This latter determination may or may not be possible on a per-language basis; and neither is mandatory to implement for any language
Use this knowledge in the ValueObjectPrinter to generalize the notion of IsObjCNil() and the respective printout
llvm-svn: 252663
Summary:
This patch adds documentation on compiling CUDA with LLVM as requested by many
engineers and researchers. It includes not only user guides but also some
internals (mostly optimizations) so that early adopters can start hacking and
contributing.
Quite a few researchers who contacted us haven't used LLVM before, which is
unsurprising as it hasn't been long since LLVM picked up CUDA. So I added a
short summary to help these folks get started with LLVM.
I expect this document to evolve substantially down the road. The user guides
will be much simplified after the Clang integration is done. However, the
internals should continue growing to include for example performance debugging
and key areas to improve.
Reviewers: chandlerc, meheff, broune, tra
Subscribers: silvas, jingyue, llvm-commits, eliben
Differential Revision: http://reviews.llvm.org/D14370
llvm-svn: 252660
This comes up when a derived class destructor is equivalent to a base
class destructor defined in the same TU, and we try to alias them.
A COFF weak alias cannot satisfy a normal undefined symbol reference
from another TU. The other TU must also mark the referenced symbol as
weak, and we can't rely on that.
Clang already has a special case here for dllexport, but we failed to
realize that the problem also applies to other non-discardable symbols
such as those from explicit template instantiations.
Fixes PR25477.
llvm-svn: 252659
This patch adds a pass for doing PowerPC peephole optimizations at the
MI level while the code is still in SSA form. This allows for easy
modifications to the instructions while depending on a subsequent pass
of DCE. Both passes are very fast due to the characteristics of SSA.
At this time, the only peepholes added are for cleaning up various
redundancies involving the XXPERMDI instruction. However, I would
expect this will be a useful place to add more peepholes for
inefficiencies generated during instruction selection. The pass is
placed after VSX swap optimization, as it is best to let that pass
remove unnecessary swaps before performing any remaining clean-ups.
The utility of these clean-ups are demonstrated by changes to four
existing test cases, all of which now have tighter expected code
generation. I've also added Eric Schweiz's bugpoint-reduced test from
PR25157, for which we now generate tight code. One other test started
failing for me, and I've fixed it
(test/Transforms/PlaceSafepoints/finite-loops.ll) as well; this is not
related to my changes, and I'm not sure why it works before and not
after. The problem is that the CHECK-NOT: of "statepoint" from test1
fails because of the "statepoint" in test2, and so forth. Adding a
CHECK-LABEL in between keeps the different occurrences of that string
properly scoped.
llvm-svn: 252651
already emitted and fix a latent bug in DIECloner where the DW_CHILDREN_yes
flag is set based on the number of children in the input DIE rather than
the number of children that are actually being cloned.
rdar://problem/23439845
llvm-svn: 252649
The attrubite is applicable to functions and variables and changes
the linkage of the subject to internal.
This is the same functionality as C-style "static", but applicable to
class methods; and the same as anonymouns namespaces, but can apply
to individual methods of a class.
Following the proposal in
http://lists.llvm.org/pipermail/cfe-dev/2015-October/045580.html
llvm-svn: 252648
Summary:
The module linker lazy links some "discardable if unused" global
values (e.g. linkonce), materializing and linking them only
if they are referenced in the module. If a comdat group contains a
linkonce member that is not referenced, however, it would not be
materialized and linked, leading to an incomplete comdat group.
If there are other object files not part of the same LTO link that also
define and use that comdat group, the linker may select the incomplete
group leading to link time unsats.
To solve this, whenever a global value body is linked, make sure we
materialize any other members of the same comdat group that are not yet
materialized. This ensures they are in the lazy link list and get linked
as well.
Added new test and adjusted old test to remove parts that didn't
make sense with fix.
Reviewers: rafael
Subscribers: dexonsmith, davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D14516
llvm-svn: 252647
This was an omission in the patch that landed initial support for
operand bundles. So far we haven't hit this, but we will once the
inliner is able to inline calls to functions that contain calls with
operand bundles.
llvm-svn: 252645
ARM V6T2 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any ARM V6T2
implementation.
The net result of allowing this speculation for the regression tests in this patch is
that we get this code:
ctlz:
clz r0, r0
bx lr
cttz:
rbit r0, r0
clz r0, r0
bx lr
Instead of:
ctlz:
cmp r0, #0
moveq r0, #32
clzne r0, r0
bx lr
cttz:
cmp r0, #0
moveq r0, #32
rbitne r0, r0
clzne r0, r0
bx lr
This will help solve a general speculation/despeculation problem noted in PR24818:
https://llvm.org/bugs/show_bug.cgi?id=24818
Differential Revision: http://reviews.llvm.org/D14469
llvm-svn: 252639
This allows avoiding the default Expand behavior which
introduces stack usage. Bitcast the scalar and replace
the missing elements with undef.
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.
llvm-svn: 252632
This is for AMDGPU to implement v2i64 extract as extract of
half of a v4i32.
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.
llvm-svn: 252630
This is a cleaned up version of a patch by John Regehr with permission. Originally found via the souper tool.
If we add an odd number to x, then bitwise-and the result with x, we know that the low bit of the result must be zero. Either it was zero in x originally, or the add cleared it in the temporary value. As a result, one of the two values anded together must have the bit cleared.
Differential Revision: http://reviews.llvm.org/D14315
llvm-svn: 252629
When configuring various llvm projects that use AddLLVM.cmake, this warning is
emitted many times, flooding the screen:
Policy CMP0007 is not set: list command no longer ignores empty elements.
The fix is removing an extra semicolon.
Differential Revision: http://reviews.llvm.org/D14339
llvm-svn: 252628
Ensure WeakAny variables are imported as ExternalWeak declarations. To
handle WeakAny more consistently and fix this issue:
1) Update helper doImportAsDefinition to properly flag WeakAny variables
and aliases as not importing defintions.
Update callers of doImportAsDefinition to remove now redundant checks for
WeakAny aliases, or ignore aliases, as appropriate.
2) Add any !doImportAsDefinition GVs to DoNotLinkFromSource set during
linking of the GV prototype, where we usually add GVs to the
DoNotLinkFromSource set for other reasons.
Remove now unnecessary adding of WeakAny aliases to
DoNotLinkFromSource set from copyGlobalAliasProto.
Remove now unnecessary guard against linking non-imported function
bodies from ModuleLinker::run.
llvm-svn: 252626
AArch64 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any AArch64
implementation.
The net result of allowing this speculation for the regression tests in this
patch is that we get this code:
ctlz:
clz w0, w0
ret
cttz:
rbit w8, w0
clz w0, w8
ret
Instead of:
ctlz:
cbz w0, .LBB0_2
clz w0, w0
ret
.LBB0_2:
orr w0, wzr, #0x20
ret
cttz:
cbz w0, .LBB1_2
rbit w8, w0
clz w0, w8
ret
.LBB1_2:
orr w0, wzr, #0x20
ret
See D14469 for the larger motivation.
Differential Revision: http://reviews.llvm.org/D14505
llvm-svn: 252625
Fixed a crash that would happen if you tried to get the name of a constructor or destructor by calling "getDeclName()" instead of calling getName() (which would assert and crash).
Added the ability to get function arguments names from SBFunction.
llvm-svn: 252622
Since 252422 we do not only distinguish two ScopArrayInfo kinds, PHI nodes
and others, but work with three kind of ScopArrayInfo objects. SCALAR, PHI and
ARRAY objects. Instead of keeping two boolean flags isPHI and isScalar and
wonder what an ScopArrayInfo object of kind (!isScalar && isPHI) is, we
list now explicitly the three different possible types of memory objects.
This change also allows us to remove the confusing nested pairs that have
been used in ArrayInfoMapTy.
llvm-svn: 252620
* Setting CMAKE_*_FLAGS_${BUILD_TYPE} isn't really needed since we're setting the same value everywhere
* functions sanitize variables differently from macros, darwin_add_embedded_builtin_libraries should be a macro otherwise it won't alter the variables.
llvm-svn: 252618
This is one of the problems noted in PR25016:
https://llvm.org/bugs/show_bug.cgi?id=25016
and:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/090998.html
The spilling problem is independent and not addressed by this patch.
The MachineCombiner was doing reassociations that don't improve or even worsen the critical path.
This is caused by inclusion of the "slack" factor when calculating the critical path of the original
code sequence. If we don't add that, then we have a more conservative cost comparison of the old code
sequence vs. a new sequence. The more liberal calculation must be preserved, however, for the AArch64
MULADD patterns because benchmark regressions were observed without that.
The two failing test cases now have identical asm that does what we want:
a + b + c + d ---> (a + b) + (c + d)
Differential Revision: http://reviews.llvm.org/D13417
llvm-svn: 252616
In case we also model scalar reads it can happen that a pointer appears in both
a scalar read access as well as the base pointer of an array access. As this
is a little surprising, we add a specific test case to document this behaviour.
To my understanding it should be OK to have a read from an array A[] and
read/write accesses to A[...]. isl is treating these arrays as unrelated as
their dimensionality differs. This seems to be correct as A[] remains constant
throughout the execution of the scop and is not affected by the reads/writes to
A[...]. If this causes confusion, it might make sense to make this behaviour
more obvious by using different names (e.g., A_scalar[], A[...]).
llvm-svn: 252615
Jonathan Roelofs