Commit Graph

255 Commits

Author SHA1 Message Date
Nicolai Haehnle 420e28c78c TableGen: Streamline how defs are instantiated
Summary:
Instantiating def's and defm's needs to perform the following steps:

- for defm's, clone multiclass def prototypes and subsitute template args
- for def's and defm's, add subclass definitions, substituting template
  args
- clone the record based on foreach loops and substitute loop iteration
  variables
- override record variables based on the global 'let' stack
- resolve the record name (this should be simple, but unfortunately it's
  not due to existing .td files relying on rather silly implementation
  details)
- for def(m)s in multiclasses, add the unresolved record as a multiclass
  prototype
- for top-level def(m)s, resolve all internal variable references and add
  them to the record keeper and any active defsets

This change streamlines how we go through these steps, by having both
def's and defm's feed into a single addDef() method that handles foreach,
final resolve, and routing the record to the right place.

This happens to make foreach inside of multiclasses work, as the new
test case demonstrates. Previously, foreach inside multiclasses was not
forbidden by the parser, but it was de facto broken.

Another side effect is that the order of "instantiated from" notes in error
messages is reversed, as the modified test case shows. This is arguably
clearer, since the initial error message ends up pointing directly to
whatever triggered the error, and subsequent notes will point to increasingly
outer layers of multiclasses. This is consistent with how C++ compilers
report nested #includes and nested template instantiations.

Change-Id: Ica146d0db2bc133dd7ed88054371becf24320447

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D44478

llvm-svn: 328117
2018-03-21 17:12:53 +00:00
Nicolai Haehnle 2ad19016c0 TableGen: Explicitly forbid self-references to field members
Summary:
Otherwise, patterns like in the test case produce cryptic error
messages about fields being resolved incompletely.

Change-Id: I713c0191f00fe140ad698675803ab1f8823dc5bd

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D44476

llvm-svn: 327850
2018-03-19 14:14:28 +00:00
Nicolai Haehnle 4186cc7c08 TableGen: Check the dynamic type of !cast<Rec>(string)
Summary:
The docs already claim that this happens, but so far it hasn't. As a
consequence, existing TableGen files get this wrong a lot, but luckily
the fixes are all reasonably straightforward.

To make this work with all the existing forms of self-references (since
the true type of a record is only built up over time), the lookup of
self-references in !cast is delayed until the final resolving step.

Change-Id: If5923a72a252ba2fbc81a889d59775df0ef31164

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D44475

llvm-svn: 327849
2018-03-19 14:14:20 +00:00
Nicolai Haehnle 18f1998a00 TableGen: Explicitly test some cases of self-references and !cast errors
Summary:
These are cases of self-references that exist today in practice. Let's
add tests for them to avoid regressions.

The self-references in PPCInstrInfo.td can be expressed in a simpler
way. Allowing this type of self-reference while at the same time
consistently doing late-resolve even for self-references is problematic
because there are references to fields that aren't in any class. Since
there's no need for this type of self-reference anyway, let's just
remove it.

Change-Id: I914e0b3e1ae7adae33855fac409b536879bc3f62

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: nemanjai, wdng, kbarton, llvm-commits

Differential Revision: https://reviews.llvm.org/D44474

llvm-svn: 327848
2018-03-19 14:14:10 +00:00
Nicolai Haehnle c47fe129cb TableGen: Remove the cast-from-string-to-variable-reference feature
Summary:
Cast-from-string for records isn't going away, but cast-from-string for
variables is a pretty dodgy feature to have, especially when referencing
template arguments. It's doubtful that this ever worked in a reliable
way, and nobody seems to be using it, so let's get rid of it and get
some related cleanups.

Change-Id: I395ac8a43fef4cf98e611f2f552300d21e99b66a

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D44195

llvm-svn: 327844
2018-03-19 14:13:37 +00:00
Nicolai Haehnle aa9ca691cd TableGen: Add !ne, !le, !lt, !ge, and !gt comparisons
Change-Id: I8e2ece677268972d578a787467f7ef52a1f33a71

Differential revision: https://reviews.llvm.org/D44114

llvm-svn: 327496
2018-03-14 11:00:57 +00:00
Nicolai Haehnle b61c26e614 TableGen: Allow dag operators to be resolved late
Change-Id: I51bb80fd5c48c8ac441ab11e43d43c1b91b4b590

Differential revision: https://reviews.llvm.org/D44113

llvm-svn: 327495
2018-03-14 11:00:48 +00:00
Nicolai Haehnle 77841b159a TableGen: Type-check BinOps
Additionally, allow more than two operands to !con, !add, !and, !or
in the same way as is already allowed for !listconcat and !strconcat.

Change-Id: I9659411f554201b90cd8ed7c7e004d381a66fa93

Differential revision: https://reviews.llvm.org/D44112

llvm-svn: 327494
2018-03-14 11:00:43 +00:00
Nicolai Haehnle ef60a26817 TableGen: Allow ? in lists
This makes using !dag more convenient in some cases.

Change-Id: I0a8c35e15ccd1ecec778fd1c8d64eee38d74517c

Differential revision: https://reviews.llvm.org/D44111

llvm-svn: 327493
2018-03-14 11:00:33 +00:00
Nicolai Haehnle 6c11865638 TableGen: Add !dag function for construction
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
2018-03-14 11:00:26 +00:00
Nicolai Haehnle fcd6525a45 TableGen: Add a defset statement
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
2018-03-09 12:24:42 +00:00
Nicolai Haehnle 8aa9d5839d TableGen: Allow arbitrary list values as ranges of foreach
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
2018-03-09 12:24:30 +00:00
Nicolai Haehnle b537605956 TableGen: add !isa operation
Change-Id: Iddb724c3ae706d82933a2d82c91d07e0e36b30e3

Differential revision: https://reviews.llvm.org/D44105

llvm-svn: 327117
2018-03-09 12:24:06 +00:00
Nicolai Haehnle d34f6843aa TableGen: Add !foldl operation
Change-Id: I63d67bf6e0b315e2d3360e47e3b62c9517f38987
llvm-svn: 326790
2018-03-06 13:49:16 +00:00
Nicolai Haehnle d4c0a5d08d TableGen: Delay instantiating inline anonymous records
Summary:
Only instantiate anonymous records once all variable references in template
arguments have been resolved. This allows patterns like the new test case,
which in practice can appear in expressions like:

  class IntrinsicTypeProfile<list<LLVMType> ty, int shift> {
    list<LLVMType> types =
      !listconcat(ty, [llvm_any_ty, LLVMMatchType<shift>]);
  }

  class FooIntrinsic<IntrinsicTypeProfile P, ...>
    : Intrinsic<..., P.types, ...>;

Without this change, the anonymous LLVMMatchType instantiation would
never get resolved.

Another consequence of this change is that anonymous inline
instantiations are uniqued via the folding set of the newly introduced
VarDefInit.

Change-Id: I7a7041a20e297cf98c9109b28d85e64e176c932a

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43756

llvm-svn: 326788
2018-03-06 13:49:01 +00:00
Nicolai Haehnle 0f529885fa TableGen: Explicitly check whether a record has been resolved
Summary:
There are various places where resolving and constant folds can
get stuck, especially around casts. We don't always signal an
error for those, because in many cases they can legitimately
occur without being an error in the "untaken branch" of an !if.

Change-Id: I3befc0e4234c8e6cc61190504702918c9f29ce5c

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43754

llvm-svn: 326786
2018-03-06 13:48:47 +00:00
Nicolai Haehnle dfda9dcc1d TableGen: Allow !cast of records, cleanup conversion machinery
Summary:
Distinguish two relationships between types: is-a and convertible-to.
For example, a bit is not an int or vice versa, but they can be
converted into each other (with range checks that you can think of
as "dynamic": unlike other type checks, those range checks do not
happen during parsing, but only once the final values have been
established).

Actually converting initializers between types is subtle: even
when values of type A can be converted to type B (e.g. int into
string), it may not be possible to do so with a concrete initializer
(e.g., a VarInit that refers to a variable of type int cannot
be immediately converted to a string).

For this reason, distinguish between getCastTo and convertInitializerTo:
the latter implements the actual conversion when appropriate, while
the former will first try to do the actual conversion and fall back
to introducing a !cast operation so that the conversion will be
delayed until variable references have been resolved.

To make the approach of adding !cast operations to work, !cast needs
to fallback to convertInitializerTo when the special string <-> record
logic does not apply.

This enables casting records to a subclass, although that new
functionality is only truly useful together with !isa, which will be
added in a later change.

The test is removed because it uses !srl on a bit sequence,
which cannot really be supported consistently, but luckily
isn't used anywhere either.

Change-Id: I98168bf52649176654ed2ec61a29bdb29970cfe7

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43753

llvm-svn: 326785
2018-03-06 13:48:39 +00:00
Nicolai Haehnle 9a84a50913 TableGen: Simplify BitsInit::resolveReferences
Summary:
No functional change intended. The removed code has a loop for
recursive resolving, which is superseded by the recursive
resolving done by the Resolver implementations.

Add a test case which was broken by an earlier version of this
change.

Change-Id: Ib208d037b77a8bbb725977f1388601fc984723d8

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43655

llvm-svn: 326784
2018-03-06 13:48:30 +00:00
Nicolai Haehnle 13080fd14e TableGen: Generalize record types to fix typeIsConvertibleTo et al.
Summary:
Allow RecordRecTy to represent the type "subclass of N superclasses",
where N may be zero. Furthermore, generate RecordRecTy instances only
with actual classes in the list.

Keeping track of multiple superclasses is required to resolve the type
of a list correctly in some cases. The old code relied on the incorrect
behavior of typeIsConvertibleTo, and an earlier version of this change
relied on a modified ordering of superclasses (it was committed in
r325884 and then reverted because unfortunately some of clang-tblgen's
backends depend on the ordering).

Previously, the DefInit for each Record would have a RecordRecTy of
that Record as its type. Now, all defs with the same superclasses will
share the same type.

This allows us to be more consistent about type checks involving records:

- typeIsConvertibleTo actually requires the LHS to be a subtype of the
  RHS

- resolveTypes will return the least supertype of given record types in
  all cases

- different record types in the two branches of an !if are handled
  correctly

Add a test that used to be accepted without flagging the obvious type
error.

Change-Id: Ib366db1a4e6a079f1a0851e469b402cddae76714

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43680

llvm-svn: 326783
2018-03-06 13:48:20 +00:00
Nicolai Haehnle b0cf9e93a6 TableGen: Resolve all template args simultaneously in AddSubClass
Summary:
Use the new resolver interface more explicitly, and avoid traversing
all the initializers multiple times.

Add a test case for a pattern that was broken by an earlier version
of this change.

An additional change is that we now remove *all* template arguments
after resolving them.

Change-Id: I86c828c8cc84c18b052dfe0f64c0d5cbf3c4e13c

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43652

llvm-svn: 326706
2018-03-05 15:21:11 +00:00
Nicolai Haehnle 8ebf7e4dfa TableGen: Reimplement !foreach using the resolving mechanism
Summary:
This changes the syntax of !foreach so that the first "parameter" is
a new syntactic variable: !foreach(x, lst, expr) will define the
variable x within the scope of expr, and evaluation of the !foreach
will substitute elements of the given list (or dag) for x in expr.

Aside from leading to a nicer syntax, this allows more complex
expressions where x is deeply nested, or even constant expressions
in which x does not occur at all.

!foreach is currently not actually used anywhere in trunk, but I
plan to use it in the AMDGPU backend. If out-of-tree targets are
using it, they can adjust to the new syntax very easily.

Change-Id: Ib966694d8ab6542279d6bc358b6f4d767945a805

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits, tpr

Differential Revision: https://reviews.llvm.org/D43651

llvm-svn: 326705
2018-03-05 15:21:04 +00:00
Nicolai Haehnle 3c80e4c514 TableGen: Allow NAME in template arguments in defm in multiclass
Summary:
NAME has already worked for def in a multiclass, since the (protoype)
record including its NAME variable is created before parsing the
superclasses. Since defm's do not have an associated single record,
support for NAME has to be implemented differently here.

Original test cases provided by Artem Belevich (tra)

Change-Id: I933b74f328c0ff202e7dc23a35b78f3505760cc9

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43656

llvm-svn: 326700
2018-03-05 14:01:38 +00:00
Nicolai Haehnle c10570f7c6 Revert "TableGen: Fix typeIsConvertibleTo for record types"
This reverts r325884.

Clang's TableGen has dependencies on the exact ordering of superclasses.
Revert this change fully for now to fix the build.

Change-Id: Ib297f5571cc7809f00838702ad7ab53d47335b26
llvm-svn: 325891
2018-02-23 11:31:49 +00:00
Nicolai Haehnle aecb68b549 TableGen: Fix typeIsConvertibleTo for record types
Summary:
Only check whether the left-hand side type is a subclass (or equal to)
the right-hand side type.

This requires a further fix in handling !if expressions and in type
resolution.

Furthermore, reverse the order of superclasses so that resolveTypes will
find a least common ancestor at least in simple cases.

Add a test that used to be accepted without flagging the obvious type
error.

Change-Id: Ib366db1a4e6a079f1a0851e469b402cddae76714

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43559

llvm-svn: 325884
2018-02-23 10:46:13 +00:00
Nicolai Haehnle 0243aaf42c TableGen: Add !size operation
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
2018-02-23 10:46:07 +00:00
Nicolai Haehnle 8fb962c04e TableGen: Allow implicit casting between string and code
Summary:
Perhaps the distinction between the two should be removed entirely
in the long term, and the [{ ... }] syntax should just be a convenient
way of writing multi-line strings.

In the meantime, a lot of existing .td files are quite relaxed about
string vs. code, and this change allows switching on more consistent
type checks without breaking those.

Change-Id: If85e3e04469e41b58e2703b62ac0032d2711713c

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43557

llvm-svn: 325799
2018-02-22 15:27:03 +00:00
Nicolai Haehnle 6d64915c87 TableGen: Fix type deduction for !foreach
Summary:
In the case of !foreach(id, input-list, transform) where the type of
input-list is list<A> and the type of transform is B, we now correctly
deduce list<B> as the type of the !foreach.

Change-Id: Ia19dd65eecc5991dd648280ba6a15f6a20fd61de

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43555

llvm-svn: 325797
2018-02-22 15:26:35 +00:00
Nicolai Haehnle e4a2cf5761 TableGen: Generalize type deduction for !listconcat
Summary:
This way, it should work even with complex operands.

Change-Id: Iaccf5bbb50bd5882a0ba5d59689e4381315fb361

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43554

llvm-svn: 325796
2018-02-22 15:26:28 +00:00
Aditya Nandakumar b63e763847 [GISel]: Make GlobalISelEmitter rule prioritization compatible with selectionDAG
This patch changes GlobalISelEmitter to rank patterns similar to how the
DAG does it (ie it computes a score for a pattern and adds the added
complexity to it).
This is so that the decision tree for GISelSelector remains compatible
with that of SelectionDAG.

https://reviews.llvm.org/D43270

llvm-svn: 325401
2018-02-16 22:37:15 +00:00
Artem Belevich d75805e0e9 [tablegen] Fixed few !foreach evaluation issues.
* !foreach on lists didn't evaluate operands of the RHS operator.
  This made nested operators silently fail.
* A typo in the code could result in a wrong value substituted
  for an operation which produced a false '!foreach requires an operator' error.
* Keep recursion over the DAG within ForeachHelper. This simplifies
  things a bit as we no longer need to pass the Type around in order
  to prevent recursion.

Differential Revision: https://reviews.llvm.org/D43083

llvm-svn: 324758
2018-02-09 18:37:55 +00:00
Artem Belevich 7d8f6fa86c [TableGen] Make sure !if is evaluated throughout class inheritance.
Without the patch !if() is only evaluated if it's used directly.
If it's passed through more than one level of class inheritance,
we end up with a reference to an anonymous record with unresolved
references to the original arguments !if may have used.

The root cause of the problem is that TernOpInit::isComplete()
was always returning false and that prevented use of the folded
value of !if() as an initializer for the record at the next level
of inheritance.

Differential Revision: https://reviews.llvm.org/D42695

llvm-svn: 323807
2018-01-30 19:29:21 +00:00
Daniel Sanders 08464524c3 [ARM][GISel] PR35965 Constrain RegClasses of nested instructions built from Dst Pattern
Summary:
Apparently, we missed on constraining register classes of VReg-operands of all the instructions
built from a destination pattern but the root (top-level) one. The issue exposed itself
while selecting G_FPTOSI for armv7: the corresponding pattern generates VTOSIZS wrapped
into COPY_TO_REGCLASS, so top-level COPY_TO_REGCLASS gets properly constrained,
while nested VTOSIZS (or rather its destination virtual register to be exact) does not.

Fixing this by issuing GIR_ConstrainSelectedInstOperands for every nested GIR_BuildMI.

https://bugs.llvm.org/show_bug.cgi?id=35965
rdar://problem/36886530

Patch by Roman Tereshin

Reviewers: dsanders, qcolombet, rovka, bogner, aditya_nandakumar, volkan

Reviewed By: dsanders, qcolombet, rovka

Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D42565

llvm-svn: 323692
2018-01-29 21:09:12 +00:00
Volkan Keles f7f2568613 [GlobalISel][TableGen] Add support for SDNodeXForm
Summary:
This patch adds CustomRenderer which renders the matched
operands to the specified instruction.

Targets can enable the matching of SDNodeXForm by adding
a definition that inherits from GICustomOperandRenderer and
GISDNodeXFormEquiv as follows.

def gi_imm8 : GICustomOperandRenderer<"renderImm8”>,
                       GISDNodeXFormEquiv<imm8_xform>;

Custom renderer functions should be of the form:
void render(MachineInstrBuilder &MIB, const MachineInstr &I);

Reviewers: dsanders, ab, rovka

Reviewed By: dsanders

Subscribers: kristof.beyls, javed.absar, llvm-commits, mgrang, qcolombet

Differential Revision: https://reviews.llvm.org/D42012

llvm-svn: 322582
2018-01-16 18:44:05 +00:00
Aleksandar Beserminji f02ad15ff1 [mips] Improve diagnostics for instruction mapping
This patch improves diagnostic for case when mapped instruction 
does not contain a field listed under RowFields.

Differential Revision: https://reviews.llvm.org/D41778

llvm-svn: 322004
2018-01-08 16:25:40 +00:00
Matt Arsenault 303327d58b TableGen: Allow setting SDNodeProperties on intrinsics
Allows preserving MachineMemOperands on intrinsics
through selection. For reasons I don't understand, this
is a static property of the pattern and the selector
deliberately goes out of its way to drop if not present.

Intrinsics already inherit from SDPatternOperator allowing
them to be used directly in instruction patterns. SDPatternOperator
has a list of SDNodeProperty, but you currently can't set them on
the intrinsic. Without SDNPMemOperand, when the node is selected
any memory operands are always dropped. Allowing setting this
on the intrinsics avoids needing to introduce another equivalent
target node just to have SDNPMemOperand set.

llvm-svn: 321212
2017-12-20 19:36:28 +00:00
Daniel Sanders 32de8bbd30 [globalisel][tablegen] Allow ImmLeaf predicates to use InstructionSelector members
NFC for currently supported targets. This resolves a problem encountered by
targets such as RISCV that reference `Subtarget` in ImmLeaf predicates.

llvm-svn: 321176
2017-12-20 14:41:51 +00:00
Quentin Colombet ec76d9c47f [TableGen][GlobalISel] Optimize MatchTable for faster instruction selection
*** Context ***

Prior to this patchw, the table generated for matching instruction was
straight forward but highly inefficient.

Basically, each pattern generates its own set of self contained checks
and actions.
E.g., TableGen generated:
// First pattern
CheckNumOperand 3
CheckOpcode G_ADD
...
Build ADDrr
// Second pattern
CheckNumOperand 3
CheckOpcode G_ADD
...
Build ADDri
// Third pattern
CheckNumOperand 3
CheckOpcode G_SUB
...
Build SUBrr

*** Problem ***

Because of that generation, a *lot* of check were redundant between each
pattern and were checked every single time until we reach the pattern
that matches.
E.g., Taking the previous table, let say we are matching a G_SUB, that
means we were going to check all the rules for G_ADD before looking at
the G_SUB rule. In particular we are going to do:
check 3 operands; PASS
check G_ADD; FAIL
; Next rule
check 3 operands; PASS (but we already knew that!)
check G_ADD; FAIL (well it is still not true)
; Next rule
check 3 operands; PASS (really!!)
check G_SUB; PASS (at last :P)

*** Proposed Solution ***

This patch introduces a concept of group of rules (GroupMatcher) that
share some predicates and only get checked once for the whole group.

This patch only creates groups with one nesting level. Conceptually
there is nothing preventing us for having deeper nest level. However,
the current implementation is not smart enough to share the recording
(aka capturing) of values. That limits its ability to do more sharing.

For the given example the current patch will generate:
// First group
CheckOpcode G_ADD

 // First pattern
 CheckNumOperand 3
 ...
 Build ADDrr
 // Second pattern
 CheckNumOperand 3
 ...
 Build ADDri

// Second group
CheckOpcode G_SUB

 // Third pattern
 CheckNumOperand 3
 ...
 Build SUBrr

But if we allowed several nesting level, it could create a sub group
for the checknumoperand 3.
(We would need to call optimizeRules on the rules within a group.)

*** Result ***

With only one level of nesting, the instruction selection pass is up
to 4x faster. For instance, one instruction now takes 500 checks,
instead of 24k! With more nesting we could get in the tens I believe.

Differential Revision: https://reviews.llvm.org/D39034

rdar://problem/34670699

llvm-svn: 321017
2017-12-18 19:47:41 +00:00
Krzysztof Parzyszek 2aaeeb40b3 Add MVT::v128i1, NFC
Hexagon HVX has type v128i8, comparing two vectors of that type will
produce v128i1 types in SelectionDAG.

llvm-svn: 320732
2017-12-14 19:05:21 +00:00
Alex Bradbury d590c85753 [TableGen] Give the option of tolerating duplicate register names
A number of architectures re-use the same register names (e.g. for both 32-bit 
FPRs and 64-bit FPRs). They are currently unable to use the tablegen'erated 
MatchRegisterName and MatchRegisterAltName, as tablegen (when built with 
asserts enabled) will fail.

When the AllowDuplicateRegisterNames in AsmParser is set, duplicated register 
names will be tolerated. A backend can then coerce registers to the desired 
register class by (for instance) implementing validateTargetOperandClass.

At least the in-tree Sparc backend could benefit from this, as does RISC-V 
(single and double precision floating point registers).

Differential Revision: https://reviews.llvm.org/D39845

llvm-svn: 320018
2017-12-07 09:51:55 +00:00
Daniel Sanders 3c1c4c0ee0 Revert r319691: [globalisel][tablegen] Split atomic load/store into separate opcode and enable for AArch64.
Some concerns were raised with the direction. Revert while we discuss it and look into an alternative

llvm-svn: 319739
2017-12-05 05:52:07 +00:00
Daniel Sanders 04e4f47e93 [globalisel][tablegen] Split atomic load/store into separate opcode and enable for AArch64.
This patch splits atomics out of the generic G_LOAD/G_STORE and into their own
G_ATOMIC_LOAD/G_ATOMIC_STORE. This is a pragmatic decision rather than a
necessary one. Atomic load/store has little in implementation in common with
non-atomic load/store. They tend to be handled very differently throughout the
backend. It also has the nice side-effect of slightly improving the common-case
performance at ISel since there's no longer a need for an atomicity check in the
matcher table.

All targets have been updated to remove the atomic load/store check from the
G_LOAD/G_STORE path. AArch64 has also been updated to mark
G_ATOMIC_LOAD/G_ATOMIC_STORE legal.

There is one issue with this patch though which also affects the extending loads
and truncating stores. The rules only match when an appropriate G_ANYEXT is
present in the MIR. For example,
  (G_ATOMIC_STORE (G_TRUNC:s16 (G_ANYEXT:s32 (G_ATOMIC_LOAD:s16 X))))
will match but:
  (G_ATOMIC_STORE (G_ATOMIC_LOAD:s16 X))
will not. This shouldn't be a problem at the moment, but as we get better at
eliminating extends/truncates we'll likely start failing to match in some
cases. The current plan is to fix this in a patch that changes the
representation of extending-load/truncating-store to allow the MMO to describe
a different type to the operation.

llvm-svn: 319691
2017-12-04 20:39:32 +00:00
Daniel Sanders 766646517f [globalisel][tablegen] Add support for importing G_ATOMIC_CMPXCHG, G_ATOMICRMW_* rules from SelectionDAG.
GIM_CheckNonAtomic has been replaced by GIM_CheckAtomicOrdering to allow it to support a wider
range of orderings. This has then been used to import patterns using nodes such
as atomic_cmp_swap, atomic_swap, and atomic_load_*.

llvm-svn: 319232
2017-11-28 22:07:05 +00:00
Daniel Sanders f76f315436 [globalisel][tablegen] Generate rule coverage and use it to identify untested rules
Summary:
This patch adds a LLVM_ENABLE_GISEL_COV which, like LLVM_ENABLE_DAGISEL_COV,
causes TableGen to instrument the generated table to collect rule coverage
information. However, LLVM_ENABLE_GISEL_COV goes a bit further than
LLVM_ENABLE_DAGISEL_COV. The information is written to files
(${CMAKE_BINARY_DIR}/gisel-coverage-* by default). These files can then be
concatenated into ${LLVM_GISEL_COV_PREFIX}-all after which TableGen will
read this information and use it to emit warnings about untested rules.

This technique could also be used by SelectionDAG and can be further
extended to detect hot rules and give them priority over colder rules.

Usage:
* Enable LLVM_ENABLE_GISEL_COV in CMake
* Build the compiler and run some tests
* cat gisel-coverage-[0-9]* > gisel-coverage-all
* Delete lib/Target/*/*GenGlobalISel.inc*
* Build the compiler

Known issues:
* ${LLVM_GISEL_COV_PREFIX}-all must be generated as a manual
  step due to a lack of a portable 'cat' command. It should be the
  concatenation of all ${LLVM_GISEL_COV_PREFIX}-[0-9]* files.
* There's no mechanism to discard coverage information when the ruleset
  changes

Depends on D39742

Reviewers: ab, qcolombet, t.p.northover, aditya_nandakumar, rovka

Reviewed By: rovka

Subscribers: vsk, arsenm, nhaehnle, mgorny, kristof.beyls, javed.absar, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D39747

llvm-svn: 318356
2017-11-16 00:46:35 +00:00
Daniel Sanders 7e52367398 [globalisel][tablegen] Import signextload and zeroextload.
Allow a pattern rewriter to be installed in CodeGenDAGPatterns and use it to
correct situations where SelectionDAG and GlobalISel disagree on
representation. For example, it would rewrite:
  (sextload:i32 $ptr)<<unindexedload>><<sextload>><<sextloadi16>
to:
  (sext:i32 (load:i16 $ptr)<<unindexedload>>)

I'd have preferred to replace the fragments and have the expansion happen
naturally as part of PatFrag expansion but the type inferencing system can't
cope with loads of types narrower than those mentioned in register classes.
This is because the SDTCisInt's on the sext constrain both the result and
operand to the 'legal' integer types (where legal is defined as 'a register
class can contain the type') which immediately rules the narrower types out.
Several targets (those with only one legal integer type) would then go on to
crash on the SDTCisOpSmallerThanOp<> when it removes all the possible types
for the result of the extend.

Also, improve isObviouslySafeToFold() slightly to automatically return true for
neighbouring instructions. There can't be any re-ordering problems if
re-ordering isn't happenning. We'll need to improve it further to handle
sign/zero-extending loads when the extend and load aren't immediate neighbours
though.

llvm-svn: 317971
2017-11-11 03:23:44 +00:00
Daniel Sanders 9cbe7c7f93 [globalisel][tablegen] Add support for multi-insn emission
The importer will now accept nested instructions in the result pattern such as
(ADDWrr $a, (SUBWrr $b, $c)). This is only valid when the nested instruction
def's a single vreg and the parent instruction consumes a single vreg where a
nested instruction is specified. The importer will automatically create a vreg
to connect the two using the type information from the pattern. This vreg will
be constrained to the register classes given in the instruction definitions*.

* REG_SEQUENCE is explicitly rejected because of this. The definition doesn't
  constrain to a register class and it therefore needs special handling.

llvm-svn: 317117
2017-11-01 19:57:57 +00:00
Daniel Sanders 1e4569fdc1 [globalisel][tablegen] Fix small spelling nits. NFC
ComplexRendererFn -> ComplexRendererFns
Corrected a couple lingering references to tied operands that were missed.

llvm-svn: 316237
2017-10-20 20:55:29 +00:00
Daniel Sanders ea8711b88e Re-commit r315885: [globalisel][tblgen] Add support for iPTR and implement am_unscaled* and am_indexed*
Summary:
iPTR is a pointer of subtarget-specific size to any address space. Therefore
type checks on this size derive the SizeInBits from a subtarget hook.

At this point, we can import the simplests G_LOAD rules and select load
instructions using them. Further patches will support for the predicates to
enable additional loads as well as the stores.

The previous commit failed on MSVC due to a failure to convert an
initializer_list to a std::vector. Hopefully, MSVC will accept this version.

Depends on D37457

Reviewers: ab, qcolombet, t.p.northover, rovka, aditya_nandakumar

Reviewed By: qcolombet

Subscribers: kristof.beyls, javed.absar, llvm-commits, igorb

Differential Revision: https://reviews.llvm.org/D37458

llvm-svn: 315887
2017-10-16 03:36:29 +00:00
Daniel Sanders a71f454765 [globalisel][tablegen] Implement unindexed load, non-extending load, and MemVT checks
Summary:
This includes some context-sensitivity in the MVT to LLT conversion so that
pointer types are tested correctly.
FIXME: I'm not happy with the way this is done since everything is a
       special-case. I've yet to find a reasonable way to implement it.

select-load.mir fails because <1 x s64> loads in tablegen get priority over s64
loads. This is fixed in the next patch and as such they should be committed
together, I've posted them separately to help with the review.

Depends on D37456

Reviewers: ab, qcolombet, t.p.northover, rovka, aditya_nandakumar

Subscribers: kristof.beyls, javed.absar, llvm-commits, igorb

Differential Revision: https://reviews.llvm.org/D37457

llvm-svn: 315884
2017-10-16 00:56:30 +00:00
Daniel Sanders df39cbae2f Re-commit r315863: [globalisel][tablegen] Import ComplexPattern when used as an operator
Summary:
It's possible for a ComplexPattern to be used as an operator in a match
pattern. This is used by the load/store patterns in AArch64 to name the
suboperands returned by ComplexPattern predicate so that they can be broken
apart and referenced independently in the result pattern.

This patch adds support for this in order to enable the import of load/store
patterns.

Depends on D37445

Hopefully fixed the ambiguous constructor that a large number of bots reported.

Reviewers: ab, qcolombet, t.p.northover, rovka, aditya_nandakumar

Reviewed By: qcolombet

Subscribers: aemerson, javed.absar, igorb, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D37456

llvm-svn: 315869
2017-10-15 18:22:54 +00:00
Daniel Sanders bb082a36d3 Revert r315863: [globalisel][tablegen] Import ComplexPattern when used as an operator
A large number of bots are failing on an ambiguous constructor call.

llvm-svn: 315866
2017-10-15 17:51:07 +00:00