This rename was made as part of
https://github.com/llvm/llvm-project/pull/147835 in order to ease
rebasing the PR, and give a nice window for other patches to get rebased
as well.
It has been a while already, so lets go ahead and rename it back.
This is a major change on how we represent nested name qualifications in
the AST.
* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.
This patch offers a great performance benefit.
It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.
This has great results on compile-time-tracker as well:
This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.
It has some other miscelaneous drive-by fixes.
About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.
There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.
How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.
The rest and bulk of the changes are mostly consequences of the changes
in API.
PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.
Fixes#136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
`sret` arguments are always going to reside in the stack/`alloca`
address space, which makes the current formulation where their AS is
derived from the pointee somewhat quaint. This patch ensures that `sret`
ends up pointing to the `alloca` AS in IR function signatures, and also
guards agains trying to pass a casted `alloca`d pointer to a `sret` arg,
which can happen for most languages, when compiled for targets that have
a non-zero `alloca` AS (e.g. AMDGCN) / map `LangAS::default` to a
non-zero value (SPIR-V). A target could still choose to do something
different here, by e.g. overriding `classifyReturnType` behaviour.
In a broader sense, this patch extends non-aliased indirect args to also
carry an AS, which leads to changing the `getIndirect()` interface. At
the moment we're only using this for (indirect) returns, but it allows
for future handling of indirect args themselves. We default to using the
AllocaAS as that matches what Clang is currently doing, however if, in
the future, a target would opt for e.g. placing indirect returns in some
other storage, with another AS, this will require revisiting.
---------
Co-authored-by: Matt Arsenault <arsenm2@gmail.com>
Co-authored-by: Matt Arsenault <Matthew.Arsenault@amd.com>
This reverts commit 81fc3add1e627c23b7270fe2739cdacc09063e54.
This breaks some LLDB tests, e.g.
SymbolFile/DWARF/x86/no_unique_address-with-bitfields.cpp:
lldb: ../llvm-project/clang/lib/AST/Decl.cpp:4604: unsigned int clang::FieldDecl::getBitWidthValue() const: Assertion `isa<ConstantExpr>(getBitWidth())' failed.
Save the bitwidth value as a `ConstantExpr` with the value set. Remove
the `ASTContext` parameter from `getBitWidthValue()`, so the latter
simply returns the value from the `ConstantExpr` instead of
constant-evaluating the bitwidth expression every time it is called.
In PR #79382, I need to add a new type that derives from
ConstantArrayType. This means that ConstantArrayType can no longer use
`llvm::TrailingObjects` to store the trailing optional Expr*.
This change refactors ConstantArrayType to store a 60-bit integer and
4-bits for the integer size in bytes. This replaces the APInt field
previously in the type but preserves enough information to recreate it
where needed.
To reduce the number of places where the APInt is re-constructed I've
also added some helper methods to the ConstantArrayType to allow some
common use cases that operate on either the stored small integer or the
APInt as appropriate.
Resolves#85124.
When splitting an entry into multiple entries, the indices of the split
entries are a combination of the original split entry's and the number
of elements we split that entry to.
Failure to do so resulted in non-sensical entries leading e.g to
assertion failures in `getCoerceAndExpandTypes` and runtime failures in
Swift programs.
For a nonzero argument, llvm::findLastSet(x) is equivalent to
llvm::Log2_32(x) or llvm::Log2_64(x). None of the calls to
llvm::findLastSet in this patch relies on llvm::findLastSet's ability
to return std::numeric_limits<T>::max() on input 0.
If we know that x is nonzero and not a power of 2, then
llvm::findLastSet(x) + 1 is the index of the bit just above the
highest set bit in x. That is, 1 << (llvm::findLastSet(x) + 1) is the
same as llvm::bit_ceil(x).
Since llvm::bit_ceil is a nop on a power of 2, we can unconditionally
call llvm::bit_ceil. The end result actually matches the comment.
Mixing LLVM and Clang address spaces can result in subtle bugs, and there
is no need for this hook to use the LLVM IR level address spaces.
Most of this change is just replacing zero with LangAS::Default,
but it also allows us to remove a few calls to getTargetAddressSpace().
This also removes a stale comment+workaround in
CGDebugInfo::CreatePointerLikeType(): ASTContext::getTypeSize() does
return the expected size for ReferenceType (and handles address spaces).
Differential Revision: https://reviews.llvm.org/D138295
Swift calling conventions stands out in the way that they are lowered in
mostly target-independent manner, with very few customization points.
As such, swift-related methods of ABIInfo do not reference the rest of
ABIInfo and vice versa.
This change follows interface segregation principle; it removes
dependency of SwiftABIInfo on ABIInfo. Targets must now implement
SwiftABIInfo separately if they support Swift calling conventions.
Almost all targets implemented `shouldPassIndirectly` the same way. This
de-facto default implementation has been moved into the base class.
`isSwiftErrorInRegister` used to be virtual, now it is not. It didn't
accept any arguments which could have an effect on the returned value.
This is now a static property of the target ABI.
Reviewed By: rusyaev-roman, inclyc
Differential Revision: https://reviews.llvm.org/D130394
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
The problem with the previous logic was that there might not be any
explicit copy/move constructor declarations, e.g. if the type is
trivial and we've never type-checked a copy of it. Relying on Sema's
computation seems much more reliable.
Also, I believe Richard's recommendation is exactly the rule we use
now on the Itanium ABI, modulo the trivial_abi attribute (which this
change of course fixes our handling of in Swift).
This does mean that we have a less portable rule for deciding
indirectness for swiftcall. I would prefer it if we just applied the
Itanium rule universally under swiftcall, but in the meantime, I need
to fix this bug.
This only arises when defining functions with class-type arguments
in C++, as we do in the Swift runtime. It doesn't affect normal Swift
operation because we don't import code as C++.
llvm-svn: 328942
We need to take type alignment padding into account whe computing physical
layouts.
The layout must be compatible with the input layout, offsets are defined in
terms of offsets within a packed struct which are computed in terms of the alloc
size of a type.
Usingthe store size we would insert padding for the following type for example:
struct {
int3 v;
long long l;
} __attribute((packed))
On x86-64 int3 is padded to int4 alignment. The swiftcc type would be
<{ <3 x float>, [4 x i8], i64 }> which is not compatible with <{ <3 x float>,
i64 }>.
The latter has i64 at offset 16 and the former at offset 20.
rdar://32618125
llvm-svn: 305956
