flexible.
If it returns a register class that's different from the input, then that's the
register class used for cross-register class copies.
If it returns a register class that's the same as the input, then no cross-
register class copies are needed (normal copies would do).
If it returns null, then it's not at all possible to copy registers of the
specified register class.
llvm-svn: 127368
regs. This is the only change in this checkin that may affects the
default scheduler. With better register tracking and heuristics, it
doesn't make sense to artificially lower the register limit so much.
Added -sched-high-latency-cycles and X86InstrInfo::isHighLatencyDef to
give the scheduler a way to account for div and sqrt on targets that
don't have an itinerary. It is currently defaults to 10 (the actual
number doesn't matter much), but only takes effect on non-default
schedulers: list-hybrid and list-ilp.
Added several heuristics that can be individually disabled for the
non-default sched=list-ilp mode. This helps us determine how much
better we can do on a given benchmark than the default
scheduler. Certain compute intensive loops run much faster in this
mode with the right set of heuristics, and it doesn't seem to have
much negative impact elsewhere. Not all of the heuristics are needed,
but we still need to experiment to decide which should be disabled by
default for sched=list-ilp.
llvm-svn: 127067
A major part of its (eventual) goal is to support a much cleaner separation between disassembly callbacks
provided by the target and the disassembler emitter itself, i.e. not requiring hardcoding of knowledge in tblgen
like the existing disassembly emitters do.
The hope is that some day this will allow us to replace the existing non-Thumb ARM disassembler and remove
some of the hacks the old one introduced to tblgen.
llvm-svn: 125966
query about available library functions. For now this just has
memset_pattern16, which exists on darwin, but it can be extended for a
bunch of other things in the future.
llvm-svn: 125965
Motivation: Improve the parsing of not usual (different from registers or
immediates) operand forms.
This commit implements only the generic support. The ARM specific modifications
will come next.
A table like the one below is autogenerated for every instruction
containing a 'ParserMethod' in its AsmOperandClass
static const OperandMatchEntry OperandMatchTable[20] = {
/* Mnemonic, Operand List Mask, Operand Class, Features */
{ "cdp", 29 /* 0, 2, 3, 4 */, MCK_Coproc, Feature_IsThumb|Feature_HasV6 },
{ "cdp", 58 /* 1, 3, 4, 5 */, MCK_Coproc, Feature_IsARM },
A matcher function very similar (but lot more naive) to
MatchInstructionImpl scans the table. After the mnemonic match, the
features are checked and if the "to be parsed" operand index is
present in the mask, there's a real match. Then, a switch like the one
below dispatch the parsing to the custom method provided in
'ParseMethod':
case MCK_Coproc:
return TryParseCoprocessorOperandName(Operands);
llvm-svn: 125030
the load, then it may be legal to transform the load and store to integer
load and store of the same width.
This is done if the target specified the transformation as profitable. e.g.
On arm, this can transform:
vldr.32 s0, []
vstr.32 s0, []
to
ldr r12, []
str r12, []
rdar://8944252
llvm-svn: 124708
default implementation for x86, going through the stack in a similr
fashion to how the codegen implements BUILD_VECTOR. Eventually this
will get matched to VINSERTF128 if AVX is available.
llvm-svn: 124307
implementation of EXTRACT_SUBVECTOR for x86, going through the stack
in a similr fashion to how the codegen implements BUILD_VECTOR.
Eventually this will get matched to VEXTRACTF128 if AVX is available.
llvm-svn: 124292
This will be used to check patterns referencing a forthcoming
INSERT_SUBVECTOR SDNode and will also be used to check
EXTRACT_SUBVECTOR nodes.
llvm-svn: 124191
flags. They are still not enable in this revision.
Added TargetInstrInfo::isZeroCost() to fix a fundamental problem with
the scheduler's model of operand latency in the selection DAG.
Generalized unit tests to work with sched-cycles.
llvm-svn: 123969
TargetInstrInfo:
Change produceSameValue() to take MachineRegisterInfo as an optional argument.
When in SSA form, targets can use it to make more aggressive equality analysis.
Machine LICM:
1. Eliminate isLoadFromConstantMemory, use MI.isInvariantLoad instead.
2. Fix a bug which prevent CSE of instructions which are not re-materializable.
3. Use improved form of produceSameValue.
ARM:
1. Teach ARM produceSameValue to look pass some PIC labels.
2. Look for operands from different loads of different constant pool entries
which have same values.
3. Re-implement PIC GA materialization using movw + movt. Combine the pair with
a "add pc" or "ldr [pc]" to form pseudo instructions. This makes it possible
to re-materialize the instruction, allow machine LICM to hoist the set of
instructions out of the loop and make it possible to CSE them. It's a bit
hacky, but it significantly improve code quality.
4. Some minor bug fixes as well.
With the fixes, using movw + movt to materialize GAs significantly outperform the
load from constantpool method. 186.crafty and 255.vortex improved > 20%, 254.gap
and 176.gcc ~10%.
llvm-svn: 123905
Fix the TargetRegisterInfo::NoRegister places where someone preferred
typing 'TargetRegisterInfo::NoRegister' instead of typing '0'.
Note that TableGen is already emitting xx::NoRegister in xxGenRegisterNames.inc.
llvm-svn: 123140
The numbering plan is now:
0 NoRegister.
[1;2^30) Physical registers.
[2^30;2^31) Stack slots.
[2^31;2^32) Virtual registers. (With -1u and -2u used by DenseMapInfo.)
Each segment is filled from the left, so any mistaken interpretation should
quickly cause crashes.
FirstVirtualRegister has been removed. TargetRegisterInfo provides predicates
conversion functions that should be used instead of interpreting register
numbers manually.
It is now legal to pass NoRegister to isPhysicalRegister() and
isVirtualRegister(). The result is false in both cases.
It is quite rare to represent stack slots in this way, so isPhysicalRegister()
and isVirtualRegister() require that isStackSlot() be checked first if it can
possibly return true. This allows a very fast implementation of the common
predicates.
llvm-svn: 123137
physical register numbers.
This makes the hack used in LiveInterval official, and lets LiveInterval be
oblivious of stack slots.
The isPhysicalRegister() and isVirtualRegister() predicates don't know about
this, so when a variable may contain a stack slot, isStackSlot() should always
be tested first.
llvm-svn: 123128
Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.
llvm-svn: 123107
Provide MRI::getNumVirtRegs() and TRI::index2VirtReg() functions to allow
iteration over virtual registers without depending on the representation of
virtual register numbers.
llvm-svn: 123098
Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.
This allows memory instructions to be moved around INLINEASM instructions.
llvm-svn: 123044
Also fix an off-by-one in SelectionDAGBuilder that was preventing shuffle
vectors from being translated to EXTRACT_SUBVECTOR.
Patch by Tim Northover.
The test changes are needed to keep those spill-q tests from testing aligned
spills and restores. If the only aligned stack objects are spill slots, we
no longer realign the stack frame. Prior to this patch, an EXTRACT_SUBVECTOR
was legalized by loading from the stack, which created an aligned frame index.
Now, however, there is nothing except the spill slot in the stack frame, so
I added an aligned alloca.
llvm-svn: 122995
DAG scheduling during isel. Most new functionality is currently
guarded by -enable-sched-cycles and -enable-sched-hazard.
Added InstrItineraryData::IssueWidth field, currently derived from
ARM itineraries, but could be initialized differently on other targets.
Added ScheduleHazardRecognizer::MaxLookAhead to indicate whether it is
active, and if so how many cycles of state it holds.
Added SchedulingPriorityQueue::HasReadyFilter to allowing gating entry
into the scheduler's available queue.
ScoreboardHazardRecognizer now accesses the ScheduleDAG in order to
get information about it's SUnits, provides RecedeCycle for bottom-up
scheduling, correctly computes scoreboard depth, tracks IssueCount, and
considers potential stall cycles when checking for hazards.
ScheduleDAGRRList now models machine cycles and hazards (under
flags). It tracks MinAvailableCycle, drives the hazard recognizer and
priority queue's ready filter, manages a new PendingQueue, properly
accounts for stall cycles, etc.
llvm-svn: 122541
