AMDGPU has some atomic instructions that do not return the previous
result, and can only be selected if there are no uses. The source
pattern will only match if the use is empty, so it should be safe to
discard the result.
When a Tablegen instruction description uses `OperandWithDefaultOps`,
isel patterns for that instruction don't have to fill in the default
value for the operand in question. But the flip side is that they
actually //can't// override the defaults even if they want to.
This will be very inconvenient for the Arm backend, when we start
wanting to write isel patterns that generate the many MVE predicated
vector instructions, in the form with predication actually enabled. So
this small Tablegen fix makes it possible to write an isel pattern
either with or without values for a defaulted operand, and have the
default values filled in only if they are not overridden.
If all the defaulted operands come at the end of the instruction's
operand list, there's a natural way to match them up to the arguments
supplied in the pattern: consume pattern arguments until you run out,
then fill in any missing instruction operands with their default
values. But if defaulted and non-defaulted operands are interleaved,
it's less clear what to do. This does happen in existing targets (the
first example I came across was KILLGT, in the AMDGPU/R600 backend),
and of course they expect the previous behaviour (that the default for
those operands is used and a pattern argument is not consumed), so for
backwards compatibility I've stuck with that.
Reviewers: nhaehnle, hfinkel, dmgreen
Subscribers: mehdi_amini, javed.absar, tpr, kristof.beyls, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63814
llvm-svn: 365114
A std::array is implemented as a template with an array inside a struct.
Older versions of clang, like 3.6, require an extra set of curly braces
around std::array initializations to avoid warnings.
The C++ language was changed regarding this by CWG 1270. So more modern
tool chains does not complain even if leaving out one level of braces.
llvm-svn: 362360
This is a new special identifier which you can use as a default in
OperandWithDefaultOps. The idea is that you use it for an input
operand of an instruction that's tied to an output operand, and its
semantics are that (in the default case) the input operand's value is
not used at all.
The detailed effect is that when instruction selection emits the
instruction in the form of a pre-regalloc MachineInstr, it creates an
IMPLICIT_DEF node to use as that input.
If you're creating an MCInst with explicit register names, then the
right handling would be to set the input operand to the same register
as the output one (honouring the tie) and to add the 'undef' flag
indicating that that register is deemed to acquire a new don't-care
definition just before we read it. But I haven't done that in this
commit, because there was no need to - no Tablegen backend seems to
autogenerate default fields in an MCInst.
Patch by: Simon Tatham
Differential Revision: https://reviews.llvm.org/D60696
llvm-svn: 362064
Includes a fix to emit a CheckOpcode for build_vector when immAllZerosV/immAllOnesV is used as a pattern root. This means it can't be used to look through bitcasts when used as a root, but that's probably ok. This extra CheckOpcode will ensure that the first match in the isel table will be a SwitchOpcode which is needed by the caching optimization in the ISel Matcher.
Original commit message:
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355784
This caused the first matcher in the isel table for many targets to Opc_Scope instead of Opc_SwitchOpcode. This leads to a significant increase in isel match failures.
llvm-svn: 355433
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355224
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
Summary:
This fixes support in DAGISelMatcher backend for DAG nodes with multiple
result values. Previously the order of results in selected DAG nodes always
matched the order of results in ISel patterns. After the change the order of
results matches the order of operands in OutOperandList instead.
For example, given this definition from the attached test case:
def INSTR : Instruction {
let OutOperandList = (outs GPR:$r1, GPR:$r0);
let InOperandList = (ins GPR:$t0, GPR:$t1);
let Pattern = [(set i32:$r0, i32:$r1, (udivrem i32:$t0, i32:$t1))];
}
the DAGISelMatcher backend currently produces a matcher that creates INSTR
nodes with the first result `$r0` and the second result `$r1`, contrary to the
order in the OutOperandList. The order of operands in OutOperandList does not
matter at all, which is unexpected (and unfortunate) because the order of
results of a DAG node does matters, perhaps a lot.
With this change, if the order in OutOperandList does not match the order in
Pattern, DAGISelMatcherGen emits CompleteMatch opcodes with the order of
results taken from OutOperandList. Backend writers can use it to express
result reorderings in TableGen.
If the order in OutOperandList matches the order in Pattern, the result of
DAGISelMatcherGen is unaffected.
Patch by Eugene Sharygin
Reviewers: andreadb, bjope, hfinkel, RKSimon, craig.topper
Reviewed By: craig.topper
Subscribers: nhaehnle, craig.topper, llvm-commits
Differential Revision: https://reviews.llvm.org/D55055
llvm-svn: 348326
Summary:
This simplifies writing predicates for pattern fragments that are
automatically re-associated or commuted.
For example, a followup patch adds patterns for fragments of the form
(add (shl $x, $y), $z) to the AMDGPU backend. Such patterns are
automatically commuted to (add $z, (shl $x, $y)), which makes it basically
impossible to refer to $x, $y, and $z generically in the PredicateCode.
With this change, the PredicateCode can refer to $x, $y, and $z simply
as `Operands[i]`.
Test confirmed that there are no changes to any of the generated files
when building all (non-experimental) targets.
Change-Id: I61c00ace7eed42c1d4edc4c5351174b56b77a79c
Reviewers: arsenm, rampitec, RKSimon, craig.topper, hfinkel, uweigand
Subscribers: wdng, tpr, llvm-commits
Differential Revision: https://reviews.llvm.org/D51994
llvm-svn: 347992
A TableGen instruction record usually contains a DAG pattern that will
describe the SelectionDAG operation that can be implemented by this
instruction. However, there will be cases where several different DAG
patterns can all be implemented by the same instruction. The way to
represent this today is to write additional patterns in the Pattern
(or usually Pat) class that map those extra DAG patterns to the
instruction. This usually also works fine.
However, I've noticed cases where the current setup seems to require
quite a bit of extra (and duplicated) text in the target .td files.
For example, in the SystemZ back-end, there are quite a number of
instructions that can implement an "add-with-overflow" operation.
The same instructions also need to be used to implement just plain
addition (simply ignoring the extra overflow output). The current
solution requires creating extra Pat pattern for every instruction,
duplicating the information about which particular add operands
map best to which particular instruction.
This patch enhances TableGen to support a new PatFrags class, which
can be used to encapsulate multiple alternative patterns that may
all match to the same instruction. It operates the same way as the
existing PatFrag class, except that it accepts a list of DAG patterns
to match instead of just a single one. As an example, we can now define
a PatFrags to match either an "add-with-overflow" or a regular add
operation:
def z_sadd : PatFrags<(ops node:$src1, node:$src2),
[(z_saddo node:$src1, node:$src2),
(add node:$src1, node:$src2)]>;
and then use this in the add instruction pattern:
defm AR : BinaryRRAndK<"ar", 0x1A, 0xB9F8, z_sadd, GR32, GR32>;
These SystemZ target changes are implemented here as well.
Note that PatFrag is now defined as a subclass of PatFrags, which
means that some users of internals of PatFrag need to be updated.
(E.g. instead of using PatFrag.Fragment you now need to use
!head(PatFrag.Fragments).)
The implementation is based on the following main ideas:
- InlinePatternFragments may now replace each original pattern
with several result patterns, not just one.
- parseInstructionPattern delays calling InlinePatternFragments
and InferAllTypes. Instead, it extracts a single DAG match
pattern from the main instruction pattern.
- Processing of the DAG match pattern part of the main instruction
pattern now shares most code with processing match patterns from
the Pattern class.
- Direct use of main instruction patterns in InferFromPattern and
EmitResultInstructionAsOperand is removed; everything now operates
solely on DAG match patterns.
Reviewed by: hfinkel
Differential Revision: https://reviews.llvm.org/D48545
llvm-svn: 336999
The return value of TreePatternNode::getChild is never null. This patch also
updates various places that use return values of getChild to also use
references. Those changes were suggested post-commit for D47463.
llvm-svn: 334764
By using std::shared_ptr for TreePatternNode, we can avoid leaking them.
Reviewers: craig.topper, dsanders, stoklund, tstellar, zturner
Reviewed By: dsanders
Differential Revision: https://reviews.llvm.org/D47463
llvm-svn: 333591
This replaces TableGen's type inference to operate on parameterized
types instead of MVTs, and as a consequence, some interfaces have
changed:
- Uses of MVTs are replaced by ValueTypeByHwMode.
- EEVT::TypeSet is replaced by TypeSetByHwMode.
This affects the way that types and type sets are printed, and the
tests relying on that have been updated.
There are certain users of the inferred types outside of TableGen
itself, namely FastISel and GlobalISel. For those users, the way
that the types are accessed have changed. For typical scenarios,
these replacements can be used:
- TreePatternNode::getType(ResNo) -> getSimpleType(ResNo)
- TreePatternNode::hasTypeSet(ResNo) -> hasConcreteType(ResNo)
- TypeSet::isConcrete -> TypeSetByHwMode::isValueTypeByHwMode(false)
For more information, please refer to the review page.
Differential Revision: https://reviews.llvm.org/D31951
llvm-svn: 313271
This opcode never happens in practice, and yet the logic we have in
place to handle it would be undefined behaviour if we ever executed
it. Remove it rather than trying to refactor code that's never
reached.
llvm-svn: 268692
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
cleanups.
Also, change code in tablegen which printed a message and then called
"exit(1)" to use PrintFatalError, instead.
This fixes instances where an empty output file was left behind after
a failed tablegen invocation, which would confuse subsequent ninja
runs into not attempting to rebuild.
Differential Revision: http://reviews.llvm.org/D9608
llvm-svn: 237058
This complicates a few algorithms due to not having random access, but
not by a huge degree I don't think (open to debate/design
discussion/etc).
llvm-svn: 223261
The problem is mostly that variadic output instruction
aren't handled, so it is rejected for having an inconsistent
number of operands, and then the right number of operands
isn't emitted.
llvm-svn: 221117
This allows the results of a ComplexPattern check to be distributed to separate
named Operands, instead of the current system where all results must apply (and
match perfectly) with a single Operand.
For example, if "some_addrmode" is a ComplexPattern producing two results, you
can write:
def : Pat<(load (some_addrmode GPR64:$base, imm:$offset)),
(INST GPR64:$base, imm:$offset)>;
This should allow neater instruction definitions in TableGen that don't put all
possible aspects of addressing into a single operand, but are still usable with
relatively simple C++ CodeGen idioms.
llvm-svn: 209206
This syntax is now preferred:
def : Pat<(subc i32:$b, i32:$c), (SUBCCrr $b, $c)>;
There is no reason to repeat the types in the output pattern.
llvm-svn: 177844
Just like register classes, value types can be used in two ways in
patterns:
(sext_inreg i32:$src, i16)
In a named leaf node like i32:$src, the value type simply provides the
type of the node directly. This simplifies type inference a lot compared
to the current practice of specifiying types indirectly with register
classes.
As an unnamed leaf node, like i16 above, the value type represents
itself as an MVT::Other immediate.
llvm-svn: 177828
of complex instruction operands (e.g. address modes).
Currently, if a Pat pattern creates an instruction that has a complex
operand (i.e. one that consists of multiple sub-operands at the MI
level), this operand must match a ComplexPattern DAG pattern with the
correct number of output operands.
This commit extends TableGen to alternatively allow match a complex
operands against multiple separate operands at the DAG level.
This allows using Pat patterns to match pre-increment nodes like
pre_store (which must have separate operands at the DAG level) onto
an instruction pattern that uses a multi-operand memory operand,
like the following example on PowerPC (will be committed as a
follow-on patch):
def STWU : DForm_1<37, (outs ptr_rc:$ea_res), (ins GPRC:$rS, memri:$dst),
"stwu $rS, $dst", LdStStoreUpd, []>,
RegConstraint<"$dst.reg = $ea_res">, NoEncode<"$ea_res">;
def : Pat<(pre_store GPRC:$rS, ptr_rc:$ptrreg, iaddroff:$ptroff),
(STWU GPRC:$rS, iaddroff:$ptroff, ptr_rc:$ptrreg)>;
Here, the pair of "ptroff" and "ptrreg" operands is matched onto the
complex operand "dst" of class "memri" in the "STWU" instruction.
Approved by Jakob Stoklund Olesen.
llvm-svn: 177428
Most places can use PrintFatalError as the unwinding mechanism was not
used for anything other than printing the error. The single exception
was CodeGenDAGPatterns.cpp, where intermediate errors during type
resolution were ignored to simplify incremental platform development.
This use is replaced by an error flag in TreePattern and bailout earlier
in various places if it is set.
llvm-svn: 166712
Some of these dyn_cast<>'s would be better phrased as isa<> or cast<>.
That will happen in a future patch.
There are also two dyn_cast_or_null<>'s slipped in instead of
dyn_cast<>'s, since they were causing crashes with just dyn_cast<>.
llvm-svn: 165646
When generating selection tables for Pat instances, TableGen relied on
an output Instruction's Pattern field being set to infer whether a
chain should be added.
This patch adds additional logic to check various flag fields so that
correct code can be generated even if Pattern is unset.
llvm-svn: 159217
Matt Arsenault