Sanjay Patel [Wed, 10 Dec 2014 16:58:54 +0000 (16:58 +0000)]
Match new shuffle codegen for MOVHPD patterns
Add patterns to match SSE (shufpd) and AVX (vpermilpd) shuffle codegen
when storing the high element of a v2f64. The existing patterns were
only checking for an unpckh type of shuffle.
[X86] Make a code path in EltsFromConsecutiveLoads work only on vectors it expects
EltsFromConsecutiveLoads was apparently only ever called for 128-bit vectors, and assumed this implicitly. r223518 started calling it for AVX-sized vectors, causing the code path that had this assumption to crash.
This adds a check to make this path fire only for 128-bit vectors.
Eric Fiselier [Wed, 10 Dec 2014 03:42:09 +0000 (03:42 +0000)]
[LIT] Add support for `UNSUPPORTED` tag to `TestRunner.parseIntegratedTestScript`
Summary:
This patch gives me just enough to leverage the existing functionality in `TestRunner` for use in `libc++` and `libc++abi` .
It does the following:
* Adds the `UNSUPPORTED` tag to `TestRunner.parseIntegratedTestScript`.
* Allows `parseIntegratedTestScript` to return an empty script if a script is not required by the caller.
David Majnemer [Wed, 10 Dec 2014 01:17:08 +0000 (01:17 +0000)]
DataLayout: Move asserts over to report_fatal_error
As indicated by the tests, it is possible to feed the AsmParser an
invalid datalayout string. We should verify the result of parsing this
string regardless of whether or not we have assertions enabled.
Matthias Braun [Wed, 10 Dec 2014 01:13:11 +0000 (01:13 +0000)]
MachineVerifier: Allow LiveInterval segments to end at a partial write.
In the subregister liveness tracking case we do not create implicit
reads on partial register writes anymore, still we need to produce a new
SSA value for partial writes so the live segment has to end.
Matthias Braun [Wed, 10 Dec 2014 01:13:04 +0000 (01:13 +0000)]
VirtRegMap: No implicit defs/uses for super registers with subreg liveness tracking.
Adding the implicit defs/uses to the superregisters is semantically questionable
but was not dangerous before as the register allocator never assigned the same
register to two overlapping LiveIntervals even when the actually live
subregisters do not overlap. With subregister liveness tracking enabled this
does actually happen and leads to subsequent bugs if we don't stop adding
the superregister defs/uses.
Matthias Braun [Wed, 10 Dec 2014 01:11:56 +0000 (01:11 +0000)]
Let tablegen compute maximum lanemask for regs/regclasses.
Let tablegen compute the combination of subregister lanemasks for all
subregisters in a register/register class. This is preparation for further
work subregister allocation
Rafael Espindola [Wed, 10 Dec 2014 00:09:35 +0000 (00:09 +0000)]
Simplify the handling of aliases in the gold plugin.
The complicated situation is when we have to keep an alias but drop a GV
that is part of the aliasee.
We used to clone the dropped GV and make the clone internal. This is wasteful
as we know the original will be dropped.
With this patch what is done instead is set the linkage of the original to
internal and replace all uses (but the one in the alias) with a new
declaration that takes the name of the old GV. This saves us from having
to copy the body.
We used to only combine intrinsics, and turn them into VLD1_UPD/VST1_UPD
when the base pointer is incremented after the load/store.
We can do the same thing for generic load/stores.
Note that we can only combine the first load/store+adds pair in
a sequence (as might be generated for a v16f32 load for instance),
because other combines turn the base pointer addition chain (each
computing the address of the next load, from the address of the last
load) into independent additions (common base pointer + this load's
offset).
Philip Reames [Tue, 9 Dec 2014 23:57:54 +0000 (23:57 +0000)]
Remove the Module pointer from GCStrategy and GCMetadataPrinter
In the current implementation, GCStrategy is a part of the ownership structure for the gc metadata which describes a Module. It also contains a reference to the module in question. As a result, GCStrategy instances are essentially Module specific.
I plan to transition away from this design. Instead, a GCStrategy will be owned by the LLVMContext. It will be a lightweight policy object which contains no information about the Modules or Functions involved, but can be easily reached given a Function.
The first step in this transition is to remove the direct Module reference from GCStrategy. This also requires removing the single user of this reference, the GCMetadataPrinter hierarchy. In theory, this will allow the lifetime of the printers to be scoped to the LLVMContext as well, but in practice, I'm not actually changing that. (Yet?)
An alternate design would have been to move the direct Module reference into the GCMetadataPrinter and change the keying of the owning maps to explicitly key off both GCStrategy and Module. I'm open to doing it that way instead, but didn't see much value in preserving the per Module association for GCMetadataPrinters.
The next change in this sequence will be to start unwinding the intertwined ownership between GCStrategy, GCModuleInfo, and GCFunctionInfo.
Hans Wennborg [Tue, 9 Dec 2014 20:39:15 +0000 (20:39 +0000)]
Try fixing MSVC build after r223802
LLVM_EXPLICIT is only supported by recent version of MSVC, and it seems
the not-so-recent versions get confused about the operator bool() when
tryint to resolve operator== calls.
This removed the operator bool()'s since they don't seem to be used
anyway.
[FastISel][AArch64] Fix a missing nullptr check in 'computeAddress'.
The load/store value type is currently not available when lowering the memcpy
intrinsic. Add the missing nullptr check to support this in 'computeAddress'.
Revert r223764 which taught instcombine about integer-based elment extraction
patterns.
This is causing Clang to miscompile itself for 32-bit x86 somehow, and likely
also on ARM and PPC. I really don't know how, but reverting now that I've
confirmed this is actually the culprit. I have a reproduction as well and so
should be able to restore this shortly.
This reverts commit r223764.
Original commit log follows:
Teach instcombine to canonicalize "element extraction" from a load of an
integer and "element insertion" into a store of an integer into actual
element extraction, element insertion, and vector loads and stores.
Previously various parts of LLVM (including instcombine itself) would
introduce integer loads and stores into the code as a way of opaquely
loading and storing "bits". In some cases (such as a memcpy of
std::complex<float> object) we will eventually end up using those bits
in non-integer types. In order for SROA to effectively promote the
allocas involved, it splits these "store a bag of bits" integer loads
and stores up into the constituent parts. However, for non-alloca loads
and tsores which remain, it uses integer math to recombine the values
into a large integer to load or store.
All of this would be "fine", except that it forces LLVM to go through
integer math to combine and split up values. While this makes perfect
sense for integers (and in fact is critical for bitfields to end up
lowering efficiently) it is *terrible* for non-integer types, especially
floating point types. We have a much more canonical way of representing
the act of concatenating the bits of two SSA values in LLVM: a vector
and insertelement. This patch teaching InstCombine to use this
representation.
With this patch applied, LLVM will no longer introduce integer math into
the critical path of every loop over std::complex<float> operations such
as those that make up the hot path of ... oh, most HPC code, Eigen, and
any other heavy linear algebra library.
For the record, I looked *extensively* at fixing this in other parts of
the compiler, but it just doesn't work:
- We really do want to canonicalize memcpy and other bit-motion to
integer loads and stores. SSA values are tremendously more powerful
than "copy" intrinsics. Not doing this regresses massive amounts of
LLVM's scalar optimizer.
- We really do need to split up integer loads and stores of this form in
SROA or every memcpy of a trivially copyable struct will prevent SSA
formation of the members of that struct. It essentially turns off
SROA.
- The closest alternative is to actually split the loads and stores when
partitioning with SROA, but this has all of the downsides historically
discussed of splitting up loads and stores -- the wide-store
information is fundamentally lost. We would also see performance
regressions for bitfield-heavy code and other places where the
integers aren't really intended to be split without seemingly
arbitrary logic to treat integers totally differently.
- We *can* effectively fix this in instcombine, so it isn't that hard of
a choice to make IMO.
Chris Bieneman [Tue, 9 Dec 2014 18:49:55 +0000 (18:49 +0000)]
Adding a new option to CMake to disable C++ atexit on llvm-shlib.
Summary:
This is desirable for WebKit and other clients of the llvm-shlib because C++ exit time destructors have a tendency to crash when invoked from multi-threaded applications.
Ideally this option will be temporary, because the ideal fix is to just not have exit time destructors.
Robert Khasanov [Tue, 9 Dec 2014 18:45:30 +0000 (18:45 +0000)]
[AVX512] Added lowering for VBROADCASTSS/SD instructions.
Lowering patterns were written through avx512_broadcast_pat multiclass as pattern generates VBROADCAST and COPY_TO_REGCLASS nodes.
Added lowering tests.
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532. Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.
I have a follow-up patch prepared for `clang`. If this breaks other
sub-projects, I apologize in advance :(. Help me compile it on Darwin
I'll try to fix it. FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.
This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.
Here's a quick guide for updating your code:
- `Metadata` is the root of a class hierarchy with three main classes:
`MDNode`, `MDString`, and `ValueAsMetadata`. It is distinct from
the `Value` class hierarchy. It is typeless -- i.e., instances do
*not* have a `Type`.
- `MDNode`'s operands are all `Metadata *` (instead of `Value *`).
- `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.
If you're referring solely to resolved `MDNode`s -- post graph
construction -- just use `MDNode*`.
- `MDNode` (and the rest of `Metadata`) have only limited support for
`replaceAllUsesWith()`.
As long as an `MDNode` is pointing at a forward declaration -- the
result of `MDNode::getTemporary()` -- it maintains a side map of its
uses and can RAUW itself. Once the forward declarations are fully
resolved RAUW support is dropped on the ground. This means that
uniquing collisions on changing operands cause nodes to become
"distinct". (This already happened fairly commonly, whenever an
operand went to null.)
If you're constructing complex (non self-reference) `MDNode` cycles,
you need to call `MDNode::resolveCycles()` on each node (or on a
top-level node that somehow references all of the nodes). Also,
don't do that. Metadata cycles (and the RAUW machinery needed to
construct them) are expensive.
- An `MDNode` can only refer to a `Constant` through a bridge called
`ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).
As a side effect, accessing an operand of an `MDNode` that is known
to be, e.g., `ConstantInt`, takes three steps: first, cast from
`Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
third, cast down to `ConstantInt`.
The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
metadata schema owners transition away from using `Constant`s when
the type isn't important (and they don't care about referring to
`GlobalValue`s).
In the meantime, I've added transitional API to the `mdconst`
namespace that matches semantics with the old code, in order to
avoid adding the error-prone three-step equivalent to every call
site. If your old code was:
- A `CallInst` -- specifically, intrinsic instructions -- can refer to
metadata through a bridge called `MetadataAsValue`. This is a
subclass of `Value` where `getType()->isMetadataTy()`.
`MetadataAsValue` is the *only* class that can legally refer to a
`LocalAsMetadata`, which is a bridged form of non-`Constant` values
like `Argument` and `Instruction`. It can also refer to any other
`Metadata` subclass.
(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)
Colin LeMahieu [Tue, 9 Dec 2014 18:16:49 +0000 (18:16 +0000)]
[Hexagon] Updating predicate register transfers and adding tstbit to allow select selection. Updating ll tests with predicate transfers that previously had nop encodings.
Frederic Riss [Tue, 9 Dec 2014 17:55:48 +0000 (17:55 +0000)]
Correctly handle complex locations expressions in replaceDbgDeclareForAlloca()
replaceDbgDeclareForAlloca() replaces an alloca by a value storing the
address of what was the alloca. If there is a dbg.declare corresponding
to that alloca, we need to lower it to a dbg.value describing the additional
dereference operation to be performed to get to the underlying variable.
This is done by adding a DW_OP_deref to the complex location part of the
location description. This deref was added to the end of the operation list,
which is wrong. The expression applies to what is described by the
dbg.{declare,value}, and as we are changing this, we need to apply the
DW_OP_deref as the first operation in the list.
Frederic Riss [Tue, 9 Dec 2014 17:03:30 +0000 (17:03 +0000)]
Initial dsymutil tool commit.
The goal of this tool is to replicate Darwin's dsymutil functionality
based on LLVM. dsymutil is a DWARF linker. Darwin's linker (ld64) does
not link the debug information, it leaves it in the object files in
relocatable form, but embbeds a `debug map` into the executable that
describes where to find the debug information and how to relocate it.
When releasing/archiving a binary, dsymutil is called to link all the DWARF
information into a `dsym bundle` that can distributed/stored along with
the binary.
With this commit, the LLVM based dsymutil is just able to parse the STABS
debug maps embedded by ld64 in linked binaries (and not all of them, for
example archives aren't supported yet).
Note that the tool directory is called dsymutil, but the executable is
currently called llvm-dsymutil. This discrepancy will disappear once the
tool will be feature complete. At this point the executable will be renamed
to dsymutil, but until then you do not want it to override the system one.
Bill Schmidt [Tue, 9 Dec 2014 16:59:57 +0000 (16:59 +0000)]
[PowerPC 4/4] Enable little-endian support for VSX.
With the foregoing three patches, VSX instructions can be used for
little endian. This patch removes the restriction that prevented
this, and re-enables the test cases from the first three patches.
Bill Schmidt [Tue, 9 Dec 2014 16:52:29 +0000 (16:52 +0000)]
[PowerPC 3/4] Little-endian adjustments for VSX vector shuffle
When performing instruction selection for ISD::VECTOR_SHUFFLE, there
is special code for handling v2f64 and v2i64 using VSX instructions.
This code must be adjusted for little-endian. Because the two inputs
are treated as a double-wide register, we must swap their order for
little endian. To get the appropriate mask elements to use with the
big-endian biased XXPERMDI instruction, we must reverse their order
and invert the bits.
A new test is added to test the 16 possible values of the shuffle
mask. It is initially disabled for reasons specified in the test. It
is re-enabled by patch 4/4.
Bill Schmidt [Tue, 9 Dec 2014 16:43:32 +0000 (16:43 +0000)]
[PowerPC 2/4] Little-endian adjustments for VSX insert/extract operations
For little endian, we need to make some straightforward adjustments in
the code expansions for scalar_to_vector and vector_extract of v2f64.
First, scalar_to_vector must place the scalar into vector element
zero. However, our implementation of SUBREG_TO_REG will place it into
big-element vector element zero (high-order bits), and for little
endian we need it in the low-order bits. The LE implementation splats
the high-order doubleword into the low-order doubleword.
Second, the meaning of (vector_extract x, 0) and (vector_extract x, 1)
must be reversed for similar reasons.
A new test is added that tests code generation for insertelement and
extractelement for both element 0 and element 1. It is disabled in
this patch but enabled in patch 4/4, for reasons stated in the test.
Robert Khasanov [Tue, 9 Dec 2014 16:38:41 +0000 (16:38 +0000)]
[AVX512] Added VPBROADCAST{BWDQ} (Load with Broadcast Integer Data from General Purpose Register) encodings for AVX512-BW/VL subsets
Added encoding tests.
This optimization is already performed by SelectionDAG, but not by FastISel.
FastISel cannot perform this optimization, because it cannot generate new
MachineBasicBlocks.
Performing this optimization at CodeGenPrepare time makes it available to both -
SelectionDAG and FastISel - and the implementation in SelectiuonDAG could be
removed. There are currenty a few differences in codegen for X86 and PPC, so
this commmit only enables it for FastISel.
Bill Schmidt [Tue, 9 Dec 2014 16:35:51 +0000 (16:35 +0000)]
[PowerPC 1/4] Little-endian adjustments for VSX loads/stores
This patch addresses the inherent big-endian bias in the lxvd2x,
lxvw4x, stxvd2x, and stxvw4x instructions. These instructions load
vector elements into registers left-to-right (with the first element
loaded into the high-order bits of the register), regardless of the
endian setting of the processor. However, these are the only
vector memory instructions that permit unaligned storage accesses, so
we want to use them for little-endian.
To make this work, a lxvd2x or lxvw4x is replaced with an lxvd2x
followed by an xxswapd, which swaps the doublewords. This works for
lxvw4x as well as lxvd2x, because for lxvw4x on an LE system the
vector elements are in LE order (right-to-left) within each
doubleword. (Thus after lxvw2x of a <4 x float> the elements will
appear as 1, 0, 3, 2. Following the swap, they will appear as 3, 2,
0, 1, as desired.) For stores, an stxvd2x or stxvw4x is replaced
with an stxvd2x preceded by an xxswapd.
Introduction of extra swap instructions provides correctness, but
obviously is not ideal from a performance perspective. Future patches
will address this with optimizations to remove most of the introduced
swaps, which have proven effective in other implementations.
The introduction of the swaps is performed during lowering of LOAD,
STORE, INTRINSIC_W_CHAIN, and INTRINSIC_VOID operations. The latter
are used to translate intrinsics that specify the VSX loads and stores
directly into equivalent sequences for little endian. Thus code that
uses vec_vsx_ld and vec_vsx_st does not have to be modified to be
ported from BE to LE.
We introduce new PPCISD opcodes for LXVD2X, STXVD2X, and XXSWAPD for
use during this lowering step. In PPCInstrVSX.td, we add new SDType
and SDNode definitions for these (PPClxvd2x, PPCstxvd2x, PPCxxswapd).
These are recognized during instruction selection and mapped to the
correct instructions.
Several tests that were written to use -mcpu=pwr7 or pwr8 are modified
to disable VSX on LE variants because code generation changes with
this and subsequent patches in this set. I chose to include all of
these in the first patch than try to rigorously sort out which tests
were broken by one or another of the patches. Sorry about that.
The new test vsx-ldst-builtin-le.ll, and the changes to vsx-ldst.ll,
are disabled until LE support is enabled because of breakages that
occur as noted in those tests. They are re-enabled in patch 4/4.
Instead, walk the obj symbol list in parallel to find the GV. This shouldn't
change anything on ELF where global symbols are not mangled, but it is a step
toward supporting other object formats.
Gold itself is ELF only, but bfd ld supports COFF and the logic in the gold
plugin could be reused on lld.
[x86] Fix the test to actually test things for the CPU names, add the
missing barcelona CPU which that test uncovered, and remove the 32-bit
x86 CPUs which I really wasn't prepared to audit and test thoroughly.
If anyone wants to clean up the 32-bit only x86 CPUs, go for it.
Also, if anyone else wants to try to de-duplicate the AMD CPUs, that'd
be cool, but from the looks of it wouldn't save as much as it did for
the Intel CPUs.
Instructions of the form [ADD Rd, pc, #imm] are manually aliased
in processInstruction() to use ADR. To accomodate this, mod_imm handling
had to be tweaked a bit. Turns out it was the manual aliasing that must
be tweaked to accommodate mod_imms instead. More information about the
parsed instruction is available at the point where processInstruction()
is invoked, which makes it easier to detect a mod_imm at that point rather
than trying to detect a potential alias when a mod_imm is being prepped.
Added a test case and fixed some white spaces as well.