As discussed in the commit thread for rGa253a2a and D73978, we can do more undef folding for FP ops.
The nnan and ninf fast-math-flags specify that if an operand is the disallowed value, the result is
poison, so we can produce an undef result.
But this doesn't work as expected (the undef operand cases remain) because of a Flags propagation
problem in SelectionDAGBuilder.
I've added DAGCombiner calls to enable these for the other cases because we've shown in other
patches that (because of the limited way that SDAG iterates), it is possible to miss simplifications
like this if they are done only at node creation time.
Several potential follow-ups to expand on this patch are possible.
Differential Revision: https://reviews.llvm.org/D75576
This changes the localizer to attempt intra-block localizer of instructions
that have local uses. This is useful because sometimes the entry block itself
has many uses of constant-like instructions, which would benefit from shortening
live ranges. Previously if an inst had no non-local uses, we wouldn't add it to
the list of instructions to attempt further intra-block localization.
This gives a 0.7% geomean code size improvement on CTMark.
Differential Revision: https://reviews.llvm.org/D75555
Summary:
This change checks for the return type in the frontend and adds a flag
to the DISubroutineType to indicate that the option should be added in
CodeViewDebug.
Previously function types sometimes appeared twice in the PDB: once with
"returns cxx udt" and once without.
See https://bugs.llvm.org/show_bug.cgi?id=44785.
Reviewers: rnk, asmith
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D75215
This fixes a miscompile that happened because a DBG_VALUE interfered
with the MachineOutliner's liveness analysis.
Inserting a DBG_VALUE after a terminator breaks predicates on MBB such
as isReturnBlock(). And the resulting DBG_VALUE cannot be "live".
I plan to introduce a MachineVerifier check for this situation in a
follow up.
rdar://59859175
Testing: check-llvm, LNT build with a stage2 compiler & entry values
enabled
Differential Revision: https://reviews.llvm.org/D75548
```
// clang -c -gdwarf-5 a.s -o a.o
.section .init; ret
.text; ret
```
.debug_info contains DW_AT_ranges and llvm-dwarfdump will report
a verification error because .debug_rnglists does not exist (not
implemented).
This patch generates .debug_rnglists for assembly files.
emitListsTableHeaderStart() in DwarfDebug.cpp can be shared with
MCDwarf.cpp. Because CodeGen depends on MC, I move the function to
MCDwarf.cpp
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D75375
Summary:
Follow up from D75377. If the subvector is byte sized and the
index is aligned to the subvector size, we can shrink the load.
Reviewers: spatel, RKSimon
Reviewed By: RKSimon
Subscribers: dbabokin, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75434
Use MIOperand in collectLocalKilledOperands to make the search
global, as we already have to search for global uses too. This
allows us to delete more dead code when tail predicating.
Differential Revision: https://reviews.llvm.org/D75167
In RDA, check against the already decided dead instructions when
looking at users. This allows an instruction to be removed if it
has multiple users, but they're all dead.
This means that IT instructions can be considered killed once all
the itstate using instructions are dead.
Differential Revision: https://reviews.llvm.org/D75245
This patch adds support for dwarf emission/dumping part of debuginfo
generation for defaulted parameters.
Reviewers: probinson, aprantl, dblaikie
Reviewed By: aprantl, dblaikie
Differential Revision: https://reviews.llvm.org/D73462
Make it a compile-time error to pass an int/unsigned/etc to
fromRawInteger.
Hopefully this prevents errors of the form:
```
for (unsigned ID : getVarLocs()) {
auto VL = LocMap[LocIndex::fromRawInteger(ID)];
...
```
I expect that the isCondCodeLegal checks should match that CC of
the node that we're going to create.
Rewriting to a switch to minimize repeated mentions of the same
constants.
This is needed for D74873, AMDGPU going to have 16 bit subregs
and the largest tuple is 32 VGPRs, which results in 64 lanes.
Differential Revision: https://reviews.llvm.org/D75378
We should be careful to allow count of re-materialization of operands to be less
then number of physical registers.
STATEPOINT instruction has a variable number of operands and potentially very big.
So re-materialization for all operands is disabled at the moment if restrict-statepoint-remat is true.
The patch relaxes the re-materialization restriction for STATEPOINT instruction allowing it for
fixed operands. Specifically it is about call target.
Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits, qcolombet, hiraditya
Differential Revision: https://reviews.llvm.org/D75335
The address calculation for the offset assumes that you can calculate the offset by multiplying the index by the store size of the element. But that only works if the element's store size is exactly its real size since we store vectors tightly packed in memory. There are improvements we could make to this like special casing extracting element 0. I think we could also handle cases where the extracted VT is byte sized and the index is aligned with the extract element count.
Differential Revision: https://reviews.llvm.org/D75377
Select_cc isn't used by all targets. X86 doesn't have optimizations
for it.
Since we already know the input to the sint_to_fp/uint_to_fp is
a setcc we can just emit a plain select using that setcc as the
condition. Other DAG combines can turn that into a select_cc on
targets that support it.
Differential Revision: https://reviews.llvm.org/D75415
We get the simple cases of this via demanded elements and other folds,
but that doesn't work if the values have >1 use, so add a dedicated
match for the pattern.
We already have this transform in IR, but it doesn't help the
motivating x86 tests (based on PR42024) because the shuffles don't
exist until after legalization and other combines have happened.
The AArch64 test shows a minimal IR example of the problem.
Differential Revision: https://reviews.llvm.org/D75348
Try again with an up-to-date version of D69471 (99317124 was a stale
revision).
---
Revise the coverage mapping format to reduce binary size by:
1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.
This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).
Rationale for changes to the format:
- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.
- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.
- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).
See CoverageMappingFormat.rst for the details on what exactly has
changed.
Fixes PR34533 [2], hopefully.
[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533
Differential Revision: https://reviews.llvm.org/D69471
Revise the coverage mapping format to reduce binary size by:
1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.
This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).
Rationale for changes to the format:
- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.
- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.
- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).
See CoverageMappingFormat.rst for the details on what exactly has
changed.
Fixes PR34533 [2], hopefully.
[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533
Differential Revision: https://reviews.llvm.org/D69471
As a narrow stopgap for the assertion failure described in PR45025, add
a describeLoadedValue override to ARMBaseInstrInfo and use it to detect
copies in which the forwarding reg is a super/sub reg of the copy
destination. For the moment this is unsupported.
Several follow ups are possible:
1) Handle VORRq. At the moment, we do not, because isCopyInstrImpl
returns early when !MI.isMoveReg().
2) In the case where forwarding reg is a super-reg of the copy
destination, we should be able to describe the forwarding reg as a
subreg within the copy destination. I'm not 100% sure about this, but
it looks like that's what's done in AArch64InstrInfo.
3) In the case where the forwarding reg is a sub-reg of the copy
destination, maybe we could describe the forwarding reg using the
copy destinaion and a DW_OP_LLVM_fragment (I guess this should be
possible after D75036).
https://bugs.llvm.org/show_bug.cgi?id=45025
rdar://59772698
Differential Revision: https://reviews.llvm.org/D75273
The alias analysis in DAG Combine looks at the BaseAlign, the Offset and
the Size of two accesses, and determines if they are known to access
different parts of memory by the fact that they are different offsets
from inside that "alignment window". It does not seem to account for
accesses that are not a multiple of the size, and may overflow from one
alignment window into another.
For example in the test case we have a 19byte memset that is splits into
a 16 byte neon store and an unaligned 4 byte store with a 15 byte
offset. This 15byte offset (with a base align of 8) wraps around to the
next alignment windows. When compared to an access that is a 16byte
offset (of the same 4byte size and 8byte basealign), the two accesses
are said not to alias.
I've fixed this here by just ensuring that the offsets are a multiple of
the size, ensuring that they don't overlap by wrapping. Fixes PR45035,
which was exposed by the UseAA changes in the arm backend.
Differential Revision: https://reviews.llvm.org/D75238
We can only report the knownbits for a SCALAR_TO_VECTOR node if we only demand the 0'th element - the upper elements are undefined and shouldn't be trusted.
This is causing a number of regressions that need addressing but we need to get the bugfix in first.
Way back in D24994, the combination of LexicalScopes::dominates and
LiveDebugValues was identified as having worst-case quadratic complexity,
but it wasn't triggered by any code path at the time. I've since run into a
scenario where this occurs, in a very large basic block where large numbers
of inlined DBG_VALUEs are present.
The quadratic-ness comes from LiveDebugValues::join calling "dominates" on
every variable location, and LexicalScopes::dominates potentially touching
every instruction in a block to test for the presence of a scope. We have,
however, already computed the presence of scopes in blocks, in the
"InstrRanges" of each scope. This patch switches the dominates method to
examine whether a block is present in a scope's InsnRanges, avoiding
walking through the whole block.
At the same time, fix getMachineBasicBlocks to account for the fact that
InsnRanges can cover multiple blocks, and add some unit tests, as Lexical
Scopes didn't have any.
Differential revision: https://reviews.llvm.org/D73725
Ensure that we're recording implicit defs, as well as visiting implicit
uses and implicit defs when we're walking through operands.
Differential Revision: https://reviews.llvm.org/D75185
According to Joseph Myers, a libm maintainer
> They were only ever an ABI (selected by use of -ffinite-math-only or
> options implying it, which resulted in the headers using "asm" to redirect
> calls to some libm functions), not an API. The change means that ABI has
> turned into compat symbols (only available for existing binaries, not for
> anything newly linked, not included in static libm at all, not included in
> shared libm for future glibc ports such as RV32), so, yes, in any case
> where tools generate direct calls to those functions (rather than just
> following the "asm" annotations on function declarations in the headers),
> they need to stop doing so.
As a consequence, we should no longer assume these symbols are available on the
target system.
Still keep the TargetLibraryInfo for constant folding.
Differential Revision: https://reviews.llvm.org/D74712
This is part 3 of a 3-part series to address a compile-time explosion
issue in LiveDebugValues.
---
Start encoding register locations within VarLoc IDs, and take advantage
of this encoding to speed up transferRegisterDef.
There is no fundamental algorithmic change: this patch simply swaps out
SparseBitVector in favor of CoalescingBitVector. That changes iteration
order (hence the test updates), but otherwise this patch is NFCI.
The only interesting change is in transferRegisterDef. Instead of doing:
```
KillSet = {}
for (ID : OpenRanges.getVarLocs())
if (DeadRegs.count(ID))
KillSet.add(ID)
```
We now do:
```
KillSet = {}
for (Reg : DeadRegs)
for (ID : intervalsReservedForReg(Reg, OpenRanges.getVarLocs()))
KillSet.add(ID)
```
By not visiting each open location every time we visit an instruction,
this eliminates some potentially quadratic behavior. The new
implementation basically does a constant amount of work per instruction
because the interval map lookups are very fast.
For a file in WebKit, this brings the time spent in LiveDebugValues down
from ~2.5 minutes to 4 seconds, reducing compile time spent in that pass
from 28% of the total to just over 1%.
Before:
```
2.49 min 27.8% 0 s LiveDebugValues::process
2.41 min 27.0% 5.40 s LiveDebugValues::transferRegisterDef
1.51 min 16.9% 1.51 min LiveDebugValues::VarLoc::isDescribedByReg() const
32.73 s 6.1% 8.70 s llvm::SparseBitVector<128u>::SparseBitVectorIterator::operator++()
```
After:
```
4.53 s 1.1% 0 s LiveDebugValues::process
3.00 s 0.7% 107.00 ms LiveDebugValues::transferRegisterCopy
892.00 ms 0.2% 406.00 ms LiveDebugValues::transferSpillOrRestoreInst
404.00 ms 0.1% 32.00 ms LiveDebugValues::transferRegisterDef
110.00 ms 0.0% 2.00 ms LiveDebugValues::getUsedRegs
57.00 ms 0.0% 1.00 ms std::__1::vector<>::push_back
40.00 ms 0.0% 1.00 ms llvm::CoalescingBitVector<>::find(unsigned long long)
```
FWIW, I tried the same approach using SparseBitVector, but got bad
results. To do that, I had to extend SparseBitVector to support 64-bit
indices and expose its lower bound operation. The problem with this is
that the performance is very hard to predict: SparseBitVector's lower
bound operation falls back to O(n) linear scans in a std::list if you're
not /very/ careful about managing iteration order. When I profiled this
the performance looked worse than the baseline.
You can see the full CoalescingBitVector-based implementation here:
https://github.com/vedantk/llvm-project/commits/try-coalescing
You can see the full SparseBitVector-based implementation here:
https://github.com/vedantk/llvm-project/commits/try-sparsebitvec-find
Depends on D74984 and D74985.
Differential Revision: https://reviews.llvm.org/D74986
This is part 2 of a 3-part series to address a compile-time explosion
issue in LiveDebugValues.
---
Each VarLoc has a unique ID: this ID is used to look up a VarLoc in the
VarLocMap, and to virtually insert a VarLoc into a VarLocSet. Instead of
inserting the VarLoc /itself/ into the VarLocSet, we insert just the ID,
because this can be represented efficiently with a SparseBitVector.
This change introduces LocIndex, a layer of abstraction on top of VarLoc
IDs. Prior to this change, an ID was just an index into a vector. With
this change, an ID encodes both an index /and/ a register location. The
type-checker ensures that conversions to and from LocIndex are correct.
For the moment the register location is always 0 (undef). We have plenty
of bits left over to encode physregs, stack slots, and other locations
in the future.
Differential Revision: https://reviews.llvm.org/D74985
The code changes here are hopefully straightforward:
1. Use MachineInstruction flags to decide if FP ops can be reassociated
(use both "reassoc" and "nsz" to be consistent with IR transforms;
we probably don't need "nsz", but that's a safer interpretation of
the FMF).
2. Check that both nodes allow reassociation to change instructions.
This is a stronger requirement than we've usually implemented in
IR/DAG, but this is needed to solve the motivating bug (see below),
and it seems unlikely to impede optimization at this late stage.
3. Intersect/propagate MachineIR flags to enable further reassociation
in MachineCombiner.
We managed to make MachineCombiner flexible enough that no changes are
needed to that pass itself. So this patch should only affect x86
(assuming no other targets have implemented the hooks using MachineIR
flags yet).
The motivating example in PR43609 is another case of fast-math transforms
interacting badly with special FP ops created during lowering:
https://bugs.llvm.org/show_bug.cgi?id=43609
The special fadd ops used for converting int to FP assume that they will
not be altered, so those are created without FMF.
However, the MachineCombiner pass was being enabled for FP ops using the
global/function-level TargetOption for "UnsafeFPMath". We managed to run
instruction/node-level FMF all the way down to MachineIR sometime in the
last 1-2 years though, so we can do better now.
The test diffs require some explanation:
1. llvm/test/CodeGen/X86/fmf-flags.ll - no target option for unsafe math was
specified here, so MachineCombiner kicks in where it did not previously;
to make it behave consistently, we need to specify a CPU schedule model,
so use the default model, and there are no code diffs.
2. llvm/test/CodeGen/X86/machine-combiner.ll - replace the target option for
unsafe math with the equivalent IR-level flags, and there are no code diffs;
we can't remove the NaN/nsz options because those are still used to drive
x86 fmin/fmax codegen (special SDAG opcodes).
3. llvm/test/CodeGen/X86/pow.ll - similar to #1
4. llvm/test/CodeGen/X86/sqrt-fastmath.ll - similar to #1, but MachineCombiner
does some reassociation of the estimate sequence ops; presumably these are
perf wins based on latency/throughput (and we get some reduction of move
instructions too); I'm not sure how it affects numerical accuracy, but the
test reflects reality better now because we would expect MachineCombiner to
be enabled if the IR was generated via something like "-ffast-math" with clang.
5. llvm/test/CodeGen/X86/vec_int_to_fp.ll - this is the test added to model PR43609;
the fadds are not reassociated now, so we should get the expected results.
6. llvm/test/CodeGen/X86/vector-reduce-fadd-fast.ll - similar to #1
7. llvm/test/CodeGen/X86/vector-reduce-fmul-fast.ll - similar to #1
Differential Revision: https://reviews.llvm.org/D74851
This will address the issue: P8198 and P8199 (from D73534).
The methods was not handle bundles properly.
Differential Revision: https://reviews.llvm.org/D74904
Summary:
If the describeLoadedValue() hook produced a DIExpression when
describing a instruction, and it was not possible to emit a call site
entry directly (the value operand was not an immediate nor a preserved
register), then that described value could not be inserted into the
worklist, and would instead be dropped, meaning that the parameter's
call site value couldn't be described.
This patch extends the worklist so that each entry has an DIExpression
that is built up when iterating through the instructions.
This allows us to describe instruction chains like this:
$reg0 = mv $fp
$reg0 = add $reg0, offset
call @call_with_offseted_fp
Since DW_OP_LLVM_entry_value operations can't be combined with any other
expression, such call site entries will not be emitted. I have added a
test, dbgcall-site-expr-entry-value.mir, which verifies that we don't
assert or emit broken DWARF in such cases.
Reviewers: djtodoro, aprantl, vsk
Reviewed By: djtodoro, vsk
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D75036
Summary:
This is a preparatory patch for D75036, in which a debug expression is
associated with each parameter register in the worklist. In that patch
the two lambda functions addToWorklist() and finishCallSiteParams() grow
a bit, so move those out to separate functions. This patch also prepares
for each parameter register having their own expression moving the
creation of the DbgValueLoc into finishCallSiteParams().
Reviewers: djtodoro, vsk
Reviewed By: djtodoro, vsk
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D75050
This may inhibit vector narrowing in general, but there's
already an inconsistency in the way that we deal with this
pattern as shown by the test diff.
We may want to add a dedicated function for narrowing fneg.
It's often folded into some other op, so moving it away from
other math ops may cause regressions that we would not see
for normal binops.
See D73978 for more details.
Add getUniqueReachingMIDef to RDA which performs a global search for
a machine instruction that produces a unique definition of a given
register at a given point. Also add two helper functions
(getMIOperand) that wrap around this functionality to get the
incoming definition uses of a given instruction. These now replace
the uses of getReachingMIDef in ARMLowOverheadLoops. getReachingMIDef
has been renamed to getReachingLocalMIDef and has been made private
along with getInstFromId.
Differential Revision: https://reviews.llvm.org/D74605
Only MCAsmStreamer (assembly output) needs to keep names of temporary labels created by
MCContext::createTempSymbol().
This change made the rL236642 optimization available for cc2as and
probably some other users.
This eliminates a behavior difference between llvm-mc -filetype=obj and cc1as, which caused
https://reviews.llvm.org/D74006#1890487
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D75097
This node reads the rounding control which means it needs to be ordered properly with operations that change the rounding control. So it needs to be chained to maintain order.
This patch adds a chain input and output to the node and connects it to the chain in SelectionDAGBuilder. I've update all in-tree targets to connect their chain through their lowering code.
Differential Revision: https://reviews.llvm.org/D75132
Unlike what I claimed in my previous commit. The caching is
actually not NFC on PHIs.
When we put a big enough max depth, we end up simulating loops.
The cache is effectively cutting the simulation short and we
get less information as a result.
E.g.,
```
v0 = G_CONSTANT i8 0xC0
jump
v1 = G_PHI i8 v0, v2
v2 = G_LSHR i8 v1, 1
```
Let say we want the known bits of v1.
- With cache:
Set v1 cache to we know nothing
v1 is v0 & v2
v0 gives us 0xC0
v2 gives us known bits of v1 >> 1
v1 is in the cache
=> v1 is 0, thus v2 is 0x80
Finally v1 is v0 & v2 => 0x80
- Without cache and enough depth to do two iteration of the loop:
v1 is v0 & v2
v0 gives us 0xC0
v2 gives us known bits of v1 >> 1
v1 is v0 & v2
v0 is 0xC0
v2 is v1 >> 1
Reach the max depth for v1...
unwinding
v1 is know nothing
v2 is 0x80
v0 is 0xC0
v1 is 0x80
v2 is 0xC0
v0 is 0xC0
v1 is 0xC0
Thus now v1 is 0xC0 instead of 0x80.
I've added a unittest demonstrating that.
NFC
Add a dump method that recursively prints an instruction and all
the instructions defining its operands and so on.
This is helpful when looking at combiner issue.
NFC
Differential Revision: https://reviews.llvm.org/D75094
MachineVerifier still takes 45-50% of total compile time with
-verify-machineinstrs, with calcRegsPassed dataflow taking ~50-60% of
MachineVerifier.
The majority of that time is spent in BBInfo::addPassed, mostly within
DenseSet implementing the sets the dataflow is operating over.
In particular, 1/4 of that DenseSet time is spent just iterating over it
(operator++), 40-50% on insertions, and most of the rest in ::count.
Given that, we're implementing custom sets just for this analysis here,
focusing on cheap insertions and O(n) iteration time (as opposed to
O(U), where U is the universe).
As it's based _mostly_ on BitVector for sparse and SmallVector for
dense, it may remotely resemble SparseSet. The difference is, our
solution is a lot less clever, doesn't have constant time `clear` that
we won't use anyway as reusing these sets across analyses is cumbersome,
and thus more space efficient and safer (got a resizable Universe and a
fallback to DenseSet for sparse if it gets too big).
With this patch MachineVerifier gets ~15-20% faster, its contribution to
total compile time drops from 45-50% to ~35%, while contribution of
calcRegsPassed to MachineVerifier drops from 50-60% to ~35% as well.
calcRegsPassed itself gets another 2x faster here.
All measured on a large suite of shaders targeting a number of GPUs.
Reviewers: bogner, stoklund, rudkx, qcolombet
Reviewed By: rudkx
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75033
Summary:
Terminators in LLVM aren't prohibited from returning values. This means that
the "callbr" instruction, which is used for "asm goto", can support "asm goto
with outputs."
This patch removes all restrictions against "callbr" returning values. The
heavy lifting is done by the code generator. The "INLINEASM_BR" instruction's
a terminator, and the code generator doesn't allow non-terminator instructions
after a terminator. In order to correctly model the feature, we need to copy
outputs from "INLINEASM_BR" into virtual registers. Of course, those copies
aren't terminators.
To get around this issue, we split the block containing the "INLINEASM_BR"
right before the "COPY" instructions. This results in two cheats:
- Any physical registers defined by "INLINEASM_BR" need to be marked as
live-in into the block with the "COPY" instructions. This violates an
assumption that physical registers aren't marked as "live-in" until after
register allocation. But it seems as if the live-in information only
needs to be correct after register allocation. So we're able to get away
with this.
- The indirect branches from the "INLINEASM_BR" are moved to the "COPY"
block. This is to satisfy PHI nodes.
I've been told that MLIR can support this handily, but until we're able to
use it, we'll have to stick with the above.
Reviewers: jyknight, nickdesaulniers, hfinkel, MaskRay, lattner
Reviewed By: nickdesaulniers, MaskRay, lattner
Subscribers: rriddle, qcolombet, jdoerfert, MatzeB, echristo, MaskRay, xbolva00, aaron.ballman, cfe-commits, JonChesterfield, hiraditya, llvm-commits, rnk, craig.topper
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D69868
Changes the handling of odd breakdowns, and avoids using
G_EXTRACT/G_INSERT. Pad with undef to a wider size, and unmerge. Also
avoid introducing instructions for the fully undef components.
Depending on the target, test suite, pipeline config and perhaps other
factors machine verifier when forced on with -verify-machineinstrs can
increase compile time 2-2.5 times over (Release, Asserts On), taking up
~60% of the time. An invaluable tool, it significantly slows down
machine verifier-enabled testing.
Nearly 75% of its time MachineVerifier spends in the calcRegsPassed
method. It's a classic forward dataflow analysis executed over sets, but
visiting MBBs in arbitrary order. We switch that to RPO here.
This speeds up MachineVerifier by about 35%, decreasing the overall
compile time with -verify-machineinstrs by 20-25% or so.
calcRegsPassed itself gets 2x faster here.
All measured on a large suite of shaders targeting a number of GPUs.
Reviewers: bogner, stoklund, rudkx, qcolombet
Reviewed By: bogner
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75032
This is the second patch as part of https://bugs.llvm.org/show_bug.cgi?id=36544
Merging in the ConstantSDNode variant of FoldConstantArithmetic. After this, I will begin merging in FoldConstantVectorArithmetic
I've ensured this patch can build & pass all lit tests in Windows and Linux environments.
Patch by @justice_adams (Justice Adams)
Differential Revision: https://reviews.llvm.org/D74881
This adds infrastructure to print and parse MIR MachineOperand comments.
The motivation for the ARM backend is to print condition code names instead of
magic constants that are difficult to read (for human beings). For example,
instead of this:
dead renamable $r2, $cpsr = tEOR killed renamable $r2, renamable $r1, 14, $noreg
t2Bcc %bb.4, 0, killed $cpsr
we now print this:
dead renamable $r2, $cpsr = tEOR killed renamable $r2, renamable $r1, 14 /* CC::always */, $noreg
t2Bcc %bb.4, 0 /* CC:eq */, killed $cpsr
This shows that MachineOperand comments are enclosed between /* and */. In this
example, the EOR instruction is not conditionally executed (i.e. it is "always
executed"), which is encoded by the 14 immediate machine operand. Thus, now
this machine operand has /* CC::always */ as a comment. The 0 on the next
conditional branch instruction represents the equal condition code, thus now
this operand has /* CC:eq */ as a comment.
As it is a comment, the MI lexer/parser completely ignores it. The benefit is
that this keeps the change in the lexer extremely minimal and no target
specific parsing needs to be done. The changes on the MIPrinter side are also
minimal, as there is only one target hooks that is used to create the machine
operand comments.
Differential Revision: https://reviews.llvm.org/D74306
Change the way that we remove the redundant iteration count code in
the presence of IT blocks. collectLocalKilledOperands has been
introduced to scan an instructions operands, collecting the killed
instructions and then visiting them too. This is used to delete the
code in the preheader which calculates the iteration count. We also
track any IT blocks within the preheader and, if we remove all the
instructions from the IT block, we also remove the IT instruction.
isSafeToRemove is used to remove any redundant uses of the iteration
count within the loop body.
Differential Revision: https://reviews.llvm.org/D74975
Summary:
This patch adds intrinsics and ISelDAG nodes for signed
and unsigned fixed-point division:
```
llvm.sdiv.fix.sat.*
llvm.udiv.fix.sat.*
```
These intrinsics perform scaled, saturating division
on two integers or vectors of integers. They are
required for the implementation of the Embedded-C
fixed-point arithmetic in Clang.
Reviewers: bjope, leonardchan, craig.topper
Subscribers: hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71550
Summary:
The type used to represent functional units in MC is
'unsigned', which is 32 bits wide. This is currently
not a problem in any upstream target as no one seems
to have hit the limit on this yet, but in our
downstream one, we need to define more than 32
functional units.
Increasing the size does not seem to cause a huge
size increase in the binary (an llc debug build went
from 1366497672 to 1366523984, a difference of 26k),
so perhaps it would be acceptable to have this patch
applied upstream as well.
Subscribers: hiraditya, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71210
This version fixes a buildbot failure cause by picking the wrong insert
point for XORs. We cannot pick the XOR binary operator as insert point,
as it is not guaranteed that both input operands for the overflow
intrinsic are defined before it.
This reverts the revert commit
c7fc0e5da6.
A question about this behavior came up on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139003.html
...and as part of backend improvements in D73978.
We decided not to implement a more general change that would have
folded any FP binop with nearly arbitrary constant + undef operand
to undef because that is not theoretically correct (even if it is
practically correct).
This is the SDAG-equivalent to the IR change in D74713.
This patch adds a cache that is valid only for the duration of a call
to getKnownBits. With such short lived cache we avoid all the problems
of cache invalidation while still getting the benefits of reusing
the information we already computed.
This cache is useful whenever an instruction occurs more than once
in a chain of computation.
E.g.,
v0 = G_ADD v1, v2
v3 = G_ADD v0, v1
Previously we would compute the known bits for:
v1, v2, v0, then v1 again and finally v3.
With the patch, now we won't have to recompute v1 again.
NFC
Summary:
This prevents BFI queries on new blocks (from
MachineSinking::GetAllSortedSuccessors) and fixes a bunch of assert failures
under -check-bfi-unknown-block-queries=true.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74511
This changes the SimplifyLibCalls utility to accept an IRBuilderBase,
which allows us to pass through the IRBuilder used by InstCombine.
This will ensure that new instructions get added to the worklist.
The annotated test-case drops from 4 to 2 InstCombine iterations thanks
to this.
To achieve this, I'm adding an IRBuilderBase::OperandBundlesGuard,
which is basically the same as the existing InsertPointGuard and
FastMathFlagsGuard, but for operand bundles. Also add a
setDefaultOperandBundles() method so these can be set outside the
constructor.
Differential Revision: https://reviews.llvm.org/D74792
Use the SelectionDAG::getValidShiftAmountConstant helper to get const/constsplat shift amounts, which allows us to drop the out of range shift amount early-out.
First step towards better non-uniform shift amount support in SimplifyDemandedBits.
I believe this was carried over from getELFKindForNamedSection since
the wasm backend originally used ELF object writing as a template.
Differential Revision: https://reviews.llvm.org/D74565
This includes both GEPs where the indexed type is a scalable vector, and
GEPs where the result type is a scalable vector.
Differential Revision: https://reviews.llvm.org/D73602
When analyzing PHIs, we gather the known bits for every operand and
merge them together to get the known bits of the result of the PHI.
It is not unusual that merging the information leads to know nothing
on the result (e.g., phi a: i8 3, b: i8 unknown, ..., after looking at the
second argument we know we will know nothing on the result), thus, as
soon as we reach that state, stop analyzing the following operand (i.e.,
on the previous example, we won't process anything after looking at `b`).
This improves compile time in particular with PHIs with a large number
of operands.
NFC.
Similar to what we already do with SimplifyDemandedVectorElts, call SimplifyDemandedBits across all the extracted elements of the source vector, treating it as single use.
There's a minor regression in store-weird-sizes.ll which will be addressed in an upcoming SimplifyDemandedBits patch.
Summary:
If the programmer adds static profile data to a branch---i.e. uses
"__builtin_expect()" or similar---then we should honor it. Otherwise,
"__builtin_expect()" is ignored in crucial situations. So we trust that
the programmer knows what they're doing until proven wrong.
Subscribers: hiraditya, JDevlieghere, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74809
Instcombine folds (a + b <u a) to (a ^ -1 <u b) and that does not match
the expected pattern in CodeGenPerpare via UAddWithOverflow.
This causes a regression over Clang 7 on both X86 and AArch64:
https://gcc.godbolt.org/z/juhXYV
This patch extends UAddWithOverflow to also catch the XOR case, if the
XOR is only used in the ICMP. This covers just a single case, but I'd
like to make sure I am not missing anything before tackling the other
cases.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: nikic, lebedev.ri
Differential Revision: https://reviews.llvm.org/D74228
On some targets, like SPARC, forming overflow ops is only profitable if
the math result is used: https://godbolt.org/z/DxSmdB
This patch adds a new MathUsed parameter to allow the targets
to make the decision and defaults to only allowing it
if the math result is used. That is the conservative choice.
This patch also updates AArch64ISelLowering, X86ISelLowering,
ARMISelLowering.h, SystemZISelLowering.h to allow forming overflow
ops if the math result is not used. On those targets using the
overflow intrinsic for the overflow check only generates better code.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D74722
https://reviews.llvm.org/D67133
While investigating some non determinism (CSE doesn't produce wrong
code, it just doesn't CSE some times) in GISel CSE on an out of tree
target, I realized that the core issue was that there were lots of code
that mutates (setReg, setRegClass etc), but doesn't notify observers
(CSE in this case but this could be any other observer). In order to
make the Observer be available in various parts of code and to avoid
having to thread it through various API, the MachineFunction now has the
observer as field. This allows it to be easily used in helper functions
such as constrainOperandRegClass.
Also added some invariant verification method in CSEInfo which can
catch these issues (when CSE is enabled).
Summary:
Unlike normal calls, call_indirects have immediate arguments that
caused a MachineVerifier failure without a small tweak to loosen the
verifier's requirements for variadicOpsAreDefs instructions.
One nice thing about the new call_indirects is that they do not need
to participate in the PCALL_INDIRECT mechanism because their post-isel
hook handles moving the function pointer argument and adding the flags
and typeindex arguments itself.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74191
This reverts commit 649aba93a2, now that
the approach started there has been shown to be workable in the patch
series culminating in https://reviews.llvm.org/D74192.
Summary:
Making `Scale` a `TypeSize` in AArch64InstrInfo::getMemOpInfo,
has the effect that all places where this information is used
(notably, TargetInstrInfo::getMemOperandWithOffset) will need
to consider Scale - and derived, Offset - possibly being scalable.
This patch adds a new operand `bool &OffsetIsScalable` to
TargetInstrInfo::getMemOperandWithOffset and fixes up all
the places where this function is used, to consider the
offset possibly being scalable.
In most cases, this means bailing out because the algorithm does not
(or cannot) support scalable offsets in places where it does some
form of alias checking for example.
Reviewers: rovka, efriedma, kristof.beyls
Reviewed By: efriedma
Subscribers: wuzish, kerbowa, MatzeB, arsenm, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, javed.absar, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72758
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
Summary:
Backends should fold the subtraction into the comparison, but not all
seem to. Moreover, on targets where pointers are not integers, such as
CHERI, an integer subtraction is not appropriate. Instead we should just
compare the two pointers directly, as this should work everywhere and
potentially generate more efficient code.
Reviewers: bogner, lebedev.ri, efriedma, t.p.northover, uweigand, sunfish
Reviewed By: lebedev.ri
Subscribers: dschuff, sbc100, arichardson, jgravelle-google, hiraditya, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74454
For a file in WebKit, this brings the time spent in LiveDebugValues down
from 16 minutes to 2 minutes. The reduction comes from iterating the set
of open variable locations just once in transferRegisterDef. Post-patch,
the most expensive item inside of transferRegisterDef is a call to
VarLoc::isDescribedByReg, which we have to do.
Testing: I built LNT using the Os-g cmake cache with & without this
patch, then diffed the object files to verify there was no binary diff.
rdar://59446577
Differential Revision: https://reviews.llvm.org/D74633
These are going to be useful in TargetLowering::SimplifyDemandedBits, so expose these helpers outside of SelectionDAG.cpp
Also add an getValidShiftAmountConstant early-out to getValidMinimumShiftAmountConstant/getValidMaximumShiftAmountConstant so we can use them for scalar cases as well.
Produce an unmerge to a narrower type and introduce a narrower shift
if needed. I wasn't sure if there was a better way to parameterize the
target's preferred shift type for the GICombineRule, so manually call
the combine helper.
Summary:
This patch implements the part of the calling convention
where SVE Vectors are passed by reference. This means the
caller must allocate stack space for these objects and
pass the address to the callee.
Reviewers: efriedma, rovka, cameron.mcinally, c-rhodes, rengolin
Reviewed By: efriedma
Subscribers: tschuett, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71216
This adds another pattern to the combiner for a case that we were not handling
to generate the REV16 instruction for ARM/Thumb2 and a bswap+ror on X86.
Differential Revision: https://reviews.llvm.org/D74032
Summary:
When using strict fp, it is required to update the
chain when performing integer type promotion of a
operand to a integer to floating point conversion.
Reviewers: craig.topper, john.brawn
Reviewed By: craig.topper
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74597
Follow-up for D74006.
When the integrated assembler is used, we use SHF_LINK_ORDER. The
linked-to symbol is part of ELFSectionKey, thus we can omit the unique
ID.
In https://reviews.llvm.org/rG8b737688c21a9755cae14cb9343930e0882164ab I
switched the condition gating the creation of the descriptor symbol from
checking the MCAsmInfo if we need to support descriptors, to if the OS
was AIX. Technically the 2 should be interchangeable: if we are
targeting AIX then we need to emit XCOFF object files, and the MCAsmInfo
must return true for needing function descriptors.
This doesn't account for lit test with runsteps that only set the arch.
Eg: test/CodeGen/XCore/section-name.ll
which when run natively on AIX we end up with a target xcore-ibm-aix and
needFunctionDescriptors is false.
This patch reverts to using the MCAsmInfo and adds an assert that the
target OS must be AIX since that is the only target using the descriptor
hook.
Differential Revision: https://reviews.llvm.org/D74622
This is more or less directly ported from the AMDGPU custom lowering
for FP_TO_FP16. I made a few minor fixups (using G_UNMERGE_VALUES
instead of creating shift/trunc to extract the two halves, and zexting
an inverted compare instead of select_cc).
This also does not include the fast math expansion the DAG which
converts to f32 and then to f16. I think that belongs in a
pre-legalize combine instead.
Like COPY instructions explained in D70616, we don't check the constraints
when combining G_UNMERGE_VALUES. Use the same logic used in D70616 to check
if registers can be replaced, or a COPY instruction needs to be built.
https://reviews.llvm.org/D70564
The goal of this patch is to maximize CPU utilization on multi-socket or high core count systems, so that parallel computations such as LLD/ThinLTO can use all hardware threads in the system. Before this patch, on Windows, a maximum of 64 hardware threads could be used at most, in some cases dispatched only on one CPU socket.
== Background ==
Windows doesn't have a flat cpu_set_t like Linux. Instead, it projects hardware CPUs (or NUMA nodes) to applications through a concept of "processor groups". A "processor" is the smallest unit of execution on a CPU, that is, an hyper-thread if SMT is active; a core otherwise. There's a limit of 32-bit processors on older 32-bit versions of Windows, which later was raised to 64-processors with 64-bit versions of Windows. This limit comes from the affinity mask, which historically is represented by the sizeof(void*). Consequently, the concept of "processor groups" was introduced for dealing with systems with more than 64 hyper-threads.
By default, the Windows OS assigns only one "processor group" to each starting application, in a round-robin manner. If the application wants to use more processors, it needs to programmatically enable it, by assigning threads to other "processor groups". This also means that affinity cannot cross "processor group" boundaries; one can only specify a "preferred" group on start-up, but the application is free to allocate more groups if it wants to.
This creates a peculiar situation, where newer CPUs like the AMD EPYC 7702P (64-cores, 128-hyperthreads) are projected by the OS as two (2) "processor groups". This means that by default, an application can only use half of the cores. This situation could only get worse in the years to come, as dies with more cores will appear on the market.
== The problem ==
The heavyweight_hardware_concurrency() API was introduced so that only *one hardware thread per core* was used. Once that API returns, that original intention is lost, only the number of threads is retained. Consider a situation, on Windows, where the system has 2 CPU sockets, 18 cores each, each core having 2 hyper-threads, for a total of 72 hyper-threads. Both heavyweight_hardware_concurrency() and hardware_concurrency() currently return 36, because on Windows they are simply wrappers over std:🧵:hardware_concurrency() -- which can only return processors from the current "processor group".
== The changes in this patch ==
To solve this situation, we capture (and retain) the initial intention until the point of usage, through a new ThreadPoolStrategy class. The number of threads to use is deferred as late as possible, until the moment where the std::threads are created (ThreadPool in the case of ThinLTO).
When using hardware_concurrency(), setting ThreadCount to 0 now means to use all the possible hardware CPU (SMT) threads. Providing a ThreadCount above to the maximum number of threads will have no effect, the maximum will be used instead.
The heavyweight_hardware_concurrency() is similar to hardware_concurrency(), except that only one thread per hardware *core* will be used.
When LLVM_ENABLE_THREADS is OFF, the threading APIs will always return 1, to ensure any caller loops will be exercised at least once.
Differential Revision: https://reviews.llvm.org/D71775
replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effect of
replaceDbgDeclare is that it moves dbg.declares around in the
instruction stream (typically by hoisting them into the entry block).
This behavior was introduced in llvm/r227544 to fix an assertion failure
(llvm.org/PR22386), but no longer appears to be necessary.
Hoisting a dbg.declare generally does not create problems. Usually,
dbg.declare either describes an argument or an alloca in the entry
block, and backends have special handling to emit locations for these.
In optimized builds, LowerDbgDeclare places dbg.values in the right
spots regardless of where the dbg.declare is. And no one uses
replaceDbgDeclare to handle things like VLAs.
However, there doesn't seem to be a positive case for moving
dbg.declares around anymore, and this reordering can get in the way of
understanding other bugs. I propose getting rid of it.
Testing: stage2 RelWithDebInfo sanitized build, check-llvm
rdar://59397340
Differential Revision: https://reviews.llvm.org/D74517
Patchable statepoint is lowered into sequence of nops, so zeroed call target
should not be on register. It is better to use getTargetConstant instead
of getConstant to select zero constant for call target.
Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D74465
Current tail duplication embedded in MBP duplicates a BB into all or none of its predecessors without too much cost analysis. So sometimes it is duplicated into cold predecessors, and in other cases it may miss the duplication into hot predecessors.
This patch improves tail duplication in 3 aspects:
A successor can be duplicated into part of its predecessors.
A more fine-grained benefit analysis, combined with 1, now a successor is duplicated into hot predecessors only.
If a successor can't be duplicated into one predecessor, it doesn't impact the duplication into other predecessors.
Differential Revision: https://reviews.llvm.org/D73387
Summary:
This was a very odd API, where you had to pass a flag into a zext
function to say whether the extended bits really were zero or not. All
callers passed in a literal true or false.
I think it's much clearer to make the function name reflect the
operation being performed on the value we're tracking (rather than on
the KnownBits Zero and One fields), so zext means the value is being
zero extended and new function anyext means the value is being extended
with unknown bits.
NFC.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74482
The isNegatibleForFree/getNegatedExpression methods currently rely on a raw char value to indicate whether a negation is beneficial or not.
This patch replaces the char return value with an NegatibleCost enum to more clearly demonstrate what is implied.
It also renames isNegatibleForFree to getNegatibleCost to more accurately reflect whats going on.
Differential Revision: https://reviews.llvm.org/D74221
Summary:
Right now the alignment of the lower half of a store is computed as
align/2, which fails for unaligned stores (align = 1), and is overly
pessimitic for, e.g. a 8 byte store aligned to 4 bytes.
Fixes PR44851
Fixes PR44877
Reviewers: gchatelet, spatel, lebedev.ri
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74311
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
Summary:
The method attempts to find loads that can be legally clustered by
looking for loads consuming the same chain glue token.
However, the old code looks at _all_ users of values produced by the
chain node -- including uses of the loaded/returned value of volatile
loads or atomics. This could lead to circular dependencies which then
failed during scheduling.
With this change, we filter out users by getResNo, i.e. by which
SDValue value they use, to ensure that we only look at users of the
chain glue token.
This appears to be a rather old bug, which is perhaps surprising.
However, the test case is actually quite fragile (i.e., it is hidden
by fairly small changes), and the test _must_ use volatile loads for
the bug to manifest.
Reviewers: arsenm, bogner, craig.topper, foad
Subscribers: MatzeB, jvesely, wdng, hiraditya, javed.absar, jfb, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74253
This adds a strict version of FP16_TO_FP and FP_TO_FP16 and uses
them to implement soft promotion for the half type. This is
enough to provide basic support for __fp16 with strictfp.
Add the necessary X86 support to use VCVTPS2PH/VCVTPH2PS when F16C
is enabled.
Instructions marked as FrameSetup do not cause requestLabelAfterInsn to
be called and so no such label is generated. Call instructions which
require call site entries to be generated require this label to be
present in order to calculate the return PC offset/address, but the
check for whether the call instruction is marked as FrameSetup was not
present.
Therefore in the case where a call instruction is marked as FrameSetup,
an assertion failure occurs if a call site entry is to be generated.
This is the case with RISC-V's implementation of save/restore via
library calls.
Differential Revision: https://reviews.llvm.org/D71593
Fixup the UserValue methods to use FragmentInfo instead of DIExpression because
the DIExpression is only ever used to get the to get the FragmentInfo. The
DIExpression is meaningless in the UserValue class because each definition point
added to a UserValue may have a unique DIExpression.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74057
Rename the class DbgValueLocation to DbgVariableValue and instances from Loc to
DbgValue. These names better express the new semantics introduced in D74053.
The class previously represented a { Location } only. It now represents a
{ Location, DIExpression } pair which together describe a value.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74055
LiveDebugVariables uses interval maps to explicitly represent DBG_VALUE
intervals. DBG_VALUEs are filtered into an interval map based on their {
Variable, DIExpression }. The interval map will coalesce adjacent entries that
use the same { Location }. Under this model, DBG_VALUEs which refer to the same
bits of the same variable will be filtered into different interval maps if they
have different DIExpressions which means the original intervals will not be
properly preserved.
This patch fixes the problem by using { Variable, Fragment } to filter the
DBG_VALUEs into maps, and coalesces adjacent entries iff they have the same
{ Location, DIExpression } pair.
The solution is not perfect because we see the similar issues appear when
partially overlapping fragments are encountered, but is far simpler than a
complete solution (i.e. D70121).
Fixes: pr41992, pr43957
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74053
A downstream test exposed a simple logic bug with the manual pointer
stripping code, fix that by just using stripPointerCasts() on the value.
I don't think there's a way to expose this issue upstream.
SUMMARY:
The patch is enable to support Mergeable2ByteCString and Mergeable4ByteCString
Reviewers: daltenty
Subscribers: wuzish, nemanjai, hiraditya
Differential Revision: https://reviews.llvm.org/D74164
Add a simplification to fuse a manual vector extract with shifts and
truncate into a bitcast.
Unpacking and packing values into vectors is only optimized with
extractelement instructions, not when manually unpacked using shifts
and truncates.
This patch simplifies shifts and truncates into a bitcast if possible.
Simplify (build_vec (trunc $1)
(trunc (srl $1 width))
(trunc (srl $1 (2 * width))) ...)
to (bitcast $1)
Differential Revision: https://reviews.llvm.org/D73892
Use the isCandidateForCallSiteEntry().
This should mostly be an NFC, but there are some parts ensuring
the moveCallSiteInfo() and copyCallSiteInfo() operate with call site
entry candidates (both Src and Dest should be the call site entry
candidates).
Differential Revision: https://reviews.llvm.org/D74122
Remove code from LegalizeTypes that allowed this to work.
We were already using BUILD_PAIR for this in some places so this
standardizes on a single way to do this.
Summary:
For CTTZ we place a set bit just past where the non-promoted type
stopped so the extended bits won't be used for the count. For
CTTZ_ZERO_UNDEF we don't care what happens if no bits are set in
the original type and we end up counting into the extended bits.
So we can just use ANY_EXTEND for both cases.
This matches what is done in type legalization for these operations.
We make no effort to force the upper bits to zero.
Differential Revision: https://reviews.llvm.org/D74111
Calls to ObjC's objc_msgSend function are done by bitcasting the function global
to the required function type signature. This patch looks through this bitcast
so that we can do a direct call with bl on arm64 instead of using an indirect blr.
Differential Revision: https://reviews.llvm.org/D74241
Add the isCandidateForCallSiteEntry predicate to MachineInstr to
determine whether a DWARF call site entry should be created for an
instruction.
For now, it's enough to have any call instruction that doesn't belong to
a blacklisted set of opcodes. For these opcodes, a call site entry isn't
meaningful.
Differential Revision: https://reviews.llvm.org/D74159
Allows more flexible use of buildMerge in places where
use operands are available as SrcOp since it does not
require explicit conversion to Register.
Simplify code with new buildMerge.
Differential Revision: https://reviews.llvm.org/D74223
This is a one off special case, since actually implementing full inline asm
support will be much more involved. This lets us compile a lot more code as a
common simple case.
Differential Revision: https://reviews.llvm.org/D74201
Printing floating point number in decimal is inconvenient for humans.
Verbose asm output will print out floating point values in comments, it
helps.
But in lots of cases, users still need additional work to covert the
decimal back to hex or binary to check the bit patterns,
especially when there are small precision difference.
Hexadecimal form is one of the supported form in LLVM IR, and easier for
debugging.
This patch try to print all FP constant in hex form instead.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D73566
The type passed to lower was invalid, so I'm not sure how this was
even working before. The source and destination type also do not have
to match, so make sure to use the right ones.
Summary: This patch introduces an API for MemOp in order to simplify and tighten the client code.
Reviewers: courbet
Subscribers: arsenm, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73964
Summary:
This patch reorders the emission of debug_str section, so that
string can come after macros.
This is necessary for macro forms like DW_MACRO_define_strp,
which emits macro as a string in debug_str section.
"linked-to section" is used by the ELF spec. By analogy, "linked-to
symbol" is a good name for the signature symbol. The word "linked-to"
implies a directed edge and makes it clear its relation with "sh_link",
while one can argue that "associated" means an undirected edge.
Also, combine tests and add precise SMLoc to improve diagnostics.
Reviewed By: eugenis, grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D74082
This reverts commit ed29dbaafa.
I'm backing out D68945, which as the discussion for D73526 shows, doesn't
seem to handle the -O0 path through the codegen backend correctly. I'll
reland the patch when a fix is worked out, apologies for all the churn.
The two parent commits are part of this revert too.
Conflicts:
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/test/DebugInfo/X86/dbg-addr-dse.ll
SelectionDAGBuilder conflict is due to a nearby change in e39e2b4a79
that's technically unrelated. dbg-addr-dse.ll conflicted because
41206b61e3 (legitimately) changes the order of two lines.
There are further modifications to dbg-value-func-arg.ll: it landed after
the patch being reverted, and I've converted indirection to be represented
by the isIndirect field rather than DW_OP_deref.
This reverts commit 3137fe4d23.
I'm backing out D68945, which this patch is a follow up for. It'll be
re-landed when D68945 is fixed.
The changes to dbg-value-func-arg.ll occur because our handling of certain
kinds of location now mixes up indirection that happens at different points
in a DIExpression. While this is a regression, it's a return to the prior
behaviour while a better patch is sought.
This reverts commit 2d3174c4df.
The overall solution for this problem is reverting D68945, which wasn't
handling the -O0 path through the codegen backend correctly. See:
discussion in D73526.
To find the instruction in the block for a given ID, first a count and then a
lookup was performed in the map, which is almost the same thing, thus doing
double the work.
Differential Revision: https://reviews.llvm.org/D73866
Summary:
ARM Type Promotion pass does not clear
the container that defines if one variable
was visited or not, missing optimization
opportunities by luck when two llvm:Values
from different functions are allocated at
the same memory address.
Also fixes a comment and uses existing
method to pop and obtain last element
of the worklist.
Reviewers: samparker
Reviewed By: samparker
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73970
This is a compile-time optimization for PHIElimination (splitting of critical
edges), which was reported at https://bugs.llvm.org/show_bug.cgi?id=44249. As
discussed there, the way to remedy the slowdowns with huge functions is to
pre-compute the live-in registers for each MBB in an efficient way in
PHIElimination.cpp and then pass that information along to
LiveVariabless::addNewBlock().
In all the huge test programs where this slowdown has been noticable, it has
dissapeared entirely with this patch.
Review: Björn Pettersson, Quentin Colombet.
Differential Revision: https://reviews.llvm.org/D73152
The legalizer produces a lot of these, and they make reading legalized
MIR annoying. For some reason, this does seem to sometimes introduce
copies of implicit def, which is dumb.
contractCrossBankCopyIntoStore() finds the instruction defines the
source register and uses its output to replace the register. There are,
however, instructions that have multiple outputs, e.g. G_UNMERGE_VALUES.
Current implementation hardcodes to operand 0 and has no way of knowing
which output should be used.
This change adds another function to directly return the register that
is the source of the register and use that for folding.
This fixes https://bugs.llvm.org/show_bug.cgi?id=44783
Differential Revision: https://reviews.llvm.org/D74005
We currently only handle mem instructions with a single define.
Avoid the call site parameter debug info when we find the case with
multiple defs, rather than throwing an assert.
Differential Revision: https://reviews.llvm.org/D73954
Summary:
This reverts commit 3ef169e586. The
purpose of this commit was to allow stack machines to perform
instruction selection for instructions with variadic defs. However,
MachineInstrs fundamentally cannot support variadic defs right now, so
this change does not turn out to be useful.
Depends on D73927.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73928
Originally committed in: 1ced28cbe7
Reverted in: f75301d16d
(reverted due to tests failing on non-linux/x86 targets, tests have since been
generalized and specialized... since Split DWARF isn't supported on non-elf
targets anyway and we have no way to run on "whatever elf target is available"
so they fail on MacOS without an explicit target triple)
This code was incorrectly emitting extra bytes into arbitrary parts of
the object file when it was meant to be hashing them to compute the DWO
ID.
Follow-up patch(es) will refactor this API somewhat to make such bugs
harder to introduce, hopefully.
This extends the RemarkStreamer to allow for other emitters (e.g.
frontends, SIL, etc.) to emit remarks through a common interface.
See changes in llvm/docs/Remarks.rst for motivation and design choices.
Differential Revision: https://reviews.llvm.org/D73676
The CATCHPAD node mostly existed to be selected into the EH_RESTORE
instruction, which sets the frame back up when 32-bit Windows exceptions
return to the parent function. However, creating this MachineInstr early
increases the risk that other passes will come along and insert
instructions that use the stack before ESP and EBP are restored. That
happened in PR44697.
Instead of representing these in the instruction stream early, delay it
until PEI. Mark the blocks where this needs to happen as EHPads, but not
funclet entry blocks. Passes after PEI have to be careful not to hoist
instructions that can use stack across frame setup instructions, so this
should be relatively reliable.
Fixes PR44697
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D73752
shouldOptimizeForSize is showing up in a profile, spending around 10%
of the pass time in one function. This should probably not be so slow,
but the much cheaper attribute check should be done first anyway.
AMDGPU and x86 at least both have separate controls for whether
denormal results are flushed on output, and for whether denormals are
implicitly treated as 0 as an input. The current DAGCombiner use only
really cares about the input treatment of denormals.
This patch reverts part of r362750 / D62650, which stopped
LiveDebugVariables from trimming leading variable location ranges down
to only covering those instructions that are in scope. I've observed some
circumstances where the number of DBG_VALUEs in a function can be
amplified in an un-necessary way, to cover more instructions that are
out of scope, leading to very slow compile times. Trimming the range
of instructions that the variables cover solves the slow compile times.
The specific problem that r362750 tries to fix is addressed by the
assignment to RStart that I've added. Any variable location that begins
at the first instruction of a block will now be considered to begin at the
start of the block. While these sound the same, the have different
SlotIndexes, and the register allocator may shoehorn additional
instructions in between the two. The test added in the past
(wrong_debug_loc_after_regalloc.ll) still works with this modification.
live-debug-variables.ll has a range trimmed to not cover the prologue of
the function, while dbg-addr-dse.ll has a DBG_VALUE sink past one
instruction with no DebugLoc, which is expected behaviour.
Differential Revision: https://reviews.llvm.org/D73691
Ensure that OptLevelChanger::SavedFastISel is initialized in the constructor.
This should be NFC - as the equivalent 'same opt level' early-out is used in the destructor as well, so SavedFastISel is only actually referenced in the general case.
Differential Revision: https://reviews.llvm.org/D73875
Under MVE, we do not have any lowering for fminimum, which a
vector_reduce_fmin without NoNan will be expanded into. As with the
other recent patches, force this to expand in the pre-isel pass. Note
that Neon lowering would be OK because the scalar fminimum uses the
vector VMIN instruction, but is probably better to just rely on the
scalar operations, which is what is done here.
Also fixes what appears to be the reversal of INF vs -INF in the
vector_reduce_fmin widening code.
This code was incorrectly emitting extra bytes into arbitrary parts of
the object file when it was meant to be hashing them to compute the DWO
ID.
Follow-up patch(es) will refactor this API somewhat to make such bugs
harder to introduce, hopefully.
Start using a new strategy with a combination of merge and unmerges.
This allows scalarizing before lowering, which in cases like
<2 x s128> avoids producing giant illegal shifts.
RegAllocGreedy uses a fairly compile time intensive splitting heuristic
called region splitting. This heuristic was disabled via another heuristic
when it is likely that it won't be worth the compile time. The only way
to control this other heuristic was via a command line option (huge-size-for-split).
This commit gives more control on this heuristic by making it overridable
by the target using a target hook in TargetRegisterInfo called
shouldRegionSplitForVirtReg.
The default implementation of this hook keeps the heuristic as it was
before this patch.
We have to be careful in SimplifyDemandedBits with loads in case we attempt to combine back to a constant (which then gets turned into a constant pool load again), but we can at least set the upper KnownBits for a ZEXTLoad to zero.
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: arsenm, dschuff, jyknight, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73885
Summary:
A Copy with a source that is zeros is the same as a Set of zeros.
This fixes the invariant that SrcAlign should always be non-null.
Reviewers: courbet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73791
The code paths in the absence of TargetMachine, TargetLowering or
TargetRegisterInfo are poorly tested. As rL285987 said, requiring
TargetPassConfig allows us to delete many (untested) checks littered
everywhere.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D73754
The current FirstMI.getDebugLoc() is actually null in almost all cases.
If it isn't, the generated .loc will be considered initial. The .loc
will have the prologue_end flag and terminate the prologue prematurely.
Also use an overload of BuildMI that will not prepend
PATCHABLE_FUNCTION_ENTRY to a MachineInstr bundle.
This is based on this llvm-dev thread http://lists.llvm.org/pipermail/llvm-dev/2019-December/137521.html
The current strategy for f16 is to promote type to float every except where the specific width is required like loads, stores, and bitcasts. This results in rounding occurring in odd places instead of immediately after arithmetic operations. This interacts in weird ways with the __fp16 type in clang which is a storage only type where arithmetic is always promoted to float. InstCombine can remove some fpext/fptruncs around such arithmetic and turn it into arithmetic on half. This wouldn't be so bad if SelectionDAG was able to put those fpext/fpround back in when it promotes.
It is also not obvious how to handle to make the existing strategy work with STRICT fp. We need to use STRICT versions of the conversions which require chain operands. But if the conversions are created for a bitcast, there is no place to get an appropriate chain from.
This patch implements a different strategy where conversions are emitted directly around arithmetic operations. And otherwise its passed around as an i16 including in arguments and return values. This can result in more conversions between arithmetic operations, but is closer to matching the IR the frontend generates for __fp16. And it will allow us to use the chain from constrained arithmetic nodes to link the STRICT_FP_TO_FP16/STRICT_FP16_TO_FP that will need to be added. I've set it up so that each target can opt into the new behavior. Converting all the targets myself was more than I was able to handle.
Differential Revision: https://reviews.llvm.org/D73749
Significant missing hashing - as per the comment this was only meant to
skip member functions (unspecified, but I think it's legible as member
function declarations, not definitions) but was skipping all named
subprograms (so only hashed child DIEs for member function definitions -
because they didn't have a direct name, but only a name given indirectly
in the DW_AT_specification-referenced DIE)
Summary:
Applying this cleanup:
- MIRBuilder.buildInstr(TargetOpcode::G_ASHR)
- .addDef(Shifted)
- .addUse(Res)
- .addUse(ShiftAmt);
+ MIRBuilder.buildAShr(Shifted, Res, ShiftAmt);
caused an assertion failure here:
llc: /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/MachineRegisterInfo.cpp:404: llvm::MachineInstr *llvm::MachineRegisterInfo::getVRegDef(unsigned int) const: Assertion `(I.atEnd() || std::next(I) == def_instr_end()) && "getVRegDef assumes a single definition or no definition"' failed.
#4 0x00000000050a6d96 in llvm::MachineRegisterInfo::getVRegDef (this=0x74606a0, Reg=2147483650) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/MachineRegisterInfo.cpp:403
#5 0x00000000066148f6 in llvm::getConstantVRegValWithLookThrough (VReg=2147483650, MRI=..., LookThroughInstrs=false, HandleFConstant=true) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/Utils.cpp:244
#6 0x00000000066147da in llvm::getConstantVRegVal (VReg=2147483650, MRI=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/Utils.cpp:210
#7 0x0000000006615367 in llvm::ConstantFoldBinOp (Opcode=101, Op1=2147483650, Op2=2147483656, MRI=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/Utils.cpp:341
#8 0x000000000657eee0 in llvm::CSEMIRBuilder::buildInstr (this=0x7465010, Opc=101, DstOps=..., SrcOps=..., Flag=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/CSEMIRBuilder.cpp:160
#9 0x0000000003645958 in llvm::MachineIRBuilder::buildAShr (this=0x7465010, Dst=..., Src0=..., Src1=..., Flags=...) at /home/jayfoad2/git/llvm-project/llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h:1298
#10 0x00000000065c35b1 in llvm::LegalizerHelper::lower (this=0x7fffffffb5f8, MI=..., TypeIdx=0, Ty=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2020
because at this point there are two instructions defining Res: the
original G_SMULO/G_UMULO and the new G_MUL that we built. The fix is
to modify the original mul in place, so that there is only ever one
definition of Res.
Reviewers: arsenm, aditya_nandakumar
Subscribers: wdng, rovka, hiraditya, volkan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72842
This allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits to create a simpler ISD::INSERT_SUBVECTOR, which is particularly useful for cases where we're splitting into subvectors anyhow.
Some code gen passes use MBFIWrapper to keep track of the frequency of new
blocks. This was not taken into account and could lead to incorrect frequencies
as MBFI silently returns zero frequency for unknown/new blocks.
Add a variant for MBFIWrapper in the PGSO query interface.
Depends on D73494.
Summary: This is a first step before changing the types to llvm::Align and introduce functions to ease client code.
Reviewers: courbet
Subscribers: arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73785
One of the exit criteria of computeKnownBits is whether we reach the max
recursive call depth. Before this patch we would check that the
depth is exactly equal to max depth to exit.
Depth may get bigger than max depth if it gets passed to a different
GISelKnownBits object.
This may happen when say a generic part uses a GISelKnownBits object
with some max depth, but then we hit TL.computeKnownBitsForTargetInstr
which creates a new GISelKnownBits object with a different and smaller
depth. In that situation, when we hit the max depth check for the first
time in the target specific GISelKnownBits object, depth may already
be bigger than the current max depth. Hence we would continue to compute
the known bits, until we ran through the full depth of the chain of
computation or ran out of stack space.
For instance, let say we have
GISelKnownBits Info(/*MaxDepth*/ = 10);
Info.getKnownBits(Foo)
// 9 recursive calls to computeKnownBitsImpl.
// Then we hit a target specific instruction.
// The target specific GISelKnownBits does this:
GISelKnownBits TargetSpecificInfo(/*MaxDepth*/ = 6)
TargetSpecificInfo.computeKnownBitsImpl() // <-- next max depth checks would
// always return false.
This commit does not have any test case, none of the in-tree targets
use computeKnownBitsForTargetInstr.
This patch addresses the issue found in https://bugs.llvm.org/show_bug.cgi?id=44585
where a DW_OP_deref was placed at the end of a dwarf expression, resulting in corrupt
symbols when debugging.
This is an attempt to reland with a few fixes for buildbot since I
haven't merged from master in a bit.
Differential Revision: https://reviews.llvm.org/D73526
We can have geps that have a scalar base pointer, and a vector index value, which
means that the base pointer must be splatted into a vector of pointers.
This fixes crashes on arm64 GlobalISel with optimizations enabled.
- Extends the comments related to function descriptors, noting how they
are only used on AIX.
- Changes the condition used to gate the creation of the current function
symbol in AsmPrinter::SetupMachineFunction to reflect being AIX
specific. The creation of the symbol is different because of AIXs
linkage conventions, not because AIX uses function descriptors.
Differential Revision: https://reviews.llvm.org/D73115
Summary:
For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after
9a24488cb6, we place the NOP sled after
the initial BTI.
```
.Lfunc_begin0:
bti c
nop
nop
.section __patchable_function_entries,"awo",@progbits,f,unique,0
.p2align 3
.xword .Lfunc_begin0
```
This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label:
```
.Lfunc_begin0:
bti c
.Lpatch0:
nop
nop
.section __patchable_function_entries,"awo",@progbits,f,unique,0
.p2align 3
.xword .Lpatch0
```
This placement is compatible with the resolution in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 .
A local linkage function whose address is not taken does not need a BTI.
Placing the patch label after BTI has the advantage that code does not
need to differentiate whether the function has an initial BTI.
Reviewers: mrutland, nickdesaulniers, nsz, ostannard
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73680
Commit 9965b12fd1 was supposed to change the offset constant when
lowering load/stores, but only introduced this change for loads. This
patch adds the same fix for stores.
This is passed to legalizeCustom, but not intrinsic. Also remove the
MRI argument, since you can get that from the MachineIRBuilder.
I'm not sure why MachineIRBuilder has a private observer member, and
this is passed separately.
For pow2 constants we should use G_SHL for pattern matching (and perf)
purposes later.
Vector support not yet implemented.
Differential Revision: https://reviews.llvm.org/D73659
For `MC_GlobalAddress` operands referencing **certain** GlobalObjects,
we can lower them to STB_LOCAL aliases to avoid costs brought by
assembler/linker's conservative decisions about symbol interposition:
* An assembler conservatively assumes a global default visibility symbol interposable (ELF
semantics). So relocations in object files are needed even if the code generator assumed
the definition exact and non-interposable.
* The relocations can cause the creation of PLT entries on some targets for -shared links.
A linker conservatively assumes a global default visibility symbol interposable (if not
otherwise constrained by -Bsymbolic/--dynamic-list/VER_NDX_LOCAL/etc).
"certain" refers to GlobalObjects in the intersection of
`hasExactDefinition() and !isInterposable()`: `external`, `appending`, `internal`, `private`.
Local linkages (`internal` and `private`) cannot be interposed. `appending` is for very
few objects LLVM interpret specially. So the set just includes `external`.
This patch emits STB_LOCAL aliases (.Lfoo$local) for such GlobalObjects, so that targets can lower
MC_GlobalAddress operands to STB_LOCAL aliases if applicable.
We may extend the scope and include GlobalAlias in the future.
LLVM's existing -fno-semantic-interposition behaviors give us license to do such optimizations:
* Various optimizations (ipconstprop, inliner, sccp, sroa, etc) treat normal ExternalLinkage
GlobalObjects as non-interposable.
* Before D72197, MC resolved a PC-relative VK_None fixup to a non-local symbol at assembly time (no
outstanding relocation), if the target is defined in the same section. Put it simply, even if IR
optimizations failed to optimize and allowed interposition for the function call in
`void foo() {} void bar() { foo(); }`, the assembler would disallow it.
This patch sets up AsmPrinter infrastructure to make -fno-semantic-interposition more so.
With and without the patch, the object file output should be identical:
`.Lfoo$local` does not take a symbol table entry.
Reviewed By: sfertile
Differential Revision: https://reviews.llvm.org/D73228
Summary:
BaseMemOpClusterMutation::apply forms store chains by looking for
control (i.e. non-data) dependencies from one mem op to another.
In the test case, clusterNeighboringMemOps successfully clusters the
loads, and then adds artificial edges to the loads' successors as
described in the comment:
// Copy successor edges from SUa to SUb. Interleaving computation
// dependent on SUa can prevent load combining due to register reuse.
The effect of this is that *data* dependencies from one load to a store
are copied as *artificial* dependencies from a different load to the
same store.
Then when BaseMemOpClusterMutation::apply looks at the stores, it finds
that some of them have a control dependency on a previous load, which
breaks the chains and means that the stores are not all considered part
of the same chain and won't all be clustered.
The fix is to only consider non-artificial control dependencies when
forming chains.
Subscribers: MatzeB, jvesely, nhaehnle, hiraditya, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71717
Add several new helpers to RDA:
- hasLocalDefBefore
- isRegDefinedAfter
- isSafeToDefRegAt
And move two bits of logic from ARMLowOverheadLoops into RDA:
- isSafeToMove
- isSafeToRemove
Both of these have some wrappers too to make them more convienent to
use.
Differential Revision: https://reviews.llvm.org/D73460
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Symbols created for merged external global variables have default
visibility. This can break programs when compiling with -Oz
-fvisibility=hidden as symbols that should be hidden will be exported at
link time.
Differential Revision: https://reviews.llvm.org/D73235
Summary:
To avoid header file circular dependency issues in passing updated MBFI (in
MBFIWrapper) to the interface of profile guided size optimizations.
A prep step for (and split off of) D73381.
Reviewers: davidxl
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73494
Summary:
This is a follow up on D61634. It adds an LLVM IR intrinsic to allow better implementation of memcpy from C++.
A follow up CL will add the intrinsics in Clang.
Reviewers: courbet, theraven, t.p.northover, jdoerfert, tejohnson
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71710
Summary:
This is mostly NFC. computeForAddSub may give more precise results in
some cases, but that doesn't seem to affect any existing GlobalISel
tests.
Subscribers: rovka, hiraditya, volkan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73431
This allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits to create a simpler ISD::EXTRACT_SUBVECTOR, which is particularly useful for cases where we're splitting into subvectors anyhow.
Differential Revision: This allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits to create a simpler ISD::EXTRACT_SUBVECTOR, which is particularly useful for cases where we're splitting into subvectors anyhow.
This patch fixes an assertion failure in DwarfExpression that is
triggered when a complex fragment has exactly the size of a
subregister of the register the DBG_VALUE points to *and* there is no
DWARF encoding for the super-register.
I took the opportunity to replace/document some magic values with
static constructor functions to make this code less confusing to read.
rdar://problem/58489125
Differential Revision: https://reviews.llvm.org/D72938
This is a revert-of-revert (i.e. this reverts commit 802bec89, which
itself reverted fa4701e1 and 79daafc9) with a fix folded in. The problem
was that call site tags weren't emitted properly when LTO was enabled
along with split-dwarf. This required a minor fix. I've added a reduced
test case in test/DebugInfo/X86/fission-call-site.ll.
Original commit message:
This allows a call site tag in CU A to reference a callee DIE in CU B
without resorting to creating an incomplete duplicate DIE for the callee
inside of CU A.
We already allow cross-CU references of subprogram declarations, so it
doesn't seem like definitions ought to be special.
This improves entry value evaluation and tail call frame synthesis in
the LTO setting. During LTO, it's common for cross-module inlining to
produce a call in some CU A where the callee resides in a different CU,
and there is no declaration subprogram for the callee anywhere. In this
case llvm would (unnecessarily, I think) emit an empty DW_TAG_subprogram
in order to fill in the call site tag. That empty 'definition' defeats
entry value evaluation etc., because the debugger can't figure out what
it means.
As a follow-up, maybe we could add a DWARF verifier check that a
DW_TAG_subprogram at least has a DW_AT_name attribute.
Update #1:
Reland with a fix to create a declaration DIE when the declaration is
missing from the CU's retainedTypes list. The declaration is left out
of the retainedTypes list in two cases:
1) Re-compiling pre-r266445 bitcode (in which declarations weren't added
to the retainedTypes list), and
2) Doing LTO function importing (which doesn't update the retainedTypes
list).
It's possible to handle (1) and (2) by modifying the retainedTypes list
(in AutoUpgrade, or in the LTO importing logic resp.), but I don't see
an advantage to doing it this way, as it would cause more DWARF to be
emitted compared to creating the declaration DIEs lazily.
Update #2:
Fold in a fix for call site tag emission in the split-dwarf + LTO case.
Tested with a stage2 ThinLTO+RelWithDebInfo build of clang, and with a
ReleaseLTO-g build of the test suite.
rdar://46577651, rdar://57855316, rdar://57840415, rdar://58888440
Differential Revision: https://reviews.llvm.org/D70350
The Version was used only to determine the size of an operand of
DW_OP_call_ref. The size was 4 for all versions apart from 2, but
the DW_OP_call_ref operation was introduced only in DWARF3. Thus,
the code may be simplified and using of Version may be eliminated.
Differential Revision: https://reviews.llvm.org/D73264
Summary:
This fixes PR44118. For cases where we have a chain like this:
R8 = R1 (entry value)
R0 = R8
call @foo R0
the code that emits call site entries using entry values would not
follow that chain, instead emitting a call site entry with R8 as
location rather than R0. Such a case was discovered when originally
adding dbgcall-site-orr-moves.mir. This patch fixes that issue. This is
done by changing the ForwardedRegWorklist set to a map in which the
worklist registers always map to the parameter registers that they
describe.
Another thing this patch fixes is that worklist registers now can
describe more than one parameter register at a time. Such a case
occurred in dbgcall-site-interpretation.mir, resulting in a call site
entry not being emitted for one of the parameters.
Reviewers: djtodoro, NikolaPrica, aprantl, vsk
Reviewed By: vsk
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D73168
Summary:
Since D70431 the describeLoadedValue() hook takes a parameter register,
meaning that it can now be asked to describe any register. This means
that we can drop the difference between explicit and implicit defines
that we previously had in collectCallSiteParameters().
I have not found any case for any upstream targets where a parameter
register is only implicitly defined, and does not overlap with any
explicit defines. I don't know if such a case would even make sense. So
as far as I have tested, this patch should be a non-functional change.
However, this reduces the complexity of the code a bit, and it will
simplify the implementation of an upcoming patch which solves PR44118.
Reviewers: djtodoro, NikolaPrica, aprantl, vsk
Reviewed By: djtodoro, vsk
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D73167
G_CTPOP is generated from llvm.ctpop.<type> intrinsics, clang generates
these intrinsics from __builtin_popcount and __builtin_popcountll.
Add lower and narrow scalar for G_CTPOP.
Lower G_CTPOP for MIPS32.
Differential Revision: https://reviews.llvm.org/D73216
llvm.cttz.<type> intrinsic has additional i1 argument is_zero_undef,
it tells whether zero as the first argument produces a defined result.
G_CTTZ is generated from llvm.cttz.<type> (<type> <src>, i1 false)
intrinsics, clang generates these intrinsics from __builtin_ctz and
__builtin_ctzll.
G_CTTZ_ZERO_UNDEF comes from llvm.cttz.<type> (<type> <src>, i1 true).
Clang generates such intrinsics as parts of expansion of builtin_ffs
and builtin_ffsll. It is also traditionally part of and many
algorithms that are now predicated on avoiding zero-value inputs.
Add narrow scalar (algorithm uses G_CTTZ_ZERO_UNDEF) for G_CTTZ.
Lower G_CTTZ and G_CTTZ_ZERO_UNDEF for MIPS32.
Differential Revision: https://reviews.llvm.org/D73215
llvm.ctlz.<type> intrinsic has additional i1 argument is_zero_undef,
it tells whether zero as the first argument produces a defined result.
MIPS clz instruction returns 32 for zero input.
G_CTLZ is generated from llvm.ctlz.<type> (<type> <src>, i1 false)
intrinsics, clang generates these intrinsics from __builtin_clz and
__builtin_clzll.
G_CTLZ_ZERO_UNDEF can also be generated from llvm.ctlz with true as
second argument. It is also traditionally part of and many algorithms
that are now predicated on avoiding zero-value inputs.
Add narrow scalar for G_CTLZ (algorithm uses G_CTLZ_ZERO_UNDEF).
Lower G_CTLZ_ZERO_UNDEF and select G_CTLZ for MIPS32.
Differential Revision: https://reviews.llvm.org/D73214
and macro FUNCTION likewise. NFCI.
Some functions like fmuladd don't really have a node, we should divide
the declaration form those have node to avoid introducing fake nodes.
Differential Revision: https://reviews.llvm.org/D72871
... as well as:
Revert "[DWARF] Defer creating declaration DIEs until we prepare call site info"
This reverts commit fa4701e197.
This reverts commit 79daafc903.
There have been reports of this assert getting hit:
CalleeDIE && "Could not find DIE for call site entry origin
Teach the GISelKnowBits analysis how to deal with PHI operations.
PHIs are essentially COPYs happening on edges, so we can just reuse
the code for COPY.
This is NFC COPY-wise has we leave Depth untouched when calling
computeKnownBitsImpl for COPYs, like it was before this patch.
Increasing Depth is however required for PHIs as they may loop back to
themselves and we would end up in an infinite loop if we were not
increasing Depth.
Differential Revision: https://reviews.llvm.org/D73317
Updated FoldConstantArithmetic method signature to match that of
FoldConstantVectorArithmetic in preparation for merging the two
functions together
https://bugs.llvm.org/show_bug.cgi?id=36544
This is the first step in combining the various
FoldConstantVectorArithmetic and FoldConstantVectorArithmetic
functions into one FoldConstantArithmetic function.
Differential Revision: https://reviews.llvm.org/D72870
Unlike the existing code that I modified here, I only handle the
case where the strict_fsetcc has a single use. Not sure exactly
how to handle multiples uses.
Testing this on X86 is hard because we already have a other
combines that get rid of lowered version of the integer setcc that
this xor will eventually become. So this combine really just
saves a bunch of extra nodes being created. Not sure about other
targets.
Differential Revision: https://reviews.llvm.org/D71816
Scheduler sends NumLoads argument into shouldClusterMemOps()
one less the actual cluster length. So for 2 instructions
it will pass just 1. Correct this number.
This is NFC for in tree targets.
Differential Revision: https://reviews.llvm.org/D73292
Previously LiveDebugValues pass would consider meta instructions that 'fiddle' with liveness of registers as register definitions when transfering register defs. This would mean that, for example, a KILL instruction would cause LiveDebugValues to terminate the range of an earlier DBG_VALUE instruction resulting in the none propogation of said DBG_VALUE instructions into later blocks.
This patch adds the check and a helpful comment, fixes a test that previously tested for the broken behaviour by coincidence and adds a test specifically for this.
reviewers: vsk, dstenb, djtodoro
Differential Revision: https://reviews.llvm.org/D73210
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.
Reviewers: xbolva00, courbet, bollu
Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73099
Similar to the function attribute `prefix` (prefix data),
"patchable-function-prefix" inserts data (M NOPs) before the function
entry label.
-fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry)
will look like:
```
.type foo,@function
.Ltmp0: # @foo
nop
foo:
.Lfunc_begin0:
# optional `bti c` (AArch64 Branch Target Identification) or
# `endbr64` (Intel Indirect Branch Tracking)
nop
.section __patchable_function_entries,"awo",@progbits,get,unique,0
.p2align 3
.quad .Ltmp0
```
-fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable
placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html):
```
(a) (b)
func: func:
.Ltmp0: bti c
bti c .Ltmp0:
nop nop
```
(a) needs no additional code. If the consensus is to go for (b), we will
need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp .
Differential Revision: https://reviews.llvm.org/D73070
Match the approach in SimplifyDemandedBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits/ComputeNumSignBits call.
Match the approach in SimplifyDemandedBits/ComputeNumSignBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits call.
Match the approach in SimplifyDemandedBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits/ComputeNumSignBits call, additionally we only ever need original demanded elts of the base vector even if the index is unknown.
The low_pc is analog to the DW_AT_call_return_pc, since it describes
the return address after the call. The DW_AT_call_pc is the address
of the call instruction, and we don't use it at the moment.
Differential Revision: https://reviews.llvm.org/D73173
Summary:
We create a number of standard types of control sections in multiple places for
things like the function descriptors, external references and the TOC anchor
among others, so it is possible for their properties to be defined
inconsistently in different places. This refactor moves their creation and
properties into functions in the TargetLoweringObjectFile class hierarchy, where
functions for retrieving various special types of sections typically seem
to reside.
Note: There is one case in PPCISelLowering which is specific to function entry
points which we don't address since we don't have access to the TLOF there.
Reviewers: DiggerLin, jasonliu, hubert.reinterpretcast
Reviewed By: jasonliu, hubert.reinterpretcast
Subscribers: wuzish, nemanjai, hiraditya, kbarton, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72347
Summary:
Without the BFI update, some hot blocks are incorrectly treated as cold code.
This fixes a FDO perf regression in the TSVC benchmark from D71288.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73146
This patch also fixes up a number of cases in DAGCombine and
SelectionDAGBuilder where the size of a scalable vector is used in a
fixed-width context (thus triggering an assertion failure).
Reviewers: efriedma, c-rhodes, rovka, cameron.mcinally
Reviewed By: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71215
The generic BaseMemOpClusterMutation calls into TargetInstrInfo to
analyze the address of each load/store instruction, and again to decide
whether two instructions should be clustered. Previously this had to
represent each address as a single base operand plus a constant byte
offset. This patch extends it to support any number of base operands.
The old target hook getMemOperandWithOffset is now a convenience
function for callers that are only prepared to handle a single base
operand. It calls the new more general target hook
getMemOperandsWithOffset.
The only requirements for the base operands returned by
getMemOperandsWithOffset are:
- they can be sorted by MemOpInfo::Compare, such that clusterable ops
get sorted next to each other, and
- shouldClusterMemOps knows what they mean.
One simple follow-on is to enable clustering of AMDGPU FLAT instructions
with both vaddr and saddr (base register + offset register). I've left
a FIXME in the code for this case.
Differential Revision: https://reviews.llvm.org/D71655
In LLVM IR, vscale can be represented with an intrinsic. For some targets,
this is equivalent to the constexpr:
getelementptr <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1
This can be used to propagate the value in CodeGenPrepare.
In ISel we add a node that can be legalized to one or more
instructions to materialize the runtime vector length.
This patch also adds SVE CodeGen support for VSCALE, which maps this
node to RDVL instructions (for scaled multiples of 16bytes) or CNT[HSD]
instructions (scaled multiples of 2, 4, or 8 bytes, respectively).
Reviewers: rengolin, cameron.mcinally, hfinkel, sebpop, SjoerdMeijer, efriedma, lattner
Reviewed by: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68203
In GlobalISel we may in some unfortunate circumstances generate PHIs with
operands that are on separate banks. If-conversion doesn't currently check for
that case and ends up generating a CSEL on AArch64 with incorrect register
operands.
Differential Revision: https://reviews.llvm.org/D72961
Summary:
WebAssembly is unique among upstream targets in that it does not at
any point use physical registers to store values. Instead, it uses
virtual registers to model positions in its value stack. This means
that some target-independent lowering activities that would use
physical registers need to use virtual registers instead for
WebAssembly and similar downstream targets. This CL generalizes the
existing `usesPhysRegsForPEI` lowering hook to
`usesPhysRegsForValues` in preparation for using it in more places.
One such place is in InstrEmitter for instructions that have variadic
defs. On register machines, it only makes sense for these defs to be
physical registers, but for WebAssembly they must be virtual registers
like any other values. This CL changes InstrEmitter to check the new
target lowering hook to determine whether variadic defs should be
physical or virtual registers.
These changes are necessary to support a generalized CALL instruction
for WebAssembly that is capable of returning an arbitrary number of
arguments. Fully implementing that instruction will require additional
changes that are described in comments here but left for a follow up
commit.
Reviewers: aheejin, dschuff, qcolombet
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71484
These names have been changed from CamelCase to camelCase, but there were
many places (comments mostly) that still used the old names.
This change is NFC.
This was unconditionally folding this to the source operand, even if the access was out of bounds. Use undef instead of the extract is not the first element.
This helps with some cases where 3-vectors are legalized and avoids processing the 4th component.
Original Patch by: arsenm (Matt Arsenault)
Differential Revision: https://reviews.llvm.org/D51589
Summary:
This was reverted in 328e0f3dca due to
chromium bot failure. This revision addresses that case.
Original commit message:
Summary:
This patch will provide support for auto return type for the C++ member
functions. Before this return type of the member function is deduced and
stored in the DIE.
This patch includes llvm side implementation of this feature.
Patch by: Awanish Pandey <Awanish.Pandey@amd.com>
Reviewers: dblaikie, aprantl, shafik, alok, SouraVX, jini.susan.george
Reviewed by: dblaikie
Differential Revision: https://reviews.llvm.org/D70524
StackColoring::remapInstructions() remaps MachineOperand frame index (e.g. %stack.1 -> %stack.0)
but does not remap FixedStackPseudoSourceValue frame index (e.g. store 4 into %stack.1.ap2.i.i)
referenced by MachineMemoryOperand.
This can cause an assertion failure when LiveDebugValues references a dead stack object.
It is difficult to craft a test case. -g, va_copy and stack-coloring are required.
I can only reproduce it on ppc32.
This intention is to move patchable-function before aarch64-branch-targets
(configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs
(see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424).
This also allows addPreEmitPass() passes to know the precise instruction sizes if they want.
Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1.
No output difference with this commit and the previous commit.
This makes the SectionLabel handling more resilient - specifically for
future PROPELLER work which will have more CU ranges (rather than just
one per function).
Ultimately it might be nice to make this more general/resilient to
arbitrary labels (rather than relying on the labels being created for CU
ranges & then being reused by ranges, loclists, and possibly other
addresses). It's possible that other (non-rnglist/loclist) uses of
addresses will need the addresses to be in SectionLabels earlier (eg:
move the CU.addRange to be done on function begin, rather than function
end, so during function emission they are already populated for other
use).
This change has 2 components:
Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded. That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.
WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run. Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase
The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.
This is a reland of rG3a05c3969c18 with fixes for the expensive-checks
and Windows builds
Differential Revision: https://reviews.llvm.org/D71681
Currently there are 4 different mechanisms for controlling denormal
flushing behavior, and about as many equivalent frontend controls.
- AMDGPU uses the fp32-denormals and fp64-f16-denormals subtarget features
- NVPTX uses the nvptx-f32ftz attribute
- ARM directly uses the denormal-fp-math attribute
- Other targets indirectly use denormal-fp-math in one DAGCombine
- cl-denorms-are-zero has a corresponding denorms-are-zero attribute
AMDGPU wants a distinct control for f32 flushing from f16/f64, and as
far as I can tell the same is true for NVPTX (based on the attribute
name).
Work on consolidating these into the denormal-fp-math attribute, and a
new type specific denormal-fp-math-f32 variant. Only ARM seems to
support the two different flush modes, so this is overkill for the
other use cases. Ideally we would error on the unsupported
positive-zero mode on other targets from somewhere.
Move the logic for selecting the flush mode into the compiler driver,
instead of handling it in cc1. denormal-fp-math/denormal-fp-math-f32
are now both cc1 flags, but denormal-fp-math-f32 is not yet exposed as
a user flag.
-cl-denorms-are-zero, -fcuda-flush-denormals-to-zero and
-fno-cuda-flush-denormals-to-zero will be mapped to
-fp-denormal-math-f32=ieee or preserve-sign rather than the old
attributes.
Stop emitting the denorms-are-zero attribute for the OpenCL flag. It
has no in-tree users. The meaning would also be target dependent, such
as the AMDGPU choice to treat this as only meaning allow flushing of
f32 and not f16 or f64. The naming is also potentially confusing,
since DAZ in other contexts refers to instructions implicitly treating
input denormals as zero, not necessarily flushing output denormals to
zero.
This also does not attempt to change the behavior for the current
attribute. The LangRef now states that the default is ieee behavior,
but this is inaccurate for the current implementation. The clang
handling is slightly hacky to avoid touching the existing
denormal-fp-math uses. Fixing this will be left for a future patch.
AMDGPU is still using the subtarget feature to control the denormal
mode, but the new attribute are now emitted. A future change will
switch this and remove the subtarget features.
Summary:
Detect a run of memory tagging instructions for adjacent stack frame slots,
and replace them with a shorter instruction sequence
* replace STG + STG with ST2G
* replace STGloop + STGloop with STGloop
This code needs to run when stack slot offsets are already known, but before
FrameIndex operands in STG instructions are eliminated; that's the
reason for the new hook in PrologueEpilogue.
This change modifies STGloop and STZGloop pseudos to take the size as an
immediate integer operand, and adds _untied variants of those pseudos
that are allowed to take the base address as a FI operand. This is needed to
simplify recognizing an STGloop instruction as operating on a stack slot
post-regalloc.
This improves memtag code size by ~0.25%, and it looks like an additional ~0.1%
is possible by rearranging the stack frame such that consecutive STG
instructions reference adjacent slots (patch pending).
Reviewers: pcc, ostannard
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70286
Extend -fxray-instrumentation-bundle to split function-entry and
function-exit into two separate options, so that it is possible to
instrument only function entry or only function exit. For use cases
that only care about one or the other this will save significant overhead
and code size.
Differential Revision: https://reviews.llvm.org/D72890
XRay allows tuning by minimum function size, but also always instruments
functions with loops in them. If the minimum function size is set to a
large value the loop instrumention ends up causing most functions to be
instrumented anyway. This adds a new flag, xray-ignore-loops, to disable
the loop detection logic.
Differential Revision: https://reviews.llvm.org/D72659
[this re-applies c0176916a4
with the correct commit message and phabricator link]
This addresses point 1 of PR44213.
https://bugs.llvm.org/show_bug.cgi?id=44213
The DW_AT_LLVM_sysroot attribute is used for Clang module debug info,
to allow LLDB to import a Clang module from source. Currently it is
part of each DW_TAG_module, however, it is the same for all modules in
a compile unit. It is more efficient and less ambiguous to store it
once in the DW_TAG_compile_unit.
This should have no effect on DWARF consumers other than LLDB.
Differential Revision: https://reviews.llvm.org/D71732
This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.
This attribute only appears in Clang module debug info.
Differential Revision: https://reviews.llvm.org/D71722
Introduce a method to walk through use-def chains to decide whether
it's possible to remove a given instruction and its users. These
instructions are then stored in a set until the end of the transform
when they're erased. This is now used to perform checks on the
iteration count (LoopDec chain), element count (VCTP chain) and the
possibly redundant iteration count.
As well as being able to remove chains of instructions, we know also
check that the sub feeding the vctp is producing the expected value.
Differential Revision: https://reviews.llvm.org/D71837
Add DemandedElts handling to ISD::ANY_EXTEND and add missing ISD::ANY_EXTEND_VECTOR_INREG handling. Despite the lack of test changes this code IS being used - its just that the ANY_EXTEND ops are legalized later on (typically to ZERO_EXTEND equivalents) so we typically manage to combine later on.
This change has 2 components:
Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded. That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.
WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run. Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase
The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.
Differential Revision: https://reviews.llvm.org/D71681
This was assuming the narrow target was the source type. Respect the
requested type when these don't match by using intermediate
merges. This avoids producing very wide, illegal shift expansions.
The algorithm here only works if the sint_to_fp doesn't do any
rounding. Otherwise it can round before the offset fixup is
applied. Add an assert to protect this.
To avoid breaking the one test in tree that tested this code
with a set of types that fail the assert, I've enabled i32->f32
to use the i64->f32 algorithm. This only occurs when f64 isn't
a legal type. If f64 is legal then we do i32->f64->f32 instead.
Differential Revision: https://reviews.llvm.org/D72794
This was dropping the invariant metadata on dead argument loads, so
they weren't deleted.
Atomics still need to be fixed the same way. Also, apparently store
was never preserving dereferencable which should also be fixed.
Recommitting e93e0d413f after reverting due to test failures, which
will hopefully now be fixed. Original commit message:
After expanding the pseudo instructions, update the liveness info.
We do this in a post-order traversal of the loop, including its
exit blocks and preheader(s).
Differential Revision: https://reviews.llvm.org/D72131
Testing compiler-rt, a new assertion failure occurs when building
the GwpAsanTestObjects object. I'm uploading a reproducer to D70597.
This reverts commit 75188b01e9.
If there are DBG_VALUEs between phi and label (after phi and before label),
DBG_VALUE will block PHI lowering after the LABEL. Moving all DBG_VALUEs
after Labels in the function ScheduleDAGSDNodes::EmitSchedule to avoid
impacting PHI lowering.
before:
PHI
DBG_VALUE
LABEL
after: (move DBG_VALUE after label)
PHI
LABEL
DBG_VALUE
then: (phi lowering after label)
LABEL
COPY
DBG_VALUE
Fixes the issue: https://bugs.llvm.org/show_bug.cgi?id=43859
Differential Revision: https://reviews.llvm.org/D70597
This was moved in October 2018, but we don't appear to be using
this for vectors on any in tree target.
Moving it back simplifies D72794 so we can share the code for i32->f32.
When tail duplication estimates a size of tail it uses instruction
count. Account for a number of instrictions in a bundle too.
Differential Revision: https://reviews.llvm.org/D72783
This now develops the same problem G_ZEXT/G_ANYEXT have where the
requested type is assumed to be the source type. This will be fixed
separately by creating intermediate merges.
Sanjay Patel