There are some that I didn't remove this round because they looked like
obvious stubs. There are dead variables in gtest too, they should be
fixed upstream.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158090 91177308-0d34-0410-b5e6-96231b3b80d8
This allows a subtarget to explicitly specify the issue width and
other properties without providing pipeline stage details for every
instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157979 91177308-0d34-0410-b5e6-96231b3b80d8
Each register unit has one or two root registers. The full set of
registers containing a given register unit can be computed as the union
of the root registers and their super-registers.
Provide an MCRegUnitRootIterator class to enumerate the roots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157753 91177308-0d34-0410-b5e6-96231b3b80d8
Register units are already used internally in TableGen to compute
register pressure sets and overlapping registers. This patch makes them
available to the code generators.
The register unit lists are differentially encoded so they can be reused
for many related registers. This keeps the total size of the lists below
200 bytes for most targets. ARM has the largest table at 560 bytes.
Add an MCRegUnitIterator for traversing the register unit lists. It
provides an abstract interface so the representation can be changed in
the future without changing all clients.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157650 91177308-0d34-0410-b5e6-96231b3b80d8
This required light surgery on the assembler and disassembler
because the instructions use an uncommon encoding. They are
the only two instructions in x86 that use register operands
and two immediates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157634 91177308-0d34-0410-b5e6-96231b3b80d8
making it stronger and more sane.
Delete the code from tblgen that produced the old code.
Besides being a path forward in intrinsic sanity, this also eliminates a bunch of
machine generated code that was compiled into Function.o
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157545 91177308-0d34-0410-b5e6-96231b3b80d8
separate side table, using the handy SequenceToOffsetTable class. This encodes all
these weird things into another 256 bytes, allowing all intrinsics to be encoded this way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156995 91177308-0d34-0410-b5e6-96231b3b80d8
are only rejected because they can't be encoded into a 32-bit unit, not because
they contain an unencodable feature.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156978 91177308-0d34-0410-b5e6-96231b3b80d8
TableGen already computes register units as the basic unit of
interference. We can use that to compute the set of overlapping
registers.
This means that we can easily compute overlap sets for one register at a
time. There is no benefit to computing all registers at once.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156960 91177308-0d34-0410-b5e6-96231b3b80d8
generated code (for Intrinsic::getType) into a table. This handles common cases right now,
but I plan to extend it to handle all cases and merge in type verification logic as well
in follow-on patches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156905 91177308-0d34-0410-b5e6-96231b3b80d8
Many targets always use the same bitwise encoding value for physical
registers in all (or most) instructions. Add this mapping to the
.td files and TableGen'erate the information and expose an accessor
in MCRegisterInfo.
patch by Tom Stellard.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156829 91177308-0d34-0410-b5e6-96231b3b80d8
Besides the weight, we also want to store up to two root registers per
unit. Most units will have a single root, the leaf register they
represent. Units created for ad hoc aliasing get two roots: The two
aliasing registers.
The root registers can be used to compute the set of overlapping
registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156792 91177308-0d34-0410-b5e6-96231b3b80d8
Register units can be used to compute if two registers overlap:
A overlaps B iff units(A) intersects units(B).
With this change, the above holds true even on targets that use ad hoc
aliasing (currently only ARM). This means that register units can be
used to implement regsOverlap() more efficiently, and the register
allocator can use the concept to model interference.
When there is no ad hoc aliasing, the register units correspond to the
maximal cliques in the register overlap graph. This is optimal, no other
register unit assignment can have fewer units.
With ad hoc aliasing, weird things are possible, and we don't try too
hard to compute the maximal cliques. The current approach is always
correct, and it works very well (probably optimally) as long as the ad
hoc aliasing doesn't have cliques larger than pairs. It seems unlikely
that any target would need more.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156763 91177308-0d34-0410-b5e6-96231b3b80d8
The ad hoc aliasing specified in the 'Aliases' list in .td files is
currently only used by computeOverlaps(). It will soon be needed to
build accurate register units as well, so build the undirected graph in
CodeGenRegister::buildObjectGraph() instead.
Aliasing is a symmetric relationship with only one direction specified
in the .td files. Make sure both directions are represented in
getExplicitAliases().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156762 91177308-0d34-0410-b5e6-96231b3b80d8
TableGen creates new register classes and sub-register indices based on
the sub-register structure present in the register bank. So far, it has
been doing that on a per-register basis, but that is not very efficient.
This patch teaches TableGen to compute topological signatures for
registers, and use that to reduce the amount of redundant computation.
Registers get the same TopoSig if they have identical sub-register
structure.
TopoSigs are not currently exposed outside TableGen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156761 91177308-0d34-0410-b5e6-96231b3b80d8
Don't compute the SuperRegs list until the sub-register graph is
completely finished. This guarantees that the list of super-registers is
properly topologically ordered, and has no duplicates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156629 91177308-0d34-0410-b5e6-96231b3b80d8
The sub-registers explicitly listed in SubRegs in the .td files form a
tree. In a complicated register bank, it is possible to have
sub-register relationships across sub-trees. For example, the ARM NEON
double vector Q0_Q1 is a tree:
Q0_Q1 = [Q0, Q1], Q0 = [D0, D1], Q1 = [D2, D3]
But we also define the DPair register D1_D2 = [D1, D2] which is fully
contained in Q0_Q1.
This patch teaches TableGen to find such sub-register relationships, and
assign sub-register indices to them. In the example, TableGen will
create a dsub_1_dsub_2 sub-register index, and add D1_D2 as a
sub-register of Q0_Q1.
This will eventually enable the coalescer to handle copies of skewed
sub-registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156587 91177308-0d34-0410-b5e6-96231b3b80d8
The .td files specify a tree of sub-registers. Store that tree as
ExplicitSubRegs lists in CodeGenRegister instead of extracting it from
the Record when needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156555 91177308-0d34-0410-b5e6-96231b3b80d8
This mapping is for internal use by TableGen. It will not be exposed in
the generated files.
Unfortunately, the mapping is not completely well-defined. The X86 xmm
registers appear with multiple sub-register indices in the ymm
registers. This is because of the odd idempotent sub_sd and sub_ss
sub-register indices. I hope to be able to eliminate them entirely, so
we can require the sub-registers to form a tree.
For now, just place the canonical sub_xmm index in the mapping, and
ignore the idempotents.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156519 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, if an instruction definition was missing the mnemonic,
the next line would just assert(). Issue a real diagnostic instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156263 91177308-0d34-0410-b5e6-96231b3b80d8
This is still a topological ordering such that every register class gets
a smaller enum value than its sub-classes.
Placing the smaller spill sizes first makes a difference for the
super-register class bit masks. When looking for a super-register class,
we usually want the smallest possible kind of super-register. That is
now available as the first bit set in the bit mask.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156222 91177308-0d34-0410-b5e6-96231b3b80d8
This manually enumerated list of super-register classes has been
superceeded by the automatically computed super-register class masks
available through SuperRegClassIterator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156151 91177308-0d34-0410-b5e6-96231b3b80d8
This is a pointer into one of the tables used by
getMatchingSuperRegClass(). It makes it possible to use a shared
implementation of that function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156121 91177308-0d34-0410-b5e6-96231b3b80d8
The RC->getSubClassMask() pointer now points to a sequence of register
class bit masks. The first bit mask is the normal sub-class mask. The
following masks are super-reg class masks used by
getMatchingSuperRegClass().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156120 91177308-0d34-0410-b5e6-96231b3b80d8
Many register classes only have a few super-registers, so it is not
necessary to keep individual bit masks for all possible sub-register
indices.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156083 91177308-0d34-0410-b5e6-96231b3b80d8
Some targets have no sub-registers at all. Use the TargetRegisterInfo
versions of composeSubRegIndices(), getSubClassWithSubReg(), and
getMatchingSuperRegClass() for those targets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156075 91177308-0d34-0410-b5e6-96231b3b80d8
When an instruction match is found, but the subtarget features it
requires are not available (missing floating point unit, or thumb vs arm
mode, for example), issue a diagnostic that identifies what the feature
mismatch is.
rdar://11257547
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155499 91177308-0d34-0410-b5e6-96231b3b80d8
Assembly matchers for instructions with a two-operand form. ARM is full
of these, for example:
add {Rd}, Rn, Rm // Rd is optional and is the same as Rn if omitted.
The property TwoOperandAliasConstraint on the instruction definition controls
when, and if, an alias will be formed. No explicit InstAlias definitions
are required.
rdar://11255754
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155172 91177308-0d34-0410-b5e6-96231b3b80d8
There's almost always a small number of instruction operands, so
use a SmallVector and save on heap allocations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155143 91177308-0d34-0410-b5e6-96231b3b80d8
Handle mixing allocatable and unallocatable register gracefully.
Simplify the pruning of register unit sets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154474 91177308-0d34-0410-b5e6-96231b3b80d8
This is a new algorithm that finds sets of register units that can be
used to model registers pressure. This handles arbitrary, overlapping
register classes. Each register class is associated with a (small)
list of pressure sets. These are the dimensions of pressure affected
by the register class's liveness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154374 91177308-0d34-0410-b5e6-96231b3b80d8
This is a new algorithm that associates registers with weighted
register units to accuretely model their effect on register
pressure. This handles registers with multiple overlapping
subregisters. It is possible, but almost inconceivable that the
algorithm fails to find an exact solution for a target description. If
an exact solution cannot be found, an inexact, but reasonable solution
will be chosen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154373 91177308-0d34-0410-b5e6-96231b3b80d8
