Introduce a function attribute 'enforce_tcb' that prevents the function
from calling other functions without the same attribute. This allows
isolating code that's considered to be somehow privileged so that it could not
use its privileges to exhibit arbitrary behavior.
Introduce an on-by-default warning '-Wtcb-enforcement' that warns
about violations of the above rule.
Introduce a function attribute 'enforce_tcb_leaf' that suppresses
the new warning within the function it is attached to. Such leaf functions
may implement common functionality between the trusted and the untrusted code
but they require extra careful audit with respect to their capabilities.
Fixes after a revert in 419ef38a50293c58078f830517f5e305068dbee6:
Fix a test.
Add workaround for GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67274).
Attribute the patch appropriately!
Differential Revision: https://reviews.llvm.org/D91898
Introduce a function attribute 'enforce_tcb' that prevents the function
from calling other functions without the same attribute. This allows
isolating code that's considered to be somehow privileged so that it could not
use its privileges to exhibit arbitrary behavior.
Introduce an on-by-default warning '-Wtcb-enforcement' that warns
about violations of the above rule.
Introduce a function attribute 'enforce_tcb_leaf' that suppresses
the new warning within the function it is attached to. Such leaf functions
may implement common functionality between the trusted and the untrusted code
but they require extra careful audit with respect to their capabilities.
Differential Revision: https://reviews.llvm.org/D91898
Add powerpcle support to clang.
For FreeBSD, assume a freestanding environment for now, as we only need it in the first place to build loader, which runs in the OpenFirmware environment instead of the FreeBSD environment.
For Linux, recognize glibc and musl environments to match current usage in Void Linux PPC.
Adjust driver to match current binutils behavior regarding machine naming.
Adjust and expand tests.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D93919
On PPC, the vector pair instructions are independent from MMA.
This patch renames the vector pair LLVM intrinsics and Clang builtins to replace the _mma_ prefix by _vsx_ in their names.
We also move the vector pair type/intrinsic/builtin tests to their own files.
Differential Revision: https://reviews.llvm.org/D91974
This patch enables the Clang type __vector_pair and its associated LLVM
intrinsics even when MMA is disabled. With this patch, the type is now controlled
by the PPC paired-vector-memops option. The builtins and intrinsics will be
renamed to drop the mma prefix in another patch.
Differential Revision: https://reviews.llvm.org/D91819
The use of the new types introduced for PowerPC MMA instructions needs to be restricted.
We add a PowerPC function checking that the given type is valid in a context in which we don't allow MMA types.
This function is called from various places in Sema where we want to prevent the use of these types.
Differential Revision: https://reviews.llvm.org/D82035
Add MMA builtin decoding. These builtins use the new PowerPC-specific types __vector_pair and __vector_quad.
So to avoid pervasive changes, we use custom type descriptors and custom decoding for these builtins.
We also use custom code generation to expand builtin calls with pointers to simpler intrinsic calls with non-pointer types.
Differential Revision: https://reviews.llvm.org/D81748
Checks to make sure that stdlib's (std::)free is being appropriately
used. Presently checks for the following misuses:
- free(&stack_object)
- free(stack_array)
Differential Revision: https://reviews.llvm.org/D89988
We now recognize this function as a builtin despite it having an
unexpected number of parameters; make sure we don't enforce that it has
only 1 argument for its 2 parameters.
Check applied to unbounded (incomplete) arrays and pointers to spot
cases where the computed address is beyond the largest possible
addressable extent of the array, based on the address space in which the
array is delcared, or which the pointer refers to.
Check helps to avoid cases of nonsense pointer math and array indexing
which could lead to linker failures or runtime exceptions. Of
particular interest when building for embedded systems with small
address spaces.
This is version 2 of this patch -- version 1 had some testing issues
due to a sign error in existing code. That error is corrected and
lit test for this chagne is extended to verify the fix.
Originally reviewed/accepted by: aaron.ballman
Original revision: https://reviews.llvm.org/D86796
Reviewed By: ebevhan
Differential Revision: https://reviews.llvm.org/D88174
This patch implements custom codegen for the vec_replace_elt and
vec_replace_unaligned builtins.
These builtins map to the @llvm.ppc.altivec.vinsw and @llvm.ppc.altivec.vinsd
intrinsics depending on the arguments. The main motivation for doing custom
codegen for these intrinsics is because there are float and double versions of
the builtin. Normally, the converting the float to an integer would be done via
fptoui in the IR. This is incorrect as fptoui truncates the value and we must
ensure the value is not truncated. Therefore, we provide custom codegen to utilize
bitcast instead as bitcasts do not truncate.
Differential Revision: https://reviews.llvm.org/D83500
Check applied to unbounded (incomplete) arrays and pointers
to spot cases where the computed address is beyond the
largest possible addressable extent of the array, based
on the address space in which the array is delcared, or
which the pointer refers to.
Check helps to avoid cases of nonsense pointer math and
array indexing which could lead to linker failures or
runtime exceptions. Of particular interest when building
for embedded systems with small address spaces.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D86796
Continue to heuristically pick the wider of the two operands for
narrowing conversion warnings so that some_char + 1 isn't treated as
being wider than a char, but use the more accurate computation for
tautological comparison warnings.
Differential Revision: https://reviews.llvm.org/D85778
This patch moves FixedPointSemantics and APFixedPoint
from Clang to LLVM ADT.
This will make it easier to use the fixed-point
classes in LLVM for constructing an IR builder for
fixed-point and for reusing the APFixedPoint class
for constant evaluation purposes.
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-August/144025.html
Reviewed By: leonardchan, rjmccall
Differential Revision: https://reviews.llvm.org/D85312
SemaBuiltinConstantArg has an early exit for that case that doesn't
produce an error and doesn't update the APInt. We need to detect that
case and not use the APInt value.
While there delete the signature of CheckX86BuiltinTileArgumentsRange
that takes a single Argument index to check. There's another version
that takes an ArrayRef and single value is convertible to an ArrayRef.
We're (temporarily) disabling ExtInt for the '__atomic' builtins so we can better design their behavior later. The idea is until we do an audit/design for the way atomic builtins are supposed to work with _ExtInt, we should leave them restricted so they don't limit our future options, such as by binding us to a sub-optimal implementation via ABI.
Example after this change:
$ cat test.c
void f(_ExtInt(64) *ptr) {
__atomic_fetch_add(ptr, 1, 0);
}
$ clang -c test.c
test.c:2:22: error: argument to atomic builtin of type '_ExtInt' is not supported
__atomic_fetch_add(ptr, 1, 0);
^
1 error generated.
Differential Revision: https://reviews.llvm.org/D84049
When a conditional expression has a throw expression it called
GetExprRange with a void expression, which caused an assertion failure.
This approach was suggested by Richard Smith.
Fixes PR46484: Clang crash in clang/lib/Sema/SemaChecking.cpp:10028
Differential Revision: https://reviews.llvm.org/D85601
This warning diagnoses cases where an expression is compared to a
constant, and the comparison is tautological due to the form of the
expression (but not merely due to its type). This applies in cases such
as comparisons of bit-fields and the result of bit-masks.
The new warning is added to the Clang diagnostic group
-Wtautological-constant-in-range-compare but not to the
formerly-equivalent GCC-compatibility diagnostic group -Wtype-limits,
which retains its old meaning of diagnosing only tautological
comparisons to extremal values of a type (eg, int > INT_MAX).
Reviewed By: rtrieu
Differential Revision: https://reviews.llvm.org/D85256
`OS << ND->getDeclName();` is equivalent to `OS << ND->getNameAsString();`
without the extra temporary string.
This is not quite a NFC since two uses of `getNameAsString` in a
diagnostic are replaced, which results in the named entity being
quoted with additional "'"s (ie: 'var' instead of var).
This patch added the following additional compile-once
run-everywhere (CO-RE) relocations:
- existence/size of typedef, struct/union or enum type
- enum value and enum value existence
These additional relocations will make CO-RE bpf programs more
adaptive for potential kernel internal data structure changes.
For existence/size relocations, the following two code patterns
are supported:
1. uint32_t __builtin_preserve_type_info(*(<type> *)0, flag);
2. <type> var;
uint32_t __builtin_preserve_field_info(var, flag);
flag = 0 for existence relocation and flag = 1 for size relocation.
For enum value existence and enum value relocations, the following code
pattern is supported:
uint64_t __builtin_preserve_enum_value(*(<enum_type> *)<enum_value>,
flag);
flag = 0 means existence relocation and flag = 1 for enum value.
relocation. In the above <enum_type> can be an enum type or
a typedef to enum type. The <enum_value> needs to be an enumerator
value from the same enum type. The return type is uint64_t to
permit potential 64bit enumerator values.
Differential Revision: https://reviews.llvm.org/D83242
Background:
-----------
There are two related argument types which can be sent into a diagnostic to
display the name of an entity: DeclarationName (ak_declarationname) or
NamedDecl* (ak_nameddecl) (there is also ak_identifierinfo for
IdentifierInfo*, but we are not concerned with it here).
A DeclarationName in a diagnostic will just be streamed to the output,
which will directly result in a call to DeclarationName::print.
A NamedDecl* in a diagnostic will also ultimately result in a call to
DeclarationName::print, but with two customisation points along the way:
The first customisation point is NamedDecl::getNameForDiagnostic which is
overloaded by FunctionDecl, ClassTemplateSpecializationDecl and
VarTemplateSpecializationDecl to print the template arguments, if any.
The second customisation point is NamedDecl::printName. By default it just
streams the stored DeclarationName into the output but it can be customised
to provide a user-friendly name for an entity. It is currently overloaded by
DecompositionDecl and MSGuidDecl.
What this patch does:
---------------------
For many diagnostics a DeclarationName is used instead of the NamedDecl*.
This bypasses the two customisation points mentioned above. This patches fix
this for diagnostics in Sema.cpp, SemaCast.cpp, SemaChecking.cpp, SemaDecl.cpp,
SemaDeclAttr.cpp, SemaDecl.cpp, SemaOverload.cpp and SemaStmt.cpp.
I have only modified diagnostics where I could construct a test-case which
demonstrates that the change is appropriate (either with this patch or the next
one).
Reviewed By: erichkeane, aaron.ballman
Differential Revision: https://reviews.llvm.org/D84656
Reapply 49e5f603d4
which had been reverted in c94332919b.
Originally reverted because I hadn't updated it in quite a while when I
got around to committing it, so there were a bunch of missing changes to
new code since I'd written the patch.
Reviewers: aaron.ballman
Differential Revision: https://reviews.llvm.org/D76646
The _ExtInt type allows custom width integers, but the atomic memory
access's operand must have a power-of-two size. _ExtInts with
non-power-of-two size should not be allowed for atomic intrinsic.
Before this change:
$ cat test.c
typedef unsigned _ExtInt(42) dtype;
void verify_binary_op_nand(dtype* pval1, dtype val2)
{ __sync_nand_and_fetch(pval1, val2); }
$ clang test.c
clang-11:
/home/ubuntu/llvm_workspace/llvm/clang/lib/CodeGen/CGBuiltin.cpp:117:
llvm::Value*
EmitToInt(clang::CodeGen::CodeGenFunction&, llvm::Value*,
clang::QualType, llvm::IntegerType*): Assertion `V->getType() ==
IntType' failed.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the
crash backtrace, preprocessed source, and associated run script.
After this change:
$ clang test.c
test.c:3:30: error: Atomic memory operand must have a power-of-two size
{ __sync_nand_and_fetch(pval1, val2); }
^
List of the atomic intrinsics that have this
problem:
__sync_fetch_and_add
__sync_fetch_and_sub
__sync_fetch_and_or
__sync_fetch_and_and
__sync_fetch_and_xor
__sync_fetch_and_nand
__sync_nand_and_fetch
__sync_and_and_fetch
__sync_add_and_fetch
__sync_sub_and_fetch
__sync_or_and_fetch
__sync_xor_and_fetch
__sync_fetch_and_min
__sync_fetch_and_max
__sync_fetch_and_umin
__sync_fetch_and_umax
__sync_val_compare_and_swap
__sync_bool_compare_and_swap
Differential Revision: https://reviews.llvm.org/D83340
There is a version that just tests (also called
isIntegerConstantExpression) & whereas this version is specifically used
when the value is of interest (a few call sites were actually refactored
to calling the test-only version) so let's make the API look more like
it.
Reviewers: aaron.ballman
Differential Revision: https://reviews.llvm.org/D76646
We were previously bypassing the conditional expression special case for binary
conditional expressions.
rdar://64134411
Differential revision: https://reviews.llvm.org/D81751
in general, value dependent is a subset of instnatiation dependent. This
would allows us to produce diagnostics for the align expression (which
is instantiation dependent but not value dependent).
Differential Revision: https://reviews.llvm.org/D83074
This was suggested in D72782 and brings the diagnostics more in line
with how argument references are handled elsewhere.
Reviewers: rjmccall, jfb, Bigcheese
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D82473
Add a new builtin-function __builtin_expect_with_probability and
intrinsic llvm.expect.with.probability.
The interface is __builtin_expect_with_probability(long expr, long
expected, double probability).
It is mainly the same as __builtin_expect besides one more argument
indicating the probability of expression equal to expected value. The
probability should be a constant floating-point expression and be in
range [0.0, 1.0] inclusive.
It is similar to builtin-expect-with-probability function in GCC
built-in functions.
Differential Revision: https://reviews.llvm.org/D79830
In C++17 the operand(s) of an overloaded operator are sequenced as for
the corresponding built-in operator when the overloaded operator is
called with the operator notation ([over.match.oper]p2).
Reported in PR35340.
Differential Revision: https://reviews.llvm.org/D81330
Reviewed By: rsmith
This patch add __builtin_matrix_column_major_store to Clang,
as described in clang/docs/MatrixTypes.rst. In the initial version,
the stride is not optional yet.
Reviewers: rjmccall, jfb, rsmith, Bigcheese
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D72782
For example:
svint32_t svget4(svint32x4_t tuple, uint64_t imm_index)
returns the subvector at `index`, which must be in range `0..3`.
svint32x3_t svset3(svint32x3_t tuple, uint64_t index, svint32_t vec)
returns a tuple vector with `vec` inserted into `tuple` at `index`,
which must be in range `0..2`.
Reviewers: c-rhodes, efriedma
Reviewed By: c-rhodes
Tags: #clang
Differential Revision: https://reviews.llvm.org/D81464
This patch add __builtin_matrix_column_major_load to Clang,
as described in clang/docs/MatrixTypes.rst. In the initial version,
the stride is not optional yet.
Reviewers: rjmccall, rsmith, jfb, Bigcheese
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D72781
_ExtInt types
- Fix computed size for _ExtInt types passed to checked arithmetic
builtins.
- Emit diagnostic when signed _ExtInt larger than 128-bits is passed
to __builtin_mul_overflow.
- Change Sema checks for builtins to accept placeholder types.
Differential Revision: https://reviews.llvm.org/D81420
Summary:
__builtin_amdgcn_atomic_inc32(int *Ptr, int Val, unsigned MemoryOrdering, const char *SyncScope)
__builtin_amdgcn_atomic_inc64(int64_t *Ptr, int64_t Val, unsigned MemoryOrdering, const char *SyncScope)
__builtin_amdgcn_atomic_dec32(int *Ptr, int Val, unsigned MemoryOrdering, const char *SyncScope)
__builtin_amdgcn_atomic_dec64(int64_t *Ptr, int64_t Val, unsigned MemoryOrdering, const char *SyncScope)
First and second arguments gets transparently passed to the amdgcn atomic
inc/dec intrinsic. Fifth argument of the intrinsic is set as true if the
first argument of the builtin is a volatile pointer. The third argument of
this builtin is one of the memory-ordering specifiers ATOMIC_ACQUIRE,
ATOMIC_RELEASE, ATOMIC_ACQ_REL, or ATOMIC_SEQ_CST following C++11 memory
model semantics. This is mapped to corresponding LLVM atomic memory ordering
for the atomic inc/dec instruction using CLANG atomic C ABI. The fourth
argument is an AMDGPU-specific synchronization scope defined as string.
Reviewers: arsenm, sameerds, JonChesterfield, jdoerfert
Reviewed By: arsenm, sameerds
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, jfb, kerbowa, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D80804
This patch add __builtin_matrix_transpose to Clang, as described in
clang/docs/MatrixTypes.rst.
Reviewers: rjmccall, jfb, rsmith, Bigcheese
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D72778
Summary:
This patch upstreams support for a new storage only bfloat16 C type.
This type is used to implement primitive support for bfloat16 data, in
line with the Bfloat16 extension of the Armv8.6-a architecture, as
detailed here:
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:
https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile
In detail this patch:
- introduces an opaque, storage-only C-type __bf16, which introduces a new bfloat IR type.
This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.
The following people contributed to this patch:
- Luke Cheeseman
- Momchil Velikov
- Alexandros Lamprineas
- Luke Geeson
- Simon Tatham
- Ties Stuij
Reviewers: SjoerdMeijer, rjmccall, rsmith, liutianle, RKSimon, craig.topper, jfb, LukeGeeson, fpetrogalli
Reviewed By: SjoerdMeijer
Subscribers: labrinea, majnemer, asmith, dexonsmith, kristof.beyls, arphaman, danielkiss, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76077
In C++17 the postfix-expression of a call expression is sequenced before
each expression in the expression-list and any default argument.
Differential Revision: https://reviews.llvm.org/D58579
Reviewed By: rsmith
When I fixed the targets specific builtins to make sure that aux-targets
are checked, it seems I didn't consider cases where the builtins check
the target info for further info. This patch bubbles the target-info
down to the individual checker functions to ensure that they validate
against the aux-target as well.
For non-aux-target invocations, this is an NFC.
Such a builtin function is mostly useful to preserve btf type id
for non-global data. For example,
extern void foo(..., void *data, int size);
int test(...) {
struct t { int a; int b; int c; } d;
d.a = ...; d.b = ...; d.c = ...;
foo(..., &d, sizeof(d));
}
The function "foo" in the above only see raw data and does not
know what type of the data is. In certain cases, e.g., logging,
the additional type information will help pretty print.
This patch implemented a BPF specific builtin
u32 btf_type_id = __builtin_btf_type_id(param, flag)
which will return a btf type id for the "param".
flag == 0 will indicate a BTF local relocation,
which means btf type_id only adjusted when bpf program BTF changes.
flag == 1 will indicate a BTF remote relocation,
which means btf type_id is adjusted against linux kernel or
future other entities.
Differential Revision: https://reviews.llvm.org/D74668
alignment information on VarDecls in more cases
This commit improves upon https://reviews.llvm.org/D21099. The code that
computes the source alignment now understands array subscript
expressions, binary operators, derived-to-base casts, and several more
expressions.
rdar://problem/59242343
Differential Revision: https://reviews.llvm.org/D78767
I discovered that when using an aux-target builtin, it was recognized as
a builtin but never checked. This patch checks for an aux-target builtin
and instead validates it against the correct target.
It does this by extracting the checking code for Target-specific
builtins into its own function, then calls with either targetInfo or
AuxTargetInfo.
Expose llvm fence instruction as clang builtin for AMDGPU target
__builtin_amdgcn_fence(unsigned int memoryOrdering, const char *syncScope)
The first argument of this builtin is one of the memory-ordering specifiers
__ATOMIC_ACQUIRE, __ATOMIC_RELEASE, __ATOMIC_ACQ_REL, or __ATOMIC_SEQ_CST
following C++11 memory model semantics. This is mapped to corresponding
LLVM atomic memory ordering for the fence instruction using LLVM atomic C
ABI. The second argument is an AMDGPU-specific synchronization scope
defined as string.
Reviewed By: sameerds
Differential Revision: https://reviews.llvm.org/D75917
This patch also adds the enum `sv_prfop` for the prefetch operation specifier
and checks to ensure the passed enum values are valid.
Reviewers: SjoerdMeijer, efriedma, ctetreau
Reviewed By: efriedma
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78674
This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDeclSpec that are
exactly identical. This non-functional change consolidates these enums
into one. The changes are to many files across clang (and comments in LLVM) so
that everything refers to the new consolidated enum in DeclObjCCommon.h.
2nd Landing Attempt...
Differential Revision: https://reviews.llvm.org/D77233
This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDeclSpec that are
exactly identical. This non-functional change consolidates these enums
into one. The changes are to many files across clang (and comments in LLVM) so
that everything refers to the new consolidated enum in DeclObjCCommon.h.
Differential Revision: https://reviews.llvm.org/D77233
Adds another bunch of of intrinsics that take immediates with
varying ranges based, some being a complex rotation immediate
which are a set of allowed immediates rather than a range.
svmla_lane: lane immediate ranging 0..(128/(1*sizeinbits(elt)) - 1)
svcmla_lane: lane immediate ranging 0..(128/(2*sizeinbits(elt)) - 1)
svdot_lane: lane immediate ranging 0..(128/(4*sizeinbits(elt)) - 1)
svcadd: complex rotate immediate [90, 270]
svcmla:
svcmla_lane: complex rotate immediate [0, 90, 180, 270]
Reviewers: efriedma, SjoerdMeijer, rovka
Reviewed By: efriedma
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76680
This patch adds a number of intrinsics that take immediates with
varying ranges based on the element size one of the operands.
svext: immediate ranging 0 to (2048/sizeinbits(elt) - 1)
svasrd: immediate ranging 1..sizeinbits(elt)
svqshlu: immediate ranging 1..sizeinbits(elt)/2
ftmad: immediate ranging 0..(sizeinbits(elt) - 1)
Reviewers: efriedma, SjoerdMeijer, rovka, rengolin
Reviewed By: SjoerdMeijer
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76679
This reverts commit 61ba1481e2.
I'm reverting this because it breaks the lldb build with
incomplete switch coverage warnings. I would fix it forward,
but am not familiar enough with lldb to determine the correct
fix.
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:3958:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
switch (qual_type->getTypeClass()) {
^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4633:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
switch (qual_type->getTypeClass()) {
^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4889:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
switch (qual_type->getTypeClass()) {
Introduction/Motivation:
LLVM-IR supports integers of non-power-of-2 bitwidth, in the iN syntax.
Integers of non-power-of-two aren't particularly interesting or useful
on most hardware, so much so that no language in Clang has been
motivated to expose it before.
However, in the case of FPGA hardware normal integer types where the
full bitwidth isn't used, is extremely wasteful and has severe
performance/space concerns. Because of this, Intel has introduced this
functionality in the High Level Synthesis compiler[0]
under the name "Arbitrary Precision Integer" (ap_int for short). This
has been extremely useful and effective for our users, permitting them
to optimize their storage and operation space on an architecture where
both can be extremely expensive.
We are proposing upstreaming a more palatable version of this to the
community, in the form of this proposal and accompanying patch. We are
proposing the syntax _ExtInt(N). We intend to propose this to the WG14
committee[1], and the underscore-capital seems like the active direction
for a WG14 paper's acceptance. An alternative that Richard Smith
suggested on the initial review was __int(N), however we believe that
is much less acceptable by WG14. We considered _Int, however _Int is
used as an identifier in libstdc++ and there is no good way to fall
back to an identifier (since _Int(5) is indistinguishable from an
unnamed initializer of a template type named _Int).
[0]https://www.intel.com/content/www/us/en/software/programmable/quartus-prime/hls-compiler.html)
[1]http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2472.pdf
Differential Revision: https://reviews.llvm.org/D73967
Summary:
This patch adds a mechanism to easily add range checks for a builtin's
immediate operands. This patch is tested with the qdech intrinsic, which takes
both an enum for the predicate pattern, as well as an immediate for the
multiplier.
Reviewers: efriedma, SjoerdMeijer, rovka
Reviewed By: efriedma, SjoerdMeijer
Subscribers: mgorny, tschuett, mgrang, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76678
WG14 has adopted N2480 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2480.pdf)
into C2x at the meetings last week, allowing parameter names of a function
definition to be elided. This patch relaxes the error so that C++ and C2x do not
diagnose this situation, and modes before C2x will allow it as an extension.
This also adds the same feature to ObjC blocks under the assumption that ObjC
wishes to follow the C standard in this regard.
instead of recursing on the stack.
This doesn't actually resolve PR45333, because we now hit stack overflow
somewhere else, but it does get us further. I've not found any way of
testing this that doesn't still crash elsewhere.
Summary: If the size parameter of `__builtin_memcpy_inline` comes from an un-instantiated template parameter current code would crash.
Reviewers: efriedma, courbet
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76504
Summary:
This patch generalizes the existing code to support CDE intrinsics
which will share some properties with existing MVE intrinsics
(some of the intrinsics will be polymorphic and accept/return values
of MVE vector types).
Specifically the patch:
* Adds new tablegen backends -gen-arm-cde-builtin-def,
-gen-arm-cde-builtin-codegen, -gen-arm-cde-builtin-sema,
-gen-arm-cde-builtin-aliases, -gen-arm-cde-builtin-header based on
existing MVE backends.
* Renames the '__clang_arm_mve_alias' attribute into
'__clang_arm_builtin_alias' (it will be used with CDE intrinsics as
well as MVE intrinsics)
* Implements semantic checks for the coprocessor argument of the CDE
intrinsics as well as the existing coprocessor intrinsics.
* Adds one CDE intrinsic __arm_cx1 to test the above changes
Reviewers: simon_tatham, MarkMurrayARM, ostannard, dmgreen
Reviewed By: simon_tatham
Subscribers: sdesmalen, mgorny, kristof.beyls, danielkiss, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D75850
Clang is missing a warning for
builtin_return_address/builtin_frame_address called with > 0 argument.
Gcc provides a warning for this via -Wframe-address:
https://gcc.gnu.org/onlinedocs/gcc/Return-Address.html
As calling these functions with argument > 0 has caused several crashes
for us, we would like to have the same warning as gcc here. This diff
adds the warning and makes it part of -Wmost.
Differential Revision: https://reviews.llvm.org/D75768
__builtin_os_log_format
This is needed to keep all the objects, including temporaries returned
by function calls, written to the buffer alive until os_log_pack_send is
called.
rdar://problem/60105410
Summary:
There was even a TODO for this.
The main motivation is to make use of call-site based
`__attribute__((alloc_align(param_idx)))` validation (D72996).
Reviewers: rsmith, erichkeane, aaron.ballman, jdoerfert
Reviewed By: rsmith
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73020
Verifies that an argument passed to __builtin_frame_address or __builtin_return_address is within the range [0, 0xFFFF]
Differential revision: https://reviews.llvm.org/D66839
Re-committed after fixed: c93112dc4f
Summary:
As @rsmith notes in https://reviews.llvm.org/D73020#inline-672219
while that is certainly UB land, it may not be actually reachable at runtime, e.g.:
```
template<int N> void *make() {
if ((N & (N-1)) == 0)
return operator new(N, std::align_val_t(N));
else
return operator new(N);
}
void *p = make<7>();
```
and we shouldn't really error-out there.
That being said, i'm not really following the logic here.
Which ones of these cases should remain being an error?
Reviewers: rsmith, erichkeane
Reviewed By: erichkeane
Subscribers: cfe-commits, rsmith
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73996
New intrinisics are implemented for when we need to port SIMD code from other
arhitectures and only load or store portions of MSA registers.
Following intriniscs are added which only load/store element 0 of a vector:
v4i32 __builtin_msa_ldrq_w (const void *, imm_n2048_2044);
v2i64 __builtin_msa_ldr_d (const void *, imm_n4096_4088);
void __builtin_msa_strq_w (v4i32, void *, imm_n2048_2044);
void __builtin_msa_str_d (v2i64, void *, imm_n4096_4088);
Differential Revision: https://reviews.llvm.org/D73644
Implement a pessimistic evaluator of the minimal required size for a buffer
based on the format string, and couple that with the fortified version to emit a
warning when the buffer size is lower than the lower bound computed from the
format string.
Differential Revision: https://reviews.llvm.org/D71566
There is llvm::Value::MaximumAlignment, which is numerically
equivalent to these constants, but we can't use it directly
because we can't include llvm IR headers in clang Sema.
So instead, copy-paste the constant, and fixup the places to use it.
This was initially reviewed in https://reviews.llvm.org/D72998
Summary:
`alloc_align` attribute takes parameter number, not the alignment itself,
so given **just** the attribute/function declaration we can't do any
sanity checking for said alignment.
However, at call site, given the actual `Expr` that is passed
into that parameter, we //might// be able to evaluate said `Expr`
as Integer Constant Expression, and perform the sanity checks.
But since there is no requirement for that argument to be an immediate,
we may fail, and that's okay.
However if we did evaluate, we should enforce the same constraints
as with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:
said alignment is a power of two, and is not greater than our magic threshold
This was initially committed in c2a9061ac5
but reverted in 00756b1823 because of
suspicious bot failures.
Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72996
Summary:
I initially encountered those assertions when trying to create
this IR `alignment` attribute from clang's `__attribute__((assume_aligned(imm)))`,
because until D72994 there is no sanity checking for the value of `imm`.
But even then, we have `llvm::Value::MaximumAlignment` constant (which is `536870912`),
which is enforced for clang attributes, and then there are some other magical constant
(`0x40000000` i.e. `1073741824` i.e. `2 * 536870912`) in
`Attribute::getWithAlignment()`/`AttrBuilder::addAlignmentAttr()`.
I strongly suspect that `0x40000000` is incorrect,
and that also should be `llvm::Value::MaximumAlignment`.
Reviewers: erichkeane, hfinkel, jdoerfert, gchatelet, courbet
Reviewed By: erichkeane
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72998
Summary:
`alloc_align` attribute takes parameter number, not the alignment itself,
so given **just** the attribute/function declaration we can't do any
sanity checking for said alignment.
However, at call site, given the actual `Expr` that is passed
into that parameter, we //might// be able to evaluate said `Expr`
as Integer Constant Expression, and perform the sanity checks.
But since there is no requirement for that argument to be an immediate,
we may fail, and that's okay.
However if we did evaluate, we should enforce the same constraints
as with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:
said alignment is a power of two, and is not greater than our magic threshold
Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72996
Summary:
Immediate vmvnq is code-generated as a simple vector constant in IR,
and left to the backend to recognize that it can be created with an
MVE VMVN instruction. The predicated version is represented as a
select between the input and the same constant, and I've added a
Tablegen isel rule to turn that into a predicated VMVN. (That should
be better than the previous VMVN + VPSEL: it's the same number of
instructions but now it can fold into an adjacent VPT block.)
The unpredicated forms of VBIC and VORR are done by enabling the same
isel lowering as for NEON, recognizing appropriate immediates and
rewriting them as ARMISD::VBICIMM / ARMISD::VORRIMM SDNodes, which I
then instruction-select into the right MVE instructions (now that I've
also reworked those instructions to use the same MC operand encoding).
In order to do that, I had to promote the Tablegen SDNode instance
`NEONvorrImm` to a general `ARMvorrImm` available in MVE as well, and
similarly for `NEONvbicImm`.
The predicated forms of VBIC and VORR are represented as a vector
select between the original input vector and the output of the
unpredicated operation. The main convenience of this is that it still
lets me use the existing isel lowering for VBICIMM/VORRIMM, and not
have to write another copy of the operand encoding translation code.
This intrinsic family is the first to use the `imm_simd` system I put
into the MveEmitter tablegen backend. So, naturally, it showed up a
bug or two (emitting bogus range checks and the like). Fixed those,
and added a full set of tests for the permissible immediates in the
existing Sema test.
Also adjusted the isel pattern for `vmovlb.u8`, which stopped matching
because lowering started turning its input into a VBICIMM. Now it
recognizes the VBICIMM instead.
Reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard
Reviewed By: dmgreen
Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72934
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
Sean Dooher