This patch teaches ubsan to insert exactly one null check for the 'this'
pointer per method/lambda.
Previously, given a load of a member variable from an instance method
('this->x'), ubsan would insert a null check for 'this', and another
null check for '&this->x', before allowing the load to occur.
Similarly, given a call to a method from another method bound to the
same instance ('this->foo()'), ubsan would a redundant null check for
'this'. There is also a redundant null check in the case where the
object pointer is a reference ('Ref.foo()').
This patch teaches ubsan to remove the redundant null checks identified
above.
Testing: check-clang, check-ubsan, and a stage2 ubsan build.
I also compiled X86FastISel.cpp with -fsanitize=null using
patched/unpatched clangs based on r293572. Here are the number of null
checks emitted:
-------------------------------------
| Setup | # of null checks |
-------------------------------------
| unpatched, -O0 | 21767 |
| patched, -O0 | 10758 |
-------------------------------------
Changes since the initial commit:
- Don't introduce any unintentional object-size or alignment checks.
- Don't rely on IRGen of C labels in the test.
Differential Revision: https://reviews.llvm.org/D29530
llvm-svn: 295515
CodeGenFunction::EmitTypeCheck accepts a bool flag which controls
whether or not null checks are emitted. Make this a bit more flexible by
changing the bool to a SanitizerSet.
Needed for an upcoming change which deals with a scenario in which we
only want to emit null checks.
llvm-svn: 295514
This reverts commit r295401. It breaks the ubsan self-host. It inserts
object size checks once per C++ method which fire when the structure is
empty.
llvm-svn: 295494
This patch teaches ubsan to insert exactly one null check for the 'this'
pointer per method/lambda.
Previously, given a load of a member variable from an instance method
('this->x'), ubsan would insert a null check for 'this', and another
null check for '&this->x', before allowing the load to occur.
Similarly, given a call to a method from another method bound to the
same instance ('this->foo()'), ubsan would a redundant null check for
'this'. There is also a redundant null check in the case where the
object pointer is a reference ('Ref.foo()').
This patch teaches ubsan to remove the redundant null checks identified
above.
Testing: check-clang and check-ubsan. I also compiled X86FastISel.cpp
with -fsanitize=null using patched/unpatched clangs based on r293572.
Here are the number of null checks emitted:
-------------------------------------
| Setup | # of null checks |
-------------------------------------
| unpatched, -O0 | 21767 |
| patched, -O0 | 10758 |
-------------------------------------
Changes since the initial commit: don't rely on IRGen of C labels in the
test.
Differential Revision: https://reviews.llvm.org/D29530
llvm-svn: 295401
This patch teaches ubsan to insert exactly one null check for the 'this'
pointer per method/lambda.
Previously, given a load of a member variable from an instance method
('this->x'), ubsan would insert a null check for 'this', and another
null check for '&this->x', before allowing the load to occur.
Similarly, given a call to a method from another method bound to the
same instance ('this->foo()'), ubsan would a redundant null check for
'this'. There is also a redundant null check in the case where the
object pointer is a reference ('Ref.foo()').
This patch teaches ubsan to remove the redundant null checks identified
above.
Testing: check-clang and check-ubsan. I also compiled X86FastISel.cpp
with -fsanitize=null using patched/unpatched clangs based on r293572.
Here are the number of null checks emitted:
-------------------------------------
| Setup | # of null checks |
-------------------------------------
| unpatched, -O0 | 21767 |
| patched, -O0 | 10758 |
-------------------------------------
Differential Revision: https://reviews.llvm.org/D29530
llvm-svn: 295391
This patch implements codegen for the reduction clause on
any parallel construct for elementary data types. An efficient
implementation requires hierarchical reduction within a
warp and a threadblock. It is complicated by the fact that
variables declared in the stack of a CUDA thread cannot be
shared with other threads.
The patch creates a struct to hold reduction variables and
a number of helper functions. The OpenMP runtime on the GPU
implements reduction algorithms that uses these helper
functions to perform reductions within a team. Variables are
shared between CUDA threads using shuffle intrinsics.
An implementation of reductions on the NVPTX device is
substantially different to that of CPUs. However, this patch
is written so that there are minimal changes to the rest of
OpenMP codegen.
The implemented design allows the compiler and runtime to be
decoupled, i.e., the runtime does not need to know of the
reduction operation(s), the type of the reduction variable(s),
or the number of reductions. The design also allows reuse of
host codegen, with appropriate specialization for the NVPTX
device.
While the patch does introduce a number of abstractions, the
expected use case calls for inlining of the GPU OpenMP runtime.
After inlining and optimizations in LLVM, these abstractions
are unwound and performance of OpenMP reductions is comparable
to CUDA-canonical code.
Patch by Tian Jin in collaboration with Arpith Jacob
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29758
llvm-svn: 295333
This patch implements codegen for the reduction clause on
any parallel construct for elementary data types. An efficient
implementation requires hierarchical reduction within a
warp and a threadblock. It is complicated by the fact that
variables declared in the stack of a CUDA thread cannot be
shared with other threads.
The patch creates a struct to hold reduction variables and
a number of helper functions. The OpenMP runtime on the GPU
implements reduction algorithms that uses these helper
functions to perform reductions within a team. Variables are
shared between CUDA threads using shuffle intrinsics.
An implementation of reductions on the NVPTX device is
substantially different to that of CPUs. However, this patch
is written so that there are minimal changes to the rest of
OpenMP codegen.
The implemented design allows the compiler and runtime to be
decoupled, i.e., the runtime does not need to know of the
reduction operation(s), the type of the reduction variable(s),
or the number of reductions. The design also allows reuse of
host codegen, with appropriate specialization for the NVPTX
device.
While the patch does introduce a number of abstractions, the
expected use case calls for inlining of the GPU OpenMP runtime.
After inlining and optimizations in LLVM, these abstractions
are unwound and performance of OpenMP reductions is comparable
to CUDA-canonical code.
Patch by Tian Jin in collaboration with Arpith Jacob
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29758
llvm-svn: 295319
Support for CUDA printf is exploited to support printf for
an NVPTX OpenMP device.
To reflect the support of both programming models, the file
CGCUDABuiltin.cpp has been renamed to CGGPUBuiltin.cpp, and
the call EmitCUDADevicePrintfCallExpr has been renamed to
EmitGPUDevicePrintfCallExpr.
Reviewers: jlebar
Differential Revision: https://reviews.llvm.org/D17890
llvm-svn: 293444
in the current lexical scope.
clang currently emits the lifetime.start marker of a variable when the
variable comes into scope even though a variable's lifetime starts at
the entry of the block with which it is associated, according to the C
standard. This normally doesn't cause any problems, but in the rare case
where a goto jumps backwards past the variable declaration to an earlier
point in the block (see the test case added to lifetime2.c), it can
cause mis-compilation.
To prevent such mis-compiles, this commit conservatively disables
emitting lifetime variables when a label has been seen in the current
block.
This problem was discussed on cfe-dev here:
http://lists.llvm.org/pipermail/cfe-dev/2016-July/050066.html
rdar://problem/30153946
Differential Revision: https://reviews.llvm.org/D27680
llvm-svn: 293106
This patch adds support for codegen of 'target teams' on the host.
This combined directive has two captured statements, one for the
'teams' region, and the other for the 'parallel'.
This target teams region is offloaded using the __tgt_target_teams()
call. The patch sets the number of teams as an argument to
this call.
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29084
llvm-svn: 293005
This patch adds support for codegen of 'target teams' on the host.
This combined directive has two captured statements, one for the
'teams' region, and the other for the 'parallel'.
This target teams region is offloaded using the __tgt_target_teams()
call. The patch sets the number of teams as an argument to
this call.
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29084
llvm-svn: 293001
This patch adds support for codegen of 'target parallel' on the host.
It is also the first combined directive that requires two or more
captured statements. Support for this functionality is included in
the patch.
A combined directive such as 'target parallel' has two captured
statements, one for the 'target' and the other for the 'parallel'
region. Two captured statements are required because each has
different implicit parameters (see SemaOpenMP.cpp). For example,
the 'parallel' has 'global_tid' and 'bound_tid' while the 'target'
does not. The patch adds support for handling multiple captured
statements based on the combined directive.
When codegen'ing the 'target parallel' directive, the 'target'
outlined function is created using the outer captured statement
and the 'parallel' outlined function is created using the inner
captured statement.
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D28753
llvm-svn: 292419
This patch adds support for codegen of 'target parallel' on the host.
It is also the first combined directive that requires two or more
captured statements. Support for this functionality is included in
the patch.
A combined directive such as 'target parallel' has two captured
statements, one for the 'target' and the other for the 'parallel'
region. Two captured statements are required because each has
different implicit parameters (see SemaOpenMP.cpp). For example,
the 'parallel' has 'global_tid' and 'bound_tid' while the 'target'
does not. The patch adds support for handling multiple captured
statements based on the combined directive.
When codegen'ing the 'target parallel' directive, the 'target'
outlined function is created using the outer captured statement
and the 'parallel' outlined function is created using the inner
captured statement.
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D28753
llvm-svn: 292374
This patch refactors code that calls codegen for target regions. Currently
the codebase only supports the 'target' directive. The patch pulls out
common target processing code into a static function that can be called
by codegen for any target directive.
Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D28752
llvm-svn: 292134
This patch is to implement sema and parsing for 'target teams distribute simd’ pragma.
Differential Revision: https://reviews.llvm.org/D28252
llvm-svn: 291579
Summary:
This patch makes the type_mismatch static data 7 bytes smaller (and it
ends up being 16 bytes smaller due to alignment restrictions, at least
on some x86-64 environments).
It revs up the type_mismatch handler version since we're breaking binary
compatibility. I will soon post a patch for the compiler-rt side.
Reviewers: rsmith, kcc, vitalybuka, pgousseau, gbedwell
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28242
llvm-svn: 291236
The special case to widen the integer literal zero when passed to
variadic function calls should only apply to variadic functions, not
unprototyped functions. This is consistent with what MSVC does. In this
test case, MSVC uses a 4-byte store to pass the 5th argument to 'kr' and
an 8-byte store to pass the zero to 'v':
void v(int, ...);
void kr();
void f(void) {
v(1, 2, 3, 4, 0);
kr(1, 2, 3, 4, 0);
}
Aaron Ballman discovered this issue in https://reviews.llvm.org/D28166
llvm-svn: 290906
This patch is to implement sema and parsing for 'target teams distribute parallel for simd’ pragma.
Differential Revision: https://reviews.llvm.org/D28202
llvm-svn: 290862
This patch is to implement sema and parsing for 'target teams distribute parallel for’ pragma.
Differential Revision: https://reviews.llvm.org/D28160
llvm-svn: 290725
This patch is to implement sema and parsing for 'target teams distribute' pragma.
Differential Revision: https://reviews.llvm.org/D28015
llvm-svn: 290508
This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.
Fingers crossed that this patch sticks this time. :)
Original commit message:
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
llvm-svn: 290297
This commit fails MSan when running test/CodeGen/object-size.c in
a confusing way. After some discussion with George, it isn't really
clear what is going on here. We can make the MSan failure go away by
testing for the invalid bit, but *why* things are invalid isn't clear.
And yet, other code in the surrounding area is doing precisely this and
testing for invalid.
George is going to take a closer look at this to better understand the
nature of the failure and recommit it, for now backing it out to clean
up MSan builds.
llvm-svn: 290169
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
Differential Revision: https://reviews.llvm.org/D14274
llvm-svn: 290149
copy constructors of classes with array members, instead using
ArrayInitLoopExpr to represent the initialization loop.
This exposed a bug in the static analyzer where it was unable to differentiate
between zero-initialized and unknown array values, which has also been fixed
here.
llvm-svn: 289618
This adds a way for us to version any UBSan handler by itself.
The patch overrides D21289 for a better implementation (we're able to
rev up a single handler).
After this, then we can land a slight modification of D19667+D19668.
We probably don't want to keep all the versions in compiler-rt (maybe we
want to deprecate on one release and remove the old handler on the next
one?), but with this patch we will loudly fail to compile when mixing
incompatible handler calls, instead of silently compiling and then
providing bad error messages.
Reviewers: kcc, samsonov, rsmith, vsk
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D21695
llvm-svn: 289444
initialization of each array element:
* ArrayInitLoopExpr is a prvalue of array type with two subexpressions:
a common expression (an OpaqueValueExpr) that represents the up-front
computation of the source of the initialization, and a subexpression
representing a per-element initializer
* ArrayInitIndexExpr is a prvalue of type size_t representing the current
position in the loop
This will be used to replace the creation of explicit index variables in lambda
capture of arrays and copy/move construction of classes with array elements,
and also C++17 structured bindings of arrays by value (which inexplicably allow
copying an array by value, unlike all of C++'s other array declarations).
No uses of these nodes are introduced by this change, however.
llvm-svn: 289413
This patch is to implement sema and parsing for 'teams distribute parallel for' pragma.
Differential Revision: https://reviews.llvm.org/D27345
llvm-svn: 289179
This patch is to implement sema and parsing for 'teams distribute parallel for simd' pragma.
Differential Revision: https://reviews.llvm.org/D27084
llvm-svn: 288294
If 'omp cancel' construct is used in a worksharing construct it may
cause hanging of the software in case if reduction clause is used. Patch fixes this problem by avoiding extra reduction processing for branches that were canceled.
llvm-svn: 287227
Summary:
r286944 introduced bugs detected by ASAN as use-after-return.
r287025 have not fixed them completely.
This reverts commit r286944 and r287025.
Reviewers: ABataev
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D26720
llvm-svn: 287069
If 'omp cancel' construct is used in a worksharing construct it may cause
hanging of the software in case if reduction clause is used. Patch fixes
this problem by avoiding extra reduction processing for branches that
were canceled.
llvm-svn: 286944
can be used to improve the locations when generating remarks for loops.
Depends on the companion LLVM change r286227.
Patch by Florian Hahn.
Differential Revision: https://reviews.llvm.org/D25764
llvm-svn: 286456
abstract information about the callee. NFC.
The goal here is to make it easier to recognize indirect calls and
trigger additional logic in certain cases. That logic will come in
a later patch; in the meantime, I felt that this was a significant
improvement to the code.
llvm-svn: 285258
Summary:
Current generation of lifetime intrinsics does not handle cases like:
```
{
char x;
l1:
bar(&x, 1);
}
goto l1;
```
We will get code like this:
```
%x = alloca i8, align 1
call void @llvm.lifetime.start(i64 1, i8* nonnull %x)
br label %l1
l1:
%call = call i32 @bar(i8* nonnull %x, i32 1)
call void @llvm.lifetime.end(i64 1, i8* nonnull %x)
br label %l1
```
So the second time bar was called for x which is marked as dead.
Lifetime markers here are misleading so it's better to remove them at all.
This type of bypasses are rare, e.g. code detects just 8 functions building
clang (2329 targets).
PR28267
Reviewers: eugenis
Subscribers: beanz, mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D24693
llvm-svn: 285176
Summary: D24693 will need access to it from other places
Reviewers: eugenis
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D24695
llvm-svn: 285158
constexpr variable.
When compiling a constexpr NSString initialized with an objective-c
string literal, CodeGen emits objc_storeStrong on an uninitialized
alloca, which causes a crash.
This patch folds the code in EmitScalarInit into EmitStoreThroughLValue
and fixes the crash by calling objc_retain on the string instead of
using objc_storeStrong.
rdar://problem/28562009
Differential Revision: https://reviews.llvm.org/D25547
llvm-svn: 284516
Summary: _BitScan intrinsics (and some others, for example _Interlocked and _bittest) are supposed to work on both ARM and x86. This is an attempt to isolate them, avoiding repeating their code or writing separate function for each builtin.
Reviewers: hans, thakis, rnk, majnemer
Subscribers: RKSimon, cfe-commits, aemerson
Differential Revision: https://reviews.llvm.org/D25264
llvm-svn: 284060
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
Vedant Kumar