The series of patches leading up to this one makes llc -O0 run 8% faster.
When deallocating a MachineFunction, there is no need to visit all
MachineInstr and MachineOperand objects to deallocate them. All their
memory come from a BumpPtrAllocator that is about to be purged, and they
have empty destructors anyway.
This only applies when deallocating the MachineFunction.
DeleteMachineInstr() should still be used to recycle MI memory during
the codegen passes.
Remove the LeakDetector support for MachineInstr. I've never seen it
used before, and now it definitely doesn't work. With this patch, leaked
MachineInstrs would be much less of a problem since all of their memory
will be reclaimed by ~MachineFunction().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171599 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of an std::vector<MachineOperand>, use MachineOperand arrays
from an ArrayRecycler living in MachineFunction.
This has several advantages:
- MachineInstr now has a trivial destructor, making it possible to
delete them in batches when destroying MachineFunction. This will be
enabled in a later patch.
- Bypassing malloc() and free() can be faster, depending on the system
library.
- MachineInstr objects and their operands are allocated from the same
BumpPtrAllocator, so they will usually be next to each other in
memory, providing better locality of reference.
- Reduce MachineInstr footprint. A std::vector is 24 bytes, the new
operand array representation only uses 8+4+1 bytes in MachineInstr.
- Better control over operand array reallocations. In the old
representation, the use-def chains would be reordered whenever a
std::vector reached its capacity. The new implementation never changes
the use-def chain order.
Note that some decisions in the code generator depend on the use-def
chain orders, so this patch may cause different assembly to be produced
in a few cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171598 91177308-0d34-0410-b5e6-96231b3b80d8
This function works like memmove() for MachineOperands, except it also
updates any use-def chains containing the moved operands.
The use-def chains are updated without affecting the order of operands
in the list. That isn't possible when using the
removeRegOperandFromUseList() and addRegOperandToUseList() functions.
Callers to follow soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171597 91177308-0d34-0410-b5e6-96231b3b80d8
This is similar to the existing Recycler allocator, but instead of
recycling individual objects from a BumpPtrAllocator, arrays of
different sizes can be allocated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171581 91177308-0d34-0410-b5e6-96231b3b80d8
A BumpPtrAllocator has an empty Deallocate() method, but
Recycler::clear() would still call it for every single object ever
allocated, bringing all those objects into cache. As a bonus,
iplist::remove() will also write to the Prev/Next pointers on all the
objects, so all those cache lines have to be written back to RAM before
the pages are given back to the OS.
Stop wasting time and memory bandwith by using the new
clearAndLeakUnsafely() function to jettison all the recycled objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171541 91177308-0d34-0410-b5e6-96231b3b80d8
The iplist::clear() function can be quite expensive because it traverses
the entire list, calling deleteNode() and removeNodeFromList() on each
element. If node destruction and deallocation can be handled some other
way, clearAndLeakNodesUnsafely() can be used to jettison all nodes
without bringing them into cache.
The function name is meant to be ominous.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171540 91177308-0d34-0410-b5e6-96231b3b80d8
Most IMPLICIT_DEF instructions are removed by the ProcessImplicitDefs
pass, and a few are reinserted by PHIElimination when a PHI argument is
<undef>.
RegisterCoalescer was assuming that all IMPLICIT_DEF live ranges look
like those created by PHIElimination, and that their live range never
leaves the basic block.
The PR14732 test case does tricks with PHI nodes that causes a longer
IMPLICIT_DEF live range to appear. This happens very rarely, but
RegisterCoalescer should be able to handle it.
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Back when this exception was added, it was skipping a lot more code, but
now it just looks like a premature optimization.
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The representation of the Operands array is going to change soon so it
can be allocated from a BumpPtrAllocator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170988 91177308-0d34-0410-b5e6-96231b3b80d8
Instructions that are inserted in a basic block can still be decorated
with addOperand(MO).
Make the two-argument addOperand() function contain the actual
implementation. This function will now always have a valid MF reference
that it can use for memory allocation.
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This function is often used to decorate dangling instructions, so a
context reference is required to allocate memory for the operands.
Also add a corresponding MachineInstrBuilder method.
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This is supposed to be a mechanical change with no functional effects.
InstrEmitter can generate all types of MachineOperands which revealed
that MachineInstrBuilder was missing a few methods, added by this patch.
Besides providing a context pointer to MI::addOperand(),
MachineInstrBuilder seems like a better fit for this code.
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Use the version that also takes an MF reference instead.
It would technically be possible to extract an MF reference from the MI
as MI->getParent()->getParent(), but that would not work for MIs that
are not inserted into any basic block.
Given the reasonably small number of places this constructor was used at
all, I preferred the compile time check to a run time assertion.
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Just like for addMemOperand(), the function pointer provides a context
for allocating memory. This will make it possible to use a better memory
allocation strategy for the MI operand list, which is currently a slow
std::vector.
Most calls to addOperand() come from MachineInstrBuilder, so give that
class an MF reference as well. Code using BuildMI() won't need changing
at all since the MF reference is already required to allocate a
MachineInstr.
Future patches will fix code that calls MI::addOperand(Op) directly, as
well as code that uses the now deprecated MachineInstrBuilder(MI)
constructor.
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The bundle flags are now maintained by the slightly higher-level
functions bundleWithPred() / bundleWithSucc() which enforce consistent
bundle flags between neighboring instructions.
See also MIBundleBuilder for an even higher-level approach to building
bundles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170475 91177308-0d34-0410-b5e6-96231b3b80d8
The bundle_iterator::operator++ function now doesn't need to dig out the
basic block and check against end(). It can use the isBundledWithSucc()
flag to find the last bundled instruction safely.
Similarly, MachineInstr::isBundled() no longer needs to look at
iterators etc. It only has to look at flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170473 91177308-0d34-0410-b5e6-96231b3b80d8
Now that the bundle flag aware APIs are all in place, it is possible to
continuously verify the flag consistency.
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The new bidirectional bundle flags are redundant, so inadvertent bundle
tearing can be detected in the machine code verifier.
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The bundle-related MI flags need to be kept in sync with the neighboring
instructions. Don't allow the bulk flag-setting setFlags() function to
change them.
Also don't copy MI flags when cloning an instruction. The clone's bundle
flags will be set when it is explicitly inserted into a bundle.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170459 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the instr_iterator versions of the splice() functions. It doesn't
seem useful to be able to splice sequences of instructions that don't
consist of full bundles.
The normal splice functions that take MBB::iterator arguments are not
changed, and they can move whole bundles around without any problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170456 91177308-0d34-0410-b5e6-96231b3b80d8
The single-element ilist::splice() function supports a noop move:
List.splice(I, List, I);
The corresponding std::list function doesn't allow that, so add a unit
test to document that behavior.
This also means that
List.splice(I, List, F);
is somewhat surprisingly not equivalent to
List.splice(I, List, F, next(F));
This patch adds an assertion to catch the illegal case I == F above.
Alternatively, we could make I == F a legal noop, but that would make
ilist differ even more from std::list.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170443 91177308-0d34-0410-b5e6-96231b3b80d8
The normal insert() function takes an MBB::iterator position, and
inserts a stand-alone MachineInstr as before.
The insert() function that takes an MBB::instr_iterator position can
insert instructions inside a bundle, and will now update the bundle
flags correctly when that happens.
When the insert position is between two bundles, it is unclear whether
the instruction should be appended to the previous bundle, prepended to
the next bundle, or stand on its own. The MBB::insert() function doesn't
bundle the instruction in that case, use the MIBundleBuilder class for
that.
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instruction.
This isn't strictly necessary at the moment because Thumb2SizeReduction
also copies all MI flags from the old instruction to the new. However, a
future patch will make that kind of direct flag tampering illegal.
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Most code is oblivious to bundles and uses the MBB::iterator which only
visits whole bundles. MBB::erase() operates on whole bundles at a time
as before.
MBB::remove() now refuses to remove bundled instructions. It is not safe
to remove all instructions in a bundle without deleting them since there
is no way of returning pointers to all the removed instructions.
MBB::remove_instr() and MBB::erase_instr() will now update bundle flags
correctly, lifting individual instructions out of bundles while leaving
the remaining bundle intact.
The MachineInstr convenience functions are updated so
eraseFromParent() erases a whole bundle as before
eraseFromBundle() erases a single instruction, leaving the rest of its bundle.
removeFromParent() refuses to operate on bundled instructions, and
removeFromBundle() lifts a single instruction out of its bundle.
These functions will no longer accidentally split or coalesce bundles -
bundle flags are updated to preserve the existing bundling, and explicit
bundleWith* / unbundleFrom* functions should be used to change the
instruction bundling.
This API update is still a work in progress. I am going to update APIs
first so they maintain bundle flags automatically when possible. Then
I'll add stricter verification of the bundle flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170384 91177308-0d34-0410-b5e6-96231b3b80d8
The new API is higher level than just manipulating the bundle flags
directly, and the setIsInsideBundle() function will disappear soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170159 91177308-0d34-0410-b5e6-96231b3b80d8
Also add an MIBundleBuilder constructor that takes an existing bundle.
Together these functions make it possible to add instructions to
existing bundles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170063 91177308-0d34-0410-b5e6-96231b3b80d8
This is still a work in progress. The purpose is to make bundling and
unbundling operations explicit, and to catch errors where bundles are
broken or created inadvertently.
The old IsInsideBundle flag is replaced by two MI flags: BundledPred
which has the same meaning as IsInsideBundle, and BundledSucc which is
set on instructions that are bundled with a successor. Having two flags
provdes redundancy to detect when a bundle is inadvertently torn by a
splice() or insert(), and it makes it possible to write bundle iterators
that don't need to peek at adjacent instructions.
The new flags can't be manipulated directly (once setIsInsideBundle is
gone). Instead there are MI functions to make and break bundle bonds.
The setIsInsideBundle function will be removed in a future commit. It
should be replaced by bundleWithPred().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169583 91177308-0d34-0410-b5e6-96231b3b80d8
A MachineInstr can only ever be constructed by CreateMachineInstr() and
CloneMachineInstr(), and those factories don't use the removed
constructors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169395 91177308-0d34-0410-b5e6-96231b3b80d8
These functions have been replaced by TRI::getRegAllocationHints() which
provides the same capabilities.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169192 91177308-0d34-0410-b5e6-96231b3b80d8
Now that there can be multiple hint registers from targets, it doesn't
make sense to have a function that returns 'the' preferred register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169190 91177308-0d34-0410-b5e6-96231b3b80d8
Targets can provide multiple hints now, so getRegAllocPref() doesn't
make sense any longer because it only returns one preferred register.
Replace it with getSimpleHint() in the remaining heuristics. This
function only
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169188 91177308-0d34-0410-b5e6-96231b3b80d8
Virtual registers with a known preferred register are prioritized by
RAGreedy. This function makes the condition explicit without depending
on getRegAllocPref().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169179 91177308-0d34-0410-b5e6-96231b3b80d8
This simplifies the hinting code quite a bit while making the targets
easier to write at the same time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169173 91177308-0d34-0410-b5e6-96231b3b80d8
This provides the same functionality as getRawAllocationOrder() for the
even/odd hints, but without the many constant register arrays.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169169 91177308-0d34-0410-b5e6-96231b3b80d8
The TargetRegisterInfo::getRegAllocationHints() function is going to
replace the existing mechanisms for providing target-dependent hints to
the register allocator: ResolveRegAllocHint() and
getRawAllocationOrder().
The new hook is more flexible because it allows the target to provide
multiple preferred candidate registers for each virtual register, and it
is easier to use because targets are not required to return a reference
to a constant array like getRawAllocationOrder().
An optional VirtRegMap argument can be used to provide target-dependent
hints that depend on the provisional assignments of other virtual
registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169154 91177308-0d34-0410-b5e6-96231b3b80d8
The TwoAddressInstructionPass takes the machine code out of SSA form by
expanding REG_SEQUENCE instructions into copies. It is no longer
necessary to rewrite the registers used by a REG_SEQUENCE instruction
because the new coalescer algorithm can do it now.
REG_SEQUENCE is just converted to a sequence of sub-register copies now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169067 91177308-0d34-0410-b5e6-96231b3b80d8
MachineCopyPropagation doesn't understand super-register liveness well
enough to be able to remove implicit defs of super-registers.
This fixes a problem in ARM/2012-01-26-CopyPropKills.ll that is exposed
by an future TwoAddressInstructionPass change. The KILL instructions are
removed before the machine code is emitted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169060 91177308-0d34-0410-b5e6-96231b3b80d8
This causes llc to repeat the module compilation N times, making it
possible to get more accurate information from -time-passes when
compiling small modules.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169040 91177308-0d34-0410-b5e6-96231b3b80d8
This avoids unidentified duplicates in the pass execution time report
when a pass runs more than once in the pass manager pipeline.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169039 91177308-0d34-0410-b5e6-96231b3b80d8
This could cause miscompilations in targets where sub-register
composition is not always idempotent (ARM).
<rdar://problem/12758887>
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No functional change, just moved header files.
Targets can inject custom passes between register allocation and
rewriting. This makes it possible to tweak the register allocation
before rewriting, using the full global interference checking available
from LiveRegMatrix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168806 91177308-0d34-0410-b5e6-96231b3b80d8
The Target library is not allowed to depend on the large CodeGen
library, but the TRI and TII classes provide abstract interfaces that
require both caller and callee to link to CodeGen.
The implementation files for these classes provide default
implementations of some of the hooks. These methods may need to
reference CodeGen, so they belong in that library.
We already have a number of methods implemented in the
TargetInstrInfoImpl sub-class because of that. I will merge that class
into the parent next.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168758 91177308-0d34-0410-b5e6-96231b3b80d8
The RegMaskSlots contains 'r' slots while NewIdx and OldIdx are 'B'
slots. This broke the checks in the assertions.
This fixes PR14302.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167625 91177308-0d34-0410-b5e6-96231b3b80d8
Explicitly allow composition of null sub-register indices, and handle
that common case in an inlinable stub.
Use a compressed table implementation instead of the previous nested
switches which generated pretty bad code.
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Partial copies can show up even when CoalescerPair.isPartial() returns
false. For example:
%vreg24:dsub_0<def> = COPY %vreg31:dsub_0; QPR:%vreg24,%vreg31
Such a partial-partial copy is not good enough for the transformation
adjustCopiesBackFrom() needs to do.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166944 91177308-0d34-0410-b5e6-96231b3b80d8
Keep the integer_insertelement test case, the new coalescer can handle
this kind of lane insertion without help from pseudo-instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166835 91177308-0d34-0410-b5e6-96231b3b80d8
Some instructions in ARM require 2 even-odd paired GPRs. This
patch adds support for such register class.
Patch by Weiming Zhao!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166816 91177308-0d34-0410-b5e6-96231b3b80d8
The isValueEqualityComparison() guard at the top of SimplifySwitch()
only applies to some of the possible transformations.
The newer transformations work just fine on large switches, and the
check on predecessor count is nonsensical.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166710 91177308-0d34-0410-b5e6-96231b3b80d8
This is a more compact, less redundant representation, and it avoids
scanning long lists of aliases for ARM D-registers, for example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166124 91177308-0d34-0410-b5e6-96231b3b80d8
All callers of these functions really want the isPhysRegOrOverlapUsed()
functionality which also checks aliases. For historical reasons, targets
without register aliases were calling isPhysRegUsed() instead.
Change isPhysRegUsed() to also check aliases, and switch all
isPhysRegOrOverlapUsed() callers to isPhysRegUsed().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166117 91177308-0d34-0410-b5e6-96231b3b80d8
The previous MRI.isPhysRegUsed(YMM0) would also return true when the
function contains a call to a function that may clobber YMM0. That's
most of them.
Checking the use-def chains allows us to skip functions that don't
explicitly mention YMM registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166110 91177308-0d34-0410-b5e6-96231b3b80d8
This is just as fast, and it makes it possible to avoid leaking the
UsedPhysRegs BitVector implementation through
MachineRegisterInfo::addPhysRegsUsed().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166083 91177308-0d34-0410-b5e6-96231b3b80d8
PR14098 contains an example where we would rematerialize a MOV8ri
immediately after the original instruction:
%vreg7:sub_8bit<def> = MOV8ri 9; GR32_ABCD:%vreg7
%vreg22:sub_8bit<def> = MOV8ri 9; GR32_ABCD:%vreg7
Besides being pointless, it is also wrong since the original instruction
only redefines part of the register, and the value read by the new
instruction is wrong.
The problem was the LiveRangeEdit::allUsesAvailableAt() didn't
special-case OrigIdx == UseIdx and found the wrong SSA value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166068 91177308-0d34-0410-b5e6-96231b3b80d8
Using the cached bit vector in MRI avoids comstantly allocating and
recomputing the reserved register bit vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165983 91177308-0d34-0410-b5e6-96231b3b80d8
Also provide an MRI::getReservedRegs() function to access the frozen
register set, and isReserved() and isAllocatable() methods to test
individual registers.
The various implementations of TRI::getReservedRegs() are quite
complicated, and many passes need to look at the reserved register set.
This patch makes it possible for these passes to use the cached copy in
MRI, avoiding a lot of malloc traffic and repeated calculations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165982 91177308-0d34-0410-b5e6-96231b3b80d8
The new coalescer can merge a dead def into an unused lane of an
otherwise live vector register.
Clear the <dead> flag when that happens since the flag refers to the
full virtual register which is still live after the partial dead def.
This fixes PR14079.
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It is possible that the live range of the value being pruned loops back
into the kill MBB where the search started. When that happens, make sure
that the beginning of KillMBB is also pruned.
Instead of starting a DFS at KillMBB and skipping the root of the
search, start a DFS at each KillMBB successor, and allow the search to
loop back to KillMBB.
This fixes PR14078.
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Completely update one interval at a time instead of collecting live
range fragments to be updated. This avoids building data structures,
except for a single SmallPtrSet of updated intervals.
Also share code between handleMove() and handleMoveIntoBundle().
Add support for moving dead defs across other live values in the
interval. The MI scheduler can do that.
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PHIElimination inserts IMPLICIT_DEF instructions to guarantee that all
PHI predecessors have a live-out value. These IMPLICIT_DEF values are
not considered to be real interference when coalescing virtual
registers:
%vreg1 = IMPLICIT_DEF
%vreg2 = MOV32r0
When joining %vreg1 and %vreg2, the IMPLICIT_DEF instruction and its
value number should simply be erased since the %vreg2 value number now
provides a live-out value for the PHI predecesor block.
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Not all instructions define a virtual register in their first operand.
Specifically, INLINEASM has a different format.
<rdar://problem/12472811>
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When the CFG contains a loop with multiple entry blocks, the traces
computed by MachineTraceMetrics don't always have the same nice
properties. Loop back-edges are normally excluded from traces, but
MachineLoopInfo doesn't recognize loops with multiple entry blocks, so
those back-edges may be included.
Avoid asserting when that happens by adding an isEarlierInSameTrace()
function that accurately determines if a dominating block is part of the
same trace AND is above the currrent block in the trace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165434 91177308-0d34-0410-b5e6-96231b3b80d8
Enable the pass by default for targets that request it, and change the
-enable-early-ifcvt to the opposite -disable-early-ifcvt.
There are still some x86 regressions when enabling early if-conversion
because of the missing machine models. Disable the pass for x86 until
machine models are added.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165075 91177308-0d34-0410-b5e6-96231b3b80d8
