is now correctly discarded.
```
int foo();
inline int v = foo();
```

(b) Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.

```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
int main() {
  bar();
  foo();
}
eof
cat > m2.cc <<'eof'
__attribute__((noinline)) void bar() {
  foo();
}
eof

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
```

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D135427
2022-10-11 15:30:07 -07:00
Jordan Rupprecht
fb27fd5f88 Revert "[LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally"
This reverts commit 4fbe33593c8132fdc48647c06f4d1455bfff1c88. It causes linking errors, with details provided internally. (Hopefully the author/reviewers will be able to upstream the internal repro).
2022-10-10 11:40:45 -07:00
Fangrui Song
4fbe33593c [LTO] Make local linkage GlobalValue in non-prevailing COMDAT available_externally
See the updated linkonce_resolution_comdat.ll. For a local linkage GV in a
non-prevailing COMDAT, it remains defined while its leader has been made
available_externally. This violates the COMDAT rule that its members must be
retained or discarded as a unit.

To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)

Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.

```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
#include "c.h"
int main() {
  bar();
  foo();
}
eof
cat > m2.cc <<'eof'
#include "c.h"
__attribute__((noinline)) void bar() {
  foo();
}
eof

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
# one _Z3foov

clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
# one _Z3foov
```

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D135427
2022-10-08 11:09:43 -07:00
Qiongsi Wu
ef399d1cfc [LTO][AIX] Invoking AIX System Assembler in LTO CodeGen
This patch teaches LTOCodeGenerator to call into the AIX system assembler to generate object files. This is in contrast to the approach taken on other platforms, where the LTOCodeGenerate calls the integrated assembler to generate object files.  We need to rely on the system assembler because the integrated assembler is incomplete at the moment.

Reviewed By: w2yehia, MaskRay

Differential Revision: https://reviews.llvm.org/D134375
2022-09-28 14:26:50 -04:00
Mircea Trofin
c625c17b88 [lld][thinlto] Include -mllvm options in the thinlto cache key
They may modify thinlto optimization.

This patch only extends support for `-mllvm`. There is another way to
pass llvm flags, `-plugin-opt`, but its processing is different and will
be provided in a subsequent patch.

Differential Revision: https://reviews.llvm.org/D134013
2022-09-19 12:04:17 -07:00
Kazu Hirata
258531b7ac Remove redundant initialization of Optional (NFC) 2022-08-20 21:18:28 -07:00
Quinn Pham
b6cc5ddc94 [libLTO] Set data-sections by default in libLTO.
This patch changes legacy LTO to set data-sections by default. The user can
explicitly unset data-sections. The reason for this patch is to match the
behaviour of lld and gold plugin. Both lld and gold plugin have data-sections on
by default.

This patch also fixes the forwarding of the clang options -fno-data-sections and
-fno-function-sections to libLTO. Now, when -fno-data/function-sections are
specified in clang, -data/function-sections=0 will be passed to libLTO to
explicitly unset data/function-sections.

Reviewed By: w2yehia, MaskRay

Differential Revision: https://reviews.llvm.org/D129401
2022-07-27 09:39:39 -05:00
Quinn Pham
70ec8cd024 Revert "[libLTO] Set data-sections by default in libLTO."
This reverts commit f565444b486d49f84297c3a279ca24d785961ea8.
2022-07-27 08:47:00 -05:00
Quinn Pham
f565444b48 [libLTO] Set data-sections by default in libLTO.
This patch changes legacy LTO to set data-sections by default. The user can
explicitly unset data-sections. The reason for this patch is to match the
behaviour of lld and gold plugin. Both lld and gold plugin have data-sections on
by default.

This patch also fixes the forwarding of the clang options -fno-data-sections and
-fno-function-sections to libLTO. Now, when -fno-data/function-sections are
specified in clang, -data/function-sections=0 will be passed to libLTO to
explicitly unset data/function-sections.

Reviewed By: w2yehia, MaskRay

Differential Revision: https://reviews.llvm.org/D129401
2022-07-27 08:34:40 -05:00
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
Jin Xin Ng
65001f5777
[LTO][ELF] Add selective --save-temps= option
Allows specific “temps” to be saved, instead of the current all-or-nothing nature of --save-temps. Multiple of these “temps” can be saved by specifying the argument multiple times.

Differential Revision: https://reviews.llvm.org/D127778
2022-07-06 10:06:18 -07:00
Jin Xin Ng
22f1273357
[ThinLTO][ELF] Add --thinlto-emit-index-files option
Allows ThinLTO indices to be written to disk on-the-fly/as-part-of “normal” linker execution. Previously ThinLTO indices could be written via --thinlto-index-only but that would cause the linker to exit early. For MLGO specifically, this enables saving the ThinLTO index files without having to restart the linker to collect data only available at later stages (i.e. output of --save-temps) of the linker's execution.

Note, this option does not currently work with:
--thinlto-object-suffix-replace, as this is intended to be used to consume minimized IR bitcode files while --thinlto-emit-index-files is intended to be run together with InProcessThinLTO (which cannot parse minimized IR).
--thinlto-prefix-replace  support is left unimplemented but can be implemented if needed

Differential Revision: https://reviews.llvm.org/D127777
2022-06-23 12:35:42 -07:00
Kazu Hirata
7a47ee51a1 [llvm] Don't use Optional::getValue (NFC) 2022-06-20 22:45:45 -07:00
Kazu Hirata
e0e687a615 [llvm] Don't use Optional::hasValue (NFC) 2022-06-20 10:38:12 -07:00
Guillaume Chatelet
f1255186c7 [NFC][Alignment] Remove max functions between Align and MaybeAlign
`llvm::max(Align, MaybeAlign)` and `llvm::max(MaybeAlign, Align)` are
not used often enough to be required. They also make the code more opaque.

Differential Revision: https://reviews.llvm.org/D128121
2022-06-20 08:37:48 +00:00
Reid Kleckner
570e76bb6c [config] Remove vestigial LLVM_VERSION_INFO
This has been superseded by the llvm/Support/VCSRevision.h header. So
far as I can tell, nothing in the CMake build sets LLVM_VERSION_INFO. It
was always undefined, and the ifdefs using it were dead. However, CMake
is very flexible, so it's possible that I missed some ways to set this
variable. One could, for example, probably pass -DLLVM_VERSION_INFO=x on
the command line and get that through to configure_file, or set the
variable in an obscure way (`set(${proj}_VERSION_INFO "x")`). I'm
reasonably confident that isn't happening, but I'd like a second
opinion.

Update the Bazel and gn builds accordingly.

Differential Revision: https://reviews.llvm.org/D126977
2022-06-07 11:36:26 -07:00
serge-sans-paille
fa5a4e1b95 [iwyu] Handle regressions in libLLVM header include
Running iwyu-diff on LLVM codebase since a96638e50ef5 detected a few
regressions, fixing them.
2022-04-13 20:53:19 +02:00