When moving an entire basic block after `InsertPoint`, currently we
check each instruction whether their users are dominated by
`InsertPoint`, however, this can be improved such that even a user is
not dominated by `InsertPoint`, as long as it appears as a subsequent
instruction in the same BB, it is safe to move.
This patch is similar to commit 751be2a064f119af74c7b9b1e52bc904d8aa114d
that enhanced hoisting an entire BB, and this patch enhances sinking an
entire BB. Please refer to the added functionality in test case
`llvm/unittests/Transforms/Utils/CodeMoverUtilsTest.cpp` that was not
supported without this patch.
https://bugs.llvm.org/show_bug.cgi?id=51735https://github.com/llvm/llvm-project/issues/51077
In the given test case:
```
4 ...
5 void bar() {
6 int End = 777;
7 int Index = 27;
8 char Var = 1;
9 for (; Index < End; ++Index)
10 ;
11 nop(Index);
12 }
13 ...
```
Missing local variable `Index` after loop `Induction Variable Elimination`. When adding a breakpoint at line `11`, LLDB does not have information on the variable. But it has info on `Var` and `End`.
This reverts the revert commit 589c7abb03448.
This patch includes a fix for any-of reductions and epilogue
vectorization. Extra test coverage for the issue that caused the revert
has been added in 399ff08e29d.
--------------------------------
Original commit message:
Update AnyOf reduction code generation to only keep track of the AnyOf
property in a boolean vector in the loop, only selecting either the new
or start value in the middle block.
The patch incorporates feedback from https://reviews.llvm.org/D153697.
This fixes the #62565, as now there aren't multiple uses of the
start/new values.
Fixes https://github.com/llvm/llvm-project/issues/62565
PR: https://github.com/llvm/llvm-project/pull/78304
Branch weight from sample-based PGO may be not inaccurate due to
sampling. If the loop body must be executed, then origin loop back
edge weight must be not less than exit weight.
When the compiler enables ALSR by default, binary inconsistency occurs
when the extractCodeRegion function is called. The reason is that the
sequence of traversing ExitBlocks containers of the SmallPtrSet type is
changed due to randomization of BasicBlock pointers.
This fixes https://github.com/llvm/llvm-project/issues/86427
Another trivial rename patch, the last big one for now, which renamed
DPMarkers to DbgMarkers. This required the field `DbgMarker` in
`Instruction` to be renamed to `DebugMarker` to avoid a clash, but
otherwise was a simple string substitution of `s/DPMarker/DbgMarker` and
a manual renaming of `DPM` to `DM` in the few places where that acronym
was used for debug markers.
This patch renames DPLabel to DbgLabelRecord, in accordance with the
ongoing DbgRecord rename. This rename was fairly trivial, since DPLabel
isn't as widely used as DPValue and has no real conflicts in either its
full or abbreviated name. As usual, the entire replacement was done
automatically, with `s/DPLabel/DbgLabelRecord/` and `s/DPL/DLR/`.
As part of the migration to ptradd
(https://discourse.llvm.org/t/rfc-replacing-getelementptr-with-ptradd/68699),
we need to change the representation of the `inrange` attribute, which
is used for vtable splitting.
Currently, inrange is specified as follows:
```
getelementptr inbounds ({ [4 x ptr], [4 x ptr] }, ptr @vt, i64 0, inrange i32 1, i64 2)
```
The `inrange` is placed on a GEP index, and all accesses must be "in
range" of that index. The new representation is as follows:
```
getelementptr inbounds inrange(-16, 16) ({ [4 x ptr], [4 x ptr] }, ptr @vt, i64 0, i32 1, i64 2)
```
This specifies which offsets are "in range" of the GEP result. The new
representation will continue working when canonicalizing to ptradd
representation:
```
getelementptr inbounds inrange(-16, 16) (i8, ptr @vt, i64 48)
```
The inrange offsets are relative to the return value of the GEP. An
alternative design could make them relative to the source pointer
instead. The result-relative format was chosen on the off-chance that we
want to extend support to non-constant GEPs in the future, in which case
this variant is more expressive.
This implementation "upgrades" the old inrange representation in bitcode
by simply dropping it. This is a very niche feature, and I don't think
trying to upgrade it is worthwhile. Let me know if you disagree.
This is the major rename patch that prior patches have built towards.
The DPValue class is being renamed to DbgVariableRecord, which reflects
the updated terminology for the "final" implementation of the RemoveDI
feature. This is a pure string substitution + clang-format patch. The
only manual component of this patch was determining where to perform
these string substitutions: `DPValue` and `DPV` are almost exclusively
used for DbgRecords, *except* for:
- llvm/lib/target, where 'DP' is used to mean double-precision, and so
appears as part of .td files and in variable names. NB: There is a
single existing use of `DPValue` here that refers to debug info, which
I've manually updated.
- llvm/tools/gold, where 'LDPV' is used as a prefix for symbol
visibility enums.
Outside of these places, I've applied several basic string
substitutions, with the intent that they only affect DbgRecord-related
identifiers; I've checked them as I went through to verify this, with
reasonable confidence that there are no unintended changes that slipped
through the cracks. The substitutions applied are all case-sensitive,
and are applied in the order shown:
```
DPValue -> DbgVariableRecord
DPVal -> DbgVarRec
DPV -> DVR
```
Following the previous rename patches, it should be the case that there
are no instances of any of these strings that are meant to refer to the
general case of DbgRecords, or anything other than the DPValue class.
The idea behind this patch is therefore that pure string substitution is
correct in all cases as long as these assumptions hold.
Since some of the users of `CodeExtractor` like `HotColdSplitting` run
late in the pipeline, returns are not cleaned to `unreachable`. So,
just emit `unreachable` directly if the function is `noreturn`.
Closes#84682
We can treat a shift by constant as a multiply by a power of 2
and we can treat an or disjoint as a 'add nsw nuw'.
I've added a helper struct similar to a struct used in
ScalarEvolution.cpp
to represent the opcode, operands, and NSW/NUW flags for normal
add/sub/mul
and shl/or that are being treated as mul/add.
I don't think we need to teach cloneIVUser about this. It will continue
to clone them using cloneBitwiseIVUser. After the cloning we will ask
for the SCEV expression for the cloned IV user and verify that it
matches
the AddRec returned by getExtendedOperandRecurrence. Since SCEV also
knows how to convert shl to mul and or disjoint to add nsw nuw, this
should
usually match. If it doesn't match, the cloned IV user will be deleted.
This patch changes DPValue::filter to be a non-member method
filterDbgVars. There are two reasons for this: firstly, the name of
DPValue is about to change to DbgVariableRecord, which will result in
every `for` loop that uses DPValue::filter to require a line break. This
is a small thing, but it makes the rename patch more difficult to
review, and is just generally more awkward for what is a fairly common
loop. Secondly, the intent is to later break up the DPValue class into
subclasses, at which point it would be better to have a non-member
function that allows template arguments for the cases we want to filter
with greater specificity.
Loop guards that apply to loop SCEV bounds allow IRCE for cases with
compound loop bounds such as:
if (K > 0 && M > 0)
for (i = 0; i < min(K, M); i++) {...}
if (K > 0 && M > 0)
for (i = min(K, M); i >= 0; i--) {...}
Otherwise SCEV couldn't prove that loops have safe bounds in these
cases.
Co-authored-by: Aleksander Popov <apopov@azul.com>
This patch continues the ongoing rename work, replacing DPValue with
DbgRecord in comments and the names of variables, both members and
fn-local. This is the most labour-intensive part of the rename, as it is
where the most decisions have to be made about whether a given comment
or variable is referring to DPValues (equivalent to debug variable
intrinsics) or DbgRecords (a catch-all for all debug intrinsics); these
decisions are not individually difficult, but comprise a fairly large
amount of text to review.
This patch still largely performs basic string substitutions followed by
clang-format; there are almost* no places where, for example, a comment
has been expanded or modified to reflect the semantic difference between
DPValues and DbgRecords. I don't believe such a change is generally
necessary in LLVM, but it may be useful in the docs, and so I'll be
submitting docs changes as a separate patch.
*In a few places, `dbg.values` was replaced with `debug intrinsics`.
As part of the effort to rename the DbgRecord classes, this patch
renames the widely-used functions that operate on DbgRecords but refer
to DbgValues or DPValues in their names to refer to DbgRecords instead;
all such functions are defined in one of `BasicBlock.h`,
`Instruction.h`, and `DebugProgramInstruction.h`.
This patch explicitly does not change the names of any comments or
variables, except for where they use the exact name of one of the
renamed functions. The reason for this is reviewability; this patch can
be trivially examined to determine that the only changes are direct
string substitutions and any results from clang-format responding to the
changed line lengths. Future patches will cover renaming variables and
comments, and then renaming the classes themselves.
Have DIBuilder conditionally insert either debug intrinsics or DbgRecord
depending on the module's IsNewDbgInfoFormat flag. The insertion methods
now return a `DbgInstPtr` (a `PointerUnion<Instruction *, DbgRecord
*>`).
Add a unittest for both modes (I couldn't find an existing test testing
insertion behaviours specifically).
This patch changes the existing assumption that DbgRecords are only ever
inserted if there's an instruction to insert-before because clang
currently inserts debug intrinsics while CodeGening (like any other
instruction) meaning it'll try inserting to the end of a block without a
terminator. We already have machinery in place to maintain the
DbgRecords when a terminator is removed - these become "trailing
DbgRecords" which are re-attached when a new instruction is inserted.
All I've done is allow this state to occur while inserting DbgRecords
too, i.e., it's not only removing terminators that causes this valid
transient state, but inserting DbgRecords into incomplete blocks too.
The C API will be updated in follow up patches.
---
Note: this doesn't mean clang is emitting DbgRecords yet, because the
modules it creates are still always in the old debug mode. That will
come in a future patch.
Instructions in unreachable basic blocks are removed, but terminators
are not. In this case, even instructions that are only referenced by
a terminator, such as a return instruction, cannot be processed
properly.
This patch changes the operand of a return instruction in an
unreachable basic block to poison if it refers to the instruction,
allowing the instruction to be properly processed.
Fixes#65107.
When reference-types feature is enabled, forcing mem2reg unconditionally
even in `-O0` has some problems described in #81575. This uses
RefTypeMem2Local pass added in #81965 instead. This also removes
`IsForced` parameter added in
890146b192
given that we don't need it anymore.
This may still hurt debug info related to reference type variables a
little during the backend transformation given that they are not stored
in memory anymore, but reference type variables are presumably rare and
it would be still a lot less damage than forcing mem2reg on the whole
program. Also this fixes the EH problem described in #81575.
Fixes#81575.
If the phi node found by matchSimpleRecurrence is not from the current
loop, then isAlmostDeadIV panics. With this patch we bail out early.
Signed-off-by: Patrick O'Neill <patrick@rivosinc.com>
---------
Signed-off-by: Patrick O'Neill <patrick@rivosinc.com>
I'd reverted this in 6c7805d5d1 after a bad stage. Original commit
messsage follows:
[NFC][RemoveDIs] Bulk update utilities to insert with iterators
As part of the RemoveDIs project we need LLVM to insert instructions using
iterators wherever possible, so that the iterators can carry a bit of
debug-info. This commit implements some of that by updating the contents of
llvm/lib/Transforms/Utils to always use iterator-versions of instruction
constructors.
There are two general flavours of update:
* Almost all call-sites just call getIterator on an instruction
* Several make use of an existing iterator (scenarios where the code is
actually significant for debug-info)
The underlying logic is that any call to getFirstInsertionPt or similar
APIs that identify the start of a block need to have that iterator passed
directly to the insertion function, without being converted to a bare
Instruction pointer along the way.
I've also switched DemotePHIToStack to take an optional iterator: it needs
to take an iterator, and having a no-insert-location behaviour appears to
be important. The constructors for ICmpInst and FCmpInst have been updated
too. They're the only instructions that take block _references_ rather than
pointers for certain calls, and a future patch is going to make use of
default-null block insertion locations.
All of this should be NFC.
As part of the RemoveDIs project we need LLVM to insert instructions using
iterators wherever possible, so that the iterators can carry a bit of
debug-info. This commit implements some of that by updating the contents of
llvm/lib/Transforms/Utils to always use iterator-versions of instruction
constructors.
There are two general flavours of update:
* Almost all call-sites just call getIterator on an instruction
* Several make use of an existing iterator (scenarios where the code is
actually significant for debug-info)
The underlying logic is that any call to getFirstInsertionPt or similar
APIs that identify the start of a block need to have that iterator passed
directly to the insertion function, without being converted to a bare
Instruction pointer along the way.
I've also switched DemotePHIToStack to take an optional iterator: it needs
to take an iterator, and having a no-insert-location behaviour appears to
be important. The constructors for ICmpInst and FCmpInst have been updated
too. They're the only instructions that take block _references_ rather than
pointers for certain calls, and a future patch is going to make use of
default-null block insertion locations.
All of this should be NFC.
With no debug intrinsics, correctly identifying the start of a block
with iterators becomes important. We need to use the iterator-returning
methods here in loop-unroll-and-jam where we're shifting PHIs around.
Otherwise they can be inserted after debug-info records, leading to
debug-info attached to PHIs, which is ill formed.
Fixes#83000
llvm.dbg.labels are deleted in SpeculativelyExecuteBB so DPLabels should
be too.
Modify existing test to check this (NB I couldn't find a dedicated
debug-info test that checks this behaviour).
Patch 2 of 3 to add llvm.dbg.label support to the RemoveDIs project. The
patch stack adds the DPLabel class, which is the RemoveDIs llvm.dbg.label
equivalent.
1. Add DbgRecord base class for DPValue and the not-yet-added
DPLabel class.
2. Add the DPLabel class.
-> 3. Add support to passes.
The next patch, #82639, will enable conversion between dbg.labels and DPLabels.
AssignemntTrackingAnalysis support could have gone two ways:
1. Have the analysis store a DPLabel representation in its results -
SelectionDAGBuilder reads the analysis results and ignores all DbgRecord
kinds.
2. Ignore DPLabels in the analysis - SelectionDAGBuilder reads the analysis
results but still needs to iterate over DPLabels from the IR.
I went with option 2 because it's less work and is no less correct than 1. It's
worth noting that causes labels to sink to the bottom of packs of debug records.
e.g., [value, label, value] becomes [value, value, label]. This shouldn't be a
problem because labels and variable locations don't have an ordering requirement.
The ordering between variable locations is maintained and the label movement is
deterministic
In LoopUnroll, peelLoop is called on the loop. After the loop is peeled
it calls simplifyLoopAfterUnroll on the loop. This call to
simplifyLoopAfterUnroll doesn't preserve the LCSSA form of the parent
loop and thus during the next call to peelLoop the LCSSA form is already
broken.
LoopPeel util takes in the PreserveLCSSA argument and it passes
on the same argument to simplifyLoop which checks if the loop is in a
valid LCSSA form, when (PreserveLCSSA = true).
This causes an assert in simplifyLoop when (PreserveLCSSA = true), as
during the last call LCSSA for the loop wasn't preserved, and thus
crashes at the following assert.
assert(L->isRecursivelyLCSSAForm(*DT, *LI) &&
"Requested to preserve LCSSA, but it's already broken.");
Upon debugging, it is evident that simplifyLoopIVs call inside
simplifyLoopAfterUnroll breaks the LCSSA form. This patch fixes
llvm#77118, it checks if the replacement of IV Users with Loop Invariant
preserves the LCSSA form. If it does not, it emits the required LCSSA
Phi instructions.
SCEVExpanderCleaner will currently remove instructions created by
SCEVExpander, but not restore poison generating flags that it may have
dropped. As such, running LIR can currently spuriously drop flags
without performing any transforms.
Fix this by keeping track of original instruction flags in SCEVExpander.
Fixes https://github.com/llvm/llvm-project/issues/82337.
Because loops in coroutines may have a co_await statement that
reschedules the coroutine to another thread, we cannot cache addresses
of thread-local variables obtained inside a loop by moving the
computation of thoes addresses outside a loop.
Since LLVM doesn't have a model for coroutine memory accesses, this
patch fixes this bug by disabling this optimization for coroutines in
the same way as https://reviews.llvm.org/D135550 and
https://reviews.llvm.org/D151774.
Patch 1 of 3 to add llvm.dbg.label support to the RemoveDIs project. The
patch stack adds a new base class
-> 1. Add DbgRecord base class for DPValue and the not-yet-added
DPLabel class.
2. Add the DPLabel class.
3. Enable dbg.label conversion and add support to passes.
Patches 1 and 2 are NFC.
In the near future we also will rename DPValue to DbgVariableRecord and
DPLabel to DbgLabelRecord, at which point we'll overhaul the function
names too. The name DPLabel keeps things consistent for now.
widenIVUse may hoist a wide induction increment and introduce new uses,
but does not recompute the wrap flags. In some cases this can make the
new uses of the wide IV inc more poisonous.
Update the code to recompute flags if needed when hoisting an IV. If
both the narrow and wide IV increment's flags match and we can re-use
the flags from the increments, there's no need to recompute the flags,
as the replacement won't make the new uses of the wide IV's increment
more poisonous.
Note that this also updates a stale comment which claimed that the widen
increment is only used if it dominates the new use.
The helper should also be used to guard the code added in da437330be,
which I am planning on doing separately once the helper lands.
Fixes https://github.com/llvm/llvm-project/issues/82243.
