Commit Graph

43355 Commits

Author SHA1 Message Date
Anastasia Stulova 769cc335e6 [OpenCL] Simplify use of C11 atomic types.
Remove requirements on extension pragma in atomic types
because it has not respected the spec wrt disabling types
and hasn't been useful either. With this change, the
developers can use atomic types from the extensions if they
are supported without enabling the pragma just like the builtin
functions

This patch does not break backward compatibility since the
extension pragma is still supported and it makes the behavior of
the compiler less strict by accepting code without needless and
inconsistent pragma statements.

Differential Revision: https://reviews.llvm.org/D100976
2021-05-14 17:43:00 +01:00
Nemanja Ivanovic 7cd2833311 [PowerPC] Add vec_vupkhpx and vec_vupklpx for XL compatibility
These are old names for these functions that XL still supports.
2021-05-14 08:02:00 -05:00
David Spickett 2db090a2eb [llvm][AsmPrinter] Restore source location to register clobber warning
Since 5de2d189e6 this particular warning
hasn't had the location of the source file containing the inline
assembly.

Fix this by reporting via LLVMContext. Which means that we no longer
have the "instantiated into assembly here" lines but they were going to
point to the start of the inline asm string anyway.

This message is already tested via IR in llvm. However we won't have
the required location info there so I've added a C file test in clang
to cover it.
(though strictly, this is testing llvm code)

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D102244
2021-05-14 08:22:57 +00:00
Michael Kruse 83ff0ff463 [Clang][OpenMP] Allow unified_shared_memory for Pascal-generation GPUs.
The Pascal architecture supports the page migration engine required for
unified_shared_memory, as indicated by NVIDIA:
 * https://developer.nvidia.com/blog/unified-memory-cuda-beginners/
 * https://developer.nvidia.com/blog/beyond-gpu-memory-limits-unified-memory-pascal/
 * https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#um-requirements

The limitation was introduced in D54493 which justified the cut-off by
the requirement for unified addressing. However, Unified Virtual
Addressing (UVA) is already available with sm20 (Fermi, Kepler,
Maxwell):
 * https://docs.nvidia.com/cuda/gpudirect-rdma/index.html#basics-of-uva-cuda-memory-management

Unified shared memory might even be possible with these, but with
migration of entire allocations on kernel startup.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D101595
2021-05-13 17:15:34 -05:00
Lang Hames 71a0609a2b [clang-repl] Temporarily disable the execute.cpp test on ppc64.
This test is failing on some builders (see [1]) with the following error:

error: Added modules have incompatible data layouts:
  e-m:e-i64:64-n32:64-S128-v256:256:256-v512:512:512 (module) vs
  E-m:a-i64:64-n32:64-S128-v256:256:256-v512:512:512 (jit)

The JIT layout is correct, but some IR module added to the JIT is using a
little-endian layout instead.

This commit disables the test on ppc64 until we can investigate further and
fix the bug.

[1] https://lab.llvm.org/staging/#/builders/126/builds/371
2021-05-13 14:39:12 -07:00
Aakanksha Patil 464e4dc50f [AMDGPU] Add gfx1034 target
Differential Revision: https://reviews.llvm.org/D102306
2021-05-13 14:25:18 -04:00
Roman Lebedev 0d8f91d2a9
[NFC] Delete two newly-added test cases
Failing on bots in unobvious ways.
2021-05-13 21:23:01 +03:00
Roman Lebedev ecc4e9e8f4
[NFC] Try to fix CodeGenCXX/thunk-wrong-return-type.cpp test 2021-05-13 21:17:31 +03:00
cynecx 8ec9fd4839 Support unwinding from inline assembly
I've taken the following steps to add unwinding support from inline assembly:

1) Add a new `unwind` "attribute" (like `sideeffect`) to the asm syntax:

```
invoke void asm sideeffect unwind "call thrower", "~{dirflag},~{fpsr},~{flags}"()
    to label %exit unwind label %uexit
```

2.) Add Bitcode writing/reading support + LLVM-IR parsing.

3.) Emit EHLabels around inline assembly lowering (SelectionDAGBuilder + GlobalISel) when `InlineAsm::canThrow` is enabled.

4.) Tweak InstCombineCalls/InlineFunction pass to not mark inline assembly "calls" as nounwind.

5.) Add clang support by introducing a new clobber: "unwind", which lower to the `canThrow` being enabled.

6.) Don't allow unwinding callbr.

Reviewed By: Amanieu

Differential Revision: https://reviews.llvm.org/D95745
2021-05-13 19:13:03 +01:00
Roman Lebedev 9d3eb7885d
[NFC] Try to fix CodeGenCXX/thunk-wrong-this.cpp test 2021-05-13 21:10:14 +03:00
Roman Lebedev 16d0381841
Return "[CGCall] Annotate `this` argument with alignment"
The original change was reverted because it was discovered
that clang mishandles thunks, and they receive wrong
attributes for their this/return types - the ones for the function
they will call, not the ones they have.

While i have tried to fix this in https://reviews.llvm.org/D100388
that patch has been up and stuck for a month now,
with little signs of progress.

So while it will be good to solve this for real,
for now we can simply avoid introducing the bug,
by not annotating this/return for thunks.

This reverts commit 6270b3a1ea,
relanding 0aa0458f14.
2021-05-13 20:33:14 +03:00
Roman Lebedev a624cec56d
[Clang][Codegen] Do not annotate thunk's this/return types with align/deref/nonnull attrs
As it was discovered in post-commit feedback
for 0aa0458f14,
we handle thunks incorrectly, and end up annotating
their this/return with attributes that are valid
for their callees, not for thunks themselves.

While it would be good to fix this properly,
and keep annotating them on thunks,
i've tried doing that in https://reviews.llvm.org/D100388
with little success, and the patch is stuck for a month now.

So for now, as a stopgap measure, subj.
2021-05-13 20:33:08 +03:00
Roman Lebedev 70aa4623de
[NFC][Clang][Codegen] Add tests with wrong attributes on this/return of thunks
From https://reviews.llvm.org/D100388
2021-05-13 20:32:40 +03:00
Valeriy Savchenko 45212dec01 [analyzer][solver] Prevent use of a null state
rdar://77686137

Differential Revision: https://reviews.llvm.org/D102240
2021-05-13 20:16:29 +03:00
Lei Huang 9469ff15b7 [PowerPC] Add clang option -m[no-]prefixed
Add user-facing front end option to turn off power10 prefixed instructions.

Reviewed By: nemanjai

Differential Revision: https://reviews.llvm.org/D102191
2021-05-13 12:02:10 -05:00
Joe Ellis 2ed7db0d20 [InstSimplify] Remove redundant {insert,extract}_vector intrinsic chains
This commit removes some redundant {insert,extract}_vector intrinsic
chains by implementing the following patterns as instsimplifies:

   (insert_vector _, (extract_vector X, 0), 0) -> X
   (extract_vector (insert_vector _, X, 0), 0) -> X

Reviewed By: peterwaller-arm

Differential Revision: https://reviews.llvm.org/D101986
2021-05-13 16:09:50 +00:00
Aaron En Ye Shi 6a67e05a26 [HIP] Add __builtin_amdgcn_groupstaticsize
Differential Revision: https://reviews.llvm.org/D102403
2021-05-13 15:50:08 +00:00
Zarko Todorovski 8fa168fc50 Parse vector bool when stdbool.h and altivec.h are included
Currently when including stdbool.h and altivec.h declaration of `vector bool` leads to
errors due to `bool` being expanded to '_Bool`. This patch allows the parser
to recognize `_Bool`.

Reviewed By: hubert.reinterpretcast, Everybody0523

Differential Revision: https://reviews.llvm.org/D102064
2021-05-13 11:48:32 -04:00
Juneyoung Lee 395607af3c Reapply [ConstantFold] Fold more operations to poison
This was reverted to mitigate mitigate miscompiles caused by
the logical and/or to bitwise and/or fold. Reapply it now that
the underlying issue has been fixed by D101191.

-----

This patch folds more operations to poison.

Alive2 proof: https://alive2.llvm.org/ce/z/mxcb9G (it does not contain tests about div/rem because they fold to poison when raising UB)

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D92270
2021-05-13 16:04:12 +02:00
Nemanja Ivanovic 39e4676ca7 [PowerPC] Provide doubleword vector predicate form comparisons on Power7
There are two reasons this shouldn't be restricted to Power8 and up:
1. For XL compatibility
2. Because clang will expand comparison operators to these intrinsics*

*Without this patch, the following causes a selection error:

int test(vector signed long a, vector signed long b) {
  return a < b;
}

This patch provides the handling for the intrinsics in the back
end and removes the Power8 guards from the predicate functions
(vec_{all|any}_{eq|ne|gt|ge|lt|le}).
2021-05-13 04:56:56 -05:00
serge-sans-paille 6045cb89e5 Use an allow list on reserved macro identifiers
The allow list is based on various official sources (see in-code comment).

This fixes https://bugs.llvm.org/show_bug.cgi?id=50248

Differential Revision: https://reviews.llvm.org/D102168
2021-05-13 09:23:47 +02:00
Vassil Vassilev 92f9852fc9 [clang-repl] Recommit "Land initial infrastructure for incremental parsing"
Original commit message:

  In http://lists.llvm.org/pipermail/llvm-dev/2020-July/143257.html we have
  mentioned our plans to make some of the incremental compilation facilities
  available in llvm mainline.

  This patch proposes a minimal version of a repl, clang-repl, which enables
  interpreter-like interaction for C++. For instance:

  ./bin/clang-repl
  clang-repl> int i = 42;
  clang-repl> extern "C" int printf(const char*,...);
  clang-repl> auto r1 = printf("i=%d\n", i);
  i=42
  clang-repl> quit

  The patch allows very limited functionality, for example, it crashes on invalid
  C++. The design of the proposed patch follows closely the design of cling. The
  idea is to gather feedback and gradually evolve both clang-repl and cling to
  what the community agrees upon.

  The IncrementalParser class is responsible for driving the clang parser and
  codegen and allows the compiler infrastructure to process more than one input.
  Every input adds to the “ever-growing” translation unit. That model is enabled
  by an IncrementalAction which prevents teardown when HandleTranslationUnit.

  The IncrementalExecutor class hides some of the underlying implementation
  details of the concrete JIT infrastructure. It exposes the minimal set of
  functionality required by our incremental compiler/interpreter.

  The Transaction class keeps track of the AST and the LLVM IR for each
  incremental input. That tracking information will be later used to implement
  error recovery.

  The Interpreter class orchestrates the IncrementalParser and the
  IncrementalExecutor to model interpreter-like behavior. It provides the public
  API which can be used (in future) when using the interpreter library.

  Differential revision: https://reviews.llvm.org/D96033
2021-05-13 06:30:29 +00:00
Vassil Vassilev f6907152db Revert "[clang-repl] Land initial infrastructure for incremental parsing"
This reverts commit 44a4000181.

We are seeing build failures due to missing dependency to libSupport and
CMake Error at tools/clang/tools/clang-repl/cmake_install.cmake
file INSTALL cannot find
2021-05-13 04:44:19 +00:00
Vassil Vassilev 44a4000181 [clang-repl] Land initial infrastructure for incremental parsing
In http://lists.llvm.org/pipermail/llvm-dev/2020-July/143257.html we have
mentioned our plans to make some of the incremental compilation facilities
available in llvm mainline.

This patch proposes a minimal version of a repl, clang-repl, which enables
interpreter-like interaction for C++. For instance:

./bin/clang-repl
clang-repl> int i = 42;
clang-repl> extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=42
clang-repl> quit

The patch allows very limited functionality, for example, it crashes on invalid
C++. The design of the proposed patch follows closely the design of cling. The
idea is to gather feedback and gradually evolve both clang-repl and cling to
what the community agrees upon.

The IncrementalParser class is responsible for driving the clang parser and
codegen and allows the compiler infrastructure to process more than one input.
Every input adds to the “ever-growing” translation unit. That model is enabled
by an IncrementalAction which prevents teardown when HandleTranslationUnit.

The IncrementalExecutor class hides some of the underlying implementation
details of the concrete JIT infrastructure. It exposes the minimal set of
functionality required by our incremental compiler/interpreter.

The Transaction class keeps track of the AST and the LLVM IR for each
incremental input. That tracking information will be later used to implement
error recovery.

The Interpreter class orchestrates the IncrementalParser and the
IncrementalExecutor to model interpreter-like behavior. It provides the public
API which can be used (in future) when using the interpreter library.

Differential revision: https://reviews.llvm.org/D96033
2021-05-13 04:23:24 +00:00
Richard Smith e1aa528d3a Handle unexpanded packs appearing in type-constraints.
For a type-constraint in a lambda signature, this makes the lambda
contain an unexpanded pack; for requirements in a requires-expressions
it makes the requires-expression contain an unexpanded pack; otherwise
it's invalid.
2021-05-12 18:45:34 -07:00
Richard Smith 2f9d8b08ea PR50306: When instantiating a generic lambda with a constrained 'auto',
properly track that it has constraints.

Previously an instantiation of a constrained generic lambda would behave
as if unconstrained because we incorrectly cached a "has no constraints"
value that we computed before the constraints from 'auto' parameters
were attached.
2021-05-12 18:45:33 -07:00
Richard Smith 4c88cfb1dc Add test for substitutability of variable templates in closure type
mangling.
2021-05-12 18:45:33 -07:00
Pushpinder Singh 10c779d206 [AMDGPU][OpenMP] Emit textual IR for -emit-llvm -S
Previously clang would print a binary blob into the bundled file
for amdgcn. With this patch, it will instead print textual IR as
expected.

Reviewed By: JonChesterfield, ronlieb

Differential Revision: https://reviews.llvm.org/D102065

Change-Id: I10c0127ab7357787769fdf9a2edd4b3071e790a1
2021-05-13 01:34:03 +00:00
Richard Smith 5bb7e81c64 Fix bad mangling of <data-member-prefix> for a closure in the initializer of a variable at global namespace scope.
This implements the direction proposed in
https://github.com/itanium-cxx-abi/cxx-abi/pull/126.

Differential Revision: https://reviews.llvm.org/D101968
2021-05-12 13:13:21 -07:00
Erich Keane 08ba9ce1ef Suppress Deferred Diagnostics in discarded statements.
It doesn't really make sense to emit language specific diagnostics
in a discarded statement, and suppressing these diagnostics results in a
programming pattern that many users will feel is quite useful.

Basically, this makes sure we only emit errors from the 'true' side of a
'constexpr if'.

It does this by making the ExprEvaluatorBase type have an opt-in option
as to whether it should visit discarded cases.

Differential Revision: https://reviews.llvm.org/D102251
2021-05-12 12:48:47 -07:00
Pratyush Das 99d63ccff0 Add type information to integral template argument if required.
Non-comprehensive list of cases:
 * Dumping template arguments;
 * Corresponding parameter contains a deduced type;
 * Template arguments are for a DeclRefExpr that hadMultipleCandidates()

Type information is added in the form of prefixes (u8, u, U, L),
suffixes (U, L, UL, LL, ULL) or explicit casts to printed integral template
argument, if MSVC codeview mode is disabled.

Differential revision: https://reviews.llvm.org/D77598
2021-05-12 19:00:08 +00:00
Nico Weber d8c227ba05 Revert "Produce warning for performing pointer arithmetic on a null pointer."
This reverts commit dfc1e31d49.
See discussion on https://reviews.llvm.org/D98798
2021-05-12 14:53:50 -04:00
Anastasia Stulova 58d18dde5c [OpenCL] Remove pragma requirement from Arm dot extension.
This removed the pointless need for extension pragma since
it doesn't disable anything properly and it doesn't need to
enable anything that is not possible to disable.

The change doesn't break existing kernels since it allows to
compile more cases i.e. without pragma statements but the
pragma continues to be accepted.

Differential Revision: https://reviews.llvm.org/D100985
2021-05-12 16:25:33 +01:00
Yaxun (Sam) Liu 98575708da [CUDA][HIP] Fix device template variables
Currently clang does not emit device template variables
instantiated only in host functions, however, nvcc is
able to do that:

https://godbolt.org/z/fneEfferY

This patch fixes this issue by refactoring and extending
the existing mechanism for emitting static device
var ODR-used by host only. Basically clang records
device variables ODR-used by host code and force
them to be emitted in device compilation. The existing
mechanism makes sure these device variables ODR-used
by host code are added to llvm.compiler-used, therefore
they are guaranteed not to be deleted.

It also fixes non-ODR-use of static device variable by host code
causing static device variable to be emitted and registered,
which should not.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D102237
2021-05-12 11:13:29 -04:00
Ben Shi 892c56eabe [clang][AVR] Redefine some types to be compatible with avr-gcc
Reviewed By: dylanmckay

Differential Revision: https://reviews.llvm.org/D100701
2021-05-12 22:05:26 +08:00
Qiu Chaofan cbd93cee9b Revert "[PowerPC] [Clang] Enable float128 feature on VSX targets"
This commit brought build break in some f128 related tests. But that's
not the root cause. There exists some differences between Clang and
GCC's definition for 128-bit float types on PPC, so macros/functions in
glibc may not work with clang -mfloat128 well. We need to handle this
carefully and reland it.
2021-05-12 16:51:52 +08:00
Qiu Chaofan febbe4b5a0 [PowerPC] [Clang] Enable float128 feature on VSX targets
Reviewed By: nemanjai, steven.zhang

Differential Revision: https://reviews.llvm.org/D92815
2021-05-12 14:33:41 +08:00
Richard Smith bb726383ac Revert "Fix bad mangling of <data-member-prefix> for a closure in the initializer of a variable at global namespace scope."
This reverts commit 697ac15a0f, for which
review was not complete. That change was accidentally pushed when
an unrelated change was pushed.
2021-05-11 17:46:18 -07:00
Richard Smith 3978333b71 Add test for PR50039.
I believe Clang's behavior is correct according to the standard here,
but this is an unusual situation for which we had no test coverage, so
I'm adding some.
2021-05-11 17:35:34 -07:00
Richard Smith 697ac15a0f Fix bad mangling of <data-member-prefix> for a closure in the initializer of a variable at global namespace scope.
This implements the direction proposed in
https://github.com/itanium-cxx-abi/cxx-abi/pull/126.

Differential Revision: https://reviews.llvm.org/D101968
2021-05-11 17:35:33 -07:00
Leonard Chan 5cb17728d1 [clang][Fuchsia] Introduce compat multilibs
These are GCC-compatible multilibs that use the generic Itanium C++ ABI
instead of the Fuchsia C++ ABI.

Differential Revision: https://reviews.llvm.org/D102030
2021-05-11 15:45:38 -07:00
Victor Huang 46475a79f8 [AIX][TLS] Diagnose use of unimplemented TLS models
Add front end diagnostics to report error for unimplemented TLS models set by
- compiler option `-ftls-model`
- attributes like `__thread int __attribute__((tls_model("local-exec"))) var_name;`

Reviewed by: aaron.ballman, nemanjai, PowerPC

Differential Revision: https://reviews.llvm.org/D102070
2021-05-11 17:21:08 -05:00
Mike Rice f90abac6ca [OpenMP] Use compound operators for reduction combiner if available.
The OpenMP spec seems to require the compound operators be used for
+, *, &, |, and ^ reduction.  So use these if a class has those operators.
If not try the simple operators as we did previously to limit the impact
to existing code.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=48584

Differential Revision: https://reviews.llvm.org/D101941
2021-05-11 11:39:12 -07:00
Fangrui Song 2075f2b296 [clang] Support -fpic -fno-semantic-interposition for RISCV
-fno-semantic-interposition (only effective with -fpic) can optimize default
visibility external linkage (non-ifunc-non-COMDAT) variable access and function
calls to avoid GOT/PLT, by using local aliases, e.g.
```
int var;
__attribute__((optnone)) int fun(int x) { return x * x; }
int test() { return fun(var); }
```

-fpic (var and fun are dso_preemptable)
```
test:
.LBB1_1:
        auipc   a0, %got_pcrel_hi(var)
        ld      a0, %pcrel_lo(.LBB1_1)(a0)
        lw      a0, 0(a0)
// fun is preemptible by default in ld -shared mode. ld will create a PLT.
        tail    fun@plt
```

vs -fpic -fno-semantic-interposition (var and fun are dso_local)
```
test:
.Ltest$local:
.LBB1_1:
        auipc   a0, %pcrel_hi(.Lvar$local)
        addi    a0, a0, %pcrel_lo(.LBB1_1)
        lw      a0, 0(a0)
// The assembler either resolves .Lfun$local at assembly time (-mno-relax
// -fno-function-sections), or produces a relocation referencing a non-preemptible
// local symbol (which can avoid PLT).
        tail    .Lfun$local
```

Note: Clang's default -fpic is more aggressive than GCC -fpic: interprocedural
optimizations (including inlining) are available but local aliases are not used.
-fpic -fsemantic-interposition can disable interprocedural optimizations.

Depends on D101875

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D101876
2021-05-11 11:38:32 -07:00
Jamie Schmeiser dfc1e31d49 Produce warning for performing pointer arithmetic on a null pointer.
Summary:
Test and produce warning for subtracting a pointer from null or subtracting
null from a pointer.  Reuse existing warning that this is undefined
behaviour.  Also add unit test for both warnings.

Reformat to satisfy clang-format.

Respond to review comments:  add additional test.

Respond to review comments:  Do not issue warning for nullptr - nullptr
in C++.

Fix indenting to satisfy clang-format.

Respond to review comments:  Add C++ tests.

Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: efriedma (Eli Friedman), nickdesaulniers (Nick Desaulniers)
Differential Revision: https://reviews.llvm.org/D98798
2021-05-11 11:29:50 -04:00
Pushpinder Singh eca3d68399 Revert "[AMDGPU][OpenMP] Emit textual IR for -emit-llvm -S"
This reverts commit 7f78e409d0.
2021-05-11 10:07:13 -05:00
Anastasia Stulova 13ea238b1e [OpenCL] Allow use of double type without extension pragma.
Simply use of extensions by allowing the use of supported
double types without the pragma. Since earlier standards
instructed that the pragma is used explicitly a new warning
is introduced in pedantic mode to indicate that use of
type without extension pragma enable can be non-portable.

This patch does not break backward compatibility since the
extension pragma is still supported and it makes the behavior
of the compiler less strict by accepting code without extra
pragma statements.

Differential Revision: https://reviews.llvm.org/D100980
2021-05-11 12:54:38 +01:00
Paulo Matos d7086af214 [WebAssembly] Support for WebAssembly globals in LLVM IR
This patch adds support for WebAssembly globals in LLVM IR, representing
them as pointers to global values, in a non-default, non-integral
address space.  Instruction selection legalizes loads and stores to
these pointers to new WebAssemblyISD nodes GLOBAL_GET and GLOBAL_SET.
Once the lowering creates the new nodes, tablegen pattern matches those
and converts them to Wasm global.get/set of the appropriate type.

Based on work by Paulo Matos in https://reviews.llvm.org/D95425.

Reviewed By: pmatos

Differential Revision: https://reviews.llvm.org/D101608
2021-05-11 11:19:29 +02:00
Craig Topper 18f3a14e13 [RISCV] Validate the SEW and LMUL operands to __builtin_rvv_vsetvli(max)
These are required to be constants, this patch makes sure they
are in the accepted range of values.

These are usually created by wrappers in the riscv_vector.h header
which should always be correct. This patch protects against a user
using the builtin directly.

Reviewed By: khchen

Differential Revision: https://reviews.llvm.org/D102086
2021-05-10 12:11:13 -07:00
Fangrui Song 68a20c7f36 [clang] Support -fpic -fno-semantic-interposition for AArch64
-fno-semantic-interposition (only effective with -fpic) can optimize default
visibility external linkage (non-ifunc-non-COMDAT) variable access and function
calls to avoid GOT/PLT, by using local aliases, e.g.
```
int var;
__attribute__((optnone)) int fun(int x) { return x * x; }
int test() { return fun(var); }
```

-fpic (var and fun are dso_preemptable)
```
test:                                   // @test
        adrp    x8, :got:var
        ldr     x8, [x8, :got_lo12:var]
        ldr     w0, [x8]
// fun is preemptible by default in ld -shared mode. ld will create a PLT.
        b       fun
```

vs -fpic -fno-semantic-interposition (var and fun are dso_local)
```
test:                                   // @test
.Ltest$local:
        adrp    x8, .Lvar$local
        ldr     w0, [x8, :lo12:.Lvar$local]
// The assembler either resolves .Lfun$local at assembly time, or produces a
// relocation referencing a non-preemptible section symbol (which can avoid PLT).
        b       .Lfun$local
```

Note: Clang's default -fpic is more aggressive than GCC -fpic: interprocedural
optimizations (including inlining) are available but local aliases are not used.
-fpic -fsemantic-interposition can disable interprocedural optimizations.

Depends on D101872

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D101873
2021-05-10 09:43:33 -07:00