This patch adds support for lowering function calls with the
rv_marker attribute. The goal is to expand such calls to the
following sequence of instructions:
BL @fn
mov x29, x29
This sequence of instructions triggers Objective-C runtime optimizations,
hence we want to ensure no instructions get moved in between them.
This patch achieves that by adding a new CALL_RVMARKER ISD node,
which gets turned into the BLR_RVMARKER pseudo, which eventually gets
expanded into the sequence mentioned above. The sequence is then marked
as instruction bundle, to avoid anything being moved in between.
@ahatanak is working on using this attribute in the front- & middle-end.
Together with the front- & middle-end changes, this should address
PR31925 for AArch64.
Reviewed By: t.p.northover
Differential Revision: https://reviews.llvm.org/D92569
Add simple pass for removing redundant vsetvli instructions within a basic block. This handles the case where the AVL register and VTYPE immediate are the same and no other instructions that change VTYPE or VL are between them.
There are going to be more opportunities for improvement in this space as we development more complex tests.
Differential Revision: https://reviews.llvm.org/D92679
If we have two unknown sizes and one GEP operand and one non-GEP
operand, then we currently simply return MayAlias. The comment says
we can't do anything useful ... but we can! We can still check that
the underlying objects are different (and do so for the GEP-GEP case).
To reduce the compile-time impact, this a) checks this early, before
doing the relatively expensive GEP decomposition that will not be
used and b) doesn't do the check if the other operand is a phi or
select. In that case, the phi/select will already recurse, so this
would just do two slightly different recursive walks that arrive at
the same roots.
Compile-time is still a bit of a mixed bag: https://llvm-compile-time-tracker.com/compare.php?from=624af932a808b363a888139beca49f57313d9a3b&to=845356e14adbe651a553ed11318ddb5e79a24bcd&stat=instructions
On average this is a small improvement, but sqlite with ThinLTO has
a 0.5% regression (lencod has a 1% improvement).
The BasicAA test case checks this by using two memsets with unknown
size. However, the more interesting case where this is useful is
the LoopVectorize test case, as analysis of accesses in loops tends
to always us unknown sizes.
Differential Revision: https://reviews.llvm.org/D92401
Addressing clang bootstrap under the dynamic linking mode running out of static
allocation of value profile nodes, reported in D81682.
Differential Revision: https://reviews.llvm.org/D92669
Extract some changes not directly related to tileLoops out of D92974:
* Refactor `createLoopSkeleton` out of `createCanonicalLoop`.
* Introduce `ComputeIP` parameter to the `createCanonicalLoop` overload inserts instructions to compute the trip count. Specifying the location is necessary to make these instructions appear before the outermost loop of a loop nest that is tiled.
* Introduce `Name` parameter to `createCanonicalLoop`. This can help better understanding the origin of values of basic blocks with many loops. The default value is "loop" instead of "for" which could be confused with the "for directive" (aka worksharing-loop) and does not apply to Fortran.
* Remove `CanonicalLoopInfo::eraseFromParent` which is currently unused and untested and was added in anticipation to be used by `tileLoops`. `eraseFromParent` has shown to be insufficient when more than a single loop is involved and is replaced by `removeUnusedBlocksFromParent` in D92974.
Reviewed By: SouraVX
Differential Revision: https://reviews.llvm.org/D93088
D73999 / commit 75af9da755721123e62b45cd0bc0c5e688a9722a
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.
However, GNU assembler accepts and GCC generates an abbreviated form:
while the first .section contains the flags and entsize, subsequent
sections simply contain the name without repeating entsize or flags.
Do likewise for better compatibility.
See https://bugs.llvm.org/show_bug.cgi?id=48201
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D92052
Currently unknown keys when inputting mapping traits have the location set to the Value.
Example:
```
YAML:1:14: error: unknown key 'UnknownKey'
{UnknownKey: SomeValue}
^~~~~~~~~
```
This is unhelpful for a user as it draws them to fix the wrong item.
Reviewed By: silvas
Differential Revision: https://reviews.llvm.org/D93037
This function is needed for when it is necessary to split the subvector
operand of an llvm.experimental.vector.insert call. Splitting the
subvector operand means performing two insertions: one inserting the
lower part of the split subvector into the destination vector, and
another for inserting the upper part.
Through experimenting, it seems quite rare to need split the subvector
operand, but this is necessary to avoid assertion errors.
Differential Revision: https://reviews.llvm.org/D92760
Although this was something that I was hoping we would not have to do,
this patch makes t2DoLoopStartTP a terminator in order to keep it at the
end of it's block, so not allowing extra MVE instruction between it and
the end. With t2DoLoopStartTP's also starting tail predication regions,
it also marks them as having side effects. The t2DoLoopStart is still
not a terminator, giving it the extra scheduling freedom that can be
helpful, but now that we have a TP version they can be treated
differently.
Differential Revision: https://reviews.llvm.org/D91887
This is the first in a series of patches that attempts to migrate
existing cost instructions to return a new InstructionCost class
in place of a simple integer. This new class is intended to be
as light-weight and simple as possible, with a full range of
arithmetic and comparison operators that largely mirror the same
sets of operations on basic types, such as integers. The main
advantage to using an InstructionCost is that it can encode a
particular cost state in addition to a value. The initial
implementation only has two states - Normal and Invalid - but these
could be expanded over time if necessary. An invalid state can
be used to represent an unknown cost or an instruction that is
prohibitively expensive.
This patch adds the new class and changes the getInstructionCost
interface to return the new class. Other cost functions, such as
getUserCost, etc., will be migrated in future patches as I believe
this to be less disruptive. One benefit of this new class is that
it provides a way to unify many of the magic costs in the codebase
where the cost is set to a deliberately high number to prevent
optimisations taking place, e.g. vectorization. It also provides
a route to represent the extremely high, and unknown, cost of
scalarization of scalable vectors, which is not currently supported.
Differential Revision: https://reviews.llvm.org/D91174
This was separated in the past because the cl::opt was in the .cpp file
but DevirtSCCRepeatedPass::run() was in the .h file. Now that
DevirtSCCRepeatedPass::run() is in the .cpp file, get rid of the tiny
maxDevirtIterationsReached(), it's bad for readability.
The declaration was introduced on Aug 2, 2016 in commit
c43aa5a5b62b21c1d38cd3d2ece7d0d5124d5180 without a corresponding
definition.
Note that we do have a definition for
MmeorySSA::OptimizeUses::optimizeUses but not for
MmeorySSA::optimizeUses.
The compiler is making no effort to preserve upper elements. To do so would require another source operand tied with the destination and a different intrinsic interface to give control of this source to the programmer.
This patch changes the tail policy to agnostic so that the CPU doesn't need to make an effort to preserve them.
This is consistent with the RVV intrinsic spec here https://github.com/riscv/rvv-intrinsic-doc/blob/master/rvv-intrinsic-rfc.md#configuration-setting
Differential Revision: https://reviews.llvm.org/D93080
Historically, we have told contributors that GnuWin32 is a pre-requisite
because our tests depend on utilities such as sed, grep, diff, and more.
However, Git on Windows includes versions of these utilities in its
installation. Furthermore, GnuWin32 has not been updated in many years.
For these reasons, it makes sense to have the ability to run llvm tests
in a way that is both:
a) Easier on the user (less stuff to install)
b) More up-to-date (The verions that ship with git are at least as
new, if not newer, than the versions in GnuWin32.
We add support for this here by attempting to detect where Git is
installed using the Windows registry, confirming the existence of
several common Unix tools, and then adding this location to lit's PATH
environment.
Differential Revision: https://reviews.llvm.org/D84380
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s
Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections. The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead.
**ELF object emission**
The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.
Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication. A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.
The format of `.pseudo_probe_desc` section looks like:
```
.section .pseudo_probe_desc,"",@progbits
.quad 6309742469962978389 // Func GUID
.quad 4294967295 // Func Hash
.byte 9 // Length of func name
.ascii "_Z5funcAi" // Func name
.quad 7102633082150537521
.quad 138828622701
.byte 12
.ascii "_Z8funcLeafi"
.quad 446061515086924981
.quad 4294967295
.byte 9
.ascii "_Z5funcBi"
.quad -2016976694713209516
.quad 72617220756
.byte 7
.ascii "_Z3fibi"
```
For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :
```
FUNCTION BODY (one for each outlined function present in the text section)
GUID (uint64)
GUID of the function
NPROBES (ULEB128)
Number of probes originating from this function.
NUM_INLINED_FUNCTIONS (ULEB128)
Number of callees inlined into this function, aka number of
first-level inlinees
PROBE RECORDS
A list of NPROBES entries. Each entry contains:
INDEX (ULEB128)
TYPE (uint4)
0 - block probe, 1 - indirect call, 2 - direct call
ATTRIBUTE (uint3)
reserved
ADDRESS_TYPE (uint1)
0 - code address, 1 - address delta
CODE_ADDRESS (uint64 or ULEB128)
code address or address delta, depending on ADDRESS_TYPE
INLINED FUNCTION RECORDS
A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
callees. Each record contains:
INLINE SITE
GUID of the inlinee (uint64)
ID of the callsite probe (ULEB128)
FUNCTION BODY
A FUNCTION BODY entry describing the inlined function.
```
To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.
**Assembling**
Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.
A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.
A example assembly looks like:
```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```
With inlining turned on, the assembly may look different around %bb2 with an inlined probe:
```
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 3 0
.pseudoprobe 6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe 837061429793323041 4 0
popq %rax
retq
```
**Disassembling**
We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.
An example disassembly looks like:
```
00000000002011a0 <foo2>:
2011a0: 50 push rax
2011a1: 85 ff test edi,edi
[Probe]: FUNC: foo2 Index: 1 Type: Block
2011a3: 74 02 je 2011a7 <foo2+0x7>
[Probe]: FUNC: foo2 Index: 3 Type: Block
[Probe]: FUNC: foo2 Index: 4 Type: Block
[Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6
2011a5: 58 pop rax
2011a6: c3 ret
[Probe]: FUNC: foo2 Index: 2 Type: Block
2011a7: bf 01 00 00 00 mov edi,0x1
[Probe]: FUNC: foo2 Index: 5 Type: IndirectCall
2011ac: ff d6 call rsi
[Probe]: FUNC: foo2 Index: 4 Type: Block
2011ae: 58 pop rax
2011af: c3 ret
```
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D91878
This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.
This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.
Differential Revision: https://reviews.llvm.org/D92952
This is a reland of rG4564553b8d8a with a fix to the lit pipeline in
llvm/test/MC/WebAssembly/comdat.ll
This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.
This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.
Differential Revision: https://reviews.llvm.org/D92952
Copy the `ProgrammersManual.rst` changes from D92522 to the Doxygen
comment for `SmallVector`, to hopefully encourage new uses migrating to
the no-explicit-`N` form.
Differential Revision: https://reviews.llvm.org/D93069
Use RegisterClass::contains instead of going through getMinimalPhysRegClass
and hasSuperClassEq.
Remove the special case for NoRegister. It's identical to the
handling for any other regsiter that isn't VRM2/M4/M8.
The loop-based probing done for stack clash protection altered R1D which
corrupted the backchain value to be stored after the probing was done.
By using R0D instead for the loop exit value, R1D is not modified.
Review: Ulrich Weigand.
Differential Revision: https://reviews.llvm.org/D92803
Inline asm can contain constructs like .bytes which may have arbitrary size.
In some cases, this causes us to miscalculate the size of blocks and therefore
offsets, causing us to incorrectly compress a JT.
To be safe, just bail out of the whole thing if we find any inline asm.
Fixes PR48255
Differential Revision: https://reviews.llvm.org/D92865
