This reverts commit a496c8be6e638ae58bb45f13113dbe3a4b7b23fd.
The workaround in c26dfc81e254c78dc23579cf3d1336f77249e1f6 should work
around the underlying problem with SUBREG_TO_REG.
And dependent commits.
Details in D150388.
This reverts commit 825b7f0ca5f2211ec3c93139f98d1e24048c225c.
This reverts commit 7a98f084c4d121244ef7286bc6503b6a181d446e.
This reverts commit b4a62b1fa546312d882fa12dfdcd015177d66826.
This reverts commit b7836d856206ec39509d42529f958c920368166b.
No conflicts in the code, few tests had conflicts in autogenerated CHECKs:
llvm/test/CodeGen/Thumb2/mve-float32regloops.ll
llvm/test/CodeGen/AMDGPU/fix-frame-reg-in-custom-csr-spills.ll
Reviewed By: alexfh
Differential Revision: https://reviews.llvm.org/D156381
Noticed by inspection of
b7836d856206ec39509d42529f958c920368166b. This was checking if the
first instruction was a copy, not the current MI. It should fully
respect the isCopyInstr result. Hopefully this fixes a reported
regression which we can extract a test from.
Replacing D143754. Right now the LiveRangeSplitting during register allocation uses
TargetOpcode::COPY instruction for splitting. For AMDGPU target that creates a
problem as we have both vector and scalar copies. Vector copies perform a copy over
a vector register but only on the lanes(threads) that are active. This is mostly sufficient
however we do run into cases when we have to copy the entire vector register and
not just active lane data. One major place where we need that is live range splitting.
Allowing targets to use their own copy instructions(if defined) will provide a lot of
flexibility and ease to lower these pseudo instructions to correct MIR.
- Introduce getTargetCopyOpcode() virtual function and use if to generate copy in Live range
splitting.
- Replace necessary MI.isCopy() checks with TII.isCopyInstr() in register allocator pipeline.
Reviewed By: arsenm, cdevadas, kparzysz
Differential Revision: https://reviews.llvm.org/D150388
This was looking for full copies produced by SplitKit, but SplitKit
introduces copy bundles if not all lanes are live. The scan for uses
needs to look at bundles, not individual instructions.
This is a prerequisite to avoiding some redundant spills due to
subregisters which will help avoid an allocation failure in a future
patch.
This change initializes the members TSI, LI, DT, PSI, and ORE pointer feilds of the SelectOptimize class to nullptr.
Reviewed By: LuoYuanke
Differential Revision: https://reviews.llvm.org/D148303
Snippet is a tiny live interval which has copy or fill like def
and copy or spill like use at the end (any of them might abcent).
Snippet has only one use/def inside interval and interval is located
in one basic block.
When inline spiller spills some reg around uses it also forces the
spilling of connected snippets those which got by splitting the
same original reg and its def is a full copy of our reg or its
last use is a full copy to our reg.
The definition of snippet is extended to allow not only one use/def
but more. However all other uses are statepoint instructions which will
fold fill into its operand. That way we do not introduce new fills/spills.
Reviewed By: qcolombet, dantrushin
Differential Revision: https://reviews.llvm.org/D138093
With D134950, targets get notified when a virtual register is created and/or
cloned. Targets can do the needful with the delegate callback. AMDGPU propagates
the virtual register flags maintained in the target file itself. They are useful
to identify a certain type of machine operands while inserting spill stores and
reloads. Since RegAllocFast spills the physical register itself, there is no way
its virtual register can be mapped back to retrieve the flags. It can be solved
by passing the virtual register as an additional argument. This argument has no
use when the spill interfaces are called during the greedy allocator or even the
PrologEpilogInserter and can pass a null register in such cases.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138656
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This was stored in LiveIntervals, but not actually used for anything
related to LiveIntervals. It was only used in one check for if a load
instruction is rematerializable. I also don't think this was entirely
correct, since it was implicitly assuming constant loads are also
dereferenceable.
Remove this and rely only on the invariant+dereferenceable flags in
the memory operand. Set the flag based on the AA query upfront. This
should have the same net benefit, but has the possible disadvantage of
making this AA query nonlazy.
Preserve the behavior of assuming pointsToConstantMemory implying
dereferenceable for now, but maybe this should be changed.
This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169
During register allocation, some instructions can have stack spills fused
into them. It means that when vregs are allocated on the stack we can
convert:
SETCCr %0
DBG_VALUE %0
to
SETCCm %stack.0
DBG_VALUE %stack.0
Unfortunately instruction referencing finds this harder: a store to the
stack doesn't have a specific operand number, therefore we don't substitute
the old operand for a new operand, and the location is dropped. This patch
implements a solution: just recognise the memory operand attached to an
instruction with a Special Number (TM), and record a substitution between
the old value and the new one.
This patch adds substitution code to InlineSpiller to record such fused
spills, and tracking in InstrRefBasedLDV to recognise such values, and
produce the value numbers for them. Everything to do with the movement of
stack-defined values is already handled in InstrRefBasedLDV.
Differential Revision: https://reviews.llvm.org/D111317
statepoint instruction uses tied-def registers to represent live gc value which
is use and def at the same time on a call.
At the same time invoke statepoint instruction is a last split point which can throw and
jump to landing pad.
As a result we have instructon which is last split point with tied-defs registers and
we need to teach Greedy RA to work with it.
The option -use-registers-for-gc-values-in-landing-pad controls whether statepoint lowering
will generate tied-defs for invoke statepoint and is off by default now.
To resolve all issues the following changes has been done.
1) Last Split point for invoke statepoint should be statepoint itself
If statepoint has a def it is a relocated gc pointer and it should be available in landing pad.
So we cannot split interval after statepoint at end of basic block.
2) Do not split interval on tied-def
If end of interval for overlap utility is a use which has tied-def we
should not split interval on this instruction due to in this case use
and def may have different registers and it breaks tied-def property.
3) Take into account Last Split Point for enterIntvAtEnd
If the use after Last Split Point is a def so it should be tied-def and
we can take the def of the tied-use as ParentVNI and thus
tied-use and tied-def will be live in resulting interval.
4) Handle the case when def is after LIP in InlineSpiller
If def of LI is after last insertion point of basic block we cannot hoist in this BB.
The example of such instruction is invoke statepoint where def represents the
relocated live gc pointer. Invoke is a last insertion point and its def is located after it.
In this case there is no place to insert spill and we bail out.
5) Fix removeBackCopies to account empty copies
RegAssignMap cannot hold empty interval, so do not set stop
to kill value if it produces empty interval.
This can happen if we remove back-copy and right before that we have another
back-copy.
For example, for parent %0 we can get
%1 = COPY %0
%2 = COPY %0
while we removing %2 we cannot set kill for %1 due to its empty.
6) Do not hoist copy to BB if its def is after LSP
If the parent def is a LastSplitPoint or later we cannot hoist copy to this basic block
because inserted copy (or re-materialization) will be located before the def.
All parts have been reviewed separately as follows:
https://reviews.llvm.org/D100747https://reviews.llvm.org/D100748https://reviews.llvm.org/D100750https://reviews.llvm.org/D100927https://reviews.llvm.org/D100945https://reviews.llvm.org/D101028
Reviewers: reames, rnk, void, MatzeB, wmi, qcolombet
Reviewed By: reames, qcolombet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D101150
This is mostly NFC except that for end of BB not previous slot is used.
Idx is used to find a def of sibling live interval in that slot.
The def on end of MBB and on previous slot of end MBB should be the same,
so it should be NFC.
Reviewers: reames, qcolombet, MatzeB, wmi, rnk
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D100922
This patch adds handling for DBG_VALUE_LIST in the MIR-passes (after
finalize-isel), excluding the debug liveness passes and DWARF emission. This
most significantly affects MachineSink, which now needs to consider all used
registers of a debug value when sinking, but for most passes this change is
simply replacing getDebugOperand(0) with an iteration over all debug operands.
Differential Revision: https://reviews.llvm.org/D92578
This patch adds a new instruction that can represent variadic debug values,
DBG_VALUE_VAR. This patch alone covers the addition of the instruction and a set
of basic code changes in MachineInstr and a few adjacent areas, but does not
correctly handle variadic debug values outside of these areas, nor does it
generate them at any point.
The new instruction is similar to the existing DBG_VALUE instruction, with the
following differences: the operands are in a different order, any number of
values may be used in the instruction following the Variable and Expression
operands (these are referred to in code as “debug operands”) and are indexed
from 0 so that getDebugOperand(X) == getOperand(X+2), and the Expression in a
DBG_VALUE_VAR must use the DW_OP_LLVM_arg operator to pass arguments into the
expression.
The new DW_OP_LLVM_arg operator is only valid in expressions appearing in a
DBG_VALUE_VAR; it takes a single argument and pushes the debug operand at the
index given by the argument onto the Expression stack. For example the
sub-expression `DW_OP_LLVM_arg, 0` has the meaning “Push the debug operand at
index 0 onto the expression stack.”
Differential Revision: https://reviews.llvm.org/D82363
VirtRegAuxInfo is an extensibility point, so the register allocator's
decision on which implementation to use should be communicated to the
other users - namely, LiveRangeEdit.
Differential Revision: https://reviews.llvm.org/D96898
This is a additional bug fix for c5be0e0cc0. The distance for
the spill instructions is wrong in previous patch.
Differential Revision: https://reviews.llvm.org/D94772
InlineSpiller::foldMemoryOperand unties registers before an attempt to fold and
does not restore tied-ness in case of failure.
I do not have a particular test for demo of invalid behavior.
This is something of clean-up.
It is better to keep the behavior correct in case some time in future it happens.
Reviewers: reames, dantrushin
Reviewed By: dantrushin, reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D94389
Change [x86] Fix tile register spill issue was causing problems for our build
using gcc-5.4.1
The problem was caused by this line:
for (const MachineInstr &MI : make_range(MIS.begin(), MI))
where MI was previously defined as a MachineBasicBlock iterator.
Differential Revision: https://reviews.llvm.org/D94415
The tile register spill need 2 instructions.
%46:gr64_nosp = MOV64ri 64
TILESTORED %stack.2, 1, killed %46:gr64_nosp, 0, $noreg, %43:tile
The first instruction load the stride to a GPR, and the second
instruction store tile register to stack slot. The optimization of merge
spill instruction is done after register allocation. And spill tile
register need create a new virtual register to for stride, so we can't
hoist tile spill instruction in postOptimization() of register
allocation. We can't hoist TILESTORED alone and we can't hoist the 2
instuctions together because MOV64ri will clobber some GPR. This patch
is to disble the spill merge for any spill which need 2 instructions.
Differential Revision: https://reviews.llvm.org/D93898
This patch implements amx programming model that discussed in llvm-dev
(http://lists.llvm.org/pipermail/llvm-dev/2020-August/144302.html).
Thank Hal for the good suggestion in the RA. The fast RA is not in the patch yet.
This patch implemeted 7 components.
1. The c interface to end user.
2. The AMX intrinsics in LLVM IR.
3. Transform load/store <256 x i32> to AMX intrinsics or split the
type into two <128 x i32>.
4. The Lowering from AMX intrinsics to AMX pseudo instruction.
5. Insert psuedo ldtilecfg and build the def-use between ldtilecfg to amx
intruction.
6. The register allocation for tile register.
7. Morph AMX pseudo instruction to AMX real instruction.
Change-Id: I935e1080916ffcb72af54c2c83faa8b2e97d5cb0
Differential Revision: https://reviews.llvm.org/D87981
Also renamed the fields to follow style guidelines.
Accessors help with readability - weight mutation, in particular,
is easier to follow this way.
Differential Revision: https://reviews.llvm.org/D87725
Implement proper folding of statepoint meta operands (deopt and GC)
when statepoint uses tied registers.
For deopt operands it is just about properly preserving tiedness
in new instruction.
For tied GC operands folding is a little bit more tricky.
We can fold tied GC operands only from InlineSpiller, because it knows
how to properly reload tied def after it was turned into memory operand.
Other users (e.g. peephole) cannot properly fold such operands as they
do not know how (or when) to reload them from memory.
We do this by un-tieing operand we want to fold in InlineSpiller
and allowing to fold only untied operands in foldPatchpoint.
Summary:
Avoid exposing details about how children are stored. This will enable
subsequent type-erasure changes.
New methods are introduced to cover common access patterns.
Change-Id: Idb5f4b1b9c84e4cc71ddb39bb52a388682f5674f
Reviewers: arsenm, RKSimon, mehdi_amini, courbet
Subscribers: qcolombet, sdardis, wdng, hiraditya, jrtc27, zzheng, atanasyan, asbirlea, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83083
It's pretty silly to diagnose on a scalar copy but the build does that:
loop variable 'SibReg' of type 'const llvm::Register' creates a copy from type 'const llvm::Register' [-Wrange-loop-analysis]
Summary:
This invariant is being violated in the test case
https://reviews.llvm.org/D77849, related to the use of the relatively
new ability for callbr to have return values, and MachineBasicBlocks
with INLINEASM_BR terminators to emit live out register defs.
As noted in the comment, this triggers invariant violations in
MachineVerifier via `llc -verify-machineinstrs` or
`llc -verify-regalloc`, since only MachineInstrs that are terminators
are allowed to follow the first terminator.
https://reviews.llvm.org/D75098 may rework this very assertion if we're
spilling via a (proposed) TCOPY MachineInstr.
Reviewers: void, efriedma, arsenm
Reviewed By: efriedma
Subscribers: qcolombet, wdng, hiraditya, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78166
Summary:
The repeated use of std::next() on a MachineBasicBlock::iterator was
clever, but we only need to reconstruct the iterator post creation of
the spill instruction.
This helps simplifying where we plan to place the spill, as discussed in
D77849.
From here, we can simplify the code a little by flipping the return code
of a helper.
Reviewers: efriedma
Reviewed By: efriedma
Subscribers: qcolombet, hiraditya, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78520
Summary:
Refactor LiveRangeCalc such that it is now split into two classes
The objective is to split all the "register specific" logic away
from LiveRangeCalc.
The two new classes created are:
- LiveRangeCalc - is meant as a generic class to compute and modify
live ranges in a generic way. This class should deal only with
SlotIndices and VNInfo objects.
- LiveIntervalCals - is meant to be equivalent to the old LiveRangeCalc.
It computes the liveness virtual registers tracked by a LiveInterval
object.
With this refactoring LiveRangeCalc can be used to implement tracking of
liveness of LiveRanges that represent other things than just registers.
Subscribers: MatzeB, qcolombet, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76584
