- Add a new TableGen backend: CodeBeads
- Add support to generate logical operand information
For the first item, it is currently a workaround of M68k's (complex)
instruction encoding. A typical architecture, especially CISC one like
X86, normally uses `MCInstrDesc::TSFlags` to carry instruction encoding
info. However, at the early days of M68k backend development, we found
it difficult to fit every possible encoding into the 64-bit
`MCInstrDesc::TSFlags`. Therefore CodeBeads was invented to provide
an alternative, arbitrary length container for instruciton encoding
info. However, in the long term we incline not to use a new TG
backend for less common pattern like what we encountered in M68k. A bug
has been created to host to discussion on migrating from CodeBeads to
more concise solution: https://bugs.llvm.org/show_bug.cgi?id=48792
The second item was also served for similar purpose. It created utility
functions that tell you the index of a `MachineOperand` in a
`MachineInst` given a logical operand index. In normal cases a logical
operand is the same as `MachineOperand`, but for operands using complex
addressing mode a logical operand might be consisting of multiple
`MachineOperand`. The TableGen-ed `getLogicalOperandIdx`, for instance,
can give you the mapping between these two concepts. Nevertheless, we
hope to remove this feature in the future if possible. Since it's not
really useful for the targets supported by LLVM now either.
Authors: myhsu, m4yers, glaubitz
Differential Revision: https://reviews.llvm.org/D88385
Some of these were found by running clang-format over the generated
code, although that complains about far more issues than I have fixed
here.
Differential Revision: https://reviews.llvm.org/D90937
This is quite expensive and it's already available.
Just ReadLegalValueTypes is taking 4 seconds for me in a debug build
for AMDGPU's -gen-instr-info, and this was introducing a second call.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
This changes the generated (Instr|Asm|Reg|Regclass)Name tables from this
form:
extern const char HexagonInstrNameData[] = {
/* 0 */ 'G', '_', 'F', 'L', 'O', 'G', '1', '0', 0,
/* 9 */ 'E', 'N', 'D', 'L', 'O', 'O', 'P', '0', 0,
/* 18 */ 'V', '6', '_', 'v', 'd', 'd', '0', 0,
/* 26 */ 'P', 'S', '_', 'v', 'd', 'd', '0', 0,
[...]
};
...to this:
extern const char HexagonInstrNameData[] = {
/* 0 */ "G_FLOG10\0"
/* 9 */ "ENDLOOP0\0"
/* 18 */ "V6_vdd0\0"
/* 26 */ "PS_vdd0\0"
[...]
};
This should make debugging and exploration a lot easier for mortals,
while providing a significant compile-time reduction for common compilers.
To avoid issues with low implementation limits, this is disabled by
default for visual studio.
To force output one way or the other, pass
`--long-string-literals=<bool>` to `tablegen`
Reviewers: mstorsjo, rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D73044
A variation of this patch was originally committed in ce23515f5a and
then reverted in e464b31c due to build failures.
This changes the generated (Instr|Asm|Reg|Regclass)Name tables from this
form:
extern const char HexagonInstrNameData[] = {
/* 0 */ 'G', '_', 'F', 'L', 'O', 'G', '1', '0', 0,
/* 9 */ 'E', 'N', 'D', 'L', 'O', 'O', 'P', '0', 0,
/* 18 */ 'V', '6', '_', 'v', 'd', 'd', '0', 0,
/* 26 */ 'P', 'S', '_', 'v', 'd', 'd', '0', 0,
[...]
};
...to this:
extern const char HexagonInstrNameData[] = {
/* 0 */ "G_FLOG10\0"
/* 9 */ "ENDLOOP0\0"
/* 18 */ "V6_vdd0\0"
/* 26 */ "PS_vdd0\0"
[...]
};
This should make debugging and exploration a lot easier for mortals,
while providing a significant compile-time reduction for common compilers.
To avoid issues with low implementation limits, this is disabled by
default for visual studio or when cross-compiling.
To force output one way or the other, pass
`--long-string-literals=<bool>` to `tablegen`
Reviewers: mstorsjo, rnk
Subscribers: llvm-commit
Differential Revision: https://reviews.llvm.org/D73044
Add a predicate to MCInstDesc that allows tools to determine whether an
instruction authenticates a pointer. This can be used by diagnostic
tools to hint at pointer authentication failures.
Differential Revision: https://reviews.llvm.org/D70329
rdar://55089604
Summary:
Extend D71677 to apply to all branch-target operands, rather than special-casing call instructions.
Also add a regression test for llvm.org/PR44272, since this finishes fixing it.
Reviewers: thakis, rnk
Reviewed By: thakis
Subscribers: merge_guards_bot, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72417
Allows targets to introduce regbankselectable
pseudo-instructions. Currently the closet feature to this is an
intrinsic. However this requires creating a public intrinsic
declaration. This litters the public intrinsic namespace with
operations we don't necessarily want to expose to IR producers, and
would rather leave as private to the backend.
Use a new instruction bit. A previous attempt tried to keep using enum
value ranges, but it turned into a mess.
llvm-svn: 373937
https://reviews.llvm.org/D66773
The OpTypes::OperandType was creating an enum for all records that
inherit from Operand, but in reality there are operands for instructions
that inherit from other types too. In particular, RegisterOperand and
RegisterClass. This commit adds those types to the list of operand types
that are tracked by the OperandType enum.
Patch by: nlguillemot
llvm-svn: 372641
Rather than an array of std::initializer_list, generate a table of
offsets and a flat array of the operands for getOperandType. This is a
bit more efficient on platforms that don't manage to get the array of
inintializer_lists initialized at link time (I'm looking at you
macOS). It's also quite quite a bit faster to compile.
llvm-svn: 366278
The InstrInfoEmitter outputs an enum called "OperandType" which gives
numerical IDs to each operand type. This patch makes use of this enum
to define a function called "getOperandType", which allows looking up
the type of an operand given its opcode and operand index.
Patch by Nicolas Guillemot. Thanks!
Differential Revision: https://reviews.llvm.org/D63320
llvm-svn: 366274
The ISD::STRICT_ nodes used to implement the constrained floating-point
intrinsics are currently never passed to the target back-end, which makes
it impossible to handle them correctly (e.g. mark instructions are depending
on a floating-point status and control register, or mark instructions as
possibly trapping).
This patch allows the target to use setOperationAction to switch the action
on ISD::STRICT_ nodes to Legal. If this is done, the SelectionDAG common code
will stop converting the STRICT nodes to regular floating-point nodes, but
instead pass the STRICT nodes to the target using normal SelectionDAG
matching rules.
To avoid having the back-end duplicate all the floating-point instruction
patterns to handle both strict and non-strict variants, we make the MI
codegen explicitly aware of the floating-point exceptions by introducing
two new concepts:
- A new MCID flag "mayRaiseFPException" that the target should set on any
instruction that possibly can raise FP exception according to the
architecture definition.
- A new MI flag FPExcept that CodeGen/SelectionDAG will set on any MI
instruction resulting from expansion of any constrained FP intrinsic.
Any MI instruction that is *both* marked as mayRaiseFPException *and*
FPExcept then needs to be considered as raising exceptions by MI-level
codegen (e.g. scheduling).
Setting those two new flags is straightforward. The mayRaiseFPException
flag is simply set via TableGen by marking all relevant instruction
patterns in the .td files.
The FPExcept flag is set in SDNodeFlags when creating the STRICT_ nodes
in the SelectionDAG, and gets inherited in the MachineSDNode nodes created
from it during instruction selection. The flag is then transfered to an
MIFlag when creating the MI from the MachineSDNode. This is handled just
like fast-math flags like no-nans are handled today.
This patch includes both common code changes required to implement the
new features, and the SystemZ implementation.
Reviewed By: andrew.w.kaylor
Differential Revision: https://reviews.llvm.org/D55506
llvm-svn: 362663
Summary:
While working on the GISel Combiner, I noticed I was producing location-less
error messages fairly often and set about fixing this. In the process, I
noticed quite a few places elsewhere in TableGen that also neglected to include
a relevant location.
This patch adds locations to errors that relate to a specific record (or a
field within it) and also have easy access to the relevant location. This is
particularly useful when multiclasses are involved as many of these errors
refer to the full name of a record and it's difficult to guess which substring
is grep-able.
Unfortunately, tablegen currently only supports Record granularity so it's not
currently possible to point at a specific Init so these sometimes point at the
record that caused the error rather than the precise origin of the error.
Reviewers: bogner, aditya_nandakumar, volkan, aemerson, paquette, nhaehnle
Reviewed By: nhaehnle
Subscribers: jdoerfert, nhaehnle, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58077
llvm-svn: 353862
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Currently, variadic operands on an MCInst are assumed to be uses,
because they come after the defs. However, this is not always the case,
for example the Arm/Thumb LDM instructions write to a variable number of
registers.
This adds a property of instruction definitions which can be used to
mark variadic operands as defs. This only affects MCInst, because
MachineInstruction already tracks use/def per operand in each instance
of the instruction, so can already represent this.
This property can then be checked in MCInstrDesc, allowing us to remove
some special cases in ARMAsmParser::isITBlockTerminator.
Differential revision: https://reviews.llvm.org/D54853
llvm-svn: 348114
Before this patch, class PredicateExpander only knew how to expand simple
predicates that performed checks on instruction operands.
In particular, the new scheduling predicate syntax was not rich enough to
express checks like this one:
Foo(MI->getOperand(0).getImm()) == ExpectedVal;
Here, the immediate operand value at index zero is passed in input to function
Foo, and ExpectedVal is compared against the value returned by function Foo.
While this predicate pattern doesn't show up in any X86 model, it shows up in
other upstream targets. So, being able to support those predicates is
fundamental if we want to be able to modernize all the scheduling models
upstream.
With this patch, we allow users to specify if a register/immediate operand value
needs to be passed in input to a function as part of the predicate check. Now,
register/immediate operand checks all derive from base class CheckOperandBase.
This patch also changes where TIIPredicate definitions are expanded by the
instructon info emitter. Before, definitions were expanded in class
XXXGenInstrInfo (where XXX is a target name).
With the introduction of this new syntax, we may want to have TIIPredicates
expanded directly in XXXInstrInfo. That is because functions used by the new
operand predicates may only exist in the derived class (i.e. XXXInstrInfo).
This patch is a non functional change for the existing scheduling models.
In future, we will be able to use this richer syntax to better describe complex
scheduling predicates, and expose them to llvm-mca.
Differential Revision: https://reviews.llvm.org/D53880
llvm-svn: 345714
Summary:
So far, `isReturn` property is used to mean both a return instruction
from a functon and the end of an EH scope, a scope that starts with a EH
scope entry BB and ends with a catchret or a cleanupret instruction.
Because WinEH uses funclets, all EH-scope-ending instructions are also
real return instruction from a function. But for wasm, they only serve
as the end marker of an EH scope but not a return instruction that
exits a function. This mismatch caused incorrect prolog and epilog
generation in wasm EH scopes. This patch fixes this.
This patch is in the same vein with rL333045, which splits
`MachineBasicBlock::isEHFuncletEntry` into `isEHFuncletEntry` and
`isEHScopeEntry`.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D50653
llvm-svn: 340325
This patch removes redundant template argument `TargetName` from TIIPredicate.
Tablegen can always infer the target name from the context. So we don't need to
force users of TIIPredicate to always specify it.
This allows us to better modularize the tablegen class hierarchy for the
so-called "function predicates". class FunctionPredicateBase has been added; it
is currently used as a building block for TIIPredicates. However, I plan to
reuse that class to model other function predicate classes too (i.e. not just
TIIPredicates). For example, this can be a first step towards implementing
proper support for dependency breaking instructions in tablegen.
This patch also adds a verification step on TIIPredicates in tablegen.
We cannot have multiple TIIPredicates with the same name. Otherwise, this will
cause build errors later on, when tablegen'd .inc files are included by cpp
files and then compiled.
Differential Revision: https://reviews.llvm.org/D50708
llvm-svn: 339706
This is a follow-up of r339552.
As pointed out by Craig in D50566, we don't need a formatted_raw_ostream to
indent strings. We can use instead raw_ostream::indent().
Internally, class PredicateExpander already keeps track of the current
indentation level. Also, the grammar for predicates is well parenthesized, and
therefore we don't need to use a formatted_raw_ostream to continuously track the
column number. Instead we can safely replace all the uses of
formatted_raw_ostream::PadToColumn() with uses of raw_ostream::indent().
By replacing formatted_raw_ostream with a simpler raw_ostream, we also avoid the
implicit check on the newline character on every print to stream.
No functional change intended.
llvm-svn: 339577
This patch introduces tablegen class MCStatement.
Currently, an MCStatement can be either a return statement, or a switch
statement.
```
MCStatement:
MCReturnStatement
MCOpcodeSwitchStatement
```
A MCReturnStatement expands to a return statement, and the boolean expression
associated with the return statement is described by a MCInstPredicate.
An MCOpcodeSwitchStatement is a switch statement where the condition is a check
on the machine opcode. It allows the definition of multiple checks, as well as a
default case. More details on the grammar implemented by these two new
constructs can be found in the diff for TargetInstrPredicates.td.
This patch makes it easier to read the body of auto-generated TargetInstrInfo
predicates.
In future, I plan to reuse/extend the MCStatement grammar to describe more
complex target hooks. For now, this is just a first step (mostly a minor
cosmetic change to polish the new predicates framework).
Differential Revision: https://reviews.llvm.org/D50457
llvm-svn: 339352
This patch adds support for AArch64 to cfi-verify.
This required three changes to cfi-verify. First, it generalizes checking if an instruction is a trap by adding a new isTrap flag to TableGen (and defining it for x86 and AArch64). Second, the code that ensures that the operand register is not clobbered between the CFI check and the indirect call needs to allow a single dereference (in x86 this happens as part of the jump instruction). Third, we needed to ensure that return instructions are not counted as indirect branches. Technically, returns are indirect branches and can be covered by CFI, but LLVM's forward-edge CFI does not protect them, and x86 does not consider them, so we keep that behavior.
In addition, we had to improve AArch64's code to evaluate the branch target of a MCInst to handle calls where the destination is not the first operand (which it often is not).
Differential Revision: https://reviews.llvm.org/D48836
llvm-svn: 337007
This patch is the second of a sequence of three patches related to LLVM-dev RFC
"MC support for varinat scheduling classes".
https://lists.llvm.org/pipermail/llvm-dev/2018-May/123181.html
The goal of this patch is to enable the resolution of variant classes in MC with
the help of a new method named `MCSubtargetInfo::resolveVariantSchedClass()`.
This patch also teaches the SubtargetEmitter how to automatically generate the
definition of method resolveVariantSchedClass(). That definition is emitted
within a sub-class of MCSubtargetInfo named XXXGenMCSubtargetInfo (where XXX is
the name of the Target).
Differential Revision: https://reviews.llvm.org/D47077
llvm-svn: 333286
This patch is the first of a sequence of three patches described by the LLVM-dev
RFC "MC support for variant scheduling classes".
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123181.html
The goal of this patch is to introduce a new class of scheduling predicates for
SchedReadVariant and SchedWriteVariant.
An MCSchedPredicate can be used instead of a normal SchedPredicate to model
checks on the instruction (either a MachineInstr or a MCInst).
Internally, an MCSchedPredicate encapsulates an MCInstPredicate definition.
MCInstPredicate allows the definition of expressions with a well-known semantic,
that can be used to generate code for both MachineInstr and MCInst.
This is the first step toward teaching to tools like lllvm-mca how to resolve
variant scheduling classes.
Differential Revision: https://reviews.llvm.org/D46695
llvm-svn: 333282
This property is needed in order to follow values movement between
registers. This property is used in TII to implement method that
returns true if simple copy like instruction is recognized, along
with source and destination machine operands.
Patch by Nikola Prica.
Differential Revision: https://reviews.llvm.org/D45204
llvm-svn: 333093
Summary:
Add a target option AllowRegisterRenaming that is used to opt in to
post-register-allocation renaming of registers. This is set to 0 by
default, which causes the hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq
fields of all opcodes to be set to 1, causing
MachineOperand::isRenamable to always return false.
Set the AllowRegisterRenaming flag to 1 for all in-tree targets that
have lit tests that were effected by enabling COPY forwarding in
MachineCopyPropagation (AArch64, AMDGPU, ARM, Hexagon, Mips, PowerPC,
RISCV, Sparc, SystemZ and X86).
Add some more comments describing the semantics of the
MachineOperand::isRenamable function and how it is set and maintained.
Change isRenamable to check the operand's opcode
hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq bit directly instead of
relying on it being consistently reflected in the IsRenamable bit
setting.
Clear the IsRenamable bit when changing an operand's register value.
Remove target code that was clearing the IsRenamable bit when changing
registers/opcodes now that this is done conservatively by default.
Change setting of hasExtraSrcRegAllocReq in AMDGPU target to be done in
one place covering all opcodes that have constant pipe read limit
restrictions.
Reviewers: qcolombet, MatzeB
Subscribers: aemerson, arsenm, jyknight, mcrosier, sdardis, nhaehnle, javed.absar, tpr, arichardson, kristof.beyls, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, escha, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D43042
llvm-svn: 325931
Most of the targets don't need the scheduler class enum.
I have an X86 scheduler model change that causes some names in the enum to become about 18000 characters long. This is because using instregex in scheduler models causes the scheduler class to get named with every instruction that matches the regex concatenated together. MSVC has a limit of 4096 characters for an identifier name. Rather than trying to come up with way to reduce the name length, I'm just going to sidestep the problem by not including the enum in X86.
llvm-svn: 320552
descriptions now tag add instructions, and the Hexagon backend is using this to
identify loop induction statements.
Patch by Sam Parker and Sjoerd Meijer.
Differential Revision: https://reviews.llvm.org/D23601
llvm-svn: 281304
Summary:
In this patch we implement the following parts of XRay:
- Supporting a function attribute named 'function-instrument' which currently only supports 'xray-always'. We should be able to use this attribute for other instrumentation approaches.
- Supporting a function attribute named 'xray-instruction-threshold' used to determine whether a function is instrumented with a minimum number of instructions (IR instruction counts).
- X86-specific nop sleds as described in the white paper.
- A machine function pass that adds the different instrumentation marker instructions at a very late stage.
- A way of identifying which return opcode is considered "normal" for each architecture.
There are some caveats here:
1) We don't handle PATCHABLE_RET in platforms other than x86_64 yet -- this means if IR used PATCHABLE_RET directly instead of a normal ret, instruction lowering for that platform might do the wrong thing. We think this should be handled at instruction selection time to by default be unpacked for platforms where XRay is not availble yet.
2) The generated section for X86 is different from what is described from the white paper for the sole reason that LLVM allows us to do this neatly. We're taking the opportunity to deviate from the white paper from this perspective to allow us to get richer information from the runtime library.
Reviewers: sanjoy, eugenis, kcc, pcc, echristo, rnk
Subscribers: niravd, majnemer, atrick, rnk, emaste, bmakam, mcrosier, mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D19904
llvm-svn: 275367
Coelacanthus