These tables were indexed by [register][subreg index] which made them,
very large and sparse.
Replace them with lists of sub-register indexes that match the existing
lists of sub-registers. MCRI::getSubReg() becomes a very short linear
search, like getSubRegIndex() already was.
llvm-svn: 160843
Now that the weird X86 sub_ss and sub_sd sub-register indexes are gone,
there is no longer a need for the CompositeIndices construct in .td
files. Sub-register index composition can be specified on the
SubRegIndex itself using the ComposedOf field.
Also enforce unique names for sub-registers in TableGen. The same
sub-register cannot be available with multiple sub-register indexes.
llvm-svn: 160842
A standalone pattern defined in a multiclass expansion should handle
null_frag references just like patterns on instructions. Follow-up to
r160333.
llvm-svn: 160384
Define a 'null_frag' SDPatternOperator node, which if referenced in an
instruction Pattern, results in the pattern being collapsed to be as-if
'[]' had been specified instead. This allows supporting a multiclass
definition where some instaniations have ISel patterns associated and
others do not.
For example,
multiclass myMulti<RegisterClass rc, SDPatternOperator OpNode = null_frag> {
def _x : myI<(outs rc:), (ins rc:), []>;
def _r : myI<(outs rc:), (ins rc:), [(set rc:, (OpNode rc:))]>;
}
defm foo : myMulti<GRa, not>;
defm bar : myMulti<GRb>;
llvm-svn: 160333
Make sure the tblgen'erated asm matcher correctly returns numoperands+1
as the ErrorInfo when the problem was that there weren't enough operands
specified.
rdar://9142751
llvm-svn: 160144
subtarget CPU descriptions and support new features of
MachineScheduler.
MachineModel has three categories of data:
1) Basic properties for coarse grained instruction cost model.
2) Scheduler Read/Write resources for simple per-opcode and operand cost model (TBD).
3) Instruction itineraties for detailed per-cycle reservation tables.
These will all live side-by-side. Any subtarget can use any
combination of them. Instruction itineraries will not change in the
near term. In the long run, I expect them to only be relevant for
in-order VLIW machines that have complex contraints and require a
precise scheduling/bundling model. Once itineraries are only actively
used by VLIW-ish targets, they could be replaced by something more
appropriate for those targets.
This tablegen backend rewrite sets things up for introducing
MachineModel type #2: per opcode/operand cost model.
llvm-svn: 159891
The TargetInstrInfo::getNumMicroOps API does not change, but soon it
will be used by MachineScheduler. Now each subtarget can specify the
number of micro-ops per itinerary class. For ARM, this is currently
always dynamic (-1), because it is used for load/store multiple which
depends on the number of register operands.
Zero is now a valid number of micro-ops. This can be used for
nop pseudo-instructions or instructions that the hardware can squash
during dispatch.
llvm-svn: 159406
When generating selection tables for Pat instances, TableGen relied on
an output Instruction's Pattern field being set to infer whether a
chain should be added.
This patch adds additional logic to check various flag fields so that
correct code can be generated even if Pattern is unset.
llvm-svn: 159217
"Invalid operand" may be a completely correct diagnostic, but it's often
insufficiently specific to really help identify and fix the problem in
assembly source. Allow a target to specify a more-specific diagnostic kind
for each AsmOperandClass derived definition and use that to provide
more detailed diagnostics when an operant of that class resulted in a
match failure.
rdar://8987109
llvm-svn: 159050
Original commit message:
Allow up to 64 functional units per processor itinerary.
This patch changes the type used to hold the FU bitset from unsigned to uint64_t.
This will be needed for some upcoming PowerPC itineraries.
llvm-svn: 159027
This makes it explicit when ScoreboardHazardRecognizer will be used.
"GenericItineraries" would only make sense if it contained real
itinerary values and still required ScoreboardHazardRecognizer.
llvm-svn: 158963
This patch changes the type used to hold the FU bitset from unsigned to uint64_t.
This will be needed for some upcoming PowerPC itineraries.
llvm-svn: 158679
When returning a 'cannot match due to missing CPU features' error code,
if there are multiple potential matches with different feature sets,
return the smallest set of missing features from the alternatives as
that's most likely to be the one that's desired.
llvm-svn: 158673
LLVM is now -Wunused-private-field clean except for
- lib/MC/MCDisassembler/Disassembler.h. Not sure why it keeps all those unaccessible fields.
- gtest.
llvm-svn: 158096
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.
llvm-svn: 158090
This allows a subtarget to explicitly specify the issue width and
other properties without providing pipeline stage details for every
instruction.
llvm-svn: 157979
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.
llvm-svn: 157753
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.
llvm-svn: 157650
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.
llvm-svn: 157634
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
llvm-svn: 157545
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.
llvm-svn: 156995
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.
llvm-svn: 156960
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.
llvm-svn: 156905
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.
llvm-svn: 156829
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.
llvm-svn: 156792
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.
llvm-svn: 156763
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().
llvm-svn: 156762
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.
llvm-svn: 156761
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.
llvm-svn: 156629
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.
llvm-svn: 156587
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.
llvm-svn: 156555
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.
llvm-svn: 156519
Previously, if an instruction definition was missing the mnemonic,
the next line would just assert(). Issue a real diagnostic instead.
llvm-svn: 156263
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.
llvm-svn: 156222
This manually enumerated list of super-register classes has been
superceeded by the automatically computed super-register class masks
available through SuperRegClassIterator.
llvm-svn: 156151
This is a pointer into one of the tables used by
getMatchingSuperRegClass(). It makes it possible to use a shared
implementation of that function.
llvm-svn: 156121
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().
llvm-svn: 156120
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.
llvm-svn: 156083
Some targets have no sub-registers at all. Use the TargetRegisterInfo
versions of composeSubRegIndices(), getSubClassWithSubReg(), and
getMatchingSuperRegClass() for those targets.
llvm-svn: 156075
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
llvm-svn: 155499
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
llvm-svn: 155172
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.
llvm-svn: 154374
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.
llvm-svn: 154373
This also avoids emitting the information twice, which led to code bloat. On i386-linux-Release+Asserts
with all targets built this change shaves a whopping 1.3 MB off clang. The number is probably exaggerated
by recent inliner changes but the methods were already enormous with the old inline cost computation.
The DWARF reg -> LLVM reg mapping doesn't seem to have holes in it, so it could be a simple lookup table.
I didn't implement that optimization yet to avoid potentially changing functionality.
There is still some duplication both in tablegen and the generated code that should be cleaned up eventually.
llvm-svn: 153837
First small step toward modeling multi-register multi-pressure. In the
future, register units can also be used to model liveness and
aliasing.
llvm-svn: 153794
Use an explicit comparator instead of the default.
The sets are sorted, but not using the default comparator. Hopefully,
this will unbreak the Linux builders.
llvm-svn: 153772
TableGen emits lists of sub-registers, super-registers, and overlaps. Put
them all in a single table and use a SequenceToOffsetTable to share
suffixes.
llvm-svn: 153761
This is similar to the StringToOffsetTable we use to produce string
tables, but it can be used for other sequences than strings, and it
eliminates entries for suffixes.
llvm-svn: 153760
The arm_neon intrinsics can create virtual registers from the DPair
register class which allows both even-odd and odd-even D-register pairs.
This fixes PR12389.
llvm-svn: 153603
We cannot limit the concatenated instruction names to 64K. ARM is
already at 32K, and it is easy to imagine a target with more
instructions.
llvm-svn: 152817
This patch limited the concatenated register names to 64K which meant
that the total number of registers was many times less than 64K.
If any compilers actually enforce the 64K limit on string literals, and
it turns out to be a problem, we should fix that problem by not using
long string literals.
llvm-svn: 152816
~0U might be i32 on 32-bit hosts, then (uint64_t)~0U might not be expected as (i64)0xFFFFFFFF_FFFFFFFF, but as (i64)0x00000000_FFFFFFFF.
llvm-svn: 152407
Original commit message:
Use uint16_t to store InstrNameIndices in MCInstrInfo. Add asserts to protect all 16-bit string table offsets. Also make sure the string to offset table string is not larger than 65536 characters since larger string literals aren't portable.
llvm-svn: 152296
Original commit message:
Use uint16_t to store InstrNameIndices in MCInstrInfo. Add asserts to protect
all 16-bit string table offsets. Also make sure the string to offset table
string is not larger than 65536 characters since larger string literals aren't
portable.
llvm-svn: 152233
With the new composite physical registers to represent arbitrary pairs
of DPR registers, we don't need the pseudo-registers anymore. Get rid of
a bunch of them that use DPR register pairs and just use the real
instructions directly instead.
llvm-svn: 152045
- Shrink the opcode field to 16 bits.
- Shrink the AsmVariantID field to 8 bits.
- Store the mnemonic string in a string table, store a 16 bit index.
- Store a pascal-style length byte in the string instead of a null terminator,
so we can avoid calling strlen on every entry we visit during mnemonic search.
Shrinks X86AsmParser.o from 434k to 201k on x86_64 and eliminates relocs from the table.
llvm-svn: 151984
Allows us to de-virtualize the function and provides access to it in
the instruction printer, which is useful for handling composite
physical registers (e.g., ARM register lists).
llvm-svn: 151815
This reverts commit 151760.
We want to move getSubReg() from TargetRegisterInfo into MCRegisterInfo,
but to do that, the type of the lookup table needs to be the same for
all targets.
llvm-svn: 151814
This allows us to make TRC non-polymorphic and value-initializable, eliminating a huge static
initializer and a ton of cruft from the generated code.
Shrinks ARMBaseRegisterInfo.o by ~100k.
llvm-svn: 151806
- The search bounds are constant, in the worst case (ARM target) it will scan over 30 uint16_ts.
- This method isn't very hot, I had problems finding a testcase where it's called more than a dozen of times (no perf impact).
llvm-svn: 151773
Instead of nested switch statements, use a lookup table. On ARM, this replaces
a 23k (x86_64 release build) function with a 16k table. Its not unlikely to
be faster, as well.
llvm-svn: 151751
This requires some gymnastics to make it available for C code. Remove the names
from the disassembler tables, making them relocation free.
llvm-svn: 150303
Make them accessible through MCInstrInfo. They are only used for debugging purposes so this doesn't
have an impact on performance. X86MCTargetDesc.o goes from 630K to 461K on x86_64.
llvm-svn: 150245
When adding the {-1, -1} entry to the DFAStateInputTable, we
need to increment the index used to populate the DFAStateEntryTable.
Otherwise, the entry table will be off by one for each transition
after the {-1, -1} entry. PR11908.
llvm-svn: 149713
It is simpler to define a composite index directly:
def ssub_2 : SubRegIndex<[dsub_1, ssub_0]>;
def ssub_3 : SubRegIndex<[dsub_1, ssub_1]>;
Than specifying the composite indices on each register:
CompositeIndices = [(ssub_2 dsub_1, ssub_0),
(ssub_3 dsub_1, ssub_1)] in ...
This also makes it clear that SubRegIndex composition is supposed to be
unique.
llvm-svn: 149556
The final tie breaker comparison also needs to return +/-1, or 0.
This is not a less() function.
This could cause otherwise identical super-classes to be ordered
unstably, depending on what the system qsort routine does with a bad
compare function.
llvm-svn: 149549
This class is used to represent SubRegIndex instances instead of the raw
Record pointers that were used before.
No functional change intended.
llvm-svn: 149418
When set, this bit indicates that a register is completely defined by
the value of its sub-registers.
Use the CoveredBySubRegs property to infer which super-registers are
call-preserved given a list of callee-saved registers. For example, the
ARM registers D8-D15 are callee-saved. This now automatically implies
that Q4-Q7 are call-preserved.
Conversely, Win64 callees save XMM6-XMM15, but the corresponding
YMM6-YMM15 registers are not call-preserved because they are not fully
defined by their sub-registers.
llvm-svn: 148363
Targets can now add CalleeSavedRegs defs to their *CallingConv.td file.
TableGen will use this to create a *_SaveList array suitable for
returning from getCalleeSavedRegs() as well as a *_RegMask bit mask
suitable for returning from getCallPreservedMask().
llvm-svn: 148346
(This time I believe I've checked all the -Wreturn-type warnings from GCC & added the couple of llvm_unreachables necessary to silence them. If I've missed any, I'll happily fix them as soon as I know about them)
llvm-svn: 148262
Craig Topper