The cleanup structs expect that pointers and (u)int64_t have the same
alignment requirements, which isn't true on sparc32, which causes
SIGBUSes.
See also: https://github.com/llvm/llvm-project/issues/66620
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
Now that #149310 has restricted lifetime intrinsics to only work on
allocas, we can also drop the explicit size argument. Instead, the size
is implied by the alloca.
This removes the ability to only mark a prefix of an alloca alive/dead.
We never used that capability, so we should remove the need to handle
that possibility everywhere (though many key places, including stack
coloring, did not actually respect this).
This extends https://github.com/llvm/llvm-project/pull/138577 to more UBSan checks, by changing SanitizerDebugLocation (formerly SanitizerScope) to add annotations if enabled for the specified ordinals.
Annotations will use the ordinal name if there is exactly one ordinal specified in the SanitizerDebugLocation; otherwise, it will use the handler name.
Updates the tests from https://github.com/llvm/llvm-project/pull/141814.
---------
Co-authored-by: Vitaly Buka <vitalybuka@google.com>
This patch is part of a stack that teaches Clang to generate Key Instructions
metadata for C and C++.
When returning a value, stores to the `retval` allocas and branches to `return`
block are put in the same atom group. They are both rank 1, which could in
theory introduce an extra step in some optimized code. This low risk currently
feels an acceptable for keeping the code a bit simpler (as opposed to adding
scaffolding to make the store rank 2).
In the case of a single return (no control flow) the return instruction inherits
the atom group of the branch to the return block when the blocks get folded
togather.
RFC:
https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668
The feature is only functional in LLVM if LLVM is built with CMake flag
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONs. Eventually that flag will be removed.
The InstrProf headers are very expensive. Avoid including them in all of
CodeGen/ by moving the CodeGenPGO member behind a unqiue_ptr.
This reduces clang build time by 0.8%.
This is a scoped helper similar to ApplyDebugLocation that creates a new source
location atom group which instructions can be added to.
A source atom is a source construct that is "interesting" for debug stepping
purposes. We use an atom group number to track the instruction(s) that implement
the functionality for the atom, plus backup instructions/source locations.
This patch is part of a stack that teaches Clang to generate Key Instructions
metadata for C and C++.
RFC:
https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668
The feature is only functional in LLVM if LLVM is built with CMake flag
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONs. Eventually that flag will be removed.
This generalizes the debug info annotation code from https://github.com/llvm/llvm-project/pull/139149 and moves it into a helper function, SanitizerAnnotateDebugInfo().
Future work can use 'ApplyDebugLocation ApplyTrapDI(*this, SanitizerAnnotateDebugInfo(Ordinal));' to add annotations to additional checks.
The 'counted_by' attribute is now available for pointers in structs.
It generates code for sanity checks as well as
__builtin_dynamic_object_size()
calculations. For example:
struct annotated_ptr {
int count;
char *buf __attribute__((counted_by(count)));
};
If the pointer's type is 'void *', use the 'sized_by' attribute, which
works similarly to 'counted_by', but can handle the 'void' base type:
struct annotated_ptr {
int count;
void *buf __attribute__((sized_by(count)));
};
If the 'count' field member occurs after the pointer, use the
'-fexperimental-late-parse-attributes' flag during compilation.
Note that 'counted_by' cannot be applied to a pointer to an incomplete
type, because the size isn't known.
struct foo;
struct annotated_ptr {
int count;
struct foo *buf __attribute__((counted_by(count))); /* invalid */
};
Signed-off-by: Bill Wendling <morbo@google.com>
This fixes emitting undefined behavior where a 64-bit generic
pointer is written to a 32-bit slot allocated for a private pointer.
This can be seen in test/CodeGenOpenCL/amdgcn-automatic-variable.cl's
wrong_pointer_alloca.
Static analysis flagged CGAtomicOptionsRAII as having an explicit
destructor but not having explicit copy ctor and assignment. Rule of
three says we should. We are just using this as an RAII object, no need
for either so they will be specified as deleted.
This patch relands https://github.com/llvm/llvm-project/pull/130990.
If the check value is passed by reference, add `memory(read)`.
Original PR description:
This patch adds `memory(argmem: read, inaccessiblemem: readwrite)` to
**recoverable** ubsan handlers in order to unblock some
memory/loop optimizations. It provides an average of 3% performance
improvement on llvm-test-suite (except for 49 test failures due to ubsan
diagnostics).
The qualifier allows programmer to directly control how pointers are
signed when they are stored in a particular variable.
The qualifier takes three arguments: the signing key, a flag specifying
whether address discrimination should be used, and a non-negative
integer that is used for additional discrimination.
```
typedef void (*my_callback)(const void*);
my_callback __ptrauth(ptrauth_key_process_dependent_code, 1, 0xe27a) callback;
```
Co-Authored-By: John McCall rjmccall@apple.com
In the LLVM middle-end we want to fold `gep inbounds null, idx -> null`:
https://alive2.llvm.org/ce/z/5ZkPx-
This pattern is common in real-world programs
(https://github.com/dtcxzyw/llvm-opt-benchmark/pull/55#issuecomment-1870963906).
Generally, it exists in some (actually) unreachable blocks, which is
introduced by JumpThreading.
However, some old-style offsetof macros are still widely used in
real-world C/C++ code (e.g., hwloc/slurm/luajit). To avoid breaking
existing code and inconvenience to downstream users, this patch removes
the inbounds flag from the struct gep if the base pointer is null.
This feature largely models the same behavior as in C++11. It is
technically a breaking change between C99 and C11, so the paper is not
being backported to older language modes.
One difference between C++ and C is that things which are rvalues in C
are often lvalues in C++ (such as the result of a ternary operator or a
comma operator).
Fixes#96486
Patches in the Key Instructions (KeyInstr) stack need to access CGF in these
functions. 2 CGF fields are passed to these functions already; at this point it
felt natural to promote them to CGF methods.
- fixes#132303
- Moves dot2add from a language builtin to a target builtin.
- Sets the scaffolding for Sema checks for DX builtins
- Setup DirectX backend as able to have target builtins
- Adds a DX TargetBuiltins emitter in
`clang/lib/CodeGen/TargetBuiltins/DirectX.cpp`
This is an expensive header, only include it where needed. Move some
functions out of line to achieve that.
This reduces time to build clang by ~0.5% in terms of instructions
retired.
Currently arm_neon.h emits C-style casts to do vector type casts. This
relies on implicit conversion between vector types to be enabled, which
is currently deprecated behaviour and soon will disappear. To ensure
NEON code will keep working afterwards, this patch changes all this
vector type casts into bitcasts.
Co-authored-by: Momchil Velikov <momchil.velikov@arm.com>
This implements the R2 semantics of P0963.
The R1 semantics, as outlined in the paper, were introduced in Clang 6.
In addition to that, the paper proposes swapping the evaluation order of
condition expressions and the initialization of binding declarations
(i.e. std::tuple-like decompositions).
This statement level construct takes no clauses and has no associated
statement, and simply labels a number of array elements as valid for
caching. The implementation here is pretty simple, but it is a touch of
a special case for parsing, so the parsing code reflects that.
Add option and statement attribute for controlling emitting of
target-specific
metadata to atomicrmw instructions in IR.
The RFC for this attribute and option is
https://discourse.llvm.org/t/rfc-add-clang-atomic-control-options-and-pragmas/80641,
Originally a pragma was proposed, then it was changed to clang
attribute.
This attribute allows users to specify one, two, or all three options
and must be applied
to a compound statement. The attribute can also be nested, with inner
attributes
overriding the options specified by outer attributes or the target's
default
options. These options will then determine the target-specific metadata
added to atomic
instructions in the IR.
In addition to the attribute, three new compiler options are introduced:
`-f[no-]atomic-remote-memory`, `-f[no-]atomic-fine-grained-memory`,
`-f[no-]atomic-ignore-denormal-mode`.
These compiler options allow users to override the default options
through the
Clang driver and front end. `-m[no-]unsafe-fp-atomics` is aliased to
`-f[no-]ignore-denormal-mode`.
In terms of implementation, the atomic attribute is represented in the
AST by the
existing AttributedStmt, with minimal changes to AST and Sema.
During code generation in Clang, the CodeGenModule maintains the current
atomic options,
which are used to emit the relevant metadata for atomic instructions.
RAII is used
to manage the saving and restoring of atomic options when entering
and exiting nested AttributedStmt.
This PR implements HLSL's initialization list behvaior as specified in
the draft language specifcation under
[*Decl.Init.Agg*](https://microsoft.github.io/hlsl-specs/specs/hlsl.html#Decl.Init.Agg).
This behavior is a bit unusual for C/C++ because intermediate braces in
initializer lists are ignored and a whole array of additional
conversions occur unintuitively to how initializaiton works in C.
The implementaiton in this PR generates a valid C/C++ initialization
list AST for the HLSL initializer so that there are no changes required
to Clang's CodeGen to support this. This design will also allow us to
use Clang's rewrite to convert HLSL initializers to valid C/C++
initializers that are equivalent. It does have the downside that it will
generate often redundant accesses during codegen. The IR optimizer is
extremely good at eliminating those so this will have no impact on the
final executable performance.
There is some opportunity for optimizing the initializer list generation
that we could consider in subsequent commits. One notable opportunity
would be to identify aggregate objects that occur in the same place in
both initializers and do not require converison, those aggregates could
be initialized as aggregates rather than fully scalarized.
Closes#56067
---------
Co-authored-by: Finn Plummer <50529406+inbelic@users.noreply.github.com>
Co-authored-by: Helena Kotas <hekotas@microsoft.com>
Co-authored-by: Justin Bogner <mail@justinbogner.com>
These files are relatively old and don't confront our formatting rules.
It's hard to change them without massive clang-format changes.
---------
Signed-off-by: Peter Rong <PeterRong@meta.com>
Implement HLSLElementwiseCast excluding support for splat cases
Do not support casting types that contain bitfields.
Partly closes#100609 and partly closes#100619
The atomic construct is a particularly complicated one. The directive
itself is pretty simple, it has 5 options for the 'atomic-clause'.
However, the associated statement is fairly complicated.
'read' accepts:
v = x;
'write' accepts:
x = expr;
'update' (or no clause) accepts:
x++;
x--;
++x;
--x;
x binop= expr;
x = x binop expr;
x = expr binop x;
'capture' accepts either a compound statement, or:
v = x++;
v = x--;
v = ++x;
v = --x;
v = x binop= expr;
v = x = x binop expr;
v = x = expr binop x;
IF 'capture' has a compound statement, it accepts:
{v = x; x binop= expr; }
{x binop= expr; v = x; }
{v = x; x = x binop expr; }
{v = x; x = expr binop x; }
{x = x binop expr ;v = x; }
{x = expr binop x; v = x; }
{v = x; x = expr; }
{v = x; x++; }
{v = x; ++x; }
{x++; v = x; }
{++x; v = x; }
{v = x; x--; }
{v = x; --x; }
{x--; v = x; }
{--x; v = x; }
While these are all quite complicated, there is a significant amount
of similarity between the 'capture' and 'update' lists, so this patch
reuses a lot of the same functions.
This patch implements the entirety of 'atomic', creating a new Sema file
for the sema for it, as it is fairly sizable.
Refactoring of how __builtin_dynamic_object_size() is calculated for
flexible array members (in preparation for adding support for the
'counted_by' attribute on pointers in structs).
The only functionality change is that we use the already emitted Expr
code to build our calculations off of rather than re-emitting the Expr.
That allows the 'StructFieldAccess' visitor to sift through all casts
and ArraySubscriptExprs to find the first MemberExpr. We build our GEPs
and calculate offsets based off of relative distances from that
MemberExpr.
The testcase passes execution tests.
Calculate the flexible array member's object size using these formulae
(note: if the calculation is negative, we return 0.):
struct p;
struct s {
/* ... */
int count;
struct p *array[] __attribute__((counted_by(count)));
};
1) 'ptr->array':
count = ptr->count;
flexible_array_member_base_size = sizeof (*ptr->array);
flexible_array_member_size =
count * flexible_array_member_base_size;
if (flexible_array_member_size < 0)
return 0;
return flexible_array_member_size;
2) '&ptr->array[idx]':
count = ptr->count;
index = idx;
flexible_array_member_base_size = sizeof (*ptr->array);
flexible_array_member_size =
count * flexible_array_member_base_size;
index_size = index * flexible_array_member_base_size;
if (flexible_array_member_size < 0 || index < 0)
return 0;
return flexible_array_member_size - index_size;
3) '&ptr->field':
count = ptr->count;
sizeof_struct = sizeof (struct s);
flexible_array_member_base_size = sizeof (*ptr->array);
flexible_array_member_size =
count * flexible_array_member_base_size;
field_offset = offsetof (struct s, field);
offset_diff = sizeof_struct - field_offset;
if (flexible_array_member_size < 0)
return 0;
return offset_diff + flexible_array_member_size;
4) '&ptr->field_array[idx]':
count = ptr->count;
index = idx;
sizeof_struct = sizeof (struct s);
flexible_array_member_base_size = sizeof (*ptr->array);
flexible_array_member_size =
count * flexible_array_member_base_size;
field_base_size = sizeof (*ptr->field_array);
field_offset = offsetof (struct s, field)
field_offset += index * field_base_size;
offset_diff = sizeof_struct - field_offset;
if (flexible_array_member_size < 0 || index < 0)
return 0;
return offset_diff + flexible_array_member_size;
---------
Signed-off-by: Bill Wendling <morbo@google.com>
This patch contains a number of changes relating to the above flag;
primarily it updates comment references to the old flag names,
"-fextend-lifetimes" and "-fextend-this-ptr" to refer to the new names,
"-fextend-variable-liveness[={all,this}]". These changes are all NFC.
This patch also removes the explicit -fextend-this-ptr-liveness flag
alias, and shortens the help-text for the main flag; these are both
changes that were meant to be applied in the initial PR (#110000), but
due to some user-error on my part they were not included in the merged
commit.
Following the previous patch which adds the "extend lifetimes" flag
without (almost) any functionality, this patch adds the real feature by
allowing Clang to emit fake uses. These are emitted as a new form of cleanup,
set for variable addresses, which just emits a fake use intrinsic when the
variable falls out of scope. The code for achieving this is simple, with most
of the logic centered on determining whether to emit a fake use for a given
address, and on ensuring that fake uses are ignored in a few cases.
Co-authored-by: Stephen Tozer <stephen.tozer@sony.com>
As part of the "RemoveDIs" work to eliminate debug intrinsics, we're
replacing methods that use Instruction*'s as positions with iterators.
This patch changes some more complex call-sites, those crossing file
boundaries and where I've had to perform some minor rewrites.
