Summary:
This allows you to make some of the defs in a multiclass or `foreach`
conditional on an expression computed from the parameters or iteration
variables.
It was already possible to simulate an if statement using a `foreach`
with a dummy iteration variable and a list constructed using `!if` so
that it had length 0 or 1 depending on the condition, e.g.
foreach unusedIterationVar = !if(condition, [1], []<int>) in { ... }
But this syntax is nicer to read, and also more convenient because it
allows an else clause.
To avoid upheaval in the implementation, I've implemented `if` as pure
syntactic sugar on the `foreach` implementation: internally, `ParseIf`
actually does construct exactly the kind of foreach shown above (and
another reversed one for the else clause if present).
Reviewers: nhaehnle, hfinkel
Reviewed By: hfinkel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71474
Summary:
This allows you to define a global or local variable to an arbitrary
value, and refer to it in subsequent definitions.
The main use I anticipate for this is if you have to compute some
difficult function of the parameters of a multiclass, and then use it
many times. For example:
multiclass Foo<int i, string s> {
defvar op = !cast<BaseClass>("whatnot_" # s # "_" # i);
def myRecord {
dag a = (op this, (op that, the other), (op x, y, z));
int b = op.subfield;
}
def myOtherRecord<"template params including", op>;
}
There are a couple of ways to do this already, but they're not really
satisfactory. You can replace `defvar x = y` with a loop over a
singleton list, `foreach x = [y] in { ... }` - but that's unintuitive
to someone who hasn't seen that workaround idiom before, and requires
an extra pair of braces that you often didn't really want. Or you can
define a nested pair of multiclasses, with the inner one taking `x` as
a template parameter, and the outer one instantiating it just once
with the desired value of `x` computed from its other parameters - but
that makes it awkward to sequentially compute each value based on the
previous ones. I think `defvar` makes things considerably easier.
You can also use `defvar` at the top level, where it inserts globals
into the same map used by `defset`. That allows you to define global
constants without having to make a dummy record for them to live in:
defvar MAX_BUFSIZE = 512;
// previously:
// def Dummy { int MAX_BUFSIZE = 512; }
// and then refer to Dummy.MAX_BUFSIZE everywhere
Reviewers: nhaehnle, hfinkel
Reviewed By: hfinkel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71407
Summary:
These allow you to get and set the operator of a dag node, without
affecting its list of arguments.
`!getop` is slightly fiddly because in many contexts you need its
return value to have a static type more specific than 'any record'. It
works to say `!cast<BaseClass>(!getop(...))`, but it's cumbersome, so
I made `!getop` take an optional type suffix itself, so that can be
written as the shorter `!getop<BaseClass>(...)`.
Reviewers: hfinkel, nhaehnle
Reviewed By: nhaehnle
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71191
Summary:
```
``!listsplat(a, size)``
A list value that contains the value ``a`` ``size`` times.
Example: ``!listsplat(0, 2)`` results in ``[0, 0]``.
```
I plan to use this in X86ScheduleBdVer2.td for LoadRes handling.
This is a little bit controversial because unlike every other binary operator
the types aren't identical.
Reviewers: stoklund, javed.absar, nhaehnle, craig.topper
Reviewed By: javed.absar
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60367
llvm-svn: 358117
This is a small addition to arithmetic operations that improves
expressiveness of the language.
Differential Revision: https://reviews.llvm.org/D58775
llvm-svn: 355187
This patch extends TableGen language with !cond operator.
Instead of embedding !if inside !if which can get cumbersome,
one can now use !cond.
Below is an example to convert an integer 'x' into a string:
!cond(!lt(x,0) : "Negative",
!eq(x,0) : "Zero",
!eq(x,1) : "One,
1 : "MoreThanOne")
Reviewed By: hfinkel, simon_tatham, greened
Differential Revision: https://reviews.llvm.org/D55758
llvm-svn: 352185
Summary:
The new rules are straightforward. The main rules to keep in mind
are:
1. NAME is an implicit template argument of class and multiclass,
and will be substituted by the name of the instantiating def/defm.
2. The name of a def/defm in a multiclass must contain a reference
to NAME. If such a reference is not present, it is automatically
prepended.
And for some additional subtleties, consider these:
3. defm with no name generates a unique name but has no special
behavior otherwise.
4. def with no name generates an anonymous record, whose name is
unique but undefined. In particular, the name won't contain a
reference to NAME.
Keeping rules 1&2 in mind should allow a predictable behavior of
name resolution that is simple to follow.
The old "rules" were rather surprising: sometimes (but not always),
NAME would correspond to the name of the toplevel defm. They were
also plain bonkers when you pushed them to their limits, as the old
version of the TableGen test case shows.
Having NAME correspond to the name of the toplevel defm introduces
"spooky action at a distance" and breaks composability:
refactoring the upper layers of a hierarchy of nested multiclass
instantiations can cause unexpected breakage by changing the value
of NAME at a lower level of the hierarchy. The new rules don't
suffer from this problem.
Some existing .td files have to be adjusted because they ended up
depending on the details of the old implementation.
Change-Id: I694095231565b30f563e6fd0417b41ee01a12589
Reviewers: tra, simon_tatham, craig.topper, MartinO, arsenm, javed.absar
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D47430
llvm-svn: 333900
Summary:
In the course of writing an experimental ANTLR grammar based on this
document, I found three errors in the documented BNF:
SimpleValues of dag type are allowed to have no operands at all after
the initial DagArg specifying the operator. For example, the value
(outs) is extremely common in backends; an example in the test suite
is test/TableGen/AsmVariant.td line 30. But the BNF doesn't allow
DagArgList to expand to the empty string (it must contain at least one
DagArg), and therefore the DagArgList specifying the operands in the
dag-shaped production for SimpleValue should be optional.
In the production for BodyItem with a 'let' and an optional RangeList,
the RangeList should have braces around it if it's present, matching
code such as "let E{7-0} = ..." on test/TableGen/BitsInit.td line 42.
Those braces aren't included in the RangeList nonterminal itself, so
instead they need to be part of the optional segment of the BodyItem
production.
Finally, the identifier after 'defm' should be optional. Again, this
is very common in the real back end .td files; an example in the test
suite is in test/TableGen/defmclass.td line 49.
Reviewers: rengolin, nhaehnle, stoklund
Reviewed By: nhaehnle
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45818
llvm-svn: 330570
This allows constructing DAG nodes with programmatically determined
names, and can simplify constructing DAG nodes in other cases as
well.
Also, add documentation and some very simple tests for the already
existing !con.
Change-Id: Ida61cd82e99752548d7109ce8da34d29da56a5f7
Differential revision: https://reviews.llvm.org/D44110
llvm-svn: 327492
Allows capturing a list of concrete instantiated defs.
This can be combined with foreach to create parallel sets of def
instantiations with less repetition in the source. This purpose is
largely also served by multiclasses, but in some cases multiclasses
can't be used.
The motivating example for this change is having a large set of
intrinsics, which are generated from the IntrinsicsBackend.td file
included by Intrinsics.td, and a corresponding set of instruction
selection patterns, which are generated via the backend's .td files.
Multiclasses cannot be used to eliminate the redundancy in this case,
because a multiclass cannot span both LLVM's common .td files and
the backend .td files at the same time.
Change-Id: I879e35042dceea542a5e6776fad23c5e0e69e76b
Differential revision: https://reviews.llvm.org/D44109
llvm-svn: 327121
The changes to FieldInit are required to make field references (Def.field)
work inside a ForeachDeclaration: previously, Def.field wasn't resolved
immediately when Def was already a fully resolved DefInit.
Change-Id: I9875baec2fc5aac8c2b249e45b9cf18c65ae699b
llvm-svn: 327120
Summary:
Returns the size of a list. I have found this to be rather useful in some
development for the AMDGPU backend where we could simplify our .td files
by concatenating list<LLVMType> for complex intrinsics. Doing so requires
us to compute the position argument for LLVMMatchType.
Basically, the usage is in a pattern that looks somewhat like this:
list<LLVMType> argtypes =
!listconcat(base,
[llvm_any_ty, LLVMMatchType<!size(base)>]);
Change-Id: I360a0b000fd488d18bea412228230fd93722bd2c
Reviewers: arsenm, craig.topper, tra, MartinO
Subscribers: wdng, llvm-commits, tpr
Differential Revision: https://reviews.llvm.org/D43553
llvm-svn: 325883
Summary:
It concatenates two or more lists. In addition to the !strconcat semantics
the lists must have the same element type.
My overall aim is to make it easy to append to Instruction.Predicates
rather than override it. This can be done by concatenating lists passed as
arguments, or by concatenating lists passed in additional fields.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: hfinkel, llvm-commits
Differential Revision: http://reviews.llvm.org/D3506
llvm-svn: 208183
Making the new TableGen documentation official and marking the old file as
"Moved". Also, reverting the original LangRef as the normative formal
description of the language, while keeping the "new" LangRef as LangIntro
for the less inlcined to reading language grammars.
We should remove TableGenFundamentals.rst one day, but for now, just a
warning that it moved will have to do, while we make sure there are no more
links to it from elsewhere.
llvm-svn: 205289
This is mainly a movement of content around to give place to new content
allowing different people to add bits to it in the right place. There is some
new content, but mostly to fill the gaps left by text movement.
I'm dropping the old syntax documentation as it has the problem of being
quickly outdated by changes and largely unnecessary to people not involved
in creating the language, but using it, which is the whole point of the
documentation.
llvm-svn: 204351
They're called code fragments, but they are really multiline string
literals. Just spotted this usage in a patch by Aaron using "code
fragments" for holding documentation text. I remember someone bemoaning
the lack of multiline string literals in TableGen, so I'm explicitly
documenting that code fragments are multiline string literals.
Let it be known that any use case needing multiline string literals in
TableGen (such as descriptions of options, or whatnot) can use use
code fragments (instead of C-style string concatenation or exceedingly
long lines). E.g.
class Bar<int n>;
class Baz<int n>;
class Doc<string desc> {
string Desc = desc;
}
def Foo : Bar<1>, Baz<3>, Doc<[{
This Foo is a Bar, and also a Baz. It can take 3 values:
* Qux
* Quux
* Quuux
}]>;
llvm-svn: 201033
DAG arguments can optionally be named:
(dag node, node:$name)
With this change, the node is also optional:
(dag node, node:$name, $name)
The missing node is treated as an UnsetInit, so the above is equivalent
to:
(dag node, node:$name, ?:$name)
This syntax is useful in output patterns where we currently require the
types of variables to be repeated:
def : Pat<(subc i32:$b, i32:$c), (SUBCCrr i32:$b, i32:$c)>;
This is preferable:
def : Pat<(subc i32:$b, i32:$c), (SUBCCrr $b, $c)>;
llvm-svn: 177843
My "excuse" for not refactoring the grammar here is to not diverge too
far from the grammar in the comments of TGParser.cpp, since I'm not
taking on the quest of majorly refactoring TGParser.cpp at the moment.
One benefit of doing this is that Ideas for refactoring and clarifying
the grammar in this document should translate almost immediately to
beneficial refactorings that can be made to TGParser.cpp.
llvm-svn: 174144
Kazuaki Ishizaki