Commit Graph

1449 Commits

Author SHA1 Message Date
Kadir Cetinkaya df48e3fbcc
Revert "[clang] Pass FoundDecl to DeclRefExpr creator for operator overloads"
This reverts commit 4e94f66531.
See https://reviews.llvm.org/D129973#3698969 for reasoning.
2022-08-04 12:14:43 +02:00
Gabriel Ravier 5674a3c880 Fixed a number of typos
I went over the output of the following mess of a command:

(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z |
 parallel --xargs -0 cat | aspell list --mode=none --ignore-case |
 grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n |
 grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)

and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).

Differential Revision: https://reviews.llvm.org/D130827
2022-08-01 13:13:18 -04:00
Danny Mösch 4e94f66531 [clang] Pass FoundDecl to DeclRefExpr creator for operator overloads
Without the "found declaration" it is later not possible to know where the operator declaration
was brought into the scope calling it.

The initial motivation for this fix came from #55095. However, this also has an influence on
`clang -ast-dump` which now prints a `UsingShadow` attribute for operators only visible through
`using` statements. Also, clangd now correctly references the `using` statement instead of the
operator directly.

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D129973
2022-07-26 21:22:18 +02:00
Chuanqi Xu 99daf6b263 [C++20] [Modules] Don't handle no linkage entities when overloading
The original implementation uses `ND->getFormalLinkage() <=
Linkage::InternalLinkage`. It is not right since the spec only says
internal linkage and it doesn't mention 'no linkage'. This matters when
we consider constructors. According to [class.ctor.general]p1,
constructors have no name so constructors have no linkage too.
2022-07-26 21:07:41 +08:00
Chuanqi Xu 15ddc09ef9 [C++20] [Modules] Handle linkage properly for specializations when overloading
Currently, the semantics of linkage in clang is slightly
different from the semantics in C++ spec. In C++ spec, only names
have linkage. So that all entities of the same should share
one linkage. But in clang, different entities of the same could
have different linkage.

It would break a use case where the template have external linkage and
its specialization have internal linkage due to its type argument is
internal linkage. The root cause is that the semantics of internal
linkage in clang is a mixed form of internal linkage and TU-local in
C++ spec. It is hard to solve the root problem and I tried to add a
workaround inplace.
2022-07-26 18:30:48 +08:00
Iain Sandoe 25558a1bfd [C++20][Modules] Update ADL to handle basic.lookup.argdep p4 [P1815R2 part 1]
This includes the revised provisions of [basic.lookup.argdep] p4

1. ADL is amended to handle p 4.3 where functions in trasitively imported modules may
become visible when they are exported in the same namespace as a visible type.

2. If a function is in a different modular TU, and has internal-linkage, we invalidate
its entry in an overload set.

[basic.lookup.argdep] p5 ex 2 now passes.

Differential Revision: https://reviews.llvm.org/D129174
2022-07-25 14:28:59 +01:00
Erich Keane 258c3aee54 Revert "Re-apply "Deferred Concept Instantiation Implementation"""
This reverts commit befa8cf087.

Apparently this breaks some libc++ builds with an apparent assertion,
 so I'm looking into that .
2022-07-01 11:20:16 -07:00
Erich Keane befa8cf087 Re-apply "Deferred Concept Instantiation Implementation""
This reverts commit d4d47e574e.

This fixes the lldb crash that was observed by ensuring that our
friend-'template contains reference to' TreeTransform properly handles a
TemplateDecl.
2022-07-01 06:51:38 -07:00
Jonas Devlieghere d4d47e574e
Revert "Deferred Concept Instantiation Implementation"
This reverts commit 2f20743952 because it
triggers an assertion when building an LLDB test program:

  Assertion failed: (InstantiatingSpecializations.empty() && "failed to
  clean up an InstantiatingTemplate?"), function ~Sema, file
  /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/clang/lib/Sema/Sema.cpp,
  line 458.

More details in https://reviews.llvm.org/D126907.
2022-06-30 11:43:10 -07:00
Erich Keane 2f20743952 Deferred Concept Instantiation Implementation
This is a continuation of D119544.  Based on @rsmith 's feed back
showing me https://eel.is/c++draft/temp#friend-9, We should properly
handle friend functions now.

Differential Revision: https://reviews.llvm.org/D126907
2022-06-30 06:47:11 -07:00
Sven van Haastregt 663e47a50f [OpenCL] Reduce emitting candidate notes for builtins
When overload resolution fails, clang emits a note diagnostic for each
candidate.  For OpenCL builtins this often leads to many repeated note
diagnostics with no new information.  Stop emitting such notes.

Update a test that was relying on counting those notes to check how
many builtins are available for certain extension configurations.

Differential Revision: https://reviews.llvm.org/D127961
2022-06-27 09:55:44 +01:00
Kazu Hirata ca4af13e48 [clang] Don't use Optional::getValue (NFC) 2022-06-20 22:59:26 -07:00
Kazu Hirata 452db157c9 [clang] Don't use Optional::hasValue (NFC) 2022-06-20 10:51:34 -07:00
Jan Svoboda b02d970b43 [clang][sema] Generate builtin operator overloads for (volatile) _Atomic types
We observed a failed assert in overloaded compound-assignment operator resolution:

```
Assertion failed: (Result.isInvalid() && "C++ binary operator overloading is missing candidates!"), function CreateOverloadedBinOp, file SemaOverload.cpp, line 13944.
...
frame #4: clang` clang::Sema::CreateOverloadedBinOp(..., Opc=BO_OrAssign, ..., PerformADL=true, AllowRewrittenCandidates=false, ...) at SemaOverload.cpp:13943
frame #5: clang` BuildOverloadedBinOp(..., Opc=BO_OrAssign, ...) at SemaExpr.cpp:15228
frame #6: clang` clang::Sema::BuildBinOp(..., Opc=BO_OrAssign, ...) at SemaExpr.cpp:15330
frame #7: clang` clang::Sema::ActOnBinOp(..., Kind=pipeequal, ...) at SemaExpr.cpp:15187
frame #8: clang` clang::Parser::ParseRHSOfBinaryExpression(..., MinPrec=Assignment) at ParseExpr.cpp:629
frame #9: clang` clang::Parser::ParseAssignmentExpression(..., isTypeCast=NotTypeCast) at ParseExpr.cpp:176
frame #10: clang` clang::Parser::ParseExpression(... isTypeCast=NotTypeCast) at ParseExpr.cpp:124
frame #11: clang` clang::Parser::ParseExprStatement(...) at ParseStmt.cpp:464
```

A simple reproducer is:

```
_Atomic unsigned an_atomic_uint;

enum { an_enum_value = 1 };

void enum1() { an_atomic_uint += an_enum_value; }
```

This patch fixes the issue by generating builtin operator overloads for (volatile) _Atomic types.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D125349
2022-06-20 11:03:29 +02:00
Maryam Moghadas 711a71d1ab PowerPC] Emit warning for incompatible vector types that are currently diagnosed with -fno-lax-vector-conversions
This patch is the last prerequisite to switch the default behaviour to -fno-lax-vector-conversions in the future.
The first path ;D124093; fixed the altivec implicit castings.

Reviewed By: amyk

Differential Revision: https://reviews.llvm.org/D126540
2022-06-16 20:28:34 -05:00
Erich Keane 017abbb258 Revert ""Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation"""""
This reverts commit a425cac31e.

There is another libc++ test, that this time causes us to hit an
assertion. Reverting, likely for a while this time.
2022-05-09 09:12:05 -07:00
Erich Keane a425cac31e "Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation""""
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.

This reverts commit 45c07db31c.
2022-05-09 06:29:47 -07:00
Nick Kreeger afa20aff6e Reverting accidental git-revert commits.
Revert "Revert "Revert "Revert "[Concepts] Fix overload resolution bug with constrained candidates""""

This reverts commit cfc2c5905e.
2022-04-23 20:12:15 -05:00
Nick Kreeger 2d80889b2a Reverting accidental git-revert commits.
Revert "Revert "Revert "[Concepts] Fix overload resolution bug with constrained candidates"""

This reverts commit a0636b5855.
2022-04-23 20:11:58 -05:00
Nick Kreeger d1b73f3412 Reverting accidental git-revert commits.
Revert "Revert "[Concepts] Fix overload resolution bug with constrained candidates""

This reverts commit f6af446b66.
2022-04-23 20:11:27 -05:00
Nick Kreeger cfc2c5905e Revert "Revert "Revert "[Concepts] Fix overload resolution bug with constrained candidates"""
This reverts commit a0636b5855.
2022-04-23 19:36:51 -05:00
Nick Kreeger a0636b5855 Revert "Revert "[Concepts] Fix overload resolution bug with constrained candidates""
This reverts commit f6af446b66.
2022-04-23 19:35:50 -05:00
Nick Kreeger f6af446b66 Revert "[Concepts] Fix overload resolution bug with constrained candidates"
This reverts commit 807e418413.
2022-04-23 19:35:41 -05:00
Roy Jacobson 807e418413 [Concepts] Fix overload resolution bug with constrained candidates
When doing overload resolution, we have to check that candidates' parameter types are equal before trying to find a better candidate through checking which candidate is more constrained.
This revision adds this missing check and makes us diagnose those cases as ambiguous calls when the types are not equal.

Fixes GitHub issue https://github.com/llvm/llvm-project/issues/53640

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D123182
2022-04-23 17:24:59 -04:00
Richard Smith 72315d02c4 Treat `std::move`, `forward`, etc. as builtins.
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
  fc30901096,
  a571f82a50,
  64c045e25b, and
  de6ddaeef3,
and reverts aa643f455a.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

Revert "Fixup D123950 to address revert of D123345"

This reverts commit aa643f455a.
2022-04-20 17:58:31 -07:00
David Tenty 98d911e01f Revert "Treat `std::move`, `forward`, etc. as builtins."
This reverts commit b27430f9f4 as the
    parent https://reviews.llvm.org/D123345 breaks the AIX CI:

    https://lab.llvm.org/buildbot/#/builders/214/builds/819
2022-04-20 19:14:37 -04:00
Roy Jacobson 76410040b9 Revert "[Concepts] Fix overload resolution bug with constrained candidates"
This reverts commit 454d1df942.
2022-04-19 07:51:21 -04:00
Roy Jacobson 454d1df942 [Concepts] Fix overload resolution bug with constrained candidates
When doing overload resolution, we have to check that candidates' parameter types are equal before trying to find a better candidate through checking which candidate is more constrained.
This revision adds this missing check and makes us diagnose those cases as ambiguous calls when the types are not equal.

Fixes GitHub issue https://github.com/llvm/llvm-project/issues/53640

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D123182
2022-04-19 04:45:28 -04:00
Richard Smith b27430f9f4 Treat `std::move`, `forward`, etc. as builtins.
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
  fc30901096,
  a571f82a50, and
  64c045e25b
which were reverted in
  e75d8b7037
due to a crasher bug where CodeGen would emit a builtin glvalue as an
rvalue if it constant-folds.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345
2022-04-17 13:26:16 -07:00
Vitaly Buka e75d8b7037 Revert "Treat `std::move`, `forward`, and `move_if_noexcept` as builtins."
Revert "Extend support for std::move etc to also cover std::as_const and"
Revert "Update test to handle opaque pointers flag flip."

It crashes on libcxx tests https://lab.llvm.org/buildbot/#/builders/85/builds/8174

This reverts commit fc30901096.
This reverts commit a571f82a50.
This reverts commit 64c045e25b.
2022-04-16 00:27:51 -07:00
Richard Smith 64c045e25b Treat `std::move`, `forward`, and `move_if_noexcept` as builtins.
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345
2022-04-15 14:09:45 -07:00
Yaxun (Sam) Liu d41445113b [CUDA][HIP] Fix hostness check with -fopenmp
CUDA/HIP determines whether a function can be called based on
the device/host attributes of callee and caller. Clang assumes the
caller is CurContext. This is correct in most cases, however, it is
not correct in OpenMP parallel region when CUDA/HIP program
is compiled with -fopenmp. This causes incorrect overloading
resolution and missed diagnostics.

To get the correct caller, clang needs to chase the parent chain
of DeclContext starting from CurContext until a function decl
or a lambda decl is reached. Sema API is adapted to achieve that
and used to determine the caller in hostness check.

Reviewed by: Artem Belevich, Richard Smith

Differential Revision: https://reviews.llvm.org/D121765
2022-03-24 15:19:47 -04:00
Benjamin Kramer 5d2ce7663b Use llvm::append_range instead of push_back loops where applicable. NFCI. 2022-03-18 01:25:34 +01:00
Roy Jacobson bc7034c1ec [Concepts] Fix an assertion failure while diagnosing constrained
function candidates

See: https://github.com/llvm/llvm-project/issues/54379

I tried to see if I can reuse ResolveAddressOfOverloadedFunction for
explicit function instantiation and so I managed to hit this ICE.

Bug was the diagnostic required an argument (%0) and specific code path
didn't pass an argument.

Differential Revision: https://reviews.llvm.org/D121646
2022-03-15 13:11:32 -07:00
Eli Friedman 27a5749625 [Sema][Windows] Don't special-case void* in __unaligned conversions.
As far as I can tell, MSVC allows the relevant conversions for all
pointer types. Found compiling a Windows SDK header.

I've verified that the updated errors in MicrosoftExtensions.cpp match
the ones that MSVC actually emits, except for the one with a FIXME. (Not
sure why this wasn't done for the patch that added the tests.)

To make up for the missing error, add a warning that triggers on
conversions that drop the __unaligned qualfier.

Differential Revision: https://reviews.llvm.org/D120936
2022-03-10 14:49:16 -08:00
Corentin Jabot c151225096 [C++2b] Implement multidimentional subscript operator
Implement P2128R6 in C++23 mode.

Unlike GCC's implementation, this doesn't try to recover when a user
meant to use a comma expression.

Because the syntax changes meaning in C++23, the patch is *NOT*
implemented as an extension. Instead, declaring an array with not
exactly 1 parameter is an error in older languages modes. There is an
off-by-default extension warning in C++23 mode.

Unlike the standard, we supports default arguments;

Ie, we assume, based on conversations in WG21, that the proposed
resolution to CWG2507 will be accepted.

We allow arrays OpenMP sections and C++23 multidimensional array to
coexist:

[a , b] multi dimensional array
[a : b] open mp section
[a, b: c] // error

The rest of the patch is relatively straight forward: we take care to
support an arbitrary number of arguments everywhere.
2022-02-08 12:10:47 -05:00
Arthur O'Dwyer f6ce456707 [clang] Correctly(?) handle placeholder types in ExprRequirements.
Bug #52905 was originally papered over in a different way, but
I believe this is the actually proper fix, or at least closer to
it. We need to detect placeholder types as close to the front-end
as possible, and cause them to fail constraints, rather than letting
them persist into later stages.

Fixes #52905.
Fixes #52909.
Fixes #53075.

Differential Revision: https://reviews.llvm.org/D118552
2022-02-01 15:16:17 -05:00
Simon Pilgrim 2e52f76a72 [SemaOverload] compareConversionFunctions - use castAs<> instead of getAs<> to avoid dereference of nullptr
The pointer is dereferenced immediately below, so assert the cast is correct instead of returning nullptr
2022-01-11 10:31:26 +00:00
Simon Pilgrim c61299e2b3 [SemaOverload] Use castAs<> instead of getAs<> to avoid dereference of nullptr
The pointer is always dereferenced inside BuildSimilarlyQualifiedPointerType, so assert the cast is correct instead of returning nullptr
2022-01-11 10:31:25 +00:00
Kazu Hirata 17d4bd3d78 [clang] Fix bugprone argument comments (NFC)
Identified with bugprone-argument-comment.
2022-01-09 00:19:49 -08:00
Chuanqi Xu 8de2d06251 [clang] Fix crash in bug52905
The root cause for the crash is the incorrect use of `cast`.
The actual type and cast-to type is different. This patch fixes the
crash by converting the `cast` to `dyn_cast`.
2021-12-29 16:22:26 +08:00
Adam Czachorowski 55a79318c6 [clang][clangd] Improve signature help for variadic functions.
This covers both C-style variadic functions and template variadic w/
parameter packs.

Previously we would return no signatures when working with template
variadic functions once activeParameter reached the position of the
parameter pack (except when it was the only param, then we'd still
show it when no arguments were given). With this commit, we now show
signathure help correctly.

Additionally, this commit fixes the activeParameter value in LSP output
of clangd in the presence of variadic functions (both kinds). LSP does
not allow the activeParamter to be higher than the number of parameters
in the active signature. With "..." or parameter pack being just one
argument, for all but first argument passed to "..." we'd report
incorrect activeParameter value. Clients such as VSCode would then treat
it as 0, as suggested in the spec) and highlight the wrong parameter.

In the future, we should add support for per-signature activeParamter
value, which exists in LSP since 3.16.0. This is not part of this
commit.

Differential Revision: https://reviews.llvm.org/D111318
2021-11-18 15:50:47 +01:00
Kazu Hirata d0ac215dd5 [clang] Use isa instead of dyn_cast (NFC) 2021-11-14 09:32:40 -08:00
Simon Pilgrim 3b3509b3cb [Sema] haveSameParameterTypes - replace repeated isNull() test with assertions
As reported on https://pvs-studio.com/en/blog/posts/cpp/0771/ (Snippet 2) - (and mentioned on rGdc4259d5a38409) we are repeating the T1.isNull() check instead of checking T2.isNull() as well, and at this point neither should be null - so we're better off with an assertion.

Differential Revision: https://reviews.llvm.org/D107347
2021-10-18 12:36:44 +01:00
Aaron Ballman b9941de0bf Fix a rejects-valid with consteval on overloaded operators
It seems that Clang 11 regressed functionality that was working in
Clang 10 regarding calling a few overloaded operators in an immediate
context. Specifically, we were not checking for immediate invocations
of array subscripting and the arrow operators, but we properly handle
the other overloaded operators.

This fixes the two problematic operators and adds some test coverage to
show they're equivalent to calling the operator directly.

This addresses PR50779.
2021-10-14 14:47:29 -04:00
Nathan Sidwell 444ec0957c [clang] p0388 array list initialization overloads
This is the second part of p0388, dealing with overloads of list
initialization to incomplete array types.  It extends the handling
added in D103088 to permit incomplete arrays.  We have to record that
the conversion involved an incomplete array, and so (re-add) a bit flag
into the standard conversion sequence object.  Comparing such
conversion sequences requires knowing (a) the number of array elements
initialized and (b) whether the initialization is of an incomplete array.

This also updates the web page to indicate p0388 is implemented (there
is no feature macro).

Differential Revision: https://reviews.llvm.org/D103908
2021-10-12 07:35:21 -07:00
Nathan Sidwell dcd74716f9 [clang] p0388 conversion to incomplete array
This implements the new implicit conversion sequence to an incomplete
(unbounded) array type.  It is mostly Richard Smith's work, updated to
trunk, testcases added and a few bugs fixed found in such testing.

It is not a complete implementation of p0388.

Differential Revision: https://reviews.llvm.org/D102645
2021-10-12 07:35:20 -07:00
Artem Belevich 6b20ea6963 [CUDA] Pass ExecConfig through BuildCallToMemberFunction
Otherwise, we fail to compile calls to CUDA kernels that are static members.

Differential Revision: https://reviews.llvm.org/D108787
2021-09-16 11:18:12 -07:00
Nathan Sidwell bb3f5f5d78 [clang] Array list initialization (pre-p0388)
Extends handling of list initialization of bounded array parameters.
This adds the missing checks on converting each initializer for both
std::initializer_list and arrays. And extends
CompareImplicitConversionSequence to compares array size, for two
conversions to array type.

As noted in this patch, there's a defect in the std concerning the
partial orderability of conversion sequences.  DR2492 has a suggested
direction that will be simple to add once it (hopefully) is accepted.

Differential Revision: https://reviews.llvm.org/D103088
2021-09-09 08:30:04 -07:00
Qiu Chaofan fae0dfa642 [Clang] Add __ibm128 type to represent ppc_fp128
Currently, we have no front-end type for ppc_fp128 type in IR. PowerPC
target generates ppc_fp128 type from long double now, but there's option
(-mabi=(ieee|ibm)longdouble) to control it and we're going to do
transition from IBM extended double-double ppc_fp128 to IEEE fp128 in
the future.

This patch adds type __ibm128 which always represents ppc_fp128 in IR,
as what GCC did for that type. Without this type in Clang, compilation
will fail if compiling against future version of libstdcxx (which uses
__ibm128 in headers).

Although all operations in backend for __ibm128 is done by software,
only PowerPC enables support for it.

There's something not implemented in this commit, which can be done in
future ones:

- Literal suffix for __ibm128 type. w/W is suitable as GCC documented.
- __attribute__((mode(IF))) should be for __ibm128.
- Complex __ibm128 type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D93377
2021-09-06 18:00:58 +08:00