Summary:
In r247104 I added the builtins for generating non-temporal memory operations,
but now I realized that they lack documentation. This patch adds some.
Differential Revision: http://reviews.llvm.org/D12785
llvm-svn: 247374
This patch depends on r246688 (D12341).
The goal is to make LLVM generate different code for these functions for a target that
has cheap branches (see PR23827 for more details):
int foo();
int normal(int x, int y, int z) {
if (x != 0 && y != 0) return foo();
return 1;
}
int crazy(int x, int y) {
if (__builtin_unpredictable(x != 0 && y != 0)) return foo();
return 1;
}
Differential Revision: http://reviews.llvm.org/D12458
llvm-svn: 246699
This change adds the new unroll metadata "llvm.loop.unroll.enable" which directs
the optimizer to unroll a loop fully if the trip count is known at compile time, and
unroll partially if the trip count is not known at compile time. This differs from
"llvm.loop.unroll.full" which explicitly does not unroll a loop if the trip count is not
known at compile time
With this change "#pragma unroll" generates "llvm.loop.unroll.enable" rather than
"llvm.loop.unroll.full" metadata. This changes the semantics of "#pragma unroll" slightly
to mean "unroll aggressively (fully or partially)" rather than "unroll fully or not at all".
The motivating example for this change was some internal code with a loop marked
with "#pragma unroll" which only sometimes had a compile-time trip count depending
on template magic. When the trip count was a compile-time constant, everything works
as expected and the loop is fully unrolled. However, when the trip count was not a
compile-time constant the "#pragma unroll" explicitly disabled unrolling of the loop(!).
Removing "#pragma unroll" caused the loop to be unrolled partially which was desirable
from a performance perspective.
llvm-svn: 244467
Support for emitting libcalls for __atomic_fetch_nand and
__atomic_{add,sub,and,or,xor,nand}_fetch was missing; add it, and some
test cases.
Differential Revision: http://reviews.llvm.org/D10847
llvm-svn: 244063
This change updates the documentation for the loop unrolling pragma behavior
change in r242047. Specifically, with that change "#pragma unroll" will not
unroll loops with a runtime trip count.
llvm-svn: 242048
This patch adds the -fsanitize=safe-stack command line argument for clang,
which enables the Safe Stack protection (see http://reviews.llvm.org/D6094
for the detailed description of the Safe Stack).
This patch is our implementation of the safe stack on top of Clang. The
patches make the following changes:
- Add -fsanitize=safe-stack and -fno-sanitize=safe-stack options to clang
to control safe stack usage (the safe stack is disabled by default).
- Add __attribute__((no_sanitize("safe-stack"))) attribute to clang that can be
used to disable the safe stack for individual functions even when enabled
globally.
Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.
Differential Revision: http://reviews.llvm.org/D6095
llvm-svn: 239762
Adds a Clang-specific implementation of C11's stdatomic.h header. On systems,
such as FreeBSD, where a stdatomic.h header is already provided, we defer to
that header instead (using our __has_include_next technology). Otherwise, we
provide an implementation in terms of our __c11_atomic_* intrinsics (that were
created for this purpose).
C11 7.1.4p1 requires function declarations for atomic_thread_fence,
atomic_signal_fence, atomic_flag_test_and_set,
atomic_flag_test_and_set_explicit, and atomic_flag_clear, and requires that
they have external linkage. Accordingly, we provide these declarations, but if
a user elides the shadowing macros and uses them, then they must have a libc
(or similar) that actually provides definitions.
atomic_flag is implemented using _Bool as the underlying type. This is
consistent with the implementation provided by FreeBSD and also GCC 4.9 (at
least when __GCC_ATOMIC_TEST_AND_SET_TRUEVAL == 1).
Patch by Richard Smith (rebased and slightly edited by me -- Richard said I
should drive at this point).
llvm-svn: 218957
This makes use of the recently-added @llvm.assume intrinsic to implement a
__builtin_assume(bool) intrinsic (to provide additional information to the
optimizer). This hooks up __assume in MS-compatibility mode to mirror
__builtin_assume (the semantics have been intentionally kept compatible), and
implements GCC's __builtin_assume_aligned as assume((p - o) & mask == 0). LLVM
now contains special logic to deal with assumptions of this form.
llvm-svn: 217349
Added cast operations to the table of vector operations. Supported status 'no' means that there are no tests in the Clang test suite for the given cast.
llvm-svn: 217055
ARMv8 adds (to both AArch32 and AArch64) acquiring and releasing
variants of the exclusive operations, in line with the C++11 memory
model.
This adds support for two new intrinsics to expose them to C & C++
developers directly: __builtin_arm_ldaex and __builtin_arm_stlex, in
direct analogy with the versions with no implicit barrier.
rdar://problem/15885451
llvm-svn: 212175
Extend the documentation for "#pragma clang loop" hints to include the unroll
and unroll_count directives.
Patch by Mark Heffernan [http://reviews.llvm.org/D4198]
llvm-svn: 211286
to the normal non-placement ::operator new and ::operator delete, but allow
optimizations like new-expressions and delete-expressions do.
llvm-svn: 210137
This adds Clang support for the ARM64 backend. There are definitely
still some rough edges, so please bring up any issues you see with
this patch.
As with the LLVM commit though, we think it'll be more useful for
merging with AArch64 from within the tree.
llvm-svn: 205100
Implement type trait primitives used in the latest edition of the Microsoft
standard C++ library type_traits header.
With this change we can parse much of the Visual Studio 2013 standard headers,
particularly anything that includes <type_traits>.
Fully implemented, available in all language modes:
* __is_constructible()
* __is_nothrow_constructible()
* __is_nothrow_assignable()
Partially implemented, semantic analysis WIP, available as MS extensions:
* __is_destructible()
* __is_nothrow_destructible()
llvm-svn: 199619
Update the documentation to clarify the intent of clang's built-in type trait
facilities, their relation to user-facing C++ type traits and means to check
for availability.
Also explain that __has_feature() is not currently up to date and should not
generally be used in user code (there's a proposal to provide more consistent
checks via __has_builtin(), see cfe-dev).
llvm-svn: 199562
This C++ feature has been marked complete since r191549, but the documentation
claimed it wasn't supported at all and the extension check misreported it as
being available in C.
No regression test; this was a short-lived typo.
llvm-svn: 199292
it. Also removes all of the microsoft C++ ABI related code from the
itanium layout builder.
Differential Revision: http://llvm-reviews.chandlerc.com/D2003
llvm-svn: 193290
This attribute allows users to use a modified C or C++ function as an ARM
exception-handling function and, with care, to successfully return control to
user-space after the issue has been dealt with.
rdar://problem/14207019
llvm-svn: 191769
LLVM supports applying conversion instructions to vectors of the same number of
elements (fptrunc, fptosi, etc.) but there had been no way for a Clang user to
cause such instructions to be generated when using builtin vector types.
C-style casting on vectors is already defined in terms of bitcasts, and so
cannot be used for these conversions as well (without leading to a very
confusing set of semantics). As a result, this adds a __builtin_convertvector
intrinsic (patterned after the OpenCL __builtin_astype intrinsic). This is
intended to aid the creation of vector intrinsic headers that create generic IR
instead of target-dependent intrinsics (in other words, this is a generic
_mm_cvtepi32_ps). As noted in the documentation, the action of
__builtin_convertvector is defined in terms of the action of a C-style cast on
each vector element.
llvm-svn: 190915
Unlike C++11's "thread_local" keyword, C11's "_Thread_local" is in the
reserved namespace, meaning we provide it unconditionally; it is marked
as KEYALL in TokenKinds.def.
This means that like all the other C11 keywords, we can expose its
presence through __has_extension().
llvm-svn: 190755
Patch by chris.wailes@gmail.com. The following functionality was added:
* The same functionality is now supported for both CXXOperatorCallExprs and CXXMemberCallExprs.
* Factored out some code in StmtVisitor.
* Removed variables from the state map when their destructors are encountered.
* Started adding documentation for the consumed analysis attributes.
llvm-svn: 189059
This allows the ObjFW runtime to correctly implement message forwarding
for messages which return a struct.
Patch by Jonathan Schleifer.
llvm-svn: 187174
cxx_init_capture. "generalized" is neither descriptive nor future-proof. No
compatibility problems expected, since we've never advertised having this
feature.
llvm-svn: 187058
This adds three overloaded intrinsics to Clang:
T __builtin_arm_ldrex(const volatile T *addr)
int __builtin_arm_strex(T val, volatile T *addr)
void __builtin_arm_clrex()
The intent is that these do what users would expect when given most sensible
types. Currently, "sensible" translates to ints, floats and pointers.
llvm-svn: 186394
& operator (ignoring any overloaded operator& for the type). The purpose of
this builtin is for use in std::addressof, to allow it to be made constexpr;
the existing implementation technique (reinterpret_cast to some reference type,
take address, reinterpert_cast back) does not permit this because
reinterpret_cast between reference types is not permitted in a constant
expression in C++11 onwards.
llvm-svn: 186053
#if defined(__has_foo("X")) && __has_foo("X")
is not a correct way to portably use __has_foo, because it is expanded to
#if 0 && 0("X")
... which is ill-formed.
Also add a missing ')'.
llvm-svn: 186047
This will enable users in security critical applications to perform
checked-arithmetic in a fast safe manner that is amenable to c.
Tests/an update to Language Extensions is included as well.
rdar://13421498.
llvm-svn: 184497
I have had several people ask me about why this builtin was not available in
clang (since it seems like a logical conclusion). This patch implements said
builtins.
Relevant tests are included as well. I also updated the Clang language extension reference.
rdar://14192664.
llvm-svn: 184227
Add __has_feature and __has_extension checks for C++1y features (based on the provisional names from
the C++ features study group), and update documentation to match.
llvm-svn: 181342
These are two related changes (one in llvm, one in clang).
LLVM:
- rename address_safety => sanitize_address (the enum value is the same, so we preserve binary compatibility with old bitcode)
- rename thread_safety => sanitize_thread
- rename no_uninitialized_checks -> sanitize_memory
CLANG:
- add __attribute__((no_sanitize_address)) as a synonym for __attribute__((no_address_safety_analysis))
- add __attribute__((no_sanitize_thread))
- add __attribute__((no_sanitize_memory))
for S in address thread memory
If -fsanitize=S is present and __attribute__((no_sanitize_S)) is not
set llvm attribute sanitize_S
llvm-svn: 176076
Language extensions are highly relevant to using clang as a compiler, so
move LanguageExtensions up into `Using Clang as a Compiler` on the
landing page.
The other documents from the now-gone `Language Extensions and Specs`
section on the landing page nicely fit hierarchically under
LanguageExtensions.rst, so put them under LanguageExtensions.rst's
toctree instead of on the landing page.
Impetus from Jordan Rose.
llvm-svn: 171409
The notes on the objc_method_family and ns_returns_retained-type attributes
have been moved to the Objective-C section, since both are used by ARC.
The notes on analyzer_noreturn are now only on the analyzer site.
The inadequacy of these docs was noticed months ago by Jonathan Sauer;
I'm only just now getting around to cleaning them up.
llvm-svn: 170261
Converts:
LanguageExtensions
LibASTMatchers
LibTooling
PCHInternals
ThreadSanitizer
Tooling
Patch by Mykhailo Pustovit!
(with minor edits by Dmitri Gribenko and Sean Silva)
llvm-svn: 170048
Sylvestre Ledru