Previously, instructions without a primary patterns wouldn't get their
properties inferred. Now, we use all single-instruction patterns for
inference, including 'def : Pat<>' instances.
This causes a lot of instruction flags to change.
- Many instructions no longer have the UnmodeledSideEffects flag because
their flags are now inferred from a pattern.
- Instructions with intrinsics will get a mayStore flag if they already
have UnmodeledSideEffects and a mayLoad flag if they already have
mayStore. This is because intrinsics properties are linear.
- Instructions with atomic_load patterns get a mayStore flag because
atomic loads can't be reordered. The correct workaround is to create
pseudo-instructions instead of using normal loads. PR13693.
llvm-svn: 162614
Instructions are now only marked as variadic if they use variable_ops in
their ins list.
A variadic SDNode is typically used for call nodes that have the call
arguments as operands.
A variadic MachineInstr can actually encode a variable number of
operands, for example ARM's stm/ldm instructions. A call instruction
does not have to be variadic. The call argument registers are added as
implicit operands.
This change remove the MCID::Variadic flags from most call and return
instructions, allowing us to better verify their operands.
llvm-svn: 162599
It is now allowed to explicitly set hasSideEffects, mayStore, and
mayLoad on instructions with patterns.
Verify that the patterns are consistent with the explicit flags.
llvm-svn: 162569
Emit TableGen errors if guessInstructionProperties is 0 and
instruction properties can't be inferred from patterns.
Allow explicit instruction properties even when they can be inferred.
This patch doesn't change the TableGen output. Redundant properties
are not yet verified because the tree has errors.
llvm-svn: 162516
Currently, TableGen just guesses instruction properties when it can't
infer them form patterns.
This adds a guessInstructionProperties flag to the instruction set
definition that will be used to disable guessing. The flag is intended
as a migration aid. It will be removed again when no more targets need
their properties guessed.
llvm-svn: 162460
When reporting an error for a defm, we would previously only report the
location of the outer defm, which is not always where the error is.
Now we also print the location of the expanded multiclass defs:
lib/Target/X86/X86InstrSSE.td:2902:12: error: foo
defm ADD : basic_sse12_fp_binop_s<0x58, "add", fadd, SSE_ALU_ITINS_S>,
^
lib/Target/X86/X86InstrSSE.td:2801:11: note: instantiated from multiclass
defm PD : sse12_fp_packed<opc, !strconcat(OpcodeStr, "pd"), OpNode, VR128,
^
lib/Target/X86/X86InstrSSE.td:194:5: note: instantiated from multiclass
def rm : PI<opc, MRMSrcMem, (outs RC:$dst), (ins RC:$src1, x86memop:$src2),
^
llvm-svn: 162409
No change in interface or functionality. Purely under-the-hood
details of the generated function that change.
The X86 assembly parser is reduced in size by over 15% and ARM by
over 10%.
No performance change by my measurements.
llvm-svn: 162337
Select instructions pick one of two virtual registers based on a
condition, like x86 cmov. On targets like ARM that support predication,
selects can sometimes be eliminated by predicating the instruction
defining one of the operands.
Teach PeepholeOptimizer to recognize select instructions, and ask the
target to optimize them.
llvm-svn: 162059
TableGen sometimes synthesizes missing sub-register indexes. Emit these
indexes as enumerators in the target namespace along with the
user-defined ones.
Also take this opportunity to stop creating new Record objects for
synthetic indexes.
llvm-svn: 161964
Refactor the TableGen'erated fixed length disassemblmer to use a
table-driven state machine rather than a massive set of nested
switch() statements.
As a result, the ARM Disassembler (ARMDisassembler.cpp) builds much more
quickly and generates a smaller end result. For a Release+Asserts build on
a 16GB 3.4GHz i7 iMac w/ SSD:
Time to compile at -O2 (averaged w/ hot caches):
Previous: 35.5s
New: 8.9s
TEXT size:
Previous: 447,251
New: 297,661
Builds in 25% of the time previously required and generates code 66% of
the size.
Execution time of the disassembler is only slightly slower (7% disassembling
10 million ARM instructions, 19.6s vs 21.0s). The new implementation has
not yet been tuned, however, so the performance should almost certainly
be recoverable should it become a concern.
llvm-svn: 161888
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
Jakob Stoklund Olesen