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:
MDNode *N = foo();
bar(isa <ConstantInt>(N->getOperand(0)));
baz(cast <ConstantInt>(N->getOperand(1)));
bak(cast_or_null <ConstantInt>(N->getOperand(2)));
bat(dyn_cast <ConstantInt>(N->getOperand(3)));
bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));
you can trivially match its semantics with:
MDNode *N = foo();
bar(mdconst::hasa <ConstantInt>(N->getOperand(0)));
baz(mdconst::extract <ConstantInt>(N->getOperand(1)));
bak(mdconst::extract_or_null <ConstantInt>(N->getOperand(2)));
bat(mdconst::dyn_extract <ConstantInt>(N->getOperand(3)));
bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));
and when you transition your metadata schema to `MDInt`:
MDNode *N = foo();
bar(isa <MDInt>(N->getOperand(0)));
baz(cast <MDInt>(N->getOperand(1)));
bak(cast_or_null <MDInt>(N->getOperand(2)));
bat(dyn_cast <MDInt>(N->getOperand(3)));
bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));
- 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.)
llvm-svn: 223802
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.
Part of the fix for rdar://19162268.
llvm-svn: 223799
Rewrite the pattern match code to work also with Values instead with
Instructions only. Also remove the no longer need matcher (m_Instruction).
llvm-svn: 223797
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.
Differential Revision: http://reviews.llvm.org/D6242
llvm-svn: 223793
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.
llvm-svn: 223792
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.
llvm-svn: 223791
This allows it to work with non trivial manglings like the one in COFF.
Amusingly, this can be tested with gold, as emit-llvm causes the plugin to
exit before any COFF is generated.
llvm-svn: 223790
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.
llvm-svn: 223788
This optimization transforms code like:
bb1:
%0 = icmp ne i32 %a, 0
%1 = icmp ne i32 %b, 0
%or.cond = or i1 %0, %1
br i1 %or.cond, label %TrueBB, label %FalseBB
into a multiple branch instructions like:
bb1:
%0 = icmp ne i32 %a, 0
br i1 %0, label %TrueBB, label %bb2
bb2:
%1 = icmp ne i32 %b, 0
br i1 %1, label %TrueBB, label %FalseBB
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.
Reviewed by Jim Grosbach
This fixes rdar://problem/19034919.
llvm-svn: 223786
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.
llvm-svn: 223783
At present each TargetRelocationHandler generates a pretty similar error
string and calls llvm_unreachable() when encountering an unknown
relocation. This is not ideal for two reasons:
1. llvm_unreachable disappears in release builds but we still want to
know if we encountered a relocation we couldn't handle in release
builds.
2. Duplication is bad - there is no need to have a per-architecture error
message.
This change adds a test for AArch64 to test whether or not the error
message actually works. The other architectures have not been tested
but they compile and check-lld passes.
llvm-svn: 223782
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.
llvm-svn: 223780
basic microarchitecture names, and add support (with tests) for parsing
all of the masic microarchitecture names for CPUs documented to be
accepted by GCC with -march. I didn't go back through the 32-bit-only
old microarchitectures, but this at least brings the recent architecture
names up to speed. This is essentially the follow-up to the LLVM commit
r223769 which did similar cleanups for the LLVM CPUs.
One particular benefit is that you can now use -march=westmere in Clang
and get the LLVM westmere processor which is a different ISA variant (!)
and so quite significant.
Much like with r223769, I would appreciate the Intel folks carefully
thinking about the macros defined, names used, etc for the atom chips
and newest primary x86 chips. The current patterns seem quite strange to
me, especially here in Clang.
Note that I haven't replicated the per-microarchitecture macro defines
provided by GCC. I'm really opposed to source code using these rather
than using ISA feature macros.
llvm-svn: 223776
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.
llvm-svn: 223774
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.
llvm-svn: 223772
Notably, this adds simple micro-architecture names for the Intel CPU
variants, and defines the old 'core'-based names as aliases. GCC has
started to simplify their documented interface to use these names as
well, so it seems like we can start to converge on a consistent pattern.
I'd appreciate Intel double checking the entries that aren't yet
documented widely, especially Atom (Bonnell and Silvermont), Knights
Landing, and Skylake. But this change shouldn't break any existing
users.
Also, ran clang-format to re-format this code and it actually worked
(modulo a tiny bug) so hopefully we can start to stop thinking about
formatting this stuff.
llvm-svn: 223769
Removed some duplicate test cases from the file /test/Transforms/InstCombine/shift.ll.
test54 and test57 were duplicates of each other.
test55 and test58 were duplicates of each other.
(Removed test57 and test58)
llvm-svn: 223767
There are still a vast range of improvements that can be done to this,
but it seems like an ok initial version. Suggestions or patches are
highly welcome.
llvm-svn: 223766
Remove setting of default style, this way is not recommended and
means that all the settings have to be duplicated to demonstrate the
c-add-style method which is a much better way of doing it.
Remove the modified date as it is better stored in SVN.
Tweak a few style parameters to make them conform to the actual LLVM
style.
llvm-svn: 223765
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.
Differential Revision: http://reviews.llvm.org/D6548
llvm-svn: 223764
This is a revert of r223521 in spirit, if not in content. I am not
sure why declarations ended up in LazilyLinkGlobalValues in the first
place; that will take some more investigation.
llvm-svn: 223763
This handles the simplest case for mov -> push conversion:
1. x86-32 calling convention, everything is passed through the stack.
2. There is no reserved call frame.
3. Only registers or immediates are pushed, no attempt to combine a mem-reg-mem sequence into a single PUSHmm.
Differential Revision: http://reviews.llvm.org/D6503
llvm-svn: 223757
For files named by -fmodule-map-file=, and files found by 'extern module'
directives, this flag specifies that we should resolve filenames relative to
the current working directory rather than relative to the directory in which
the module map file resides. This is aimed at fixing path handling, in
particular for relative -I paths, when building modules that represent
components of the current project (rather than libraries installed on the
current system, which the current project has as dependencies, where we'd
typically expect the module map files to be looked up implicitly).
llvm-svn: 223753
Duncan P. N. Exon Smith