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.
Commit 1b531d54f623 (#74203) removed the usage of unique_ptrs of arrays
in favour of using vectors, but inadvertently increased peak memory
usage by removing the ability to deallocate vector memory that was no
longer needed mid-LDV.
In that same review, it was pointed out that `FuncValueTable` typedef
could be removed, since it was "just a vector".
This commit addresses both issues by making `FuncValueTable` a real data
structure, capable of mapping BBs to ValueTables and able to free
ValueTables as needed.
This reduces peak memory usage in the compiler by 10% in the benchmarks
flagged by the original review.
As a consequence, we had to remove a handful of instances of the
"declare-then-initialize" antipattern in unittests, as the
FuncValueTable class is no longer default-constructible.
These are usually difficult to reason about, and they were being used to
pass raw pointers around with array semantic (i.e., we were using
operator [] on raw pointers). To put it in InstrRef terminology: we were
passing a pointer to a ValueTable but using it as if it were a
FuncValueTable.
These could have easily been SmallVectors, which now allow us to have
reference semantics in some places, as well as simpler initialization.
In the future, we can use even more pass-by-reference with some extra
changes in the code.
This is a conservative workaround for broken liveness tracking of
SUBREG_TO_REG to speculatively fix all targets. The current reported
failures are on X86 only, but this issue should appear for all targets
that use SUBREG_TO_REG. The next minimally correct refinement would be
to disallow only implicit defs.
The coalescer now introduces implicit-defs of the super register to
track the dependency on other subregisters. If we see such an implicit
operand, we cannot simply treat the subregister def as the result
operand in case downstream users depend on the implicitly defined
parts. Really target implementations should be considering the
implicit defs and trying to interpret them appropriately (maybe with
some generic helpers). The full implicit def could possibly be
reported as the move result, rather than the subregister def but that
requires additional work.
Hopefully fixes#64060 as well.
This needs to be applied to the release branch.
https://reviews.llvm.org/D156346
Use big obj copy in range for-loop will call copy constructor every time,
which can be avoided by use ref instead.
Reviewed By: skan
Differential Revision: https://reviews.llvm.org/D150024
Fixes: https://github.com/llvm/llvm-project/issues/62725
This patch fixes an error in which a DBG_INSTR_REF referring to a DBG_PHI in a
block that is not directly reachable from the entry block results in a crash
during LiveDebugValues. Note that this fix prevents a crash from occurring, but
will give undef locations to users of these PHIs even if a valid location exists.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D150707
Looks like code assumes that it will be always set, but it's not true:
https://reviews.llvm.org/D150420. This is temporarily suppression to enabled
stricter msan on a bot.
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
With D68945, more DBG_VALUEs were created without the indirect operand,
instead relying on OP_deref to accomplish the same effect.
At the time, however, we were not able to handle arbitrary expressions
in combination with OP_LLVM_entry_value, so D71416 prevented the use of
such operation in the presence of expressions.
As per the comment in DIExpression::isValid, "we support only entry
values of a simple register location." As such, a simple deref operation
should be supported. In fact, D80345 added support for indirect
DBG_VALUEs.
Taken the patches above into consideration, this commit relaxes the
restrictions on which expressions are allowed for entry value
candidates: the expression must be either empty or a single dereference
operator.
This patch is useful for D141381, which adds support for storing the
address of ABI-indirect parameters on the stack.
Depends on D142160
Differential Revision: https://reviews.llvm.org/D142654
This adds the missing handling for defs for target index operands, as is
already done for registers.
There are two kinds of target indices: local indices and stack operands.
- Locals are something similar to registers in Wasm-land. For local
indices, we can check for local-defining instructions (`local.set` or
`local.tee`).
- Wasm is a stack machine, so we have values in certain Wasm value stack
location, which change when Wasm instructions produce or consume
values. So basically any value-producing instrucion, i.e., instruction
with defs, can change values in the Wasm stack. But I think we don't
need to worry about this here, because `WebAssemblyDebugFixup`, which
runs right before this analysis, makes sure to insert terminating
`DBG_VALUE $noreg` instructions whenever a stack value gets popped.
After `WebAssemblyDebugFixup`, there shouldn't be any `DBG_VALUE`s for
stack operands that don't have a terminating `DBG_VALUE $noreg` within
the same BB.
So this CL only works on `DBG_VALUE`s for locals. When we encounter a
`local.set` or `local.tee` instructions, we delete `DBG_VALUE`s for
those target index locations from the open range set, so they will not
be availble in `OutLocs`. For example,
```
bb.0:
successors: %bb.1
DBG_VALUE target-index(wasm-local) + 2, $noreg, "var", ...
...
local.set 2 ...
bb.1:
; predecessors: %bb.0
; We shouldn't add `DBG_VALUE target (wasm-local) + 2 here because
; it was killed by 'local.set' in bb.0
```
After disabling register coalescing at -O1, the average PC ranges
covered for Emscripten core benchmarks is currently 20.6% in the LLVM
tot. After applying D138943 and this CL, the coverage goes up to 57%.
This also enables LiveDebugValues analysis in the Wasm pipeline by
default.
Reviewed By: dschuff, jmorse
Differential Revision: https://reviews.llvm.org/D140373
This enables `LiveDebugValues` analysis for Wasm. `DBG_VALUE`s expire at
the end of a BB, and this is the analysis extends their lifetime when
possible, greatly increasing the coverage of variable debug info.
Specifically, this removes the current constraint that this analysis is
only used with physical registers, which was first introduced in D18421,
because Wasm uses only virtual registers. I don't think there's anything
inherent in this analysis that only applies to physical registers; it
was just because all targets using this analysis ran this at the end of
their compiliation pipeline, at which point all their vregs had been
allocated, and Wasm's debug info infrastructure was not really set up
yet, so it was not using it.
This adds supports to Wasm-specific target-index operands, defined in
2166d9529a/llvm/lib/Target/WebAssembly/WebAssembly.h (L87-L100).
Among these, `TI_LOCAL`, `TI_LOCAL_INDIRECT`, and `TI_OPERAND_STACK` are
used by Wasm `DBG_VALUE` instructions.
This does not yet handle mutable target indices, i.e., this does not
terminate a `DBG_VALUE` for a local index when we encounter a new
`local.set` or `local.tee`. It will be implemented as a follow-up.
Reviewed By: dschuff, jmorse
Differential Revision: https://reviews.llvm.org/D138943
Following support from the previous patches in this stack being added for
variadic DBG_INSTR_REFs to exist, this patch modifies LiveDebugValues to
handle those instructions. Support already exists for DBG_VALUE_LISTs, which
covers most of the work needed to handle these instructions; this patch only
modifies the transferDebugInstrRef function to correctly track them.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D133927
Prior to this patch, variadic DIExpressions (i.e. ones that contain
DW_OP_LLVM_arg) could only be created by salvaging debug values to create
stack value expressions, resulting in a DBG_VALUE_LIST being created. As of
the previous patch in this patch stack, DBG_INSTR_REF's syntax has been
changed to match DBG_VALUE_LIST in preparation for supporting variadic
expressions. This patch adds some minor changes needed to allow variadic
expressions that aren't stack values to exist, and allows variadic expressions
that are trivially reduceable to non-variadic expressions to be handled
similarly to non-variadic expressions.
Reviewed by: jmorse
Differential Revision: https://reviews.llvm.org/D133926
This patch makes two notable changes to the MIR debug info representation,
which result in different MIR output but identical final DWARF output (NFC
w.r.t. the full compilation). The two changes are:
* The introduction of a new MachineOperand type, MO_DbgInstrRef, which
consists of two unsigned numbers that are used to index an instruction
and an output operand within that instruction, having a meaning
identical to first two operands of the current DBG_INSTR_REF
instruction. This operand is only used in DBG_INSTR_REF (see below).
* A change in syntax for the DBG_INSTR_REF instruction, shuffling the
operands to make it resemble DBG_VALUE_LIST instead of DBG_VALUE,
and replacing the first two operands with a single MO_DbgInstrRef-type
operand.
This patch is the first of a set that will allow DBG_INSTR_REF
instructions to refer to multiple machine locations in the same manner
as DBG_VALUE_LIST.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D129372
Currently the instruction referencing live debug values has 3 separate
places where we iterate over all known locations to find the best machine
location for a set of values at a given point in the program. Each of these
places has an implementation of this check, and one of them has slightly
different logic to the others. This patch moves the check for the "quality"
of a machine location into a separate function, which also avoids repeatedly
calling expensive functions, giving a slight performance improvement.
Differential Revision: https://reviews.llvm.org/D140412
This patch adds a new function that can be used to check all the
properties, other than the machine values, of a pair of debug values for
equivalence. This is done by folding the "directness" into the
expression, converting the expression to variadic form if it is not
already in that form, and then comparing directly. In a few places which
check whether two debug values are identical to see if their ranges can
be merged, this function will correctly identify cases where two debug
values are expressed differently but have the same meaning, allowing
those ranges to be correctly merged.
Differential Revision: https://reviews.llvm.org/D136173
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 done as a test for D137302 and it makes sense to push these changes
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D137493
This patch builds on prior support patches to enable support for
variadic debug values in InstrRefLDV, allowing DBG_VALUE_LISTs to
have their ranges extended.
Differential Revision: https://reviews.llvm.org/D128212
This patch adds the last of the changes required to enable
DBG_VALUE_LIST handling in InstrRefLDV, handling variadic debug values
during the transfer tracking step. Most of the changes are fairly
straightforward, and based around tracking multiple locations per
variable in TransferTracker::VLocTracker.
Differential Revision: https://reviews.llvm.org/D128211
