This patch provides a means to specify section-names for global variables,
functions and static variables, using #pragma directives.
This feature is only defined to work sensibly for ELF targets.
One can specify section names as:
#pragma clang section bss="myBSS" data="myData" rodata="myRodata" text="myText"
One can "unspecify" a section name with empty string e.g.
#pragma clang section bss="" data="" text="" rodata=""
Reviewers: Roger Ferrer, Jonathan Roelofs, Reid Kleckner
Differential Revision: https://reviews.llvm.org/D33412
llvm-svn: 304705
This is a recommit of r300539 that was reverted in r300543 due to test failures.
The original commit message is displayed below:
The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.
Differential Revision: https://reviews.llvm.org/D30009
llvm-svn: 300556
The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.
Differential Revision: https://reviews.llvm.org/D30009
llvm-svn: 300539
This adds the new pragma and the first variant, contract(on/off/fast).
The pragma has the same block scope rules as STDC FP_CONTRACT, i.e. it can be
placed at the beginning of a compound statement or at file scope.
Similarly to STDC FP_CONTRACT there is no need to use attributes. First an
annotate token is inserted with the parsed details of the pragma. Then the
annotate token is parsed in the proper contexts and the Sema is updated with
the corresponding FPOptions using the shared ActOn function with STDC
FP_CONTRACT.
After this the FPOptions from the Sema is propagated into the AST expression
nodes. There is no change here.
I was going to add a 'default' option besides 'on/off/fast' similar to STDC
FP_CONTRACT but then decided against it. I think that we'd have to make option
uppercase then to avoid using 'default' the keyword. Also because of the
scoped activation of pragma I am not sure there is really a need a for this.
Differential Revision: https://reviews.llvm.org/D31276
llvm-svn: 299470
The alias was only ever used on darwin and had some issues there,
and isn't used in practice much. Also fixes a problem with -mno-altivec
not turning off -maltivec.
Also add a diagnostic for faltivec/fno-altivec that directs users to use
maltivec options and include the altivec.h file explicitly.
llvm-svn: 298449
Summary:
With this commit simple coroutines can be created in plain C using coroutine builtins.
Reviewers: rnk, EricWF, rsmith
Subscribers: modocache, mgorny, mehdi_amini, beanz, cfe-commits
Differential Revision: https://reviews.llvm.org/D24373
llvm-svn: 283155
Summary:
This is similar to other loop pragmas like 'vectorize'. Currently it
only has state values: distribute(enable) and distribute(disable). When
one of these is specified the corresponding loop metadata is generated:
!{!"llvm.loop.distribute.enable", i1 true/false}
As a result, loop distribution will be attempted on the loop even if
Loop Distribution in not enabled globally. Analogously, with 'disable'
distribution can be turned off for an individual loop even when the pass
is otherwise enabled.
There are some slight differences compared to the existing loop pragmas.
1. There is no 'assume_safety' variant which makes its handling slightly
different from 'vectorize'/'interleave'.
2. Unlike the existing loop pragmas, it does not have a corresponding
numeric pragma like 'vectorize' -> 'vectorize_width'. So for the
consistency checks in CheckForIncompatibleAttributes we don't need to
check it against other pragmas. We just need to check for duplicates of
the same pragma.
Reviewers: rsmith, dexonsmith, aaron.ballman
Subscribers: bob.wilson, cfe-commits, hfinkel
Differential Revision: http://reviews.llvm.org/D19403
llvm-svn: 272656
MSVC now supports the __is_assignable type trait intrinsic,
to enable easier and more efficient implementation of the
Standard Library's is_assignable trait.
As of Visual Studio 2015 Update 3, the VC Standard Library
implementation uses the new intrinsic unconditionally.
The implementation is pretty straightforward due to the previously
existing is_nothrow_assignable and is_trivially_assignable.
We handle __is_assignable via the same code as the other two except
that we skip the extra checks for nothrow or triviality.
Patch by Dave Bartolomeo!
Differential Revision: http://reviews.llvm.org/D20492
llvm-svn: 270458
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
Nico Weber