Commit Graph

74 Commits

Author SHA1 Message Date
Artem Belevich 13e9b4d768 [CUDA] Improve target attribute checking for function templates.
* __host__ __device__ functions are no longer considered to be
  redeclarations of __host__ or __device__ functions. This prevents
  unintentional merging of target attributes across them.
* Function target attributes are not considered (and must match) during
  explicit instantiation and specialization of function templates.

Differential Revision: https://reviews.llvm.org/D25809

llvm-svn: 288962
2016-12-07 19:27:16 +00:00
Justin Lebar 2dfbe9a3b4 [CUDA] Rename cuda_builtin_vars.h to __clang_cuda_builtin_vars.h.
Summary: This matches the idiom we use for our other CUDA wrapper headers.

Reviewers: tra

Subscribers: beanz, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D24978

llvm-svn: 283679
2016-10-08 22:16:08 +00:00
Justin Lebar 4a759ff44c [CUDA] Add missing ':' to noexcept.cu test.
llvm-svn: 283280
2016-10-05 00:27:38 +00:00
Justin Lebar 3e6449b4f4 [CUDA] Mark device functions as nounwind.
Summary:
This prevents clang from emitting 'invoke's and catch statements.

Things previously mostly worked thanks to TryToMarkNoThrow() in
CodeGenFunction.  But this is not a proper IPO, and it doesn't properly
handle cases like mutual recursion.

Fixes bug 30593.

Reviewers: tra

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25166

llvm-svn: 283272
2016-10-04 23:41:49 +00:00
Justin Lebar e060feb7b1 [CUDA] Disallow overloading destructors.
Summary:
We'd attempted to allow this, but turns out we were doing a very bad
job.  :)

Making this work properly would be a giant change in clang.  For
example, we'd need to make CXXRecordDecl::getDestructor()
context-sensitive, because the destructor you end up with depends on
where you're calling it from.

For now (and hopefully for ever), just disallow overloading of
destructors in CUDA.

Reviewers: rsmith

Subscribers: cfe-commits, tra

Differential Revision: https://reviews.llvm.org/D24571

llvm-svn: 283120
2016-10-03 16:48:23 +00:00
Justin Lebar 18e2d82297 [CUDA] Raise an error if a wrong-side call is codegen'ed.
Summary:
Some function calls in CUDA are allowed to appear in
semantically-correct programs but are an error if they're ever
codegen'ed.  Specifically, a host+device function may call a host
function, but it's an error if such a function is ever codegen'ed in
device mode (and vice versa).

Previously, clang made no attempt to catch these errors.  For the most
part, they would be caught by ptxas, and reported as "call to unknown
function 'foo'".

Now we catch these errors and report them the same as we report other
illegal calls (e.g. a call from a host function to a device function).

This has a small change in error-message behavior for calls that were
previously disallowed (e.g. calls from a host to a device function).
Previously, we'd catch disallowed calls fairly early, before doing
additional semantic checking e.g. of the call's arguments.  Now we catch
these illegal calls at the very end of our semantic checks, so we'll
only emit a "illegal CUDA call" error if the call is otherwise
well-formed.

Reviewers: tra, rnk

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D23242

llvm-svn: 278759
2016-08-15 23:00:49 +00:00
Artem Belevich 4c09318be2 [CUDA] Place GPU binary into .nv_fatbin section and align it by 8.
This matches the way nvcc encapsulates GPU binaries into host object file.
Now cuobjdump can deal with clang-compiled object files.

Differential Revision: https://reviews.llvm.org/D23429

llvm-svn: 278549
2016-08-12 18:44:01 +00:00
Justin Lebar e56360a2cd [CUDA] Align kernel launch args correctly when the LLVM type's alignment is different from the clang type's alignment.
Summary:
Before this patch, we computed the offsets in memory of args passed to
GPU kernel functions by throwing all of the args into an LLVM struct.

clang emits packed llvm structs basically whenever it feels like it, and
packed structs have alignment 1.  So we cannot rely on the llvm type's
alignment matching the C++ type's alignment.

This patch fixes our codegen so we always respect the clang types'
alignments.

Reviewers: rnk

Subscribers: cfe-commits, tra

Differential Revision: https://reviews.llvm.org/D22879

llvm-svn: 276927
2016-07-27 22:36:21 +00:00
Justin Bogner 2d5de7e568 NVPTX: Use the nvvm builtins to read SRegs rather than the legacy ptx ones
The ptx spellings were removed from LLVM in r274769.

llvm-svn: 274770
2016-07-07 16:41:08 +00:00
Justin Lebar 27ee130e38 [CUDA] Give templated device functions internal linkage, templated kernels external linkage.
Summary:
This lets LLVM perform IPO over these functions.  In particular, it
allows LLVM to emit ld.global.nc for loads to __restrict pointers in
kernels that are never written to.

Reviewers: rsmith

Subscribers: cfe-commits, tra

Differential Revision: http://reviews.llvm.org/D21337

llvm-svn: 274261
2016-06-30 18:41:33 +00:00
Artem Belevich bcec9dac14 [CUDA] Add implicit conversion of __launch_bounds__ arguments to rvalue.
Fixes clang crash reported in PR27778.

Differential Revision: http://reviews.llvm.org/D20985

llvm-svn: 271951
2016-06-06 22:54:57 +00:00
Justin Lebar f179364341 [CUDA] Conservatively mark inline asm as convergent.
Summary:
This is particularly important because a some convergent CUDA intrinsics
(e.g.  __shfl_down) are implemented in terms of inline asm.

Reviewers: tra

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D20836

llvm-svn: 271336
2016-05-31 21:27:13 +00:00
Reid Kleckner a769fd50ba Avoid depending on test inputes that aren't in Inputs
Some people have weird CI systems that run each test subdirectory
independently without access to other parallel trees.

Unfortunately, this means we have to suffer some duplication until Art
can sort out how to share these types.

llvm-svn: 270164
2016-05-20 00:38:25 +00:00
Artem Belevich 3650bbeebc [CUDA] Do not allow non-empty destructors for global device-side variables.
According to Cuda Programming guide (v7.5, E2.3.1):
> __device__, __constant__ and __shared__ variables defined in namespace
> scope, that are of class type, cannot have a non-empty constructor or a
> non-empty destructor.

Clang already deals with device-side constructors (see D15305).
This patch enforces similar rules for destructors.

Differential Revision: http://reviews.llvm.org/D20140

llvm-svn: 270108
2016-05-19 20:13:53 +00:00
Artem Belevich 85b6f63f42 [CUDA] Split device-var-init.cu tests into separate Sema and CodeGen parts.
Codegen tests for device-side variable initialization are subset of test
cases used to verify Sema's part of the job.
Including CodeGenCUDA/device-var-init.cu from SemaCUDA makes it easier to
keep both sides in sync.

Differential Revision: http://reviews.llvm.org/D20139

llvm-svn: 270107
2016-05-19 20:13:39 +00:00
Artem Belevich 31c3bad499 [CUDA] Enable fusing FP ops (-ffp-contract=fast) for CUDA by default.
This matches default nvcc behavior and gives substantial
performance boost on GPU where fmad is much cheaper compared to add+mul.

Differential Revision: http://reviews.llvm.org/D20341

llvm-svn: 270094
2016-05-19 18:44:45 +00:00
Justin Lebar 3b30b7eef6 [CUDA] Fix flush-denormals.cu test so that it checks what it intends to CHECK.
FileCheck does not evaluate plain CHECKs if you pass -check-prefix; you
have to ask for it explicitly.

llvm-svn: 269000
2016-05-10 00:34:50 +00:00
Artem Belevich 4d430badeb [CUDA] Restrict init of local __shared__ variables to empty constructors only.
Allow only empty constructors for local __shared__ variables in a way
identical to restrictions imposed on dynamic initializers for global
variables on device.

Differential Revision: http://reviews.llvm.org/D20039

llvm-svn: 268982
2016-05-09 22:09:56 +00:00
Artem Belevich 0c0ada01b6 [CUDA] Only __shared__ variables can be static local on device side.
According to CUDA programming guide (v7.5):
> E.2.9.4: Within the body of a device or global function, only
> shared variables may be declared with static storage class.

Differential Revision: http://reviews.llvm.org/D20034

llvm-svn: 268962
2016-05-09 19:36:08 +00:00
Artem Belevich ca2b951cbc [CUDA] Make sure device-side __global__ functions are always visible.
__global__ functions are a special case in CUDA.

Even when the symbol would normally not be externally
visible according to C++ rules, they still must be visible
in CUDA GPU object so host-side stub can launch them.

Differential Revision: http://reviews.llvm.org/D19748

llvm-svn: 268299
2016-05-02 20:30:03 +00:00
Justin Lebar d3a44f6885 [CUDA] Add -fcuda-flush-denormals-to-zero.
Summary:
Setting this flag causes all functions are annotated with the
"nvvm-f32ftz" = "true" attribute.

In addition, we annotate the module with "nvvm-reflect-ftz" set
to 0 or 1, depending on whether -cuda-flush-denormals-to-zero is set.
This is read by the NVVMReflect pass.

Reviewers: tra, rnk

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18671

llvm-svn: 265435
2016-04-05 18:26:20 +00:00
Justin Lebar 19b648eae3 [CUDA] Add -disable-llvm-passes to CodeGenCUDA/link-device-bitcode.cu. NFC
We already have this flag in most of the file, but we need it everywhere
else, to disable the NVVMReflect pass, which we're explicitly checking
doesn't run here.  (Upcoming changes to llvm will cause it to be run.)

llvm-svn: 264969
2016-03-30 23:45:38 +00:00
Justin Lebar 25c4a81e79 [CUDA] Remove three obsolete CUDA cc1 flags.
Summary:
* -fcuda-target-overloads

  Previously unconditionally set to true by the driver.  Necessary for
  correct functioning of the compiler -- our CUDA headers wrapper won't
  compile without this.

* -fcuda-disable-target-call-checks

  Previously unconditionally set to true by the driver.  Necessary to
  compile almost any external CUDA code -- almost all libraries assume
  that host+device code can call host or device functions.

* -fcuda-allow-host-calls-from-host-device

  No effect when target overloading is enabled.

Reviewers: tra

Subscribers: rsmith, cfe-commits

Differential Revision: http://reviews.llvm.org/D18416

llvm-svn: 264739
2016-03-29 16:24:16 +00:00
Justin Lebar e5eed04d52 [CUDA] Merge most of CodeGenCUDA/function-overload.cu into SemaCUDA/function-overload.cu.
Summary:
Previously we were using the codegen test to ensure that we choose the
right overload.  But we can do this within sema, with a bit of
cleverness.

I left the constructor/destructor checks in CodeGen, because these
overloads (particularly on the destructors) are hard to check in Sema.

Reviewers: tra

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18386

llvm-svn: 264207
2016-03-23 22:42:30 +00:00
Artem Belevich 3609085dc4 Fixed test failure platforms with name mangling different from Linux.
* Run cc with -triple x86_64-linux-gnu to make symbol mangling predictable.
* Use temporary file as a fake GPU input so its content
  does not interfere with pattern matching.

llvm-svn: 262516
2016-03-02 21:03:20 +00:00
Artem Belevich 8c1ec1ef38 [CUDA] Do not generate unnecessary runtime init code.
Differential Revision: http://reviews.llvm.org/D17780

llvm-svn: 262499
2016-03-02 18:28:53 +00:00
Artem Belevich 42e1949b46 [CUDA] Emit host-side 'shadows' for device-side global variables
... and register them with CUDA runtime.

This is needed for commonly used cudaMemcpy*() APIs that use address of
host-side shadow to access their counterparts on device side.

Fixes PR26340

Differential Revision: http://reviews.llvm.org/D17779

llvm-svn: 262498
2016-03-02 18:28:50 +00:00
Justin Lebar ddd97faeec [CUDA] Mark all CUDA device-side function defs, decls, and calls as convergent.
Summary:
This is important for e.g. the following case:

  void sync() { __syncthreads(); }
  void foo() {
    do_something();
    sync();
    do_something_else():
  }

Without this change, if the optimizer does not inline sync() (which it
won't because __syncthreads is also marked as noduplicate, for now
anyway), it is free to perform optimizations on sync() that it would not
be able to perform on __syncthreads(), because sync() is not marked as
convergent.

Similarly, we need a notion of convergent calls, since in the case when
we can't statically determine a call's target(s), we need to know
whether it's safe to perform optimizations around the call.

This change is conservative; the optimizer will remove these attrs where
it can, see r260318, r260319.

Reviewers: majnemer

Subscribers: cfe-commits, jhen, echristo, tra

Differential Revision: http://reviews.llvm.org/D17056

llvm-svn: 261779
2016-02-24 21:55:11 +00:00
Artem Belevich 186091094a [CUDA] Tweak attribute-based overload resolution to match nvcc behavior.
This is an artefact of split-mode CUDA compilation that we need to
mimic. HD functions are sometimes allowed to call H or D functions. Due
to split compilation mode device-side compilation will not see host-only
function and thus they will not be considered at all. For clang both H
and D variants will become function overloads visible to
compiler. Normally target attribute is considered only if C++ rules can
not determine which function is better. However in this case we need to
ignore functions that would not be present during current compilation
phase before we apply normal overload resolution rules.

Changes:
* introduced another level of call preference to better describe
  possible call combinations.
* removed WrongSide functions from consideration if the set contains
  SameSide function.
* disabled H->D, D->H and G->H calls. These combinations are
  not allowed by CUDA and we were reluctantly allowing them to work
  around device-side calls to math functions in std namespace.
  We no longer need it after r258880.

Differential Revision: http://reviews.llvm.org/D16870

llvm-svn: 260697
2016-02-12 18:29:18 +00:00
Justin Lebar 9a2c0fbaf5 [CUDA] Don't crash when trying to printf a non-scalar object.
Summary:
We can't do the right thing, since there's no right thing to do, but at
least we can not crash the compiler.

Reviewers: majnemer, rnk

Subscribers: cfe-commits, jhen, tra

Differential Revision: http://reviews.llvm.org/D17103

llvm-svn: 260479
2016-02-11 02:00:52 +00:00
Artem Belevich 97c01c35f8 [CUDA] Do not allow dynamic initialization of global device side variables.
In general CUDA does not allow dynamic initialization of
global device-side variables. One exception is that CUDA allows
records with empty constructors as described in section E2.2.1 of
CUDA 7.5 Programming guide.

This patch applies initializer checks for all device-side variables.
Empty constructors are accepted, but no code is generated for them.

Differential Revision: http://reviews.llvm.org/D15305

llvm-svn: 259592
2016-02-02 22:29:48 +00:00
Justin Lebar c0e42750da [CUDA] Generate CUDA's printf alloca in its function's entry block.
Summary:
This is necessary to prevent llvm from generating stacksave intrinsics
around this alloca.  NVVM doesn't have a stack, and we don't handle said
intrinsics.

Reviewers: rnk, echristo

Subscribers: cfe-commits, jhen, tra

Differential Revision: http://reviews.llvm.org/D16664

llvm-svn: 259122
2016-01-28 23:58:28 +00:00
Justin Lebar cd2f6bbd5c [CUDA] Don't generate aliases for static extern "C" functions.
Summary:
These aliases are done to support inline asm, but there's nothing we can
do: NVPTX doesn't support aliases.

Reviewers: tra

Subscribers: cfe-commits, jhen, echristo

Differential Revision: http://reviews.llvm.org/D16501

llvm-svn: 258734
2016-01-25 22:36:37 +00:00
Justin Lebar 3039a593db [CUDA] Make printf work.
Summary:
The code in CGCUDACall is largely based on a patch written by Eli
Bendersky:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20140324/210218.html

That patch implemented an LLVM pass lowering printf to vprintf; this
one does something similar, but in Clang codegen.

Reviewers: echristo

Subscribers: cfe-commits, jhen, tra, majnemer

Differential Revision: http://reviews.llvm.org/D16372

llvm-svn: 258642
2016-01-23 21:28:14 +00:00
Artem Belevich 9b9294674b [CUDA] Make vtable construction aware of host/device side of CUDA compilation.
C++ emits vtables for classes that have key function present in the
current TU. While we compile CUDA the fact that key function was found
in this TU does not mean that we are going to generate code for it. E.g.
vtable for a class with host-only methods should not (and can not) be
generated on device side, because we'll never generate code for them
during device-side compilation.

This patch adds an extra CUDA-specific check during key method computation
and filters out potential key methods that are not suitable for this side
of CUDA compilation.

When we codegen vtable, entries for unsuitable methods are set to null.

Differential Revision: http://reviews.llvm.org/D15309

llvm-svn: 255911
2015-12-17 18:12:36 +00:00
Artem Belevich 5d40ae3a46 Allow linking multiple bitcode files.
Linking options for particular file depend on the option that specifies the file.
Currently there are two:

* -mlink-bitcode-file links in complete content of the specified file.
* -mlink-cuda-bitcode links in only the symbols needed by current TU.
   Linked symbols are internalized. This bitcode linking mode is used to
   link device-specific bitcode provided by CUDA.

Files are linked in order they are specified on command line.

-mlink-cuda-bitcode replaces -fcuda-uses-libdevice flag.

Differential Revision: http://reviews.llvm.org/D13913

llvm-svn: 251427
2015-10-27 17:56:59 +00:00
Artem Belevich 7b41f70e6c [CUDA] __global__ functions should always be visible externally.
Adjust __global__ functions with DiscardableODR linkage to use
StrongODR linkage instead, so they are visible externally.

Differential Revision: http://reviews.llvm.org/D13067

llvm-svn: 248400
2015-09-23 17:44:53 +00:00
Artem Belevich 94a55e8169 [CUDA] Allow function overloads in CUDA based on host/device attributes.
The patch makes it possible to parse CUDA files that contain host/device
functions with identical signatures, but different attributes without
having to physically split source into host-only and device-only parts.

This change is needed in order to parse CUDA header files that have
a lot of name clashes with standard include files.

Gory details are in design doc here: https://goo.gl/EXnymm
Feel free to leave comments there or in this review thread.

This feature is controlled with CC1 option -fcuda-target-overloads
and is disabled by default.

Differential Revision: http://reviews.llvm.org/D12453

llvm-svn: 248295
2015-09-22 17:22:59 +00:00
Artem Belevich c3fa25def7 [CUDA] Add implicit __attribute__((used)) to all __global__ functions.
This makes sure that we emit kernels that were instantiated from the
host code and which would never be explicitly referenced by anything
else on device side.

Differential Revision: http://reviews.llvm.org/D11666

llvm-svn: 248293
2015-09-22 17:22:51 +00:00
Artem Belevich 7cb25c9b69 [CUDA] Postprocess bitcode linked in during device-side CUDA compilation.
Link in and internalize the symbols we need from supplied bitcode library.

Differential Revision: http://reviews.llvm.org/D11664

llvm-svn: 247317
2015-09-10 18:24:23 +00:00
Artem Belevich da1851ca58 [CUDA] Allow trivial constructors as initializer for __shared__ variables.
Differential Revision: http://reviews.llvm.org/D12739

llvm-svn: 247307
2015-09-10 17:26:58 +00:00
Jingyue Wu 284ebe237f [CUDA] Change initializer for CUDA device code based on CUDA documentation.
Summary:
According to CUDA documentation, global variables declared with __device__,
__constant__ can be initialized from host code, so mark them as
externally initialized. Because __shared__ variables cannot have an
initialization as part of their declaration and since the value maybe kept
across different kernel invocation, the value of __shared__ is effectively
undefined instead of zero initialized.

Wrongly using zero initializer may cause illegitimate optimization, e.g.
removing unused __constant__ variable because it's not updated in the device
code and the value is initialized with zero.

Test Plan: test/CodeGenCUDA/address-spaces.cu

Patch by Xuetian Weng

Reviewers: jholewinski, eliben, tra, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12241

llvm-svn: 245786
2015-08-22 05:49:28 +00:00
Daniel Jasper 3b0f87d289 Revert "[CUDA] Add implicit __attribute__((used)) to all __global__ functions."
This is breaking internal test. I'll provide a reproduction.

llvm-svn: 244583
2015-08-11 11:02:09 +00:00
Artem Belevich b7e4aab40c [CUDA] Add implicit __attribute__((used)) to all __global__ functions.
This allows emitting kernels that were instantiated from the host code
and which would never be explicitly referenced otherwise.

Differential Revision: http://reviews.llvm.org/D11666

llvm-svn: 244501
2015-08-10 20:57:02 +00:00
Artem Belevich e958275250 [cuda] Fixed test case failure on s390x
llvm-svn: 237007
2015-05-11 18:35:58 +00:00
Artem Belevich 8d062ad560 Fixed test failure on machines with 32-bit size_t.
llvm-svn: 236773
2015-05-07 21:06:03 +00:00
Artem Belevich 52cc487ba8 [cuda] Include GPU binary into host object file and generate init/deinit code.
- added -fcuda-include-gpubinary option to incorporate results of
  device-side compilation into host-side one.
- generate code to register GPU binaries and associated kernels
  with CUDA runtime and clean-up on exit.
- added test case for init/deinit code generation.

Differential Revision: http://reviews.llvm.org/D9507

llvm-svn: 236765
2015-05-07 19:34:16 +00:00
Artem Belevich 0488d1e4ba [cuda] treat file scope __asm as __host__ and ignore it during device-side compilation.
Currently clang emits file-scope asm during *both* host and device
compilation modes which is usually a wrong thing to do.

There's no way to attach any attribute to an __asm statement, so
there's no way to differentiate between host-side and device-side
file-scope asm.  This patch makes clang to match nvcc behavior and
emit file-scope-asm only during host-side compilation.

Differential Revision: http://reviews.llvm.org/D9270

llvm-svn: 235905
2015-04-27 18:52:00 +00:00
Artem Belevich 7093e40641 [cuda] Allow using integral non-type template parameters as launch_bounds attribute arguments.
- Changed CUDALaunchBounds arguments from integers to Expr* so they can
   be saved in AST for instantiation.
 - Added support for template instantiation of launch_bounds attrubute.
 - Moved evaluation of launch_bounds arguments to NVPTXTargetCodeGenInfo::
   SetTargetAttributes() where it can be done after template instantiation.
 - Added a warning on negative launch_bounds arguments.
 - Amended test cases.

Differential Revision: http://reviews.llvm.org/D8985

llvm-svn: 235452
2015-04-21 22:55:54 +00:00
Artem Belevich 4e192df778 [cuda] Added support for CUDA built-in variables.
Added cuda_builtin_vars.h which implements built-in CUDA variables
using __declattr(property).

Fields of built-in variables (except for warpSize) are implemented
using __declattr(property) which replaces read/write of a member field
with a call to a getter/setter member function, in this case with
appropriate NVPTX builtin.

Added a test case to check diagnostics on attempt to construct or
improperly access a built-in variable.

Differential Revision: http://reviews.llvm.org/D9064

llvm-svn: 235448
2015-04-21 22:14:13 +00:00