Fixes#129900
If `operator delete` was called after an unsuccessful constructor call
after `operator new`, we ran into undefined behaviour.
This was discovered by our malfunction tests while preparing an upgrade
to LLVM 20, that explicitly check for such kind of bugs.
Inspired by PR #127944, this patch adds an option to print profile metadata inline with respect to the instruction (or function) it annotates - this saves one time from having to search up and down large textual modules to find this info.
…argetMachine
RISC-V's data layout is determined by the ABI, not just the target
triple. However, the TargetMachine is created using the data layout from
the target triple, which is not always correct. This patch uses the
target ABI from the module and passes it to the TargetMachine, ensuring
that the data layout is set correctly according to the ABI.
The same problem will happen with other targets like MIPS, but
unfortunately, MIPS didn't emit the target-abi into the module flags, so
this patch only fixes the issue for RISC-V.
NOTE: MIPS with -mabi=n32 can trigger the same issue.
Another possible solution is add new parameter to the TargetMachine
constructor, but that would require changes in all the targets.
The module currently stores the target triple as a string. This means
that any code that wants to actually use the triple first has to
instantiate a Triple, which is somewhat expensive. The change in #121652
caused a moderate compile-time regression due to this. While it would be
easy enough to work around, I think that architecturally, it makes more
sense to store the parsed Triple in the module, so that it can always be
directly queried.
For this change, I've opted not to add any magic conversions between
std::string and Triple for backwards-compatibilty purses, and instead
write out needed Triple()s or str()s explicitly. This is because I think
a decent number of them should be changed to work on Triple as well, to
avoid unnecessary conversions back and forth.
The only interesting part in this patch is that the default triple is
Triple("") instead of Triple() to preserve existing behavior. The former
defaults to using the ELF object format instead of unknown object
format. We should fix that as well.
There was an assert in GetConstant checked if Bound is constant.
However, GetConstant was only called when IsConstant==true.
This refactor attempts to get rid of the assert by combining GetConstant
and IsContstant.
This patch adds a function attribute `riscv_vls_cc` for RISCV VLS
calling
convention which takes 0 or 1 argument, the argument is the `ABI_VLEN`
which is the `VLEN` for passing the fixed-vector arguments, it wraps the
argument as a scalable vector(VLA) using the `ABI_VLEN` and uses the
corresponding mechanism to handle it. The range of `ABI_VLEN` is [32,
65536],
if not specified, the default value is 128.
Here is an example of VLS argument passing:
Non-VLS call:
```
void original_call(__attribute__((vector_size(16))) int arg) {}
=>
define void @original_call(i128 noundef %arg) {
entry:
...
ret void
}
```
VLS call:
```
void __attribute__((riscv_vls_cc(256))) vls_call(__attribute__((vector_size(16))) int arg) {}
=>
define riscv_vls_cc void @vls_call(<vscale x 1 x i32> %arg) {
entry:
...
ret void
}
}
```
The first Non-VLS call passes generic vector argument of 16 bytes by
flattened integer.
On the contrary, the VLS call uses `ABI_VLEN=256` which wraps the
vector to <vscale x 1 x i32> where the number of scalable vector
elements
is calaulated by: `ORIG_ELTS * RVV_BITS_PER_BLOCK / ABI_VLEN`.
Note: ORIG_ELTS = Vector Size / Type Size = 128 / 32 = 4.
PsABI PR: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/pull/418
C-API PR: https://github.com/riscv-non-isa/riscv-c-api-doc/pull/68
Relative to the previous attempt this includes two fixes:
* Adjust callCapturesBefore() to not skip captures(ret: address,
provenance) arguments, as these will not count as a capture
at the call-site.
* When visiting uses during stack slot optimization, don't skip
the ModRef check for passthru captures. Calls can both modref
and be passthru for captures.
------
This extends CaptureTracking to support inferring non-trivial
CaptureInfos. The focus of this patch is to only support FunctionAttrs,
other users of CaptureTracking will be updated in followups.
The key API changes here are:
* DetermineUseCaptureKind() now returns a UseCaptureInfo where the UseCC
component specifies what is captured at that Use and the ResultCC
component specifies what may be captured via the return value of the
User. Usually only one or the other will be used (corresponding to
previous MAY_CAPTURE or PASSTHROUGH results), but both may be set for
call captures.
* The CaptureTracking::captures() extension point is passed this
UseCaptureInfo as well and then can decide what to do with it by
returning an Action, which is one of: Stop: stop traversal.
ContinueIgnoringReturn: continue traversal but don't follow the
instruction return value. Continue: continue traversal and follow the
instruction return value if it has additional CaptureComponents.
For now, this patch retains the (unsound) special logic for comparison
of null with a dereferenceable pointer. I'd like to switch key code to
take advantage of address/address_is_null before dropping it.
This PR mainly intends to introduce necessary API changes and basic
inference support, there are various possible improvements marked with
TODOs.
Replace some more nvvm.annotations with function attributes,
auto-upgrading the annotations as needed. These new attributes will be
more idiomatic and compile-time efficient than the annotations.
- !"maxntid[xyz]" -> "nvvm.maxntid"
- !"reqntid[xyz]" -> "nvvm.reqntid"
- !"cluster_dim_[xyz]" -> "nvvm.cluster_dim"
`llvm.wasm.throw` intrinsic can throw but it was not invokable. Not sure
what the rationale was when it was first written that way, but I think
at least in Emscripten's C++ exception support with the Wasm port of
libunwind, `__builtin_wasm_throw`, which is lowered down to
`llvm.wasm.rethrow`, is used only within `_Unwind_RaiseException`, which
is an one-liner and thus does not need an `invoke`:
720e97f76d/system/lib/libunwind/src/Unwind-wasm.c (L69)
(`_Unwind_RaiseException` is called by `__cxa_throw`, which is generated
by the `throw` C++ keyword)
But this does not address other direct uses of the builtin in C++, whose
use I'm not sure about but is not prohibited. Also other language
frontends may need to use the builtin in different functions, which has
`try`-`catch`es or destructors.
This makes `llvm.wasm.throw` invokable in the backend. To do that, this
adds a custom lowering routine to `SelectionDAGBuilder::visitInvoke`,
like we did for `llvm.wasm.rethrow`.
This does not generate `invoke`s for `__builtin_wasm_throw` yet, which
will be done by a follow-up PR.
Addresses #124710.
The llvm.fake.use intrinsic is used to prevent certain values from being
optimized out for the benefit of debug info; it is not, however, a debug
or pseudo instruction itself and necessarily must not be treated as one,
since its purpose is to act like a normal instruction. In the original
commit that added them, the IR intrinsic however was treated as one in
`getPrevNonDebugInstruction` (but _not_ in `getNextNonDebugInstruction`,
or in the MIR equivalents). This patch correctly treats it as a
non-debug instruction.
An Ada program can have types that are subranges of other types. This
patch adds a new DIType node, DISubrangeType, to represent this concept.
I considered extending the existing DISubrange to do this, but as
DISubrange does not derive from DIType, that approach seemed more
disruptive.
A DISubrangeType can be used both as an ordinary type, but also as the
type of an array index. This is also important for Ada.
Ada subrange types can also be stored using a bias. Representing this in
the DWARF required the use of an extension. GCC has been emitting this
extension for years, so I've reused it here.
Check that the input register is an inreg argument to the parent
function. (See the comment in `IntrinsicsAMDGPU.td`.)
This LLVM defect was identified via the AMD Fuzzing project.
---------
Co-authored-by: Matt Arsenault <arsenm2@gmail.com>
DICompositeType has an attribute representing the name of a type, but
currently it isn't possible to set this for array types via the
DIBuilder method. This patch adds a new overload of
DIBuilder::createArrayType that allows "full" construction of an array
type. This is useful for Ada, where arrays are a bit more first-class
than C.
Make sure that this intrinsic is being followed by unreachable.
This LLVM defect was identified via the AMD Fuzzing project.
Thanks to @rovka for helping me solve this issue!
The standard libcalls for half to float and float to half conversion are
__extendhfsf2 and __truncsfhf2. However, LLVM currently uses
__gnu_h2f_ieee and __gnu_f2h_ieee instead. As far as I can tell, these
libcalls are an ARM-ism and only provided by libgcc on that platform.
compiler-rt always provides both libcalls.
Use the standard libcalls by default, and only use the __gnu libcalls on
ARM.
This patch adds a new __builtin_assume_dereferenceable to encode
dereferenceability of a pointer using llvm.assume with an operand
bundle.
For now the builtin only accepts constant sizes, I am planning to drop
this restriction in a follow-up change.
This can be used to better optimize cases where a pointer is known to be
dereferenceable, e.g. unconditionally loading from p2 when vectorizing
the loop.
int *get_ptr();
void foo(int* src, int x) {
int *p2 = get_ptr();
__builtin_assume_aligned(p2, 4);
__builtin_assume_dereferenceable(p2, 4000);
for (unsigned I = 0; I != 1000; ++I) {
int x = src[I];
if (x == 0)
x = p2[I];
src[I] = x;
}
}
PR: https://github.com/llvm/llvm-project/pull/121789
Relative to the previous attempt, this adjusts isEscapeSource()
to not treat calls with captures(ret: address, provenance) or similar
arguments as escape sources. This addresses the miscompile reported at:
https://github.com/llvm/llvm-project/pull/125880#issuecomment-2656632577
The implementation uses a helper function on CallBase to make this
check a bit more efficient (e.g. by skipping the byval checks) as
checking attributes on all arguments if fairly expensive.
------
This extends CaptureTracking to support inferring non-trivial
CaptureInfos. The focus of this patch is to only support FunctionAttrs,
other users of CaptureTracking will be updated in followups.
The key API changes here are:
* DetermineUseCaptureKind() now returns a UseCaptureInfo where the UseCC
component specifies what is captured at that Use and the ResultCC
component specifies what may be captured via the return value of the
User. Usually only one or the other will be used (corresponding to
previous MAY_CAPTURE or PASSTHROUGH results), but both may be set for
call captures.
* The CaptureTracking::captures() extension point is passed this
UseCaptureInfo as well and then can decide what to do with it by
returning an Action, which is one of: Stop: stop traversal.
ContinueIgnoringReturn: continue traversal but don't follow the
instruction return value. Continue: continue traversal and follow the
instruction return value if it has additional CaptureComponents.
For now, this patch retains the (unsound) special logic for comparison
of null with a dereferenceable pointer. I'd like to switch key code to
take advantage of address/address_is_null before dropping it.
This PR mainly intends to introduce necessary API changes and basic
inference support, there are various possible improvements marked with
TODOs.
Model C/C++ `errno` macro by adding a corresponding `errno`
memory location kind to the IR. Preliminary work to separate
`errno` writes from other memory accesses, to the benefit of
alias analyses and optimization correctness.
Previous discussion: https://discourse.llvm.org/t/rfc-modelling-errno-memory-effects/82972.
After #124287 updated several functions to return iterators rather than
Instruction *, it was no longer straightforward to pass their result to
DIBuilder. This commit updates DIBuilder methods to accept an
InsertPosition instead, so that they can be called with an iterator
(preferred), or with a deprecation warning an Instruction *, or a
BasicBlock *. This commit also updates the existing calls to the
DIBuilder methods to pass in iterators.
As a special exception, DIBuilder::insertDeclare() keeps a separate
overload accepting a BasicBlock *InsertAtEnd. This is because despite
the name, this method does not insert at the end of the block, therefore
this cannot be handled implicitly by using InsertPosition.
This is a (very belated) reland of 0a362f12ec60a49a054befec8620a8e69523af54,
which I originally reverted due to flang test failures.
This marks mul constant expressions as undesirable, which means that
we will no longer create them by default, but they can still be
created explicitly.
Part of:
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179
This patch attempts to reland
https://github.com/llvm/llvm-project/pull/120780 while addressing the
issues that caused the patch to be reverted.
Namely:
1. The patch had included code from the llvm/Passes directory in the
llvm/CodeGen directory.
2. The patch increased the backend compile time by 2% due to adding a
very expensive include in MachineFunctionPass.h
The patch has been re-structured so that there is no dependency between
the llvm/Passes and llvm/CodeGen directory, by moving the base class,
`class DroppedVariableStats` to the llvm/IR directory.
The expensive include in MachineFunctionPass.h has been changed to
contain forward declarations instead of other header includes which was
pulling a ton of code into MachineFunctionPass.h and should resolve any
issues when it comes to compile time increase.
After #124287 updated several functions to return iterators rather than
Instruction *, it was no longer straightforward to pass their result to
DIBuilder. This commit updates DIBuilder methods to accept an
InsertPosition instead, so that they can be called with an iterator
(preferred), or with a deprecation warning an Instruction *, or a
BasicBlock *. This commit also updates the existing calls to the
DIBuilder methods to pass in iterators.
Replace some more nvvm.annotations with function attributes,
auto-upgrading the annotations as needed. These new attributes will be
more idiomatic and compile-time efficient than the annotations.
- !"maxclusterrank" / !"cluster_max_blocks" -> "nvvm.maxclusterrank"
- !"minctasm" -> "nvvm.minctasm"
- !"maxnreg" -> "nvvm.maxnreg"
This is an upstream proposal from
e60884cb98
We observed malfunctioning StripNonLineTableDebugInfo during debugging
and it's caused by out-of-order evaluation, this is a C++ level semantic
ambiguity issue, refer
https://en.cppreference.com/w/cpp/language/eval_order
Solution is simply separating one line into two.
Add initial parsing/sema support for new assumption clause so clause can
be specified. For now, it's ignored, just like the others.
Added support for 'no_openmp_construct' to release notes.
Testing
- Updated appropriate LIT tests.
- Testing: check-all
I ran into this while working on a different patch where I'm emitting a
zero-valued DWARF enum field which shouldn't be skipped.
This patch checks the (currently unused) `ShouldSkipZero` before
deciding to skip printing this field. Based on git history this seems
like an oversight from the initial refactor that introduced this. We
have a similar check in `printInt`.
Wasn't sure how to best test this, but tests in an upcoming patch rely
on this functionality (see
https://github.com/llvm/llvm-project/pull/126045).
Currently the only place `ShouldSkipZero` is set to `false` is when
emitting the `DW_LANG_` enum. But the language codes start at `0x1`. So
it never exercised this codepath (and we should probably just make it
not pass this parameter).
When creating `EnumDecl`s from DWARF for Objective-C `NS_ENUM`s, the
Swift compiler tries to figure out if it should perform "swiftification"
of that enum (which involves renaming the enumerator cases, etc.). The
heuristics by which it determines whether we want to swiftify an enum is
by checking the `enum_extensibility` attribute (because that's what
`NS_ENUM` pretty much are). Currently LLDB fails to attach the
`EnumExtensibilityAttr` to `EnumDecl`s it creates (because there's not
enough info in DWARF to derive it), which means we have to fall back to
re-building Swift modules on-the-fly, slowing down expression evaluation
substantially. This happens around
4b3931c8ce/lib/ClangImporter/ImportEnumInfo.cpp (L37-L59)
To speed up Swift exression evaluation, this patch proposes encoding the
C/C++/Objective-C `enum_extensibility` attribute in DWARF via a new
`DW_AT_APPLE_ENUM_KIND`. This would currently be only used from the LLDB
Swift plugin. But may be of interest to other language plugins as well
(though I haven't come up with a concrete use-case for it outside of
Swift).
I'm open to naming suggestions of the various new attributes/attribute
constants proposed here. I tried to be as generic as possible if we
wanted to extend it to other kinds of enum properties (e.g., flag
enums).
The new attribute would look as follows:
```
DW_TAG_enumeration_type
DW_AT_type (0x0000003a "unsigned int")
DW_AT_APPLE_enum_kind (DW_APPLE_ENUM_KIND_Closed)
DW_AT_name ("ClosedEnum")
DW_AT_byte_size (0x04)
DW_AT_decl_file ("enum.c")
DW_AT_decl_line (23)
DW_TAG_enumeration_type
DW_AT_type (0x0000003a "unsigned int")
DW_AT_APPLE_enum_kind (DW_APPLE_ENUM_KIND_Open)
DW_AT_name ("OpenEnum")
DW_AT_byte_size (0x04)
DW_AT_decl_file ("enum.c")
DW_AT_decl_line (27)
```
Absence of the attribute means the extensibility of the enum is unknown
and abides by whatever the language rules of that CU dictate.
This does feel like a big hammer for quite a specific use-case, so I'm
happy to discuss alternatives.
Alternatives considered:
* Re-using an existing DWARF attribute to express extensibility. E.g., a
`DW_TAG_enumeration_type` could have a `DW_AT_count` or
`DW_AT_upper_bound` indicating the number of enumerators, which could
imply closed-ness. I felt like a dedicated attribute (which could be
generalized further) seemed more applicable. But I'm open to re-using
existing attributes.
* Encoding the entire attribute string (i.e., `DW_TAG_LLVM_annotation
("enum_extensibility((open))")`) on the `DW_TAG_enumeration_type`. Then
in LLDB somehow parse that out into a `EnumExtensibilityAttr`. I haven't
found a great API in Clang to parse arbitrary strings into AST nodes
(the ones I've found required fully formed C++ constructs). Though if
someone knows of a good way to do this, happy to consider that too.
These three intrinsics are similar to llvm.vector.(de)interleave2 but
work with 3/5/7 vector operands or results.
For RISC-V, it's important to have them in order to support segmented
load/store with factor of 2 to 8: factor of 2/4/8 can be synthesized
from (de)interleave2; factor of 6 can be synthesized from factor of 2
and 3; factor 5 and 7 have their own intrinsics added by this patch.
This patch only adds codegen support for these intrinsics, we still need
to teach vectorizer to generate them as well as teaching
InterleavedAccessPass to use them.
---------
Co-authored-by: Craig Topper <craig.topper@sifive.com>
Add a new AutoUpgrade function to convert some legacy nvvm.annotations
metadata to function level attributes. These attributes are quicker to
look-up so improve compile time and are more idiomatic than using
metadata which should not include required information that changes the
meaning of the program.
Currently supported annotations are:
- !"kernel" -> ptx_kernel calling convention
- !"align" -> alignstack parameter attributes (return not yet supported)
This PR removes the old `nocapture` attribute, replacing it with the new
`captures` attribute introduced in #116990. This change is
intended to be essentially NFC, replacing existing uses of `nocapture`
with `captures(none)` without adding any new analysis capabilities.
Making use of non-`none` values is left for a followup.
Some notes:
* `nocapture` will be upgraded to `captures(none)` by the bitcode
reader.
* `nocapture` will also be upgraded by the textual IR reader. This is to
make it easier to use old IR files and somewhat reduce the test churn in
this PR.
* Helper APIs like `doesNotCapture()` will check for `captures(none)`.
* MLIR import will convert `captures(none)` into an `llvm.nocapture`
attribute. The representation in the LLVM IR dialect should be updated
separately.
The check for `isOSWindows() || isUEFI()` is used in several places
across the codebase. Introducing `isOSWindowsOrUEFI()` in Triple.h
to simplify these checks.
gcc and clang won't complain about calls to deprecated functions, if
you're calling from a function that is deprecated too. However, MSVC
does care, and expands into maaany deprecation warnings for
getFirstNonPHI.
Suppress this by converting the inlineable copy of getFirstNonPHI into a
non-inline copy.
The RemoveDIs project [0] makes debug intrinsics obsolete and to support
this instruction iterators carry an extra bit of debug information. To
maintain debug information accuracy insertion needs to be performed with a
BasicBlock::iterator rather than with Instruction pointers, otherwise the
extra bit of debug information is lost.
To that end, we're deprecating getFirstNonPHI and moveBefore for
instruction pointers. They're replaced by getFirstNonPHIIt and an
iterator-taking moveBefore: switching to the replacement is
straightforwards, and 99% of call-sites need only to unwrap the iterator
with &* or call getIterator() on an Instruction pointer.
The exception is when inserting instructions at the start of a block: if
you call getFirstNonPHI() (or begin() or getFirstInsertionPt()) and then
insert something at that position, you must pass the BasicBlock::iterator
returned into the insertion method. Unwrapping with &* and then calling
getIterator strips the debug-info bit we wish to preserve. Please do
contact us about any use case that's confusing or unclear [1].
[0] https://llvm.org/docs/RemoveDIsDebugInfo.html
[1] https://discourse.llvm.org/t/psa-ir-output-changing-from-debug-intrinsics-to-debug-records/79578
