All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Summary:
The associated debug value is updated when the virtual source register
of a copy is completely eliminated and replaced with a rematerialize
value in the defed register of the copy. As the debug value now is
associated with another register it also need to be moved, otherwise
the debug value isn't valid.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: MatzeB, llvm-commits, qcolombet
Differential Revision: https://reviews.llvm.org/D38024
llvm-svn: 317880
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.
llvm-svn: 317647
Summary:
The comments in the code said
// Remove <def,read-undef> flags. This def is now a partial redef.
but the code didn't just remove read-undef, it could introduce new ones which
could cause errors.
E.g. if we have something like
%vreg1<def> = IMPLICIT_DEF
%vreg2:subreg1<def, read-undef> = op %vreg3, %vreg4
%vreg2:subreg2<def> = op %vreg6, %vreg7
and we merge %vreg1 and %vreg2 then we should not set undef on the second subreg
def, which the old code did.
Now we solve this by actually do what the code comment says. We remove
read-undef flags rather than remove or introduce them.
Reviewers: qcolombet, MatzeB
Reviewed By: MatzeB
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38616
llvm-svn: 315564
Implement shouldCoalesce() to help regalloc avoid running out of GR128
registers.
If a COPY involving a subreg of a GR128 is coalesced, the live range of the
GR128 virtual register will be extended. If this happens where there are
enough phys-reg clobbers present, regalloc will run out of registers (if
there is not a single GR128 allocatable register available).
This patch tries to allow coalescing only when it can prove that this will be
safe by checking the (local) interval in question.
Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D37899https://bugs.llvm.org/show_bug.cgi?id=34610
llvm-svn: 314516
Summary:
To delete an instruction the coalescer needs to call eraseFromParent()
on the MachineInstr, insert it in the ErasedInstrs list and update the
Live Ranges structure. This patch re-factors the code to do all that in
one function. This will also fix cases where previous code wasn't
inserting deleted instructions in the ErasedList.
Reviewers: qcolombet, kparzysz
Reviewed By: qcolombet
Subscribers: MatzeB, llvm-commits, qcolombet
Differential Revision: https://reviews.llvm.org/D36204
llvm-svn: 309915
Summary:
During remat, some subranges might end up having invalid segments which caused problems for later
coalescing.
Added in a check to remove segments that are invalidated as part of the remat.
See http://llvm.org/PR33524
Subscribers: MatzeB, qcolombet
Differential Revision: https://reviews.llvm.org/D34391
llvm-svn: 307247
Summary:
removePartialRedundency optimization introduces a state in the
RegisterCoalescer where an instruction pointed to in the WorkList
is deleted from the MBB and then removed from the ErasedList.
This patch updates the ErasedList to be used globally by not erasing
erased Instructions from it to solve the problem.
The patch also accounts for the case where an Instruction was previously
deleted and the same memory was reused by BuildMI to create a new instruction.
Reviewers: kparzysz, qcolombet
Reviewed By: qcolombet
Subscribers: MatzeB, qcolombet, llvm-commits
Differential Revision: https://reviews.llvm.org/D34902
llvm-svn: 306915
pruneSubRegValues() needs to remove subregister ranges starting at
instructions that later get removed by eraseInstrs(). It missed to check
one case in which eraseInstrs() would remove an instruction.
Fixes http://llvm.org/PR32688
llvm-svn: 303396
joinReservedPhysReg() can only deal with a liverange in a single basic
block when copying from a vreg into a physreg.
See also rdar://30306405
Differential Revision: https://reviews.llvm.org/D29436
llvm-svn: 294268
An assert occurs when calling SlotIndexes::getInstructionIndex with
a DBG_VALUE instruction because the function expects an instruction
with a slot index. However, there is no slot index for a DBG_VALUE
instruction.
Differential Revision: https://reviews.llvm.org/D29048
llvm-svn: 294070
In r292621, the recommit fixes a bug related with live interval update
after the partial redundent copy is moved.
This recommit solves an additional bug related to the lack of update of
subranges.
The original patch is to solve the performance problem described in
PR27827. Register coalescing sometimes cannot remove a copy because of
interference. But if we can find a reverse copy in one of the predecessor
block of the copy, the copy is partially redundent and we may remove the
copy partially by moving it to the predecessor block without the
reverse copy.
Differential Revision: https://reviews.llvm.org/D28585
Re-apply r292621
Revert "Revert rL292621. Caused some internal build bot failures in apple."
This reverts commit r292984.
Original patch: Wei Mi <wmi@google.com>
Subrange fix: Mostly Matthias Braun <matze@braunis.de>
llvm-svn: 293353
The recommit fixes a bug related with live interval update after the partial
redundent copy is moved.
The original patch is to solve the performance problem described in PR27827.
Register coalescing sometimes cannot remove a copy because of interference.
But if we can find a reverse copy in one of the predecessor block of the copy,
the copy is partially redundent and we may remove the copy partially by moving
it to the predecessor block without the reverse copy.
Differential Revision: https://reviews.llvm.org/D28585
llvm-svn: 292621
The patch is to solve the performance problem described in PR27827.
Register coalescing sometimes cannot remove a copy because of interference.
But if we can find a reverse copy in one of the predecessor block of the copy,
the copy is partially redundent and we may remove the copy partially by moving
it to the predecessor block without the reverse copy.
Differential Revision: https://reviews.llvm.org/D28585
llvm-svn: 292292
reserved physreg in RegisterCoalescer.
Previously, we only checked for clobbers when merging into a READ of
the physreg, but not when merging from a WRITE to the physreg.
Differential Revision: https://reviews.llvm.org/D28527
llvm-svn: 291942
Specifically avoid implicit conversions from/to integral types to
avoid potential errors when changing the underlying type. For example,
a typical initialization of a "full" mask was "LaneMask = ~0u", which
would result in a value of 0x00000000FFFFFFFF if the type was extended
to uint64_t.
Differential Revision: https://reviews.llvm.org/D27454
llvm-svn: 289820
The coalescer eliminates copies from reserved registers of the form:
%vregX = COPY %rY
in the case where %rY is a reserved register. However this turns out to
be invalid if only some of the subregisters are reserved (see also
https://reviews.llvm.org/D26648).
Differential Revision: https://reviews.llvm.org/D26687
llvm-svn: 288428
When copying to/from a constant register interferences can be ignored.
Also update the documentation for isConstantPhysReg() to make it more
obvious that this transformation is valid.
Differential Revision: https://reviews.llvm.org/D26106
llvm-svn: 286503
The register allocator can split a live interval of a register into a set
of smaller intervals. After the allocation of registers is complete, the
rewriter will modify the IR to replace virtual registers with the corres-
ponding physical registers. At this stage, if a register corresponding
to a subregister of a virtual register is used, the rewriter will check
if that subregister is undefined, and if so, it will add the <undef> flag
to the machine operand. The function verifying liveness of the subregis-
ter would assume that it is undefined, unless any of the subranges of the
live interval proves otherwise.
The problem is that the live intervals created during splitting do not
have any subranges, even if the original parent interval did. This could
result in the <undef> flag placed on a register that is actually defined.
Differential Revision: http://reviews.llvm.org/D21189
llvm-svn: 279625
This is mostly a mechanical change to make TargetInstrInfo API take
MachineInstr& (instead of MachineInstr* or MachineBasicBlock::iterator)
when the argument is expected to be a valid MachineInstr. This is a
general API improvement.
Although it would be possible to do this one function at a time, that
would demand a quadratic amount of churn since many of these functions
call each other. Instead I've done everything as a block and just
updated what was necessary.
This is mostly mechanical fixes: adding and removing `*` and `&`
operators. The only non-mechanical change is to split
ARMBaseInstrInfo::getOperandLatencyImpl out from
ARMBaseInstrInfo::getOperandLatency. Previously, the latter took a
`MachineInstr*` which it updated to the instruction bundle leader; now,
the latter calls the former either with the same `MachineInstr&` or the
bundle leader.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
Note: I updated WebAssembly, Lanai, and AVR (despite being
off-by-default) since it turned out to be easy. I couldn't run tests
for AVR since llc doesn't link with it turned on.
llvm-svn: 274189
This fixes a use-after-free introduced 3 years ago, in r182872 ;)
The code more or less worked because the memory that CopyMI was
pointing to happened to still be valid, but lots of tests would crash
if you ran under ASAN with the recycling allocator changes from
llvm.org/PR26808
llvm-svn: 264455
Rematerializing and merging into a bigger register class at the same
time, requires the subregister range lanemasks getting remapped to the
new register class.
This fixes http://llvm.org/PR26805
llvm-svn: 262768
copy coalescing with enabled subregister liveness can reveal undef uses,
previously this was only checked for the SrcReg in updateRegDefsUses()
but we need to check DstReg as well.
llvm-svn: 262767
Take MachineInstr by reference instead of by pointer in SlotIndexes and
the SlotIndex wrappers in LiveIntervals. The MachineInstrs here are
never null, so this cleans up the API a bit. It also incidentally
removes a few implicit conversions from MachineInstrBundleIterator to
MachineInstr* (see PR26753).
At a couple of call sites it was convenient to convert to a range-based
for loop over MachineBasicBlock::instr_begin/instr_end, so I added
MachineBasicBlock::instrs.
llvm-svn: 262115
The register coalescer can rematerialize constants that define
more of a register than the copy it is going to replace was going
to do.
This is valid in the case the register was undef before the
copy happened.
This patch makes sure that all the subranges defined by the new
rematerialization instructions have at least a dead def.
Review: http://reviews.llvm.org/D16693
llvm-svn: 259614
When rematerializing a computation by replacing the copy, use the copy's
location. The location of the copy is more representative of the
original program.
This partially fixes PR10003.
llvm-svn: 259469
Allowing imprecise lane masks in case of more than 32 sub register lanes
lead to some tricky corner cases, and I need another bugfix for another
one. Instead I rather declare lane masks as precise and let tablegen
abort if we do not have enough bits.
This does not affect any in-tree target, even AMDGPU only needs 16 lanes
at the moment. If the 32 lanes turn out to be a problem in the future,
then we can easily change the LaneBitmask typedef to uint64_t.
Differential Revision: http://reviews.llvm.org/D14557
llvm-svn: 253279
