15 Commits

Author SHA1 Message Date
Jessica Paquette
1514f3b2c8 [AArch64][GlobalISel] Don't perform the mul const combine with G_PTR_ADD
A G_MUL + G_PTR_ADD can also be folded into a madd. So, conservatively, we
shouldn't combine when the G_MUL is used by a G_PTR_ADD either.

Differential Revision: https://reviews.llvm.org/D96457
2021-02-10 15:30:45 -08:00
Matt Arsenault
581d13f8ae GlobalISel: Return APInt from getConstantVRegVal
Returning int64_t was arbitrarily limiting for wide integer types, and
the functions should handle the full generality of the IR.

Also changes the full form which returns the originally defined
vreg. Add another wrapper for the common case of just immediately
converting to int64_t (arguably this would be useful for the full
return value case as well).

One possible issue with this change is some of the existing uses did
break without conversion to getConstantVRegSExtVal, and it's possible
some without adequate test coverage are now broken.
2020-12-22 22:23:58 -05:00
Amara Emerson
2262393090 [AArch64][GlobalISel] Port some AArch64 target specific MUL combines from SDAG.
These do things like turn a multiply of a pow-2+1 into a shift and and add,
which is a common pattern that pops up, and is universally better than expensive
madd instructions with a constant.

I've added check lines to an existing codegen test since the code being ported
is almost identical, however the mul by negative pow2 constant tests don't generate
the same code because we're missing some generic G_MUL combines still.

Differential Revision: https://reviews.llvm.org/D91125
2020-11-10 22:21:13 -08:00
Amara Emerson
393b55380a [AArch64][GlobalISel] Add combine for G_EXTRACT_VECTOR_ELT to allow selection of pairwise FADD.
For the <2 x float> case, instead of adding another combine or legalization to
get it into a <4 x float> form, I'm just adding a GISel specific selection
pattern to cover it.

Differential Revision: https://reviews.llvm.org/D90699
2020-11-03 17:25:14 -08:00
Jessica Paquette
147b9497e7 [AArch64][GlobalISel] Split post-legalizer combiner to allow for lowering at -O0
There are a lot of combines in AArch64PostLegalizerCombiner which exist to
facilitate instruction matching in the selector. (E.g. matching for G_ZIP and
other shuffle vector pseudos)

It still makes sense to select these instructions at -O0.

Matching earlier in a combiner can reduce complexity in the selector
significantly. For example, a good portion of our selection code for compares
would be a lot easier to represent in a combine.

This patch moves matching combines into a "AArch64PostLegalizerLowering"
combiner which runs at all optimization levels.

Also, while we're here, improve the documentation for the
AArch64PostLegalizerCombiner, and fix up the filepath in its file comment.

And also add a 'r' which somehow got dropped from a bunch of function names.

https://reviews.llvm.org/D89820
2020-10-22 14:43:25 -07:00
Amara Emerson
a513fdec90 [AArch64][GlobalISel] Add a post-legalize combine for lowering vector-immediate G_ASHR/G_LSHR.
In order to select the immediate forms using the imported patterns, we need to
lower them into new G_VASHR/G_VLSHR target generic ops. Add a combine to do this
matching build_vector of constant operands.

With this, we get selection for free.
2020-09-21 16:04:52 -07:00
Amara Emerson
d8ba622209 [AArch64][GlobalISel] Selection support for vector DUP[X]lane instructions.
In future, we'd like to use the perfect-shuffle mechanism to deal with these
shuffle permutations. For now, this improves performance by avoiding the
super-expensive const-pool load + tbl instruction.

Differential Revision: https://reviews.llvm.org/D84866
2020-07-29 11:41:37 -07:00
Jessica Paquette
7fb84dff69 [AArch64][GlobalISel] Port buildvector -> dup pattern from AArch64ISelLowering
Given this:

```
%x:_(<n x sK>) = G_BUILD_VECTOR %lane, ...
...
%y:_(<n x sK>) = G_SHUFFLE_VECTOR %x(<n x sK>), %foo, shufflemask(0, 0, ...)
```

We can produce:

```
%y:_(<n x sK) = G_DUP %lane(sK)
```

Doesn't seem to be too common, but AArch64ISelLowering attempts to do this
before trying to produce a DUPLANE. Might as well port it.

Also make it so that when the splat has an undef mask, we try setting it to
0. SDAG does this, and it makes sure that when we get the build vector operand,
we actually get a source operand.

Differential Revision: https://reviews.llvm.org/D81979
2020-06-25 14:19:06 -07:00
Daniel Sanders
e35ba09961 [gicombiner] Allow generated combiners to store additional members
Summary:
Adds the ability to add members to a generated combiner via
a State base class. In the current AArch64PreLegalizerCombiner
this is used to make Helper available without having to
provide it to every call.

As part of this, split the command line processing into a
separate object so that it still only runs once even though
the generated combiner is constructed more frequently.

Depends on D81862

Reviewers: aditya_nandakumar, bogner, volkan, aemerson, paquette, arsenm

Reviewed By: arsenm

Subscribers: jvesely, wdng, nhaehnle, kristof.beyls, hiraditya, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81863
2020-06-16 14:47:04 -07:00
Jessica Paquette
3495b884de [AArch64][GlobalISel] Add G_EXT and select ext using it
Add selection support for ext via a new opcode, G_EXT and a post-legalizer
combine which matches it.

Add an `applyEXT` function, because the AArch64ext patterns require a register
for the immediate. So, we have to create a G_CONSTANT to get these without
writing new patterns or modifying the existing ones.

Tests are the same as arm64-ext.ll.

Also prevent ext from firing on the zip test. It has higher priority, so we
don't want it potentially getting in the way of mask tests.

Also fix up the shuffle-splat test, because ext is now selected there. The
test was incorrectly regbank selected before, which could cause a verifier
failure when you emit copies.

Differential Revision: https://reviews.llvm.org/D81436
2020-06-15 12:20:59 -07:00
Jessica Paquette
d3a56f062b [AArch64][GlobalISel] Allow G_DUP for elements smaller than 32 B.
We select all of these via patterns now, so there's no reason to disallow this.

Update select-dup.mir to show that we correctly select the smaller types.

Differential Revision: https://reviews.llvm.org/D81322
2020-06-12 09:40:34 -07:00
Jessica Paquette
cb2d8b30ad [AArch64][GlobalISel] Select trn1 and trn2
Same idea as for zip, uzp, etc. Teach the post-legalizer combiner to recognize
G_SHUFFLE_VECTORs that are trn1/trn2 instructions.

- Add G_TRN1 and G_TRN2
- Port mask matching code from AArch64ISelLowering
- Produce G_TRN1 and G_TRN2 in the post-legalizer combiner
- Select via importer

Add select-trn.mir to test selection.

Add postlegalizer-combiner-trn.mir to test the combine. This is similar to the
existing arm64-trn test.

Note that both of these tests contain things we currently don't legalize.

I figured it would be easier to test these now rather than later, since once
we legalize the G_SHUFFLE_VECTORs, it's not guaranteed that someone will update
the tests.

Differential Revision: https://reviews.llvm.org/D81182
2020-06-09 10:55:19 -07:00
Simon Pilgrim
a375463ad0 Fix Wdocumentation warning. NFC.
The raw unsigned Opc value has been replaced with the ShuffleVectorPseudo MatchInfo wrapper struct.
2020-06-09 13:53:39 +01:00
Jessica Paquette
8f262a686e [AArch64][GlobalISel] Move dup optimization into post-legalizer combiner
Since all of the other G_SHUFFLE_VECTOR transforms are going there, let's do
this with dup as well. This is nice, because it lets us split up the original
code into matching, register bank selection, and instruction selection.

- Create G_DUP, make it equivalent to AArch64dup

- Add a post-legalizer combine which is 90% a copy-and-paste from
  tryOptVectorDup, except with shuffle matching closer to what SelectionDAG
  does in `ShuffleVectorSDNode::isSplatMask`.

- Teach RegBankSelect about G_DUP. Since dup selection relies on the correct
  register bank for FP/GPR dup selection, this is necessary.

- Kill `tryOptVectorDup`, since it's now entirely handled by G_DUP.

- Add testcases for the combine, RegBankSelect, and selection. The selection
  test gives the same selection results as the old test.

Differential Revision: https://reviews.llvm.org/D81221
2020-06-05 17:46:28 -07:00
Amara Emerson
e53f558057 [AArch64][GlobalISel] Move GlobalISel source files to a dedicated subdir.
Differential Revision: https://reviews.llvm.org/D81116
2020-06-04 10:51:38 -07:00