Commit Graph

61 Commits

Author SHA1 Message Date
Yaxun (Sam) Liu dc6a0b0ec7 [HIP] Align device binary
To facilitate faster loading of device binaries and share them among processes,
HIP runtime favors their alignment being 4096 bytes. HIP runtime can load
unaligned device binaries, however, aligning them at 4096 bytes results in
faster loading and less shared memory usage.

This patch adds an option -bundle-align to clang-offload-bundler which allows
bundles to be aligned at specified alignment. By default it is 1, which is NFC
compared to existing format.

This patch then aligns embedded fat binary and device binary inside fat binary
at 4096 bytes.

It has been verified this change does not cause significant overall file size increase
for typical HIP applications (less than 1%).

Differential Revision: https://reviews.llvm.org/D88734
2020-10-02 18:10:44 -04:00
Yaxun (Sam) Liu 849d4405f5 [HIP] Fix rocm detection
Do not detect device library by default in rocm detector.
Only detect device library in Rocm and HIP toolchain.

Separate detection of HIP runtime and Rocm device library.

Detect rocm path by version file in host toolchains.

Also added detecting rocm version and printing rocm
installation path and version with -v.

Fixed include path and device library detection for
ROCm 3.5.

Added --hip-version option. Renamed --hip-device-lib-path
to --rocm-device-lib-path.

Fixed default value for -fhip-new-launch-api.

Added default -std option for HIP.

Differential Revision: https://reviews.llvm.org/D82930
2020-07-10 23:20:15 -04:00
Michael Liao b952d799ca [cuda][hip] Fix `RegisterVar` function prototype.
Summary:
- `RegisterVar` has `void` return type and `size_t` in its variable size
  parameter in HIP or CUDA 9.0+.

Reviewers: tra, yaxunl

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77398
2020-04-03 12:57:09 -04:00
Michael Liao cb6389360b Fix GCC warning on enum class bitfield. NFC. 2020-03-28 10:20:34 -04:00
Michael Liao 5be9b8cbe2 [cuda][hip] Add CUDA builtin surface/texture reference support.
Summary: - Re-commit after fix Sema checks on partial template specialization.

Reviewers: tra, rjmccall, yaxunl, a.sidorin

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76365
2020-03-27 17:18:49 -04:00
Artem Belevich fe8063e1a0 Revert "[cuda][hip] Add CUDA builtin surface/texture reference support."
This reverts commit 6a9ad5f3f4.
The patch breaks CUDA copmilation.

Differential Revision: https://reviews.llvm.org/D76365
2020-03-27 10:01:38 -07:00
Michael Liao 6a9ad5f3f4 [cuda][hip] Add CUDA builtin surface/texture reference support.
Summary:
- Even though the bindless surface/texture interfaces are promoted,
  there are still code using surface/texture references. For example,
  [PR#26400](https://bugs.llvm.org/show_bug.cgi?id=26400) reports the
  compilation issue for code using `tex2D` with texture references. For
  better compatibility, this patch proposes the support of
  surface/texture references.
- Due to the absent documentation and magic headers, it's believed that
  `nvcc` does use builtins for texture support. From the limited NVVM
  documentation[^nvvm] and NVPTX backend texture/surface related
  tests[^test], it's believed that surface/texture references are
  supported by replacing their reference types, which are annotated with
  `device_builtin_surface_type`/`device_builtin_texture_type`, with the
  corresponding handle-like object types, `cudaSurfaceObject_t` or
  `cudaTextureObject_t`, in the device-side compilation. On the host
  side, that global handle variables are registered and will be
  established and updated later when corresponding binding/unbinding
  APIs are called[^bind]. Surface/texture references are most like
  device global variables but represented in different types on the host
  and device sides.
- In this patch, the following changes are proposed to support that
  behavior:
  + Refine `device_builtin_surface_type` and
    `device_builtin_texture_type` attributes to be applied on `Type`
    decl only to check whether a variable is of the surface/texture
    reference type.
  + Add hooks in code generation to replace that reference types with
    the correponding object types as well as all accesses to them. In
    particular, `nvvm.texsurf.handle.internal` should be used to load
    object handles from global reference variables[^texsurf] as well as
    metadata annotations.
  + Generate host-side registration with proper template argument
    parsing.

---
[^nvvm]: https://docs.nvidia.com/cuda/pdf/NVVM_IR_Specification.pdf
[^test]: https://raw.githubusercontent.com/llvm/llvm-project/master/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
[^bind]: See section 3.2.11.1.2 ``Texture reference API` in [CUDA C Programming Guide](https://docs.nvidia.com/cuda/pdf/CUDA_C_Programming_Guide.pdf).
[^texsurf]: According to NVVM IR, `nvvm.texsurf.handle` should be used.  But, the current backend doesn't have that supported. We may revise that later.

Reviewers: tra, rjmccall, yaxunl, a.sidorin

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76365
2020-03-26 14:44:52 -04:00
Yaxun (Sam) Liu 22c457a869 [HIP] Fix device stub name
HIP emits a device stub function for each kernel in host code.

The HIP debugger requires device stub function to have a different unmangled name as the kernel.

Currently the name of the device stub function is the mangled name with a postfix .stub. However,
this does not work with the HIP debugger since the unmangled name is the same as the kernel.

This patch adds prefix __device__stub__ to the unmangled name of the device stub before mangling,
therefore the device stub function has a valid mangled name which is different than the device kernel
name. The device side kernel name is kept unchanged. kernels with extern "C" also gets the prefix added
to the corresponding device stub function.

Differential Revision: https://reviews.llvm.org/D68578
2020-03-09 16:40:05 -04:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Guillaume Chatelet c79099e0f4 [Alignment][Clang][NFC] Add CharUnits::getAsAlign
Summary:
This is a prerequisite to removing `llvm::GlobalObject::setAlignment(unsigned)`.
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: jholewinski, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68274

llvm-svn: 373592
2019-10-03 13:00:29 +00:00
Yaxun Liu 1282889347 [HIP] Support new kernel launching API
Differential Revision: https://reviews.llvm.org/D67947

llvm-svn: 372773
2019-09-24 19:16:40 +00:00
Kadir Cetinkaya 3c9391aad9 [clang][CodeGen] Remove std::move on temporary
llvm-svn: 363563
2019-06-17 14:23:06 +00:00
Michael Liao e40f879eb2 [HIP] Add the interface deriving the stub name of device kernels.
Summary:
- Revise the interface to derive the stub name and simplify the
  assertion of it.

Reviewers: yaxunl, tra

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63335

llvm-svn: 363553
2019-06-17 12:51:36 +00:00
Aaron Enye Shi 6d37f326fc [HIP-Clang] Fat binary should not be produced for non GPU code
clang-format the changes to CUDA and HIP fat binary.

Reviewers: yaxunl, tra

Differential Revision: https://reviews.llvm.org/D60141

llvm-svn: 357532
2019-04-02 21:54:41 +00:00
Aaron Enye Shi 8129521318 [HIP-Clang] Fat binary should not be produced for non GPU code 2
Also for CUDA, we need to disable producing these fat binary functions when there is no GPU code.

Reviewers: yaxunl, tra

Differential Revision: https://reviews.llvm.org/D60141

llvm-svn: 357526
2019-04-02 20:49:41 +00:00
Aaron Enye Shi 13d8e92940 [HIP-Clang] Fat binary should not be produced for non GPU code
Skip producing the fat binary functions for HIP when no device code is present.

Reviewers: yaxunl

Differential Review: https://reviews.llvm.org/D60141

llvm-svn: 357520
2019-04-02 20:10:18 +00:00
Yaxun Liu e739ac0e25 [HIP] change kernel stub name
Add .stub to kernel stub function name so that it is different from kernel
name in device code. This is necessary to let debugger find correct symbol
for kernel.

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354948
2019-02-27 02:02:52 +00:00
Yaxun Liu 00ebc0cb92 revert r354615: [HIP] change kernel stub name
It caused regressions.

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354651
2019-02-22 04:20:12 +00:00
Yaxun Liu 8d7cf0e2d4 [HIP] change kernel stub name
Add .stub to kernel stub function name so that it is different from kernel
name in device code. This is necessary to let debugger find correct symbol
for kernel

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354615
2019-02-21 20:12:16 +00:00
Yaxun Liu c18e9ecd4f [CUDA][HIP] Use device side kernel and variable names when registering them
__hipRegisterFunction and __hipRegisterVar need to accept device side kernel and variable names
so that HIP runtime can associate kernel stub functions in host code with kernel symbols in fat binaries,
and associate shadow variables in host code with device variables in fat binaries.

Currently, clang assumes kernel functions and device variables have the same name as the kernel
stub functions and shadow variables. However, when host is compiled in windows with MSVC C++
ABI and device is compiled with Itanium C++ ABI (e.g. AMDGPU), kernels and device symbols in fat
binary are mangled differently than host.

This patch gets the device side kernel and variable name by mangling them in the mangle context
of aux target.

Differential Revision: https://reviews.llvm.org/D58163

llvm-svn: 354004
2019-02-14 02:00:09 +00:00
Artem Belevich 4071763bb8 Basic CUDA-10 support.
Differential Revision: https://reviews.llvm.org/D57771

llvm-svn: 353232
2019-02-05 22:38:58 +00:00
James Y Knight 9871db064d [opaque pointer types] Pass function types for runtime function calls.
Emit{Nounwind,}RuntimeCall{,OrInvoke} have been modified to take a
FunctionCallee as an argument, and CreateRuntimeFunction has been
modified to return a FunctionCallee. All callers have been updated.

Additionally, CreateBuiltinFunction is removed, as it was redundant
with CreateRuntimeFunction after some previous changes.

Differential Revision: https://reviews.llvm.org/D57668

llvm-svn: 353184
2019-02-05 16:42:33 +00:00
James Y Knight 916db651c8 Remove redundant FunctionDecl argument from a couple functions.
This argument was added in r254554 in order to support the
pass_object_size attribute. However, in r296076, the attribute's
presence is now also represented in FunctionProtoType's
ExtParameterInfo, and thus it's unnecessary to pass along a separate
FunctionDecl.

The functions modified are:
 RequiredArgs::forPrototype{,Plus}, and
 CodeGenTypes::ConvertFunctionType.

After this, it's also (again) unnecessary to have a separate
ConvertFunctionType function ConvertType, so convert callers back to
the latter, leaving the former as an internal helper function.

llvm-svn: 352946
2019-02-02 01:48:23 +00:00
Artem Belevich c62214da3d [CUDA] add support for the new kernel launch API in CUDA-9.2+.
Instead of calling CUDA runtime to arrange function arguments,
the new API constructs arguments in a local array and the kernels
are launched with __cudaLaunchKernel().

The old API has been deprecated and is expected to go away
in the next CUDA release.

Differential Revision: https://reviews.llvm.org/D57488

llvm-svn: 352799
2019-01-31 21:34:03 +00:00
James Y Knight 3933addd30 Cleanup: replace uses of CallSite with CallBase.
llvm-svn: 352595
2019-01-30 02:54:28 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Artem Belevich 93552b39c9 [CUDA] Use all 64 bits of GUID in __nv_module_id
getGUID() returns an uint64_t and "%x" only prints 32 bits of it.
Use PRIx64 format string to print all 64 bits.

Differential Revision: https://reviews.llvm.org/D52938

llvm-svn: 343875
2018-10-05 18:39:58 +00:00
Yaxun Liu 9767089d00 [HIP] Support early finalization of device code for -fno-gpu-rdc
This patch renames -f{no-}cuda-rdc to -f{no-}gpu-rdc and keeps the original
options as aliases. When -fgpu-rdc is off,
clang will assume the device code in each translation unit does not call
external functions except those in the device library, therefore it is possible
to compile the device code in each translation unit to self-contained kernels
and embed them in the host object, so that the host object behaves like
usual host object which can be linked by lld.

The benefits of this feature is: 1. allow users to create static libraries which
can be linked by host linker; 2. amortized device code linking time.

This patch modifies HIP action builder to insert actions for linking device
code and generating HIP fatbin, and pass HIP fatbin to host backend action.
It extracts code for constructing command for generating HIP fatbin as
a function so that it can be reused by early finalization. It also modifies
codegen of HIP host constructor functions to embed the device fatbin
when it is available.

Differential Revision: https://reviews.llvm.org/D52377

llvm-svn: 343611
2018-10-02 17:48:54 +00:00
Yaxun Liu 94ff57f5b1 [HIP] Make __hip_gpubin_handle hidden to avoid being merged across different shared libraries
Different shared libraries contain different fat binary, which is stored in a global variable
__hip_gpubin_handle. Since different compilation units share the same fat binary, this
variable has linkonce linkage. However, it should not be merged across different shared
libraries.

This patch set the visibility of the global variable to be hidden, which will make it invisible
in the shared library, therefore preventing it from being merged.

Differential Revision: https://reviews.llvm.org/D50596

llvm-svn: 340056
2018-08-17 17:47:31 +00:00
Yaxun Liu f99752b66b [HIP] Register/unregister device fat binary only once
HIP generates one fat binary for all devices after linking. However, for each compilation
unit a ctor function is emitted which register the same fat binary. Measures need to be
taken to make sure the fat binary is only registered once.

Currently each ctor function calls __hipRegisterFatBinary and stores the returned value
to __hip_gpubin_handle. This patch changes the linkage of __hip_gpubin_handle to be linkonce
so that they are shared between LLVM modules. Then this patch adds check of value of
__hip_gpubin_handle to make sure __hipRegisterFatBinary is only called once. The code
is equivalent to

void *_gpubin_handle;
void ctor() {
  if (__hip_gpubin_handle == 0) {
    __hip_gpubin_handle = __hipRegisterFatBinary(...);
  }
  // register kernels and variables.
}
The patch also does similar change to dtors so that __hipUnregisterFatBinary
is called once.

Differential Revision: https://reviews.llvm.org/D49083

llvm-svn: 337631
2018-07-20 22:45:24 +00:00
Artem Belevich 5ce0a08cf6 [CUDA] Place all CUDA sections in __NV_CUDA segment on Mac.
That's where CUDA binaries appear to put them.

Differential Revision: https://reviews.llvm.org/D48615

llvm-svn: 335880
2018-06-28 17:15:52 +00:00
Artem Belevich c66d254ded [CUDA] Use atexit() to call module destructor.
This matches the way NVCC does it. Doing module cleanup at global
destructor phase used to work, but is, apparently, too late for
the CUDA runtime in CUDA-9.2, which ends up crashing with double-free.

Differential Revision: https://reviews.llvm.org/D48613

llvm-svn: 335763
2018-06-27 18:32:51 +00:00
Jonas Hahnfeld 3b9cbba9a8 [CUDA] Fix emission of constant strings in sections
CGM.GetAddrOfConstantCString() sets the adress of the created GlobalValue
to unnamed. When emitting the object file LLVM will mark the surrounding
section as SHF_MERGE iff the string is nul-terminated and contains no
other nuls (see IsNullTerminatedString). This results in problems when
saving temporaries because LLVM doesn't set an EntrySize, so reading in
the serialized assembly file fails.
This never happened for the GPU binaries because they usually contain
a nul-character somewhere. Instead this only affected the module ID
when compiling relocatable device code.

However, this points to a potentially larger problem: If we put a
constant string into a named section, we really want the data to end
up in that section in the object file. To avoid LLVM merging sections
this patch unmarks the GlobalVariable's address as unnamed which also
fixes the problem of invalid serialized assembly files when saving
temporaries.

Differential Revision: https://reviews.llvm.org/D47902

llvm-svn: 334281
2018-06-08 11:17:08 +00:00
Yaxun Liu 29155b01c1 [HIP] Support offloading by linker script
To support linking device code in different source files, it is necessary to
embed fat binary at host linking stage.

This patch emits an external symbol for fat binary in host codegen, then
embed the fat binary by lld through a linker script.

Differential Revision: https://reviews.llvm.org/D46472

llvm-svn: 332724
2018-05-18 15:07:56 +00:00
Yaxun Liu 887c569bcb [HIP] Add hip input kind and codegen for kernel launching
HIP is a language similar to CUDA (https://github.com/ROCm-Developer-Tools/HIP/blob/master/docs/markdown/hip_kernel_language.md ).
The language syntax is very similar, which allows a hip program to be compiled as a CUDA program by Clang. The main difference
is the host API. HIP has a set of vendor neutral host API which can be implemented on different platforms. Currently there is open source
implementation of HIP runtime on amdgpu target (https://github.com/ROCm-Developer-Tools/HIP).

This patch adds support of input kind and language standard hip.

When hip file is compiled, both LangOpts.CUDA and LangOpts.HIP is turned on. This allows compilation of hip program as CUDA
in most cases and only special handling of hip program is needed LangOpts.HIP is checked.

This patch also adds support of kernel launching of HIP program using HIP host API.

When -x hip is not specified, there is no behaviour change for CUDA.

Patch by Greg Rodgers.
Revised and lit test added by Yaxun Liu.

Differential Revision: https://reviews.llvm.org/D44984

llvm-svn: 330790
2018-04-25 01:10:37 +00:00
Jonas Hahnfeld f5527c2381 [CUDA] Register relocatable GPU binaries
nvcc generates a unique registration function for each object file
that contains relocatable device code. Unique names are achieved
with a module id that is also reflected in the function's name.

Differential Revision: https://reviews.llvm.org/D42922

llvm-svn: 330425
2018-04-20 13:04:45 +00:00
Jonas Hahnfeld e768132f94 [CUDA] Include single GPU binary, NFCI.
Binaries for multiple architectures are combined by fatbinary,
so the current code was effectively not needed.

Differential Revision: https://reviews.llvm.org/D43461

llvm-svn: 326342
2018-02-28 17:53:46 +00:00
Serge Guelton 1d993270b3 Suppress all uses of LLVM_END_WITH_NULL. NFC.
Use variadic templates instead of relying on <cstdarg> + sentinel.

This enforces better type checking and makes code more readable.

Differential revision: https://reviews.llvm.org/D32550

llvm-svn: 302572
2017-05-09 19:31:30 +00:00
John McCall 5ad740756f Promote ConstantInitBuilder to be a public CodeGen API; it's
a generally useful utility for other frontends.  NFC.

llvm-svn: 296806
2017-03-02 20:04:19 +00:00
John McCall 23c9dc6585 ConstantBuilder -> ConstantInitBuilder for clarity, and
move the member classes up to top level to allow forward
declarations to name them.  NFC.

llvm-svn: 288079
2016-11-28 22:18:27 +00:00
John McCall 6c9f1fdb5c Introduce a helper class for building complex constant initializers. NFC.
I've adopted this in most of the places it makes sense, but v-tables
and CGObjCMac will need a second pass.

llvm-svn: 287437
2016-11-19 08:17:24 +00:00
Justin Lebar d14fe8830e [CUDA] Use the right section and constant names for fatbins when compiling for macos.
Reviewers: tra

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26777

llvm-svn: 287287
2016-11-18 00:41:31 +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
Benjamin Kramer 6d1c10bb8e [CUDA] Move argument type lists to the stack. NFC.
llvm-svn: 274433
2016-07-02 12:03:57 +00:00
Benjamin Kramer 309347385e Use arrays or initializer lists to feed ArrayRefs instead of SmallVector where possible.
No functionality change intended

llvm-svn: 274432
2016-07-02 11:41:41 +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 21e5d4fcfa [CUDA] Invoke ptxas and fatbinary during compilation.
Summary:
Previously we compiled CUDA device code to PTX assembly and embedded
that asm as text in our host binary.  Now we compile to PTX assembly and
then invoke ptxas to assemble the PTX into a cubin file.  We gather the
ptx and cubin files for each of our --cuda-gpu-archs and combine them
using fatbinary, and then embed that into the host binary.

Adds two new command-line flags, -Xcuda_ptxas and -Xcuda_fatbinary,
which pass args down to the external tools.

Reviewers: tra, echristo

Subscribers: cfe-commits, jhen

Differential Revision: http://reviews.llvm.org/D16082

llvm-svn: 257809
2016-01-14 21:41:27 +00:00
John McCall 7f416cc426 Compute and preserve alignment more faithfully in IR-generation.
Introduce an Address type to bundle a pointer value with an
alignment.  Introduce APIs on CGBuilderTy to work with Address
values.  Change core APIs on CGF/CGM to traffic in Address where
appropriate.  Require alignments to be non-zero.  Update a ton
of code to compute and propagate alignment information.

As part of this, I've promoted CGBuiltin's EmitPointerWithAlignment
helper function to CGF and made use of it in a number of places in
the expression emitter.

The end result is that we should now be significantly more correct
when performing operations on objects that are locally known to
be under-aligned.  Since alignment is not reliably tracked in the
type system, there are inherent limits to this, but at least we
are no longer confused by standard operations like derived-to-base
conversions and array-to-pointer decay.  I've also fixed a large
number of bugs where we were applying the complete-object alignment
to a pointer instead of the non-virtual alignment, although most of
these were hidden by the very conservative approach we took with
member alignment.

Also, because IRGen now reliably asserts on zero alignments, we
should no longer be subject to an absurd but frustrating recurring
bug where an incomplete type would report a zero alignment and then
we'd naively do a alignmentAtOffset on it and emit code using an
alignment equal to the largest power-of-two factor of the offset.

We should also now be emitting much more aggressive alignment
attributes in the presence of over-alignment.  In particular,
field access now uses alignmentAtOffset instead of min.

Several times in this patch, I had to change the existing
code-generation pattern in order to more effectively use
the Address APIs.  For the most part, this seems to be a strict
improvement, like doing pointer arithmetic with GEPs instead of
ptrtoint.  That said, I've tried very hard to not change semantics,
but it is likely that I've failed in a few places, for which I
apologize.

ABIArgInfo now always carries the assumed alignment of indirect and
indirect byval arguments.  In order to cut down on what was already
a dauntingly large patch, I changed the code to never set align
attributes in the IR on non-byval indirect arguments.  That is,
we still generate code which assumes that indirect arguments have
the given alignment, but we don't express this information to the
backend except where it's semantically required (i.e. on byvals).
This is likely a minor regression for those targets that did provide
this information, but it'll be trivial to add it back in a later
patch.

I partially punted on applying this work to CGBuiltin.  Please
do not add more uses of the CreateDefaultAligned{Load,Store}
APIs; they will be going away eventually.

llvm-svn: 246985
2015-09-08 08:05:57 +00:00