[[Change-Id:
Ic349022bb99ef91f5396e462ade0366bc772ae02](https://github.com/llvm/llvm-project/pull/123531)](https://github.com/llvm/llvm-project/pull/123531)
moved isDead() from DeadMachineInstrElim to MachineInstr . In the
process of moving, I reordered the checks to improve chances of early
exit, but this has caused a slight increase in compile time.
This PR reverts back to the original order of checks.
Provide isDead interface for access to ad-hoc isDead queries.
LivePhysRegs is optional: if not provided, pessimistically check
deadness of a single MI without doing the LivePhysReg walk; if provided
it is assumed to be at the position of MI.
Once we get to SelectionDAG the IR should not be changing anymore, so we
can use BatchAAResults rather than AAResults to cache AA queries.
This should be a NFC change for targets that enable AA during codegen
(such as AArch64), but also give a nice compile-time improvement in some
cases. See:
https://github.com/llvm/llvm-project/pull/123787#issuecomment-2606797041
Note: This follows Nikita's suggestion on #123787.
Fixes the "use after poison" issue introduced by #121516 (see
<https://github.com/llvm/llvm-project/pull/121516#issuecomment-2585912395>).
The root cause of this issue is that #121516 introduced "Called Global"
information for call instructions modeling how "Call Site" info is
stored in the machine function, HOWEVER it didn't copy the
copy/move/erase operations for call site information.
The fix is to rename and update the existing copy/move/erase functions
so they also take care of Called Global info.
Currently LLVMContext::emitError emits any error as an "inline asm"
error which does not make any sense. InlineAsm appears to be special,
in that it uses a "LocCookie" from srcloc metadata, which looks like
a parallel mechanism to ordinary source line locations. This meant
that other types of failures had degraded source information reported
when available.
Introduce some new generic error types, and only use inline asm
in the appropriate contexts. The DiagnosticInfo types are still
a bit of a mess, and I'm not sure why DiagnosticInfoWithLocationBase
exists instead of just having an optional DiagnosticLocation in the
base class.
DK_Generic is for any error that derives from an IR level instruction,
and thus can pull debug locations directly from it. DK_GenericWithLoc
is functionally the generic codegen error, since it does not depend
on the IR and instead can construct a DiagnosticLocation from the
MI debug location.
Merge GlobalISel's isTriviallyDead and DeadMachineInstructionElim's
isDead code and remove all unnecessary checks from the hot path by
looping over the operands before doing any other checks.
See #105950 for why DeadMIElim needs to remove LIFETIME markers even
though they probably shouldn't generally be considered dead.
x86 CTMark O3: -0.1%
AArch64 GlobalISel CTMark O0: -0.6%, O2: -0.2%
MachineFunction's probably should not include a backreference to
the owning MachineModuleInfo. Most of these references were used
just to query the MCContext, which MachineFunction already directly
stores. Other contexts are using it to query the LLVMContext, which
can already be accessed through the IR function reference.
Fixes#82659
There are some functions, such as `findRegisterDefOperandIdx` and `findRegisterDefOperand`, that have too many default parameters. As a result, we have encountered some issues due to the lack of TRI parameters, as shown in issue #82411.
Following @RKSimon 's suggestion, this patch refactors 9 functions, including `{reads, kills, defines, modifies}Register`, `registerDefIsDead`, and `findRegister{UseOperandIdx, UseOperand, DefOperandIdx, DefOperand}`, adjusting the order of the TRI parameter and making it required. In addition, all the places that call these functions have also been updated correctly to ensure no additional impact.
After this, the caller of these functions should explicitly know whether to pass the `TargetRegisterInfo` or just a `nullptr`.
Remove getSizeOrUnknown call when MachineMemOperand is created. For Scalable
TypeSize, the MemoryType created becomes a scalable_vector.
2 MMOs that have scalable memory access can then use the updated BasicAA that
understands scalable LocationSize.
Original Patch by Harvin Iriawan
Co-authored-by: David Green <david.green@arm.com>
This is part of #70452 that changes the type used for the external
interface of MMO to LocationSize as opposed to uint64_t. This means the
constructors take LocationSize, and convert ~UINT64_C(0) to
LocationSize::beforeOrAfter(). The getSize methods return a
LocationSize.
This allows us to be more precise with unknown sizes, not accidentally
treating them as unsigned values, and in the future should allow us to
add proper scalable vector support but none of that is included in this
patch. It should mostly be an NFC.
Global ISel is still expected to use the underlying LLT as it needs, and
are not expected to see unknown sizes for generic operations. Most of
the changes are hopefully fairly mechanical, adding a lot of getValue()
calls and protecting them with hasValue() where needed.
This is a small part of #70452, attempting to take a small simpler part
of it in isolation to simplify what remains. It changes the getSpillSize,
getFoldedSpillSize, getRestoreSize and getFoldedRestoreSize methods to return
optional<LocationSize> instead of unsigned. The code is intended to be the
same, keeping the optional<> to specify when there was no size found, with some
minor adjustments to make sure that unknown (~UINT64_C(0)) sizes are handled
sensibly. Hopefully as more unsigned's are converted to LocationSize's the use
of ~UINT64_C(0) can be cleaned up too.
We were allowing extra immediate arguments, and only bothering to check
if registers were implicit or not.
Also consolidate extra operand checks in verifier, to make this
testable. We had 3 different places checking if you were trying to build
an instruction with more operands than allowed by the definition. We had
an assertion in addOperand, a direct check in the MIRParser to avoid the
assertion, and the machine verifier checks. Remove the assert and parser
check so the verifier can provide a consistent verification experience,
which will also handle instructions modified in place.
When using the inline asm constraint string "rm" (or "g"), we generally
would like the compiler to choose "r", but it is permitted to choose "m"
if there's register pressure. This is distinct from "r" in which the
register is not permitted to be spilled to the stack.
The decision of which to use must be made at some point. Currently, the
instruction selection frameworks (ISELs) make the choice, and the
register allocators had better be able to handle the result.
Steal a bit from Storage when using register operands to disambiguate
between the two cases. Add helpers/getters/setters, and print in MIR
when such a register is foldable.
The getter will later be used by the register allocation frameworks (and
asserted by the ISELs) while the setters will be used by the instruction
selection frameworks.
Link: https://github.com/llvm/llvm-project/issues/20571
As alluded to in #20571, it would be nice if we could mutate operand
lists of MachineInstr's more safely. Add an insert method that together
with removeOperand allows for easier splicing of operands.
Splitting this patch off early to get feedback; I need to either:
- mutate an INLINEASM{_BR} MachinInstr's MachineOperands from being
registers (physical or virtual) to memory
(MachineOperandType::MO_FrameIndex). These are not 1:1 operand
replacements, but N:M operand replacements. i.e. we need to
update 2 MachineOperands into the middle of the operand list to 5 (at
least for x86_64).
- copy, modify, write a new MachineInstr which has its relevant operands
replaced.
Either approaches are hazarded by existing references to either the
operands being moved, or the instruction being removed+replaced. For my
purposes in regalloc, either seem to work for me, so hopefully reviewers
can help me determine which approach is preferable. The second would
involve no new methods on MachineInstr.
One question I had while looking at this was: "why does MachineInstr
have BOTH a NumOperands member AND a MCInstrDesc member that itself has
a NumOperands member? How many operands can a MachineInstr have? Do I
need to update BOTH (keeping them in sync)?" FWICT, only "variadic"
MachineInstrs have MCInstrDesc with NumOperands (of the MCInstrDesc) set
to zero. If the MCInstrDesc's NumOperands is non-zero, then the
NumOperands
on the MachineInstr itself cannot exceed this value (IIUC) else an
assert will
be triggered.
For most non-psuedo instructions (or at least non-varidic instructions),
insert is less likely to be useful.
To run the newly added unittest:
$ pushd llvm/build; ninja CodeGenTests; popd
$ ./llvm/build/unittests/CodeGen/CodeGenTests \
--gtest_filter=MachineInstrTest.SpliceOperands
This is meant to mirror `MCInst::insert`.
Enable FoldImmediate for X86 by implementing X86InstrInfo::FoldImmediate.
Also enhanced peephole by deleting identical instructions after FoldImmediate.
Differential Revision: https://reviews.llvm.org/D151848
reland [InlineAsm] wrap ConstraintCode in enum class NFC (#66003)
This reverts commit ee643b706be2b6bef9980b25cc9cc988dab94bb5.
Fix up build failures in targets I missed in #66003
Kept as 3 commits for reviewers to see better what's changed. Will
squash when
merging.
- reland [InlineAsm] wrap ConstraintCode in enum class NFC (#66003)
- fix all the targets I missed in #66003
- fix off by one found by llvm/test/CodeGen/SystemZ/inline-asm-addr.ll
This reverts commit 2ca4d136124d151216aac77a0403dcb5c5835bcd.
Also revert the followup, "[InlineAsm] fix botched merge conflict resolution"
This reverts commit 8b9bf3a9f715ee5dce96eb1194441850c3663da1.
There were SystemZ and Mips build errors, too many to fix forward.
Similar to
commit 2fad6e69851e ("[InlineAsm] wrap Kind in enum class NFC")
Fix the TODOs added in
commit 93bd428742f9 ("[InlineAsm] refactor InlineAsm class NFC
(#65649)")
I would like to steal one of these bits to denote whether a kind may be
spilled by the register allocator or not, but I'm afraid to touch of any
this code using bitwise operands.
Make flags a first class type using bitfields, rather than launder data
around via `unsigned`.
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:
* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).
Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.
Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)
This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D149367
Should add some minor type safety to the use of this information, since
there's quite a bit of metadata being laundered through an `unsigned`.
I'm looking to potentially add more bitfields to that `unsigned`, but I
find InlineAsm's big ol' bag of enum values and usage of `unsigned`
confusing, type-unsafe, and un-ergonomic. These can probably be better
abstracted.
I think the lack of static_cast outside of InlineAsm indicates the prior
code smell fixed here.
Reviewed By: qcolombet
Differential Revision: https://reviews.llvm.org/D159242
This reverts commit 8d0c3db388143f4e058b5f513a70fd5d089d51c3.
Causes crashes, see comments in https://reviews.llvm.org/D149367.
Some follow-up fixes are also reverted:
This reverts commit 636269f4fca44693bfd787b0a37bb0328ffcc085.
This reverts commit 5966079cf4d4de0285004eef051784d0d9f7a3a6.
This reverts commit e7294dbc85d24a08c716d9babbe7f68390cf219b.
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:
* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).
Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.
Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)
This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D149367
MachineVerifier does not check that DBG_VALUE, DBG_VALUE_LIST and
DBG_INSTR_REF have the expected number of operands, so printing them
(e.g. with -print-after-all) should not crash.
Differential Revision: https://reviews.llvm.org/D156226
In https://reviews.llvm.org/D149445, it was lowered from 32 to 16bits, which
broke an internal project of ours. The relevant code being compiled is a fairly
large nested switch that results in a PHI node with 65k+ operands, which can't
easily be turned into a table for perf reasons.
This change unifies `NumOperands`, `Flags`, and `AsmPrinterFlags` into a packed
7-byte struct, which `CapOperands` can follow as the 8th byte, rounding it up
to a nice alignment before the `Info` field.
rdar://111217742&109362033
Differential revision: https://reviews.llvm.org/D153791
Sometimes an developer would like to have more control over cmov vs branch. We have unpredictable metadata in LLVM IR, but currently it is ignored by X86 backend. Propagate this metadata and avoid cmov->branch conversion in X86CmovConversion for cmov with this metadata.
Example:
```
int MaxIndex(int n, int *a) {
int t = 0;
for (int i = 1; i < n; i++) {
// cmov is converted to branch by X86CmovConversion
if (a[i] > a[t]) t = i;
}
return t;
}
int MaxIndex2(int n, int *a) {
int t = 0;
for (int i = 1; i < n; i++) {
// cmov is preserved
if (__builtin_unpredictable(a[i] > a[t])) t = i;
}
return t;
}
```
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D118118
Some metadata prettyprinting, including variable prettyprinting and
debug line info comments, is currently only supported for `DBG_VALUE`.
This allows `DBG_INSTR_REF` can be printed in the same way.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D150620
This is rework of;
- D30046 (LLT)
Since I have introduced `llvm-min-tblgen` as D146352, `llvm-tblgen`
may depend on `CodeGen`.
`LowLevlType.h` originally belonged to `CodeGen`. Almost all userse are
still under `CodeGen` or `Target`. I think `CodeGen` is the right place
to put `LowLevelType.h`.
`MachineValueType.h` may be moved as well. (later, D149024)
I have made many modules depend on `CodeGen`. It is consistent but
inefficient. It will be split out later, D148769
Besides, I had to isolate MVT and LLT in modmap, since
`llvm::PredicateInfo` clashes between `TableGen/CodeGenSchedule.h`
and `Transforms/Utils/PredicateInfo.h`.
(I think better to introduce namespace llvm::TableGen)
Depends on D145937, D146352, and D148768.
Differential Revision: https://reviews.llvm.org/D148767
