Today the optimization is limited to:
- `[ClassName alloc]`
- `[self alloc]` when within a class method
However it means that when code is written this way:
```
@interface MyObject
- (id)copyWithZone:(NSZone *)zone
{
return [[self.class alloc] _initWith...];
}
@end
```
... then the optimization doesn't kick in and `+[NSObject alloc]` ends
up in IMP caches where it could have been avoided. It turns out that
`+alloc` -> `+[NSObject alloc]` is the most cached SEL/IMP pair in the
entire platform which is rather silly).
There's two theoretical risks allowing this optimization:
1. if the receiver is nil (which it can't be today), but it turns out
that `objc_alloc()`/`objc_alloc_init()` cope with a nil receiver,
2. if the `Clas` type for the receiver is a lie. However, for such a
code to work today (and not fail witn an unrecognized selector
anyway) you'd have to have implemented the `-alloc` **instance
method**.
Fortunately, `objc_alloc()` doesn't assume that the receiver is a
Class, it basically starts with a test that is similar to
`if (receiver->isa->bits & hasDefaultAWZ) { /* fastpath */ }`.
This bit is only set on metaclasses by the runtime, so if an instance
is passed to this function by accident, its isa will fail this test,
and `objc_alloc()` will gracefully fallback to `objc_msgSend()`.
The one thing `objc_alloc()` doesn't support is tagged pointer
instances. None of the tagged pointer classes implement an instance
method called `'alloc'` (actually there's a single class in the
entire Apple codebase that has such a method).
Differential Revision: https://reviews.llvm.org/D71682
Radar-Id: rdar://problem/58058316
Reviewed-By: Akira Hatanaka
Signed-off-by: Pierre Habouzit <phabouzit@apple.com>
Summary:
Before this change, X86_32ABIInfo::classifyArgument would be called
twice on vector arguments to vectorcall functions. This function has
side effects to track GPR register usage, and this would lead to
incorrect GPR usage in some cases. The specific case I noticed is from
running out of XMM registers with mixed FP and vector arguments and no
aggregates of any kind. Consider this prototype:
void __vectorcall vectorcall_indirect_vec(
double xmm0, double xmm1, double xmm2, double xmm3, double xmm4,
__m128 xmm5,
__m128 ecx,
int edx,
__m128 mem);
classifyArgument has no effects when called on a plain FP type, but when
called on a vector type, it modifies FreeRegs to model GPR consumption.
However, this should not happen during the vector call first pass.
I refactored the code to unify vectorcall HVA logic with regcall HVA
logic. The conventions pass HVAs in registers differently (expanded vs.
not expanded), but if they do not fit in registers, they both pass them
indirectly by address.
Reviewers: erichkeane, craig.topper
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72110
For IR input files, we currently use LLVM diagnostic handler even the
compilation is from clang. As a result, we are not able to use -Rpass
to get the transformation reports. Some warnings are not handled
properly either: We found many mysterious warnings in our ThinLTO backend
compilations in SamplePGO and CSPGO. An example of the warning:
"warning: net/proto2/public/metadata_lite.h:51:21: 0.02% (1 / 4999)"
This turns out to be a warning by Wmisexpect, which is supposed to be
filtered out by default. But since the filter is in clang's
diagnostic hander, we emit these incomplete warnings from LLVM's
diagnostic handler.
This patch uses clang diagnostic handler for IR input files. We create
a fake backendconsumer just to install the diagnostic handler.
With this change, we will have proper handling of all the warnings and we can
use -Rpass* options in IR input files compilation.
Also note that with is patch, LLVM's diagnostic options, like
"-mllvm -pass-remarks=*", are no longer be able to get optimization remarks.
Differential Revision: https://reviews.llvm.org/D72523
There are no special virtual function handlers (like __cxa_pure_virtual)
defined for NVPTX target, so just emit such functions as null pointers
to prevent issues with linking and unresolved references.
Summary:
This patch adds an option to limit debug info by only emitting complete class
type information when its constructor is emitted. This applies to classes
that have nontrivial user defined constructors.
I implemented the option by adding another level to `DebugInfoKind`, and
a flag `-flimit-debug-info-constructor`.
Total object file size on Windows, compiling with RelWithDebInfo:
before: 4,257,448 kb
after: 2,104,963 kb
And on Linux
before: 9,225,140 kb
after: 4,387,464 kb
According to the Windows clang.pdb files, here is a list of types that are no
longer complete with this option enabled: https://reviews.llvm.org/P8182
Reviewers: rnk, dblaikie
Subscribers: aprantl, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72427
Summary:
Previously, since these aggregates are > 2*XLen, Clang would think they
were being returned indirectly and thus would decrease the number of
available GPRs available by 1. For long argument lists this could lead
to a struct argument incorrectly being passed indirectly.
Reviewers: asb, lenary
Reviewed By: asb, lenary
Subscribers: luismarques, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, sameer.abuasal, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D69590
The option will limit debug info by only emitting complete class
type information when its constructor is emitted.
This patch changes comparisons with LimitedDebugInfo to use the new
level instead.
Differential Revision: https://reviews.llvm.org/D72427
Just marking a symbol as weak_odr/linkonce_odr isn't enough for
actually tolerating multiple copies of it at linking on windows,
it has to be made a proper comdat; make it comdat for all platforms
for consistency.
This should hopefully fix
https://bugzilla.mozilla.org/show_bug.cgi?id=1566288.
Differential Revision: https://reviews.llvm.org/D71572
GCC supports the conditional operator on VectorTypes that acts as a
'select' in C++ mode. This patch implements the support. Types are
converted as closely to GCC's behavior as possible, though in a few
places consistency with our existing vector type support was preferred.
Note that this implementation is different from the OpenCL version in a
number of ways, so it unfortunately required a different implementation.
First, the SEMA rules and promotion rules are significantly different.
Secondly, GCC implements COND[i] != 0 ? LHS[i] : RHS[i] (where i is in
the range 0- VectorSize, for each element). In OpenCL, the condition is
COND[i] < 0 ? LHS[i]: RHS[i].
In the process of implementing this, it was also required to make the
expression COND ? LHS : RHS type dependent if COND is type dependent,
since the type is now dependent on the condition. For example:
T ? 1 : 2;
Is not typically type dependent, since the result can be deduced from
the operands. HOWEVER, if T is a VectorType now, it could change this
to a 'select' (basically a swizzle with a non-constant mask) with the 1
and 2 being promoted to vectors themselves.
While this is a change, it is NOT a standards incompatible change. Based
on my (and D. Gregor's, at the time of writing the code) reading of the
standard, the expression is supposed to be type dependent if ANY
sub-expression is type dependent.
Differential Revision: https://reviews.llvm.org/D71463
which is the default TLS model for non-PIC objects. This allows large/
many thread local variables or a compact/fast code in an executable.
Specification is same as that of GCC. For example, the code model
option precedes the TLS size option.
TLS access models other than local-exec are not changed. It means
supoort of the large code model is only in the local exec TLS model.
Patch By KAWASHIMA Takahiro (kawashima-fj <t-kawashima@fujitsu.com>)
Reviewers: dmgreen, mstorsjo, t.p.northover, peter.smith, ostannard
Reviewd By: peter.smith
Committed by: peter.smith
Differential Revision: https://reviews.llvm.org/D71688
Summary:
This patch will provide support for auto return type for the C++ member
functions.
This patch includes clang side implementation of this feature.
Patch by: Awanish Pandey <Awanish.Pandey@amd.com>
Reviewers: dblaikie, aprantl, shafik, alok, SouraVX, jini.susan.george
Reviewed by: dblaikie
Differential Revision: https://reviews.llvm.org/D70524
This fixes a regression introduced in
2b4fa5348e that caused us to emit
shutdown-time destruction for variables with ARC ownership, using
C++-specific functions that don't exist in C implementations.
In the backend, this feature is implemented with the function attribute
"patchable-function-entry". Both the attribute and XRay use
TargetOpcode::PATCHABLE_FUNCTION_ENTER, so the two features are
incompatible.
Reviewed By: ostannard, MaskRay
Differential Revision: https://reviews.llvm.org/D72222
This feature is generic. Make it applicable for AArch64 and X86 because
the backend has only implemented NOP insertion for AArch64 and X86.
Reviewed By: nickdesaulniers, aaron.ballman
Differential Revision: https://reviews.llvm.org/D72221
Summary:
Avoid using the `nocf_check` attribute with Control Flow Guard. Instead, use a
new `"guard_nocf"` function attribute to indicate that checks should not be
added on indirect calls within that function. Add support for
`__declspec(guard(nocf))` following the same syntax as MSVC.
Reviewers: rnk, dmajor, pcc, hans, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: aaron.ballman, tomrittervg, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72167
Update the IRBuilder to generate constrained FP comparisons in
CreateFCmp when IsFPConstrained is true, similar to the other
places in the IRBuilder.
Also, add a new CreateFCmpS to emit signaling FP comparisons,
and use it in clang where comparisons are supposed to be signaling
(currently, only when emitting code for the <, <=, >, >= operators).
Note that there is currently no way to add fast-math flags to a
constrained FP comparison, since this is implemented as an intrinsic
call that returns a boolean type, and FMF are only allowed for calls
returning a floating-point type. However, given the discussion around
https://bugs.llvm.org/show_bug.cgi?id=42179, it seems that FCmp itself
really shouldn't have any FMF either, so this is probably OK.
Reviewed by: craig.topper
Differential Revision: https://reviews.llvm.org/D71467
If a system header provides an (inline) implementation of some of their
function, clang still matches on the function name and generate the appropriate
llvm builtin, e.g. memcpy. This behavior is in line with glibc recommendation «
users may not provide their own version of symbols » but doesn't account for the
fact that glibc itself can provide inline version of some functions.
It is the case for the memcpy function when -D_FORTIFY_SOURCE=1 is on. In that
case an inline version of memcpy calls __memcpy_chk, a function that performs
extra runtime checks. Clang currently ignores the inline version and thus
provides no runtime check.
This code fixes the issue by detecting functions whose name is a builtin name
but also have an inline implementation.
Differential Revision: https://reviews.llvm.org/D71082
down to pass builder in ltobackend.
Currently CodeGenOpts like UnrollLoops/VectorizeLoop/VectorizeSLP in clang
are not passed down to pass builder in ltobackend when new pass manager is
used. This is inconsistent with the behavior when new pass manager is used
and thinlto is not used. Such inconsistency causes slp vectorization pass
not being enabled in ltobackend for O3 + thinlto right now. This patch
fixes that.
Differential Revision: https://reviews.llvm.org/D72386
This change introduces three new builtins (which work on both pointers
and integers) that can be used instead of common bitwise arithmetic:
__builtin_align_up(x, alignment), __builtin_align_down(x, alignment) and
__builtin_is_aligned(x, alignment).
I originally added these builtins to the CHERI fork of LLVM a few years ago
to handle the slightly different C semantics that we use for CHERI [1].
Until recently these builtins (or sequences of other builtins) were
required to generate correct code. I have since made changes to the default
C semantics so that they are no longer strictly necessary (but using them
does generate slightly more efficient code). However, based on our experience
using them in various projects over the past few years, I believe that adding
these builtins to clang would be useful.
These builtins have the following benefit over bit-manipulation and casts
via uintptr_t:
- The named builtins clearly convey the semantics of the operation. While
checking alignment using __builtin_is_aligned(x, 16) versus
((x & 15) == 0) is probably not a huge win in readably, I personally find
__builtin_align_up(x, N) a lot easier to read than (x+(N-1))&~(N-1).
- They preserve the type of the argument (including const qualifiers). When
using casts via uintptr_t, it is easy to cast to the wrong type or strip
qualifiers such as const.
- If the alignment argument is a constant value, clang can check that it is
a power-of-two and within the range of the type. Since the semantics of
these builtins is well defined compared to arbitrary bit-manipulation,
it is possible to add a UBSAN checker that the run-time value is a valid
power-of-two. I intend to add this as a follow-up to this change.
- The builtins avoids int-to-pointer casts both in C and LLVM IR.
In the future (i.e. once most optimizations handle it), we could use the new
llvm.ptrmask intrinsic to avoid the ptrtoint instruction that would normally
be generated.
- They can be used to round up/down to the next aligned value for both
integers and pointers without requiring two separate macros.
- In many projects the alignment operations are already wrapped in macros (e.g.
roundup2 and rounddown2 in FreeBSD), so by replacing the macro implementation
with a builtin call, we get improved diagnostics for many call-sites while
only having to change a few lines.
- Finally, the builtins also emit assume_aligned metadata when used on pointers.
This can improve code generation compared to the uintptr_t casts.
[1] In our CHERI compiler we have compilation mode where all pointers are
implemented as capabilities (essentially unforgeable 128-bit fat pointers).
In our original model, casts from uintptr_t (which is a 128-bit capability)
to an integer value returned the "offset" of the capability (i.e. the
difference between the virtual address and the base of the allocation).
This causes problems for cases such as checking the alignment: for example, the
expression `if ((uintptr_t)ptr & 63) == 0` is generally used to check if the
pointer is aligned to a multiple of 64 bytes. The problem with offsets is that
any pointer to the beginning of an allocation will have an offset of zero, so
this check always succeeds in that case (even if the address is not correctly
aligned). The same issues also exist when aligning up or down. Using the
alignment builtins ensures that the address is used instead of the offset. While
I have since changed the default C semantics to return the address instead of
the offset when casting, this offset compilation mode can still be used by
passing a command-line flag.
Reviewers: rsmith, aaron.ballman, theraven, fhahn, lebedev.ri, nlopes, aqjune
Reviewed By: aaron.ballman, lebedev.ri
Differential Revision: https://reviews.llvm.org/D71499
Summary:
A few of the ARM MVE builtins directly return a structure type. This
causes an assertion failure at code-gen time if you try to assign the
result of the builtin to a variable, because the `RValue` created in
`EmitBuiltinExpr` from the `llvm::Value` produced by codegen is always
made by `RValue::get()`, which creates a non-aggregate `RValue` that
will fail an assertion when `AggExprEmitter::withReturnValueSlot` calls
`Src.getAggregatePointer()`. A similar failure occurs if you try to use
the struct return value directly to extract one field, e.g.
`vld2q(address).val[0]`.
The existing code-gen tests for those MVE builtins pass the returned
structure type directly to the C `return` statement, which apparently
managed to avoid that particular code path, so we didn't notice the
crash.
Now `EmitBuiltinExpr` checks the evaluation kind of the builtin's return
value, and does the necessary handling for aggregate returns. I've added
two extra test cases, both of which crashed before this change.
Reviewers: dmgreen, rjmccall
Reviewed By: rjmccall
Subscribers: kristof.beyls, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72271
Use canonical decls instead of mangled names in the set of already
emitted decls. This allows to reduce the number of function calls for
getting declarations mangled names and speedup the compilation.
properties of the protocol it inherits
This fixes a bug where the type string for a @dynamic property of an
@implementation didn't have 'D' in it when the protocol it conforms to
redeclares the property declared in the base protocol.
rdar://problem/45503561
Added codegen support for lastprivate conditional. According to the
standard, if when the conditional modifier appears on the clause, if an
assignment to a list item is encountered in the construct then the
original list item is assigned the value that is assigned to the new
list item in the sequentially last iteration or lexically last section
in which such an assignment is encountered.
We look for the assignment operations and check if the left side
references lastprivate conditional variable. Then the next code is
emitted:
if (last_iv_a <= iv) {
last_iv_a = iv;
last_a = lp_a;
}
At the end the implicit barrier is generated to wait for the end of all
threads and then in the check for the last iteration the private copy is
assigned the last value.
if (last_iter) {
lp_a = last_a; // <--- new code
a = lp_a; // <--- store of private value to the original variable.
}
There's quite a lot of references to Polly in the LLVM CMake codebase. However
the registration pattern used by Polly could be useful to other external
projects: thanks to that mechanism it would be possible to develop LLVM
extension without touching the LLVM code base.
This patch has two effects:
1. Remove all code specific to Polly in the llvm/clang codebase, replaicing it
with a generic mechanism
2. Provide a generic mechanism to register compiler extensions.
A compiler extension is similar to a pass plugin, with the notable difference
that the compiler extension can be configured to be built dynamically (like
plugins) or statically (like regular passes).
As a result, people willing to add extra passes to clang/opt can do it using a
separate code repo, but still have their pass be linked in clang/opt as built-in
passes.
Differential Revision: https://reviews.llvm.org/D61446
clang/lib/CodeGen/CodeGenModule performs the -mpie-copy-relocations
check and sets dso_local on applicable global variables. We don't need
to duplicate the work in TargetMachine shouldAssumeDSOLocal.
Verified that -mpie-copy-relocations can still emit PC relative
relocations for external variable accesses.
clang -target x86_64 -fpie -mpie-copy-relocations -c => R_X86_64_PC32
clang -target aarch64 -fpie -mpie-copy-relocations -c => R_AARCH64_ADR_PREL_PG_HI21+R_AARCH64_LDST64_ABS_LO12_NC
We already recognize the __builtin versions of these, might as well
recognize the libcall version.
Differential Revision: https://reviews.llvm.org/D72028
This replaces the fsub -0.0 idiom with an fneg instruction. We didn't see to have a test that showed the current codegen. Just some tests for constant folding and a test that was only checking the declare lines for libcalls. The latter just checked that we did not have a declare for @conj when using __builtin_conj.
Differential Revision: https://reviews.llvm.org/D72012
We have an fneg instruction now and should use it instead of the fsub -0.0 idiom. Looks like we had no test that showed that we handled the negation cases here so I've added new tests.
Differential Revision: https://reviews.llvm.org/D72010
This allows to use the OpenMPIRBuilder for parallel regions. Code was
extracted from D61953 and adapted to work with the new version (D70109).
All but one feature should be supported. An update of this patch will
provide test coverage and privatization other than shared.
Reviewed By: fghanim
Differential Revision: https://reviews.llvm.org/D70290
This removes the OpenMPProcBindClauseKind enum in favor of
llvm::omp::ProcBindKind which lives in OpenMPConstants.h and was
introduced in D70109.
No change in behavior is expected.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D70289
As a permanent and generic solution to the problem of variable
finalization (destructors, lastprivate, ...), this patch introduces the
finalization stack. The objects on the stack describe (1) the
(structured) regions the OpenMP-IR-Builder is currently constructing,
(2) if these are cancellable, and (3) the callback that will perform the
finalization (=cleanup) when necessary.
As the finalization can be necessary multiple times, at different source
locations, the callback takes the position at which code is currently
generated. This position will also encode the destination of the "region
exit" block *iff* the finalization call was issues for a region
generated by the OpenMPIRBuilder. For regions generated through the old
Clang OpenMP code geneneration, the "region exit" is determined by Clang
inside the finalization call instead (see getOMPCancelDestination).
As a first user, the parallel + cancel barrier interaction is changed.
In contrast to the temporary solution before, the barrier generation in
Clang does not need to be aware of the "CancelDestination" block.
Instead, the finalization callback is and, as described above, later
even that one does not need to be.
D70109 will be updated to use this scheme.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D70258
Amy Huang