Sample re-annotation is required in LTO time to achieve a reasonable post-inline profile quality. However, we have seen that such LTO-time re-annotation degrades profile quality. This is mainly caused by preLTO code duplication that is done by passes such as loop unrolling, jump threading, indirect call promotion etc, where samples corresponding to a source location are aggregated multiple times due to the duplicates. In this change we are introducing a concept of distribution factor for pseudo probes so that samples can be distributed for duplicated probes scaled by a factor. We hope that optimizations duplicating code well-maintain the branch frequency information (BFI) based on which probe distribution factors are calculated. Distribution factors are updated at the end of preLTO pipeline to reflect an estimated portion of the real execution count.
This change also introduces a pseudo probe verifier that can be run after each IR passes to detect duplicated pseudo probes.
A saturated distribution factor stands for 1.0. A pesudo probe will carry a factor with the value ranged from 0.0 to 1.0. A 64-bit integral distribution factor field that represents [0.0, 1.0] is associated to each block probe. Unfortunately this cannot be done for callsite probes due to the size limitation of a 32-bit Dwarf discriminator. A 7-bit distribution factor is used instead.
Changes are also needed to the sample profile inliner to deal with prorated callsite counts. Call sites duplicated by PreLTO passes, when later on inlined in LTO time, should have the callees’s probe prorated based on the Prelink-computed distribution factors. The distribution factors should also be taken into account when computing hotness for inline candidates. Also, Indirect call promotion results in multiple callisites. The original samples should be distributed across them. This is fixed by adjusting the callisites' distribution factors.
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D93264
Previously, operator== would consider the actual equality of the pairs
(lhs.Value, lhs.State) == (rhs.Value, rhs.State). However, if an invalid
cost was involved in a call to operator<, only the state would be
compared. Thus, it was not the case that ({2, Invalid} < {3, Invalid} ||
{2, Invalid} > {3, Invalid} || {2, Invalid} == {3, Invalid}).
This patch implements a true total ordering, where cost state is
considered first, then value. While it's not really imporant that
{2, Invalid} be considered to be less than {3, Invalid}, it's not a
problem either. This patch also implements operator== in terms of
operator<, so the two definitions will be kept in sync.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D95803
Add per-reloc-type attribute bits and migrate code from per-target file into target independent code, driven by reloc attributes.
Many cleanups
Differential Revision: https://reviews.llvm.org/D95121
In binutils, the flag is defined for ELFOSABI_GNU and ELFOSABI_FREEBSD.
It can be used to mark a section as a GC root.
In practice, the flag has generic semantics and can be applied to many
EI_OSABI values, so we consider it generic.
Differential Revision: https://reviews.llvm.org/D95728
This change implemented call site prioritized BFS profile guided inlining for sample profile loader. The new inlining strategy maximize the benefit of context-sensitive profile as mentioned in the follow up discussion of CSSPGO RFC. The change will not affect today's AutoFDO as it's opt-in. CSSPGO now defaults to the new FDO inliner, but can fall back to today's replay inliner using a switch (`-sample-profile-prioritized-inline=0`).
Motivation
With baseline AutoFDO, the inliner in sample profile loader only replays previous inlining, and the use of profile is only for pruning previous inlining that turned out to be cold. Due to the nature of replay, the FDO inliner is simple with hotness being the only decision factor. It has the following limitations that we're improving now for CSSPGO.
- It doesn't take inline candidate size into account. Since it's doing replay, the size growth is bounded by previous CGSCC inlining. With context-sensitive profile, FDO inliner is no longer limited by previous inlining, so we need to take size into account to avoid significant size bloat.
- The way it looks at hotness is not accurate. It uses total samples in an inlinee as proxy for hotness, while what really matters for an inline decision is the call site count. This is an unfortunate fall back because call site count and callee entry count are not reliable due to dwarf based correlation, especially for inlinees. Now paired with pseudo-probe, we have accurate call site count and callee's entry count, so we can use that to gauge hotness more accurately.
- It treats all call sites from a block as hot as long as there's one call site considered hot. This is normally true, but since total samples is used as hotness proxy, this transitiveness within block magnifies the inacurate hotness heuristic. With pseduo-probe and the change above, this is no longer an issue for CSSPGO.
New FDO Inliner
Putting all the requirement for CSSPGO together, we need a top-down call site prioritized BFS inliner. Here're reasons why each component is needed.
- Top-down: We need a top-down inliner to better leverage context-sensitive profile, so inlining is driven by accurate context profile, and post-inline is also accurate. This is already implemented in https://reviews.llvm.org/D70655.
- Size Cap: For top-down inliner, taking function size into account for inline decision alone isn't sufficient to control size growth. We also need to explicitly cap size growth because with top-down inlining, we can grow inliner size significantly with large number of smaller inlinees even if each individually passes the cost/size check.
- Prioritize call sites: With size cap, inlining order also becomes important, because if we stop inlining due to size budget limit, we'd want to use budget towards the most beneficial call sites.
- BFS inline: Same as call site prioritization, if we stop inlining due to size budget limit, we want a balanced inline tree, rather than going deep on one call path.
Note that the new inliner avoids repeatedly evaluating same set of call site, so it should help with compile time too. For this reason, we could transition today's FDO inliner to use a queue with equal priority to avoid wasted reevaluation of same call site (TODO).
Speculative indirect call promotion and inlining is also supported now with CSSPGO just like baseline AutoFDO.
Tunings and knobs
I created tuning knobs for size growth/cap control, and for hot threshold separate from CGSCC inliner. The default values are selected based on initial tuning with CSSPGO.
Results
Evaluated with an internal LLVM fork couple months ago, plus another change to adjust hot-threshold cutoff for context profile (will send up after this one), the new inliner show ~1% geomean perf win on spec2006 with CSSPGO, while reducing code size too. The measurement was done using train-train setup, MonoLTO w/ new pass manager and pseudo-probe. Note that this is just a starting point - we hope that the new inliner will open up more opportunity with CSSPGO, but it will certainly take more time and effort to make it fully calibrated and ready for bigger workloads (we're working on it).
Differential Revision: https://reviews.llvm.org/D94001
Extend applyLoopGuards() to take into account conditions/assumes proving some
value %v to be divisible by D by rewriting %v to (%v / D) * D. This lets the
loop unroller and the loop vectorizer identify more loops as not requiring
remainder loops.
Differential Revision: https://reviews.llvm.org/D95521
Previously file entries in the -ivfsoverlay yaml could map to a file in the
external file system, but directories had to list their contents in the form of
other file entries or directories. Allowing directory entries to map to a
directory in the external file system makes it possible to present an external
directory's contents in a different location and (in combination with the
'fallthrough' option) overlay one directory's contents on top of another.
rdar://problem/72485443
Differential Revision: https://reviews.llvm.org/D94844
This patch let the yaml encoding use Hex64 values for NumBlocks, BB AddressOffset, BB Size, and BB Metadata.
Additionally, it changes the decoded values in elf2yaml to uint64_t to match DataExtractor::getULEB128 return type.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D95767
C identifier name input sections such as __llvm_prf_* are GC roots so
they cannot be discarded. In LLD, the SHF_LINK_ORDER flag overrides the
C identifier name semantics.
The !associated metadata may be attached to a global object declaration
with a single argument that references another global object, and it
gets lowered to SHF_LINK_ORDER flag. When a function symbol is discarded
by the linker, setting up !associated metadata allows linker to discard
counters, data and values associated with that function symbol.
Note that !associated metadata is only supported by ELF, it does not have
any effect on non-ELF targets.
Differential Revision: https://reviews.llvm.org/D76802
This is another step (see D95452) towards correcting fast-math-flags
bugs in vector reductions.
There are multiple bugs visible in the test diffs, and this is still
not working as it should. We still use function attributes (rather
than FMF) to drive part of the logic, but we are not checking for
the correct FP function attributes.
Note that FMF may not be propagated optimally on selects (example
in https://llvm.org/PR35607 ). That's why I'm proposing to union the
FMF of a fcmp+select pair and avoid regressions on existing vectorizer
tests.
Differential Revision: https://reviews.llvm.org/D95690
This is a (rather delayed) follow up to commit 0129cd5. This commit is entirely NFC, the semantic change to leverage the new information will be submitted separate with a test case.
If we instantiate self-referenced anonymous records in foreach and
multiclass, the NAME value will point to incorrect record. It's because
anonymous name is resolved too early.
This patch adds AnonymousNameInit to represent an anonymous record name.
When instantiating an anonymous record, it will update the referred name.
Differential Revision: https://reviews.llvm.org/D95309
The AArch64 DAG combine added by D90945 & D91433 extends the index
of a scalable masked gather or scatter to i32 if necessary.
This patch removes the combine and instead adds shouldExtendGSIndex, which
is used by visitMaskedGather/Scatter in SelectionDAGBuilder to query whether
the index should be extended before calling getMaskedGather/Scatter.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D94525
To set non-default rounding mode user usually calls function 'fesetround'
from standard C library. This way has some disadvantages.
* It creates unnecessary dependency on libc. On the other hand, setting
rounding mode requires few instructions and could be made by compiler.
Sometimes standard C library even is not available, like in the case of
GPU or AI cores that execute small kernels.
* Compiler could generate more effective code if it knows that a particular
call just sets rounding mode.
This change introduces new IR intrinsic, namely 'llvm.set.rounding', which
sets current rounding mode, similar to 'fesetround'. It however differs
from the latter, because it is a lower level facility:
* 'llvm.set.rounding' does not return any value, whereas 'fesetround'
returns non-zero value in the case of failure. In glibc 'fesetround'
reports failure if its argument is invalid or unsupported or if floating
point operations are unavailable on the hardware. Compiler usually knows
what core it generates code for and it can validate arguments in many
cases.
* Rounding mode is specified in 'fesetround' using constants like
'FE_TONEAREST', which are target dependent. It is inconvenient to work
with such constants at IR level.
C standard provides a target-independent way to specify rounding mode, it
is used in FLT_ROUNDS, however it does not define standard way to set
rounding mode using this encoding.
This change implements only IR intrinsic. Lowering it to machine code is
target-specific and will be implemented latter. Mapping of 'fesetround'
to 'llvm.set.rounding' is also not implemented here.
Differential Revision: https://reviews.llvm.org/D74729
If we're going to end up expanding anyway, we should do it early
so we don't create extra operations to handle the bytes added by
promotion.
This is helfpul on RISCV where we might have to promote i16 all
the way to i64.
Differential Revision: https://reviews.llvm.org/D95756
This patch removes some options that have been duplicated in
LTOCodeGenerator and instead use lto::Config directly to manage the
options.
This is a cleanup after 6a59f0560648.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95738
Current dsymutil implementation of hasLiveMemoryLocation()/hasLiveAddressRange()
and applyValidRelocs() assume that calls should be done in certain order
(from first Dies to last). Multi-thread implementation might call these methods
in other order(it might process compilation units in order other than they are physically
located), so we remove restriction that searching for relocations should be done
in ascending order. This change does not introduce noticable performance degradation.
The testing results for clang binary:
golden-dsymutil/dsymutil 23787992
clang MD5: 5efa8fd9355ebf81b65f24db5375caa2
elapsed time=91sec
build-Release/bin/dsymutil 23855616
clang MD5: 5efa8fd9355ebf81b65f24db5375caa2
elapsed time=91sec
Differential Revision: https://reviews.llvm.org/D93106
This patch adds an option to enable the new pass manager in
LTOCodeGenerator. It also updates a few tests with legacy PM specific
tests, which started failing after 6a59f0560648 when
LLVM_ENABLE_NEW_PASS_MANAGER=true.
This patch updates LTOCodeGenerator to use the utilities provided by
LTOBackend to run middle-end optimizations and backend code generation.
This is a first step towards unifying the code used by libLTO's C API
and the newer, C++ interface (see PR41541).
The immediate motivation is to allow using the new pass manager when
doing LTO using libLTO's C API, which is used on Darwin, among others.
With the changes, there are no codegen/stats differences when building
MultiSource/SPEC2000/SPEC2006 on Darwin X86 with LTO, compared
to without the patch.
Reviewed By: steven_wu
Differential Revision: https://reviews.llvm.org/D94487
As a fixme notes, both of these directory iterator implementations are
conceptually similar and duplicate the functionality of returning and uniquing
entries across two or more directories. This patch combines them into a single
class 'CombiningDirIterImpl'.
This also drops the 'Redirecting' prefix from RedirectingDirEntry and
RedirectingFileEntry to save horizontal space. There's no loss of clarity as
they already have to be prefixed with 'RedirectingFileSystem::' whenever
they're referenced anyway.
rdar://problem/72485443
Differential Revision: https://reviews.llvm.org/D94857
Remove the call to setFlags in favour of creating the instruction with
the correct flags in the first place, so we don't have to explicitly
notify the observer.
Differential Revision: https://reviews.llvm.org/D95681
splitCodeGen does not need to take ownership of the module, as it
currently clones the original module for each split operation.
There is an ~4 year old fixme to change that, but until this is
addressed, the function can just take a reference to the module.
This makes the transition of LTOCodeGenerator to use LTOBackend a bit
easier, because under some circumstances, LTOCodeGenerator needs to
write the original module back after codegen.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95222
Various *TargetStreamer.h need formatted_raw_ostream but rely on a
forward declaration of formatted_raw_ostream in MCStreamer.h. This
patch adds forward declarations right in *TargetStreamer.h.
While we are at it, this patch removes the one in MCStreamer.h, where
it is unnecessary.
This patch allows targets to define multiple cost
values for each register so that the cost model
can be more flexible and better used during the
register allocation as per the target requirements.
For AMDGPU the VGPR allocation will be more efficient
if the register cost can be associated dynamically
based on the calling convention.
Reviewed By: qcolombet
Differential Revision: https://reviews.llvm.org/D86836
Add an `enable_if` to the generic `IntrusiveRefCntPtr` constructors so
that std::is_convertible gives an honest answer when the underlying
pointers cannot be converted. Added `static_assert`s to the test suite
to verify.
Also combine generic constructors from `IntrusiveRefCntPtr<X>&&` and
`const IntrusiveRefCntPtr<X>&`. At first glance this appears to be an
infinite loop, but the real copy/move constructors are spelled out
separately above. Added a unit test to verify.
Differential Revision: https://reviews.llvm.org/D95498
Treat hint instructions like G_ASSERT_ZEXT like COPY instructions in helpers
which walk through copies.
This ensures that instructions like G_ASSERT_ZEXT won't impact any optimizations
that rely on these helpers.
Differential Revision: https://reviews.llvm.org/D95577
These are widened to a wider UADDE/USUBE, with the overflow value
unused, and with the same synthesis of a new overflow value as for the
O operations.
Reviewed By: paquette
Differential Revision: https://reviews.llvm.org/D95326
This adds a generic opcode which communicates that a type has already been
zero-extended from a narrower type.
This is intended to be similar to AssertZext in SelectionDAG.
For example,
```
%x_was_extended:_(s64) = G_ASSERT_ZEXT %x, 16
```
Signifies that the top 48 bits of %x are known to be 0.
This is useful in cases like this:
```
define i1 @zeroext_param(i8 zeroext %x) {
%cmp = icmp ult i8 %x, -20
ret i1 %cmp
}
```
In AArch64, `%x` must use a 32-bit register, which is then truncated to a 8-bit
value.
If we know that `%x` is already zero-ed out in the relevant high bits, we can
avoid the truncate.
Currently, in GISel, this looks like this:
```
_zeroext_param:
and w8, w0, #0xff ; We don't actually need this!
cmp w8, #236
cset w0, lo
ret
```
While SDAG does not produce the truncation, since it knows that it's
unnecessary:
```
_zeroext_param:
cmp w0, #236
cset w0, lo
ret
```
This patch
- Adds G_ASSERT_ZEXT
- Adds MIRBuilder support for it
- Adds MachineVerifier support for it
- Documents it
It also puts G_ASSERT_ZEXT into its own class of "hint instruction." (There
should be a G_ASSERT_SEXT in the future, maybe a G_ASSERT_ALIGN as well.)
This allows us to skip over hints in the legalizer etc. These can then later
be selected like COPY instructions or removed.
Differential Revision: https://reviews.llvm.org/D95564
This patch adds the ability to evaluate the state machine for CIE and FDE unwind objects and produce a UnwindTable with all UnwindRow objects needed to unwind registers. It will also dump the UnwindTable for each CIE and FDE when dumping DWARF .debug_frame or .eh_frame sections in llvm-dwarfdump or llvm-objdump. This allows users to see what the unwind rows actually look like for a given CIE or FDE instead of just seeing a list of opcodes.
This patch adds new classes: UnwindLocation, RegisterLocations, UnwindRow, and UnwindTable.
UnwindLocation is a class that describes how to unwind a register or Call Frame Address (CFA).
RegisterLocations is a class that tracks registers and their UnwindLocations. It gets populated when parsing the DWARF call frame instruction opcodes for a unwind row. The registers are mapped from their register numbers to the UnwindLocation in a map.
UnwindRow contains the result of evaluating a row of DWARF call frame instructions for the CIE, or a row from a FDE. The CIE can produce a set of initial instructions that each FDE that points to that CIE will use as the seed for the state machine when parsing FDE opcodes. A UnwindRow for a CIE will not have a valid address, whille a UnwindRow for a FDE will have a valid address.
The UnwindTable is a class that contains a sorted (by address) vector of UnwindRow objects and is the result of parsing all opcodes in a CIE, or FDE. Parsing a CIE should produce a UnwindTable with a single row. Parsing a FDE will produce a UnwindTable with one or more UnwindRow objects where all UnwindRow objects have valid addresses. The rows in the UnwindTable will be sorted from lowest Address to highest after parsing the state machine, or an error will be returned if the table isn't sorted. To parse a UnwindTable clients can use the following methods:
static Expected<UnwindTable> UnwindTable::create(const CIE *Cie);
static Expected<UnwindTable> UnwindTable::create(const FDE *Fde);
A valid table will be returned if the DWARF call frame instruction opcodes have no encoding errors. There are a few things that can go wrong during the evaluation of the state machine and these create functions will catch and return them.
Differential Revision: https://reviews.llvm.org/D89845
The header would include OrcJIT headers in OrcTargetProcess, which is not desired. All common declarations should be in OrcShared.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D95606
Currently we don't allow the following definition:
```
Sections:
- Type: SectionHeaderTable
- Name: .foo
Type: SHT_PROGBITS
```
We report an error: "SectionHeaderTable can't be empty. Use 'NoHeaders' key to drop the section header table".
It was implemented in this way earlier, when `SectionHeaderTable`
was a dedicated key outside of the `Sections` list. And we did not
allow to select where the table is written.
Currently it makes sense to allow it, because a user might
want to place the default section header table at an arbitrary position,
e.g. before other sections. In this case it is not convenient and error prone
to require specifying all sections:
```
Sections:
- Type: SectionHeaderTable
Sections:
- Name: .foo
- Name: .strtab
- Name: .shstrtab
- Name: .foo
Type: SHT_PROGBITS
```
This patch allows empty SectionHeaderTable definitions.
Differential revision: https://reviews.llvm.org/D95341
NativeEnumInjectedSources.h needs PDBFile but relies on a
forward declaration of PDBFile in InjectedSourceStream.h.
This patch adds a forward declaration right in
NativeEnumInjectedSources.h.
While we are at it, this patch removes the one in
InjectedSourceStream.h, where it is unnecessary.
This change brings up support of context-sensitive profiles in the format of extended binary. Existing sample profile reader/writer/merger code is being tweaked to reflect the fact of bracketed input contexts, like (`[...]`). The paired brackets are also needed in extbinary profiles because we don't yet have an otherwise good way to tell calling contexts apart from regular function names since the context delimiter `@` can somehow serve as a part of the C++ mangled names.
Reviewed By: wmi, wenlei
Differential Revision: https://reviews.llvm.org/D95547
Identify dynamically exported symbols (--export-dynamic[-symbol=],
--dynamic-list=, or definitions needed to preempt shared objects) and
prevent their LTO visibility from being upgraded.
This helps avoid use of whole program devirtualization when there may
be overrides in dynamic libraries.
Differential Revision: https://reviews.llvm.org/D91583
The two operations have acted differently since Clang 8, but were
unfortunately mangled the same. The new mangling uses new "vendor
extended expression" syntax proposed in
https://github.com/itanium-cxx-abi/cxx-abi/issues/112
GCC had the same mangling problem, https://gcc.gnu.org/PR88115, and
will hopefully be switching to the same mangling as implemented here.
Additionally, fix the mangling of `__uuidof` to use the new extension
syntax, instead of its previous nonstandard special-case.
Adjusts the demangler accordingly.
Differential Revision: https://reviews.llvm.org/D93922
Previously, Clang was able to mangle the Swift calling
convention but 'MicrosoftDemangle.cpp' was not able to demangle it.
Reviewed By: compnerd, rnk
Differential Revision: https://reviews.llvm.org/D95053
I am trying to untangle the fast-math-flags propagation logic
in the vectorizers (see a6f022127 for SLP).
The loop vectorizer has a mix of checking FP function attributes,
IR-level FMF, and just wrong assumptions.
I am trying to avoid regressions while fixing this, and I think
the IR-level logic is good enough for that, but it's hard to say
for sure. This would be the 1st step in the clean-up.
The existing test that I changed to include 'fast' actually shows
a miscompile: the function only had the equivalent of nnan, but we
created new instructions that had fast (all FMF set). This is
similar to the example in https://llvm.org/PR35538
Differential Revision: https://reviews.llvm.org/D95452
Imported functions and variable get the visibility from the module supplying the
definition. However, non-imported definitions do not get the visibility from
(ELF) the most constraining visibility among all modules (Mach-O) the visibility
of the prevailing definition.
This patch
* adds visibility bits to GlobalValueSummary::GVFlags
* computes the result visibility and propagates it to all definitions
Protected/hidden can imply dso_local which can enable some optimizations (this
is stronger than GVFlags::DSOLocal because the implied dso_local can be
leveraged for ELF -shared while default visibility dso_local has to be cleared
for ELF -shared).
Note: we don't have summaries for declarations, so for ELF if a declaration has
the most constraining visibility, the result visibility may not be that one.
Differential Revision: https://reviews.llvm.org/D92900
FaultsMapParser lived in CodeGen and was forcing llvm-objdump to
link CodeGen and everything CodeGen depends on.
This was previously attempted in r240364 to fix a link failure.
The CodeGen dependency was independently added to fix the same
link failure, and that ended up being kept.
Removing the dependency seems like the correct layering for
llvm-objdump.
Reviewed By: MaskRay, jhenderson
Differential Revision: https://reviews.llvm.org/D95414
kernels loop and enter data had a too restrictive constraint for the wait clause.
The wait clause is allowed multiple times and not only once. This patch fix this problem.
Reviewed By: SouraVX
Differential Revision: https://reviews.llvm.org/D95469
This gives the user control over which expander to use, which in turn
allows the user to decide what to do with the expanded instructions.
Used in D75980.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D94295
Restriction on clauses for the EXIT DATA directive were not fully correct.
This patch fixes the situation. The async, if and finalize clauses are allowed
only once.
Reviewed By: SouraVX
Differential Revision: https://reviews.llvm.org/D95470
Restriction on clauses for the HOST_DATA directive were not fully correct.
This patch fixes the situation. The if and if_present clauses are allowed
only once.
Reviewed By: SouraVX
Differential Revision: https://reviews.llvm.org/D95473
AMDGPUInstructionSelector.h needs TargetRegisterClass but relies on a
forward declaration of TargetRegisterClass in InstructionSelector.h.
This patch adds a forward declaration right in
AMDGPUInstructionSelector.h.
While we are at it, this patch removes the one in
InstructionSelector.h, where it is unnecessary.
This change implements support for applying profile instrumentation
only to selected files or functions. The implementation uses the
sanitizer special case list format to select which files and functions
to instrument, and relies on the new noprofile IR attribute to exclude
functions from instrumentation.
Differential Revision: https://reviews.llvm.org/D94820
Add a new `raw_pwrite_ostream` variant, `buffer_unique_ostream`, which
is like `buffer_ostream` but with unique ownership of the stream it's
wrapping. Use this in CompilerInstance to simplify the ownership of
non-seeking output streams, avoiding logic sprawled around to deal with
them specially.
This also simplifies future work to encapsulate output files in a
different class.
Differential Revision: https://reviews.llvm.org/D93260
Before this change, when reading ELF file, elfabi determines number of
entries in .dynsym by reading the .gnu.hash section. This change makes
elfabi read section headers directly first. This change allows elfabi
works on ELF files which do not have .gnu.hash sections.
Differential Revision: https://reviews.llvm.org/D93362
There are two use cases.
Assembler
We have accrued some code gated on MCAsmInfo::useIntegratedAssembler(). Some
features are supported by latest GNU as, but we have to use
MCAsmInfo::useIntegratedAs() because the newer versions have not been widely
adopted (e.g. SHF_LINK_ORDER 'o' and 'unique' linkage in 2.35, --compress-debug-sections= in 2.26).
Linker
We want to use features supported only by LLD or very new GNU ld, or don't want
to work around older GNU ld. We currently can't represent that "we don't care
about old GNU ld". You can find such workarounds in a few other places, e.g.
Mips/MipsAsmprinter.cpp PowerPC/PPCTOCRegDeps.cpp X86/X86MCInstrLower.cpp
AArch64 TLS workaround for R_AARCH64_TLSLD_MOVW_DTPREL_* (PR ld/18276),
R_AARCH64_TLSLE_LDST8_TPREL_LO12 (https://bugs.llvm.org/show_bug.cgi?id=36727https://sourceware.org/bugzilla/show_bug.cgi?id=22969)
Mixed SHF_LINK_ORDER and non-SHF_LINK_ORDER components (supported by LLD in D84001;
GNU ld feature request https://sourceware.org/bugzilla/show_bug.cgi?id=16833 may take a while before available).
This feature allows to garbage collect some unused sections (e.g. fragmented .gcc_except_table).
This patch adds `-fbinutils-version=` to clang and `-binutils-version` to llc.
It changes one codegen place in SHF_MERGE to demonstrate its usage.
`-fbinutils-version=2.35` means the produced object file does not care about GNU
ld<2.35 compatibility. When `-fno-integrated-as` is specified, the produced
assembly can be consumed by GNU as>=2.35, but older versions may not work.
`-fbinutils-version=none` means that we can use all ELF features, regardless of
GNU as/ld support.
Both clang and llc need `parseBinutilsVersion`. Such command line parsing is
usually implemented in `llvm/lib/CodeGen/CommandFlags.cpp` (LLVMCodeGen),
however, ClangCodeGen does not depend on LLVMCodeGen. So I add
`parseBinutilsVersion` to `llvm/lib/Target/TargetMachine.cpp` (LLVMTarget).
Differential Revision: https://reviews.llvm.org/D85474
This change implements support for applying profile instrumentation
only to selected files or functions. The implementation uses the
sanitizer special case list format to select which files and functions
to instrument, and relies on the new noprofile IR attribute to exclude
functions from instrumentation.
Differential Revision: https://reviews.llvm.org/D94820
Loop peeling removes conditions from loop bodies that become invariant
after a small number of iterations. When triggered, this leads to fewer
compares and possibly PHIs in loop bodies, enabling further
optimizations. The current cost-model of loop peeling should be quite
conservative/safe, i.e. only peel if a condition in the loop becomes
known after peeling.
For example, see PR47671, where loop peeling enables vectorization by
removing a PHI the vectorizer does not understand. Granted, the
loop-vectorizer could also be taught about constant PHIs, but loop
peeling is likely to enable other optimizations as well.
This has an impact on quite a few benchmarks from
MultiSource/SPEC2000/SPEC2006 on X86 with -O3 -flto, for example
Same hash: 186 (filtered out)
Remaining: 51
Metric: loop-vectorize.LoopsVectorized
Program base patch diff
test-suite...ve-susan/automotive-susan.test 8.00 9.00 12.5%
test-suite...nal/skidmarks10/skidmarks.test 35.00 31.00 -11.4%
test-suite...lications/sqlite3/sqlite3.test 41.00 43.00 4.9%
test-suite...s/ASC_Sequoia/AMGmk/AMGmk.test 25.00 26.00 4.0%
test-suite...006/450.soplex/450.soplex.test 88.00 89.00 1.1%
test-suite...TimberWolfMC/timberwolfmc.test 120.00 119.00 -0.8%
test-suite.../CINT2006/403.gcc/403.gcc.test 215.00 216.00 0.5%
test-suite...006/447.dealII/447.dealII.test 957.00 958.00 0.1%
test-suite...ternal/HMMER/hmmcalibrate.test 75.00 75.00 0.0%
Same hash: 186 (filtered out)
Remaining: 51
Metric: loop-vectorize.LoopsAnalyzed
Program base patch diff
test-suite...ks/Prolangs-C/agrep/agrep.test 440.00 434.00 -1.4%
test-suite...nal/skidmarks10/skidmarks.test 312.00 308.00 -1.3%
test-suite...marks/7zip/7zip-benchmark.test 6399.00 6323.00 -1.2%
test-suite...lications/minisat/minisat.test 134.00 135.00 0.7%
test-suite...rks/FreeBench/pifft/pifft.test 295.00 297.00 0.7%
test-suite...TimberWolfMC/timberwolfmc.test 1879.00 1869.00 -0.5%
test-suite...pplications/treecc/treecc.test 689.00 691.00 0.3%
test-suite...T2000/300.twolf/300.twolf.test 1593.00 1597.00 0.3%
test-suite.../Benchmarks/Bullet/bullet.test 1394.00 1392.00 -0.1%
test-suite...ications/JM/ldecod/ldecod.test 1431.00 1429.00 -0.1%
test-suite...6/464.h264ref/464.h264ref.test 2229.00 2230.00 0.0%
test-suite...lications/sqlite3/sqlite3.test 2590.00 2589.00 -0.0%
test-suite...ications/JM/lencod/lencod.test 2732.00 2733.00 0.0%
test-suite...006/453.povray/453.povray.test 3395.00 3394.00 -0.0%
Note the -11% regression in number of loops vectorized for skidmarks. I
suspect this corresponds to the fact that those loops are gone now (see
the reduction in number of loops analyzed by LV).
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D88471
We already set the `sh_entsize` field in a single place
for all non-implicit sections.
This patch reorders the logic slightly and with it
we finally have the only one place where the `sh_entsize` is set.
obj2yaml will not dump the `EntSize` key for `SHT_DYNSYM/SHT_SYMTAB` sections anymore,
when the value of `sh_entsize` is equal to `sizeof(Elf_Sym)`
Note that this also seems revealed an issue in llvm-objcopy:
Previously yaml2obj set the `sh_entsize` for the `.symtab` section to 0x18,
now we it sets it for `SHT_SYMTAB` sections, i.e. by type.
But the `llvm-objcopy/ELF/only-keep-debug.test` has a `.symtab` section of type `SHT_STRTAB`,
and now yaml2obj sets the `sh_entsize` to 0 for it.
I had to update the corresponding check lines for `ES`, but the behavior of
`llvm-objcopy` should be fixed instead I think.
I've added a TODO and a comment.
Differential revision: https://reviews.llvm.org/D95364
A default version (@@) is only available for defined symbols.
Currently we use "@@" for undefined symbols too.
This patch fixes the issue and improves our test case.
Differential revision: https://reviews.llvm.org/D95219
To be able to refer to constant keypaths (e.g. `defvar cplusplus = LangOpts<"CPlusPlus">`) inside `ImpliedByAnyOf`, let's accept strings instead of `Option` instances.
This somewhat weakens the guarantees that we're referring to an existing (option) record, but we can still use the option.KeyPath syntax to simulate this.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D95344
AMDGPULegalizerInfo.h needs MachineIRBuilder but relies on a forward
declaration of MachineIRBuilder in LegalizerInfo.h. This patch adds a
forward declaration right in AMDGPULegalizerInfo.h.
While we are at it, this patch removes the one in LegalizerInfo.h,
where it is unnecessary.
The current algorithm just tries to localize defs as far as they can go, and in
the case of G_PHI operands, it clones the def into the predecessor block for
each incoming edge. When multiple edges have the same register value, this can
cause unnecessary code bloat, and inhibit later optimizations.
This change checks if a given phi operand is unique in the phi, if not the
def of that register is not localized to the predecessor.
Differential Revision: https://reviews.llvm.org/D95406
This change leverages the work done in D83743 to replay in the SampleProfile inliner to also be used in the CGSCC inliner. NOTE: currently restricted to non-ML advisors only.
The added switch `-cgscc-inline-replay=<remarks file>` will replay the inlining decisions in that file where the remarks file is generated via `-Rpass=inline`. The aim here is to make it easier to analyze changes that would modify inlining heuristics to be separated from this behavior. Doing so allows easier examination of assembly and runtime behavior compared to the baseline rather than trying to dig through the large churn caused by inlining.
In LTO compilation, since inlining is done twice you can separately specify replay by passing the flag to the FE (`-cgscc-inline-replay=`) and to the linker (`-Wl,cgscc-inline-replay=`) with the remarks generated from their respective places.
Testing on mysqld by comparing the inline decisions between base (generates remarks.txt) and diff (replay using identical input/tools with remarks.txt) and examining the inlining sites with `diff` shows 14,000 mismatches out of 247,341 for a ~94% replay accuracy. I believe this gap can be narrowed further though for the general case we may never achieve full accuracy. For my personal use, this is close enough to be representative: I set the baseline as the one generated by the replay on identical input/toolset and compare that to my modified input/toolset using the same replay.
Testing:
ninja check-llvm
newly added test correctly replays CGSCC inlining decisions
Reviewed By: mtrofin, wenlei
Differential Revision: https://reviews.llvm.org/D94334
Refactor the duplicated canonicalize-path logic in `FileCollector` and
`ModulesDependencyCollector` into a new utility called
`PathCanonicalizer` that's shared. This popped up when tracking down a
bug common to both in https://reviews.llvm.org/D95202.
As drive-bys, update a few names and comments to better reflect the
effect of the code, delay removal of `..`s to avoid an unnecessary extra
string copy, and leave behind a couple of FIXMEs for future
consideration.
Differential Revision: https://reviews.llvm.org/D95279
This reverts commit 53176c168061d6f26dcf3ce4fa59288b7d67255e, which
introduceed a layering violation. LLVM's IR library can't include
headers from Analysis.
Don't emit an output dash for an empty sequence. Take emitting a vector
of strings for example:
std::vector<std::string> Strings = {"foo", "bar"};
LLVM_YAML_IS_SEQUENCE_VECTOR(std::string)
yout << Strings;
This emits the following YAML document.
---
- foo
- bar
...
When the vector is empty, this generates the following result:
---
- []
...
Although this is valid YAML, it does not match what we meant to emit.
The result is a one-element sequence consisting of an empty list.
Indeed, if we were to try to read this again we get an error:
YAML:2:4: error: not a mapping
- []
The problem is the output dash before the empty list. The correct output
would be:
---
[]
...
This patch fixes that by not emitting the output dash for an empty
sequence.
Differential revision: https://reviews.llvm.org/D95280
or claimRV calls in the IR
Background:
This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.
https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue
What this patch does to fix the problem:
- The front-end annotates calls with attribute "clang.arc.rv"="retain"
or "clang.arc.rv"="claim", which indicates the call is implicitly
followed by a marker instruction and a retainRV/claimRV call that
consumes the call result. This is currently done only when the target
is arm64 and the optimization level is higher than -O0.
- ARC optimizer temporarily emits retainRV/claimRV calls after the
annotated calls in the IR and removes the inserted calls after
processing the function.
- ARC contract pass emits retainRV/claimRV calls after the annotated
calls. It doesn't remove the attribute on the call since the backend
needs it to emit the marker instruction. The retainRV/claimRV calls
are emitted late in the pipeline to prevent optimization passes from
transforming the IR in a way that makes it harder for the ARC
middle-end passes to figure out the def-use relationship between the
call and the retainRV/claimRV calls (which is the cause of PR31925).
- The function inliner removes the autoreleaseRV call in the callee that
returns the result if nothing in the callee prevents it from being
paired up with the calls annotated with "clang.arc.rv"="retain/claim"
in the caller. If the call is annotated with "claim", a release call
is inserted since autoreleaseRV+claimRV is equivalent to a release. If
it cannot find an autoreleaseRV call, it tries to transfer the
attributes to a function call in the callee. This is important since
ARC optimizer can remove the autoreleaseRV call returning the callee
result, which makes it impossible to pair it up with the retainRV or
claimRV call in the caller. If that fails, it simply emits a retain
call in the IR if the call is annotated with "retain" and does nothing
if it's annotated with "claim".
- This patch teaches dead argument elimination pass not to change the
return type of a function if any of the calls to the function are
annotated with attribute "clang.arc.rv". This is necessary since the
pass can incorrectly determine nothing in the IR uses the function
return, which can happen since the front-end no longer explicitly
emits retainRV/claimRV calls in the IR, and change its return type to
'void'.
Future work:
- Use the attribute on x86-64.
- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
calls annotated with the attributes.
rdar://71443534
Differential Revision: https://reviews.llvm.org/D92808
For a function that returns InstructionCost, it is very tempting to write:
return InstructionCost::Invalid;
But that actually returns InstructionCost(1 /* int value of Invalid */))
which has a totally different meaning. By marking this constructor as
`delete`, this can no longer happen.
This was discussed in D93678 thread.
Currently we have one special chunk - Fill.
This patch re implements the "SectionHeaderTable" key to become a special chunk too.
With that we are able to place the section header table at any location,
just like we place sections.
Differential revision: https://reviews.llvm.org/D95140
For now, we correct the result for sqrt if iteration > 0. This doesn't make
sense as they are not strict relative.
Reviewed By: dmgreen, spatel, RKSimon
Differential Revision: https://reviews.llvm.org/D94480
Reassociating some patterns to generate more fma instructions to
reduce register pressure.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D92071
Frame-base materialization may insert vector instructions before EXEC is initialised.
Fix this by moving lowering of llvm.amdgcn.init.exec later in backend.
Also remove SI_INIT_EXEC_LO pseudo as this is not necessary.
Reviewed By: ruiling
Differential Revision: https://reviews.llvm.org/D94645
InstrEmitter.h needs TargetMachine but relies on a forward declaration
of TargetMachine in MachineOperand.h. This patch adds a forward
declaration right in InstrEmitter.h.
While we are at it, this patch removes the one in MachineOperand.h,
where it is unnecessary.
In the cloning infrastructure, only track an MDNode mapping,
without explicitly storing the Metadata mapping, same as is done
during inlining. This makes things slightly simpler.
To simplify the transition to using LTOBackend, move DisableVerify to
the LTOCodeGenerator class, like most/all other options.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95223
Similar to D92887, LoopRotation also needs duplicate the noalias scopes when rotating a `@llvm.experimental.noalias.scope.decl` across a block boundary.
This is based on the version from the Full Restrict paches (D68511).
The problem it fixes also showed up in Transforms/Coroutines/ex5.ll after D93040 (when enabling strict checking with -verify-noalias-scope-decl-dom).
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D94306
This is a fix for https://bugs.llvm.org/show_bug.cgi?id=39282. Compared to D90104, this version is based on part of the full restrict patched (D68484) and uses the `@llvm.experimental.noalias.scope.decl` intrinsic to track the location where !noalias and !alias.scope scopes have been introduced. This allows us to only duplicate the scopes that are really needed.
Notes:
- it also includes changes and tests from D90104
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D92887
The tileLoops method implements the code generation part of the tile directive introduced in OpenMP 5.1. It takes a list of loops forming a loop nest, tiles it, and returns the CanonicalLoopInfo representing the generated loops.
The implementation takes n CanonicalLoopInfos, n tile size Values and returns 2*n new CanonicalLoopInfos. The input CanonicalLoopInfos are invalidated and BBs not reused in the new loop nest removed from the function.
In a modified version of D76342, I was able to correctly compile and execute a tiled loop nest.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D92974
Add an intrinsic type class to represent the
llvm.experimental.noalias.scope.decl intrinsic, to make code
working with it a bit nicer by hiding the metadata extraction
from view.
This patch adds a new InstModificationIRStrategy to mutate flags/options
for instructions. For example, it may add or remove nuw/nsw flags from
add, mul, sub, shl instructions or change the predicate for icmp
instructions.
Subtle changes such as those mentioned above should lead to a more
interesting range of inputs. The presence or absence of overflow flags
can expose subtle bugs, for example.
Reviewed By: bogner
Differential Revision: https://reviews.llvm.org/D94905
LoopUtils.h needs ICFLoopSafetyInfo but relies on a forward
declaration of ICFLoopSafetyInfo in IVDescriptors.h. This patch adds
a forward declaration right in LoopUtils.h.
While we are at it, this patch removes the one in IVDescriptors.h,
where it is unnecessary.
With the addition of the `willreturn` attribute, functions that may
not return (e.g. due to an infinite loop) are well defined, if they are
not marked as `willreturn`.
This patch updates `wouldInstructionBeTriviallyDead` to not consider
calls that may not return as dead.
This patch still provides an escape hatch for intrinsics, which are
still assumed as willreturn unconditionally. It will be removed once
all intrinsics definitions have been reviewed and updated.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D94106
If i change it to AssertingVH instead, a number of existing tests fail,
which means we don't consistently remove from the set when deleting blocks,
which means newly-created blocks may happen to appear in that set
if they happen to occupy the same memory chunk as did some block
that was in the set originally.
There are many places where we delete blocks,
and while we could probably consistently delete from LoopHeaders
when deleting a block in transforms located in SimplifyCFG.cpp itself,
transforms located elsewhere (Local.cpp/BasicBlockUtils.cpp) also may
delete blocks, and it doesn't seem good to teach them to deal with it.
Since we at most only ever delete from LoopHeaders,
let's just delegate to WeakVH to do that automatically.
But to be honest, personally, i'm not sure that the idea
behind LoopHeaders is sound.
The target features are obtained as a list of features/attributes.
Instead of storing them in a single string, store the vector. This
matches lto::Config's behavior and simplifies the transition to
lto::backend().
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95224
Rather than reimplement, use a `using` declaration to bring in
`SmallVectorImpl<char>`'s assign and append implementations in
`SmallString`.
The `SmallString` versions were missing reference invalidation
assertions from `SmallVector`. This patch also fixes a bug in
`llvm::FileCollector::addFileImpl`, which was a copy/paste from
`clang::ModuleDependencyCollector::copyToRoot`, both caught by the
no-longer-skipped assertions.
As a drive-by, this also sinks the `const SmallVectorImpl&` versions of
these methods down into `SmallVectorImpl`, since I imagine they'd be
useful elsewhere.
Differential Revision: https://reviews.llvm.org/D95202
The only caller of this function is in the LocalStackSlotAllocation
and it creates base register of class returned by the target's
getPointerRegClass(). AMDGPU wants to use a different reg class
here so let materializeFrameBaseRegister to just create and return
whatever it wants.
Differential Revision: https://reviews.llvm.org/D95268
This patch addresses inconsistencies in the way fallthrough is handled
in the RedirectingFileSystem. Rather than trying to change the working
directory of the external filesystem, the RedirectingFileSystem will
canonicalize every path before handing it down. This guarantees that
relative paths are resolved relative to the RedirectingFileSystem's
working directory.
This allows us to have a strictly virtual working directory, and still
fallthrough for absolute paths, but not for relative paths that would
get resolved incorrectly at the lower layer (for example, in case of the
RealFileSystem, because the strictly virtual path does not exist).
Differential revision: https://reviews.llvm.org/D95188
The widenScalar implementation for signed and unsigned overflowing
operations were very similar: both are checked by truncating the result
and then re-sign/zero-extending it and checking that it matches the
computed operation.
Using a truncate + zero-extend for the unsigned case instead of manually
producing the AND instruction like before leads to an extra copy
instruction during legalization, but this should be harmless.
Differential Revision: https://reviews.llvm.org/D95035
This is to support the memory routines vec_malloc, vec_calloc, vec_realloc, and vec_free. These routines manage memory that is 16-byte aligned. And they are only available on AIX.
Differential Revision: https://reviews.llvm.org/D94710
This patch implements codegen for __managed__ variable attribute for HIP.
Diagnostics will be added later.
Differential Revision: https://reviews.llvm.org/D94814
When adding an enum attribute to an AttributeList, avoid going
through an AttrBuilder and instead directly add the attribute to
the correct set. Going through AttrBuilder is expensive, because
it requires all string attributes to be reconstructed.
This can be further improved by inserting the attribute at the
right position and using the AttributeSetNode::getSorted() API.
This recovers the small compile-time regression from D94633.
This speeds up setLastUser enough to give a 5% to 10% speed up on
trivial invocations of opt and llc, as measured by:
perf stat -r 100 opt -S -o /dev/null -O3 /dev/null
perf stat -r 100 llc -march=amdgcn /dev/null -filetype null
Don't dump last use information unless -debug-pass=Details to avoid
printing lots of spam that will break some existing lit tests. Before
this patch, dumping last use information was broken anyway, because it
used InversedLastUser before it had been populated.
Differential Revision: https://reviews.llvm.org/D92309
Allocation was removed from ilist in 2016 in the git commit
b5da00533510.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D93953
Having a custom inliner doesn't really fit in with the new PM's
pipeline. It's also extra technical debt.
amdgpu-inline only does a couple of custom things compared to the normal
inliner:
1) It disables inlining if the number of BBs in a function would exceed
some limit
2) It increases the threshold if there are pointers to private arrays(?)
These can all be handled as TTI inliner hooks.
There already exists a hook for backends to multiply the inlining
threshold.
This way we can remove the custom amdgpu-inline pass.
This caused inline-hint.ll to fail, and after some investigation, it
looks like getInliningThresholdMultiplier() was previously getting
applied twice in amdgpu-inline (https://reviews.llvm.org/D62707 fixed it
not applying at all, so some later inliner change must have fixed
something), so I had to change the threshold in the test.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D94153
Add factory to create streams for logging the reproducer. Allows for more general logging (beyond file) and logging the configuration/module separately (logged in order, configuration before module).
Also enable querying filename of ToolOutputFile.
Differential Revision: https://reviews.llvm.org/D94868
The fault-only-first-load instructions can reduce VL if an element
other than element 0 triggers a memory fault. This can be used to
vectorize loops with data dependent exit conditions like strcmp or
strlen.
This patch adds a VL output to these intrinsics so that the new
VL value can be captured by software. This will be expanded to
'csrr gpr, vl' after the vleff instruction during SelectionDAG.
By doing this with one intrinsic we are able to guarantee that the
csrr reads the VL value produced by the vleff instruction. Having
it as a separate intrinsic would make it impossible to guarantee
ordering without making every other vector intrinsic have side
effects.
The intrinsics are expanded during lowering into two ISD nodes
that are glued together. These ISD nodes will go
through isel separately, but should maintain the glue so that they
get emitted adjacently by InstrEmitter.
I've only ran the chain through the vleff instruction, allowing
the READ_VL to be deleted if it is unused.
Reviewed By: HsiangKai
Differential Revision: https://reviews.llvm.org/D94286
Upgrade RISC-V V extension to v1.0-08a0b46.
Indexed load/store have ordered and unordered form.
New whole vector load/store.
Differential Revision: https://reviews.llvm.org/D93614
This adds cost modelling for the inloop vectorization added in
745bf6cf4471. Up until now they have been modelled as the original
underlying instruction, usually an add. This happens to works OK for MVE
with instructions that are reducing into the same type as they are
working on. But MVE's instructions can perform the equivalent of an
extended MLA as a single instruction:
%sa = sext <16 x i8> A to <16 x i32>
%sb = sext <16 x i8> B to <16 x i32>
%m = mul <16 x i32> %sa, %sb
%r = vecreduce.add(%m)
->
R = VMLADAV A, B
There are other instructions for performing add reductions of
v4i32/v8i16/v16i8 into i32 (VADDV), for doing the same with v4i32->i64
(VADDLV) and for performing a v4i32/v8i16 MLA into an i64 (VMLALDAV).
The i64 are particularly interesting as there are no native i64 add/mul
instructions, leading to the i64 add and mul naturally getting very
high costs.
Also worth mentioning, under NEON there is the concept of a sdot/udot
instruction which performs a partial reduction from a v16i8 to a v4i32.
They extend and mul/sum the first four elements from the inputs into the
first element of the output, repeating for each of the four output
lanes. They could possibly be represented in the same way as above in
llvm, so long as a vecreduce.add could perform a partial reduction. The
vectorizer would then produce a combination of in and outer loop
reductions to efficiently use the sdot and udot instructions. Although
this patch does not do that yet, it does suggest that separating the
input reduction type from the produced result type is a useful concept
to model. It also shows that a MLA reduction as a single instruction is
fairly common.
This patch attempt to improve the costmodelling of in-loop reductions
by:
- Adding some pattern matching in the loop vectorizer cost model to
match extended reduction patterns that are optionally extended and/or
MLA patterns. This marks the cost of the reduction instruction correctly
and the sext/zext/mul leading up to it as free, which is otherwise
difficult to tell and may get a very high cost. (In the long run this
can hopefully be replaced by vplan producing a single node and costing
it correctly, but that is not yet something that vplan can do).
- getExtendedAddReductionCost is added to query the cost of these
extended reduction patterns.
- Expanded the ARM costs to account for these expanded sizes, which is a
fairly simple change in itself.
- Some minor alterations to allow inloop reduction larger than the highest
vector width and i64 MVE reductions.
- An extra InLoopReductionImmediateChains map was added to the vectorizer
for it to efficiently detect which instructions are reductions in the
cost model.
- The tests have some updates to show what I believe is optimal
vectorization and where we are now.
Put together this can greatly improve performance for reduction loop
under MVE.
Differential Revision: https://reviews.llvm.org/D93476
This fixes the final (I think?) reference invalidation in `SmallVector`
that we need to fix to align with `std::vector`. (There is still some
left in the range insert / append / assign, but the standard calls that
UB for `std::vector` so I think we don't care?)
For POD-like types, reimplement `emplace_back()` in terms of
`push_back()`, taking a copy even for large `T` rather than lose the
realloc optimization in `grow_pod()`.
For other types, split the grow operation in three and construct the new
element in the middle.
- `mallocForGrow()` calculates the new capacity and returns the result
of `safe_malloc()`. We only need a single definition per
`SmallVectorBase` so this is defined in SmallVector.cpp to avoid code
size bloat. Moving this part of non-POD grow to the source file also
allows the logic to be easily shared with `grow_pod`, and
`report_size_overflow()` and `report_at_maximum_capacity()` can move
there too.
- `moveElementsForGrow()` moves elements from the old to the new
allocation.
- `takeAllocationForGrow()` frees the old allocation and saves the
new allocation and capacity .
`SmallVector:assign(size_type, const T&)` also uses the split-grow
operations for non-POD, but it also has a semantic change when not
growing. Previously, assign would start with `clear()`, and so the old
elements were destructed and all elements of the new vector were
copy-constructed (potentially invalidating references). The new
implementation skips destruction and uses copy-assignment for the prefix
of the new vector that fits. The new semantics match what libc++ does
for `std::vector::assign()`.
Note that the following is another possible implementation:
```
void assign(size_type NumElts, ValueParamT Elt) {
std::fill_n(this->begin(), std::min(NumElts, this->size()), Elt);
this->resize(NumElts, Elt);
}
```
The downside of this simpler implementation is that if the vector has to
grow there will be `size()` redundant copy operations.
(I had planned on splitting this patch up into three for committing
(after getting performance numbers / initial review), but I've realized
that if this does for some reason need to be reverted we'll probably
want to revert the whole package...)
Differential Revision: https://reviews.llvm.org/D94739
Make this look more like the DAG handling and move to common code.
I also noticed AArch64 seems to not be properly adding the
physreg:virtreg mapping to the function live ins.
Summary:
The custom mapper API did not previously support the mapping names added previously. This means they were not present if a user requested debugging information while using the mapper functions. This adds basic support for passing the mapped names to the runtime library.
Reviewers: jdoerfert
Differential Revision: https://reviews.llvm.org/D94806
Previous code build the model that tile config register is the user of
each AMX instruction. There is a problem for the tile config register
spill. When across function, the ldtilecfg instruction may be inserted
on each AMX instruction which use tile config register. This cause all
tile data register clobber.
To fix this issue, we remove the model of tile config register. We
analyze the regmask of call instruction and insert ldtilecfg if there is
any tile data register live across the call. Inserting the sttilecfg
before the call is unneccessary, because the tile config doesn't change
and we can just reload the config.
Besides we also need check tile config register interference. Since we
don't model the config register we should check interference from the
ldtilecfg to each tile data register def.
ldtilecfg
/ \
BB1 BB2
/ \
call BB3
/ \
%1=tileload %2=tilezero
We can start from the instruction of each tile def, and backward to
ldtilecfg. If there is any call instruction, and tile data register is
not preserved, we should insert ldtilecfg after the call instruction.
Differential Revision: https://reviews.llvm.org/D94155
This makes the following improvements.
For `SHT_GNU_versym`:
* yaml2obj: set `sh_link` to index of `.dynsym` section automatically.
For `SHT_GNU_verdef`:
* yaml2obj: set `sh_link` to index of `.dynstr` section automatically.
* yaml2obj: set `sh_info` field automatically.
* obj2yaml: don't dump the `Info` field when its value matches the number of version definitions.
For `SHT_GNU_verneed`:
* yaml2obj: set `sh_link` to index of `.dynstr` section automatically.
* yaml2obj: set `sh_info` field automatically.
* obj2yaml: don't dump the `Info` field when its value matches the number of version dependencies.
Also, simplifies few test cases.
Differential revision: https://reviews.llvm.org/D94956
This reverts commit d97f776be5f8cd3cd446fe73827cd355f6bab4e1.
The original problem was due to build failures in shared lib builds. D95079
moved ImportedFunctionsInliningStatistics under Analysis, unblocking
this.
This is related to D94982. We want to call these APIs from the Analysis
component, so we can't leave them under Transforms.
Differential Revision: https://reviews.llvm.org/D95079
This reverts commit 5b7aef6eb4b2930971029b984cb2360f7682e5a5 and relands
6529d7c5a45b1b9588e512013b02f891d71bc134.
The ASan error was debugged and determined to be the fault of an invalid
object file input in our test suite, which was fixed by my last change.
LLD's project policy is that it assumes input objects are valid, so I
have added a comment about this assumption to the relocation bounds
check.
Run the ObjCARCContractPass during LTO. The legacy LTO backend (under
LTO/ThinLTOCodeGenerator.cpp) already does this; this diff just adds that
behavior to the new LTO backend. Without that pass, the objc.clang.arc.use
intrinsic will get passed to the instruction selector, which doesn't know how to
handle it.
In order to test both the new and old pass managers, I've also added support for
the `--[no-]lto-legacy-pass-manager` flags.
P.S. Not sure if the ordering of the pass within the pipeline matters...
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D94547
When using 2 InlinePass instances in the same CGSCC - one for other
mandatory inlinings, the other for the heuristic-driven ones - the order
in which the ImportedFunctionStats would be output-ed would depend on
the destruction order of the inline passes, which is not deterministic.
This patch moves the ImportedFunctionStats responsibility to the
InlineAdvisor to address this problem.
Differential Revision: https://reviews.llvm.org/D94982
Add the aarch64[_be]-*-gnu_ilp32 targets to support the GNU ILP32 ABI for AArch64.
The needed codegen changes were mostly already implemented in D61259, which added support for the watchOS ILP32 ABI. The main changes are:
- Wiring up the new target to enable ILP32 codegen and MC.
- ILP32 va_list support.
- ILP32 TLSDESC relocation support.
There was existing MC support for ELF ILP32 relocations from D25159 which could be enabled by passing "-target-abi ilp32" to llvm-mc. This was changed to check for "gnu_ilp32" in the target triple instead. This shouldn't cause any issues since the existing support was slightly broken: it was generating ELF64 objects instead of the ELF32 object files expected by the GNU ILP32 toolchain.
This target has been tested by running the full rustc testsuite on a big-endian ILP32 system based on the GCC ILP32 toolchain.
Reviewed By: kristof.beyls
Differential Revision: https://reviews.llvm.org/D94143
The pass analysis uses "sets" implemented using a SmallVector type
to keep track of Used, Preserved, Required and RequiredTransitive
passes. When having nested analyses we could end up with duplicates
in those sets, as there was no checks to see if a pass already
existed in the "set" before pushing to the vectors. This idea with
this patch is to avoid such duplicates by avoiding pushing elements
that already is contained when adding elements to those sets.
To align with the above PMDataManager::collectRequiredAndUsedAnalyses
is changed to skip adding both the Required and RequiredTransitive
passes to its result vectors (since RequiredTransitive always is
a subset of Required we ended up with duplicates when traversing
both sets).
Main goal with this is to avoid spending time verifying the same
analysis mulitple times in PMDataManager::verifyPreservedAnalysis
when iterating over the Preserved "set". It is assumed that removing
duplicates from a "set" shouldn't have any other negative impact
(I have not seen any problems so far). If this ends up causing
problems one could do some uniqueness filtering of the vector being
traversed in verifyPreservedAnalysis instead.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D94416
If constants are hidden behind G_ANYEXT we can treat them same way as G_SEXT.
For that purpose we extend getConstantVRegValWithLookThrough with option
to handle G_ANYEXT same way as G_SEXT.
Differential Revision: https://reviews.llvm.org/D92219
When constraining an operand register using constrainOperandRegClass(),
the function may emit a COPY in case the provided register class does
not match the current operand register class. However, the operand
itself is not updated to make use of the COPY, thereby resulting in
incorrect code. This patch fixes that bug by updating the machine
operand accordingly.
Reviewed By: dsanders
Differential Revision: https://reviews.llvm.org/D91244
For Zvlsseg, we need continuous vector registers for the values. We need
to define new register classes for the different combinations of (number
of fields and LMUL). For example,
when the number of fields(NF) = 3, LMUL = 2, the values will be assigned
to (V0M2, V2M2, V4M2), (V2M2, V4M2, V6M2), (V4M2, V6M2, V8M2), ...
We define the vlseg intrinsics with multiple outputs. There is no way to
describe the codegen patterns with multiple outputs in the tablegen
files. We do the codegen in RISCVISelDAGToDAG and use EXTRACT_SUBREG to
extract the values of output.
The multiple scalable vector values will be put into a struct. This
patch is depended on the support for scalable vector struct.
Differential Revision: https://reviews.llvm.org/D94229
Currently LLVM is relying on ValueTracking's `isKnownNonZero` to attach `nonnull`, which can return true when the value is poison.
To make the semantics of `nonnull` consistent with the behavior of `isKnownNonZero`, this makes the semantics of `nonnull` to accept poison, and return poison if the input pointer isn't null.
This makes many transformations like below legal:
```
%p = gep inbounds %x, 1 ; % p is non-null pointer or poison
call void @f(%p) ; instcombine converts this to call void @f(nonnull %p)
```
Instead, this semantics makes propagation of `nonnull` to caller illegal.
The reason is that, passing poison to `nonnull` does not immediately raise UB anymore, so such program is still well defined, if the callee does not use the argument.
Having `noundef` attribute there re-allows this.
```
define void @f(i8* %p) { ; functionattr cannot mark %p nonnull here anymore
call void @g(i8* nonnull %p) ; .. because @g never raises UB if it never uses %p.
ret void
}
```
Another attribute that needs to be updated is `align`. This patch updates the semantics of align to accept poison as well.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D90529
separate sections.
For ThinLTO, all the function profiles without context has been annotated to
outline functions if possible in prelink phase. In postlink phase, profile
annotation in postlink phase is only meaningful for function profile with
context. If the profile is large, it is better to split the profile into two
parts, one with context and one without, so the profile reading in postlink
phase only has to read the part with context. To have the profile splitting,
we extend the ExtBinary format to support different section arrangement. It
will be flexible to add other section layout in the future without the need
to create new class inheriting from ExtBinary class.
Differential Revision: https://reviews.llvm.org/D94435
If we are able to compare with 0 instead of 1, we might be able
to fold the setcc into a beqz/bnez.
Often these setccs start life as an xor that gets converted to
a setcc by DAG combiner's rebuildSetcc. I looked into a detecting
(xor X, 1) and converting to (seteq X, 0) based on boolean contents
being 0/1 in rebuildSetcc instead of using computeKnownBits. It was
very perturbing to AMDGPU tests which I didn't look closely at.
It had a few changes on a couple other targets, but didn't seem
to be much if any improvement.
Reviewed By: lenary
Differential Revision: https://reviews.llvm.org/D94730
Just like llvm.assume, there are a lot of cases where we can just ignore llvm.experimental.noalias.scope.decl.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D93042
This is a restricted version of the combine in `DAGCombiner::MatchLoadCombine`.
(See D27861)
This tries to recognize patterns like below (assuming a little-endian target):
```
s8* x = ...
s32 val = a[0] | (a[1] << 8) | (a[2] << 16) | (a[3] << 24)
->
s32 val = *((i32)a)
s8* x = ...
s32 val = a[3] | (a[2] << 8) | (a[1] << 16) | (a[0] << 24)
->
s32 val = BSWAP(*((s32)a))
```
(This patch also handles the big-endian target case as well, in which the first
example above has a BSWAP, and the second example above does not.)
To recognize the pattern, this searches from the last G_OR in the expression
tree.
E.g.
```
Reg Reg
\ /
OR_1 Reg
\ /
OR_2
\ Reg
.. /
Root
```
Each non-OR register in the tree is put in a list. Each register in the list is
then checked to see if it's an appropriate load + shift logic.
If every register is a load + potentially a shift, the combine checks if those
loads + shifts, when OR'd together, are equivalent to a wide load (possibly with
a BSWAP.)
To simplify things, this patch
(1) Only handles G_ZEXTLOADs (which appear to be the common case)
(2) Only works in a single MachineBasicBlock
(3) Only handles G_SHL as the bit twiddling to stick the small load into a
specific location
An IR example of this is here: https://godbolt.org/z/4sP9Pj (lifted from
test/CodeGen/AArch64/load-combine.ll)
At -Os on AArch64, this is a 0.5% code size improvement for CTMark/sqlite3,
and a 0.4% improvement for CTMark/7zip-benchmark.
Also fix a bug in `isPredecessor` which caused it to fail whenever `DefMI` was
the first instruction in the block.
Differential Revision: https://reviews.llvm.org/D94350
The TableGen emitter for directives has two slots for flangClass information and this was mainly
to be able to keep up with the legacy openmp parser at the time. Now that all clauses are encapsulated in
AccClause or OmpClause, these two strings are not necessary anymore and were the the source of couple
of problem while working with the generic structure checker for OpenMP.
This patch remove the flangClassValue string from DirectiveBase.td and use the string flangClass as the
placeholder for the encapsulated class.
Reviewed By: sameeranjoshi
Differential Revision: https://reviews.llvm.org/D94821
This CPU supports all v8.5a features except BTI, and so identifies as v8.5a to
Clang. A bit weird, but the best way for things like xnu to detect the new
features it cares about.
This patch updates the llvm module map to reflect changes made in
`24672ddea3c97fd1eca3e905b23c0116d7759ab8` and fixes the module builds
(`-DLLVM_ENABLE_MODULES=On`).
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This patch computes the cost for vector.reduce<operand> for scalable vectors.
The cost is split into two parts: the legalization cost and the horizontal
reduction.
Differential Revision: https://reviews.llvm.org/D93639
D84108 exposed a bad interaction between inlining and loop-rotation
during regular LTO, which is causing notable regressions in at least
CINT2006/473.astar.
The problem boils down to: we now rotate a loop just before the vectorizer
which requires duplicating a function call in the preheader when compiling
the individual files ('prepare for LTO'). But this then prevents further
inlining of the function during LTO.
This patch tries to resolve this issue by making LoopRotate more
conservative with respect to rotating loops that have inline-able calls
during the 'prepare for LTO' stage.
I think this change intuitively improves the current situation in
general. Loop-rotate tries hard to avoid creating headers that are 'too
big'. At the moment, it assumes all inlining already happened and the
cost of duplicating a call is equal to just doing the call. But with LTO,
inlining also happens during full LTO and it is possible that a previously
duplicated call is actually a huge function which gets inlined
during LTO.
From the perspective of LV, not much should change overall. Most loops
calling user-provided functions won't get vectorized to start with
(unless we can infer that the function does not touch memory, has no
other side effects). If we do not inline the 'inline-able' call during
the LTO stage, we merely delayed loop-rotation & vectorization. If we
inline during LTO, chances should be very high that the inlined code is
itself vectorizable or the user call was not vectorizable to start with.
There could of course be scenarios where we inline a sufficiently large
function with code not profitable to vectorize, which would have be
vectorized earlier (by scalarzing the call). But even in that case,
there probably is no big performance impact, because it should be mostly
down to the cost-model to reject vectorization in that case. And then
the version with scalarized calls should also not be beneficial. In a way,
LV should have strictly more information after inlining and make more
accurate decisions (barring cost-model issues).
There is of course plenty of room for things to go wrong unexpectedly,
so we need to keep a close look at actual performance and address any
follow-up issues.
I took a look at the impact on statistics for
MultiSource/SPEC2000/SPEC2006. There are a few benchmarks with fewer
loops rotated, but no change to the number of loops vectorized.
Reviewed By: sanwou01
Differential Revision: https://reviews.llvm.org/D94232
Element sections will also need flags, so we shouldn't squat the
WASM_SEGMENT namespace.
Depends on D90948.
Differential Revision: https://reviews.llvm.org/D92315
The code here is checking to see if two sets are identical.
OtherBlocksSet should point to OtherL->getBlocksSet() instead.
Differential Revision: https://reviews.llvm.org/D94926
This patch adds the default value of 1 to drop_begin.
In the llvm codebase, 70% of calls to drop_begin have 1 as the second
argument. The interface similar to with std::next should improve
readability.
This patch converts a couple of calls to drop_begin as examples.
Differential Revision: https://reviews.llvm.org/D94858
DefaultAttrIntrinsics was introduced to add very common attributes to a
large set of intrinsics.
Currently the added attributes include:
nofree nosync nounwind willreturn
I think those should hold for most AArch64 target intrinsics, but
there are too many to check manually. This patch makes most AArch64 target
intrinsics DefaultAttrsIntrinsics.
Some notable exceptions I think are exclusive loads and stores as well
as the memory barrier intrinsics, for which nosync does not apply I
think.
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D94687
Keys matching the tombstone/empty special values cannot be inserted in a
DenseMap. Under some circumstances, LV tries to add members to an
interleave group that match the special values. Skip adding such
members. This is unlikely to have any impact in practice, because
interleave groups with such indices are very likely to not be
vectorized, due to gaps.
This issue has been surfaced by fuzzing, see
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=11638
`ELFDumper.cpp` implements the functionality that allows to get symbol versions.
It is used for dumping versioned symbols.
This helps to implement https://bugs.llvm.org/show_bug.cgi?id=48670 ("make llvm-nm -D print version names"):
we can move out and reuse the code from `ELFDumper.cpp`.
This is what this patch do: it moves the related functionality to `ELFFile<ELFT>`.
Differential revision: https://reviews.llvm.org/D94771
RISC-V would like to use a struct of scalable vectors to return multiple
values from intrinsics. This woud also be needed for target independent
intrinsics like llvm.sadd.overflow.
This patch removes the existing restriction for this. I've modified
StructType::isSized to consider a struct containing scalable vectors
as unsized so the verifier won't allow loads/stores/allocas of these
structs.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D94142
Reassociating some patterns to generate more fma instructions to
reduce register pressure.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D92071
add one use check to lookThruCopyLike.
The root node is safe to be deleted if we are sure that every
definition in the copy chain only has one use.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D92069
There are no changes relative to the original commit. However, an issue
this exposed in BasicAA assumption tracking has been fixed in the
previous commit.
-----
An alias query currently works out roughly like this:
* Look up location pair in cache.
* Perform BasicAA logic (including cache lookup and insertion...)
* Perform a recursive query using BestAAResults.
* Look up location pair in cache (and thus do not recurse into BasicAA)
* Query all the other AA providers.
* Query all the other AA providers.
This is a lot of unnecessary work, all ultimately caused by the
BestAAResults query at the end of aliasCheck(). The reason we perform
it, is that aliasCheck() is getting called recursively, and we of
course want those recursive queries to also make use of other AA
providers, not just BasicAA. We can solve this by making the recursive
queries directly use BestAAResults (which will check both BasicAA
and other providers), rather than recursing into aliasCheck().
There are some tradeoffs:
* We can no longer pass through the precomputed underlying object
to aliasCheck(). This is not a major concern, because nowadays
getUnderlyingObject() is quite cheap.
* Results from other AA providers are no longer cached inside
BasicAA. The way this worked was already a bit iffy, in that a
result could be cached, but if it was MayAlias, we'd still end
up re-querying other providers anyway. If we want to cache
non-BasicAA results, we should do that in a more principled manner.
In any case, despite those tradeoffs, this works out to be a decent
compile-time improvment. I think it also simplifies the mental model
of how BasicAA works. It took me quite a while to fully understand
how these things interact.
Differential Revision: https://reviews.llvm.org/D90094
D91936 placed the tracking for the assumptions into BasicAA.
However, when recursing over phis, we may use fresh AAQI instances.
In this case AssumptionBasedResults from an inner AAQI can reesult
in a removal of an element from the outer AAQI.
To avoid this, move the tracking into AAQI. This generally makes
more sense, as the NoAlias assumptions themselves are also stored
in AAQI.
The test case only produces an assertion failure with D90094
reapplied. I think the issue exists independently of that change
as well, but I wasn't able to come up with a reproducer.
This patch removes some ancient options as a clean-up before moving
code-gen to use LTOBackend in D94487.
I think it would preferable to remove those ancient options, because
1. There are no corresponding options in LTOBackend based tools,
2. There are no unit tests for them,
3. They are not passed through by Clang,
4. At least for GNVLoadPRE, users could just use GVN's `enable-load-pre`.
Alternatively we could add support for those options to lto::Config &
co, but I think it would be better to remove them, unless they are
actually used in practice.
Reviewed By: steven_wu, tejohnson
Differential Revision: https://reviews.llvm.org/D94783
