18 Commits

Author SHA1 Message Date
Kazu Hirata
4412cfa854
[clang] Use [[fallthrough]] instead of LLVM_FALLTHROUGH (NFC) (#163085)
[[fallthrough]] is now part of C++17, so we don't need to use
LLVM_FALLTHROUGH.
2025-10-12 20:49:11 -07:00
Matheus Izvekov
2ec71d93ad
[clang] NFC: introduce Type::getAsEnumDecl, and cast variants for all TagDecls (#155463)
And make use of those.

These changes are split from prior PR #155028, in order to decrease the
size of that PR and facilitate review.
2025-08-26 16:05:59 -03:00
Matheus Izvekov
dc8596d548
[clang] NFC: change more places to use Type::getAsTagDecl and friends (#155313)
This changes a bunch of places which use getAs<TagType>, including
derived types, just to obtain the tag definition.

This is preparation for #155028, offloading all the changes that PR used
to introduce which don't depend on any new helpers.
2025-08-25 20:18:56 -03:00
Matheus Izvekov
91cdd35008
[clang] Improve nested name specifier AST representation (#147835)
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:

![image](https://github.com/user-attachments/assets/700dce98-2cab-4aa8-97d1-b038c0bee831)

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
2025-08-09 05:06:53 -03:00
Jonas Paulsson
6d03f51f0c
[SystemZ] Add support for 16-bit floating point. (#109164)
- _Float16 is now accepted by Clang.

- The half IR type is fully handled by the backend.

- These values are passed in FP registers and converted to/from float around
  each operation.

- Compiler-rt conversion functions are now built for s390x including the missing
  extendhfdf2 which was added.

Fixes #50374
2025-04-16 20:02:56 +02:00
Alex Voicu
39ec9de7c2
[clang][CodeGen] sret args should always point to the alloca AS, so use that (#114062)
`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>
2025-02-14 11:20:45 +00:00
Mats Jun Larsen
54e0c2bbe2
[CodeGen][SystemZ] Replace PointerType::getUnqual(Type) with opaque version (NFC) (#126280)
Follow-up to #126278
2025-02-08 13:22:53 +00:00
Rahul Joshi
fa789dffb1
[NFC] Rename Intrinsic::getDeclaration to getOrInsertDeclaration (#111752)
Rename the function to reflect its correct behavior and to be consistent
with `Module::getOrInsertFunction`. This is also in preparation of
adding a new `Intrinsic::getDeclaration` that will have behavior similar
to `Module::getFunction` (i.e, just lookup, no creation).
2024-10-11 05:26:03 -07:00
Jonas Paulsson
14120227a3
Target ABI: improve call parameters extensions handling (#100757)
For the purpose of verifying proper arguments extensions per the target's ABI,
introduce the NoExt attribute that may be used by a target when neither sign-
or zeroextension is required (e.g. with a struct in register). The purpose of
doing so is to be able to verify that there is always one of these attributes
present and by this detecting cases where sign/zero extension is actually
missing.

As a first step, this patch has the verification step done for the SystemZ
backend only, but left off by default until all known issues have been
addressed.

Other targets/front-ends can now also add NoExt attribute where needed and do
this check in the backend.
2024-09-19 16:59:31 +02:00
Ulrich Weigand
9af3628ce7 [SystemZ] Fix transparent_union calling convention
The SystemZ ABI code was missing code to handle the transparent_union
extension.  Arguments of such types are specified to be passed like
the first member of the union, instead of according to the usual
ABI calling convention for aggregates.

This did not make much difference in practice as the SystemZ ABI
already specifies that 1-, 2-, 4- or 8-byte aggregates are passed
in registers.  However, there *is* a difference if the first member
of the transparent union is a scalar integer type smaller than word
size - if passed as a scalar, it needs to be zero- or sign-extended
to word size, while if passed as aggregate, it is not.

Fixed by adding code to handle transparent_union similar to what
is done on other targets.
2024-07-18 17:43:28 +02:00
Mariya Podchishchaeva
6d973b4548
[clang][CodeGen] Return RValue from EmitVAArg (#94635)
This should simplify handling of resulting value by the callers.
2024-06-17 13:29:20 +02:00
Akira Hatanaka
84780af4b0
[CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (#86923)
To authenticate pointers, CodeGen needs access to the key and
discriminators that were used to sign the pointer. That information is
sometimes known from the context, but not always, which is why `Address`
needs to hold that information.

This patch adds methods and data members to `Address`, which will be
needed in subsequent patches to authenticate signed pointers, and uses
the newly added methods throughout CodeGen. Although this patch isn't
strictly NFC as it causes CodeGen to use different code paths in some
cases (e.g., `mergeAddressesInConditionalExpr`), it doesn't cause any
changes in functionality as it doesn't add any information needed for
authentication.

In addition to the changes mentioned above, this patch introduces class
`RawAddress`, which contains a pointer that we know is unsigned, and
adds several new functions for creating `Address` and `LValue` objects.

This reapplies d9a685a9dd589486e882b722e513ee7b8c84870c, which was
reverted because it broke ubsan bots. There seems to be a bug in
coroutine code-gen, which is causing EmitTypeCheck to use the wrong
alignment. For now, pass alignment zero to EmitTypeCheck so that it can
compute the correct alignment based on the passed type (see function
EmitCXXMemberOrOperatorMemberCallExpr).
2024-03-28 06:54:36 -07:00
Akira Hatanaka
f75eebab88
Revert "[CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (#86721)" (#86898)
This reverts commit d9a685a9dd589486e882b722e513ee7b8c84870c.

The commit broke ubsan bots.
2024-03-27 18:14:04 -07:00
Akira Hatanaka
d9a685a9dd
[CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (#86721)
To authenticate pointers, CodeGen needs access to the key and
discriminators that were used to sign the pointer. That information is
sometimes known from the context, but not always, which is why `Address`
needs to hold that information.

This patch adds methods and data members to `Address`, which will be
needed in subsequent patches to authenticate signed pointers, and uses
the newly added methods throughout CodeGen. Although this patch isn't
strictly NFC as it causes CodeGen to use different code paths in some
cases (e.g., `mergeAddressesInConditionalExpr`), it doesn't cause any
changes in functionality as it doesn't add any information needed for
authentication.

In addition to the changes mentioned above, this patch introduces class
`RawAddress`, which contains a pointer that we know is unsigned, and
adds several new functions for creating `Address` and `LValue` objects.

This reapplies 8bd1f9116aab879183f34707e6d21c7051d083b6. The commit
broke msan bots because LValue::IsKnownNonNull was uninitialized.
2024-03-27 12:24:49 -07:00
Akira Hatanaka
b311756450
Revert "[CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (#67454)" (#86674)
This reverts commit 8bd1f9116aab879183f34707e6d21c7051d083b6.

It appears that the commit broke msan bots.
2024-03-26 07:37:57 -07:00
Akira Hatanaka
8bd1f9116a
[CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (#67454)
To authenticate pointers, CodeGen needs access to the key and
discriminators that were used to sign the pointer. That information is
sometimes known from the context, but not always, which is why `Address`
needs to hold that information.

This patch adds methods and data members to `Address`, which will be
needed in subsequent patches to authenticate signed pointers, and uses
the newly added methods throughout CodeGen. Although this patch isn't
strictly NFC as it causes CodeGen to use different code paths in some
cases (e.g., `mergeAddressesInConditionalExpr`), it doesn't cause any
changes in functionality as it doesn't add any information needed for
authentication.

In addition to the changes mentioned above, this patch introduces class
`RawAddress`, which contains a pointer that we know is unsigned, and
adds several new functions for creating `Address` and `LValue` objects.
2024-03-25 18:05:42 -07:00
Youngsuk Kim
44e63ffe2b [clang] Replace uses of CGBuilderTy::CreateElementBitCast (NFC)
* Add `Address::withElementType()` as a replacement for
  `CGBuilderTy::CreateElementBitCast`.

* Partial progress towards replacing `CreateElementBitCast`, as it no
  longer does what its name suggests. Either replace its uses with
  `Address::withElementType()`, or remove them if no longer needed.

* Remove unused parameter 'Name' of `CreateElementBitCast`

Reviewed By: barannikov88, nikic

Differential Revision: https://reviews.llvm.org/D153196
2023-06-18 04:13:15 +03:00
Sergei Barannikov
992cb98462 [clang][CodeGen] Break up TargetInfo.cpp [8/8]
This commit breaks up CodeGen/TargetInfo.cpp into a set of *.cpp files,
one file per target. There are no functional changes, mostly just code moving.

Non-code-moving changes are:
* A virtual destructor has been added to DefaultABIInfo to pin the vtable to a cpp file.
* A few methods of ABIInfo and DefaultABIInfo were split into declaration + definition
  in order to reduce the number of transitive includes.
* Several functions that used to be static have been placed in clang::CodeGen
  namespace so that they can be accessed from other cpp files.

RFC: https://discourse.llvm.org/t/rfc-splitting-clangs-targetinfo-cpp/69883

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D148094
2023-06-17 07:14:50 +03:00