Commit Graph

81 Commits

Author SHA1 Message Date
Petar Avramovic 0713c82b13 [GlobalISel]: Add a getConstantIntVRegVal utility
Returns ConstantInt from G_CONSTANT instruction given its def register.

Differential Revision: https://reviews.llvm.org/D99733
2021-04-27 10:52:07 +02:00
Jessica Paquette 91bbb914e0 [AArch64][GlobalISel] Regbankselect + select @llvm.aarch64.neon.uaddlv
It turns out we actually import a bunch of selection code for intrinsics. The
imported code checks that the register banks on the G_INTRINSIC instruction
are correct. If so, it goes ahead and selects it.

This adds code to AArch64RegisterBankInfo to allow us to correctly determine
register banks on intrinsics which have known register bank constraints.

For now, this only handles @llvm.aarch64.neon.uaddlv. This is necessary for
porting AArch64TargetLowering::LowerCTPOP.

Also add a utility for getting the intrinsic ID from a G_INTRINSIC instruction.
This seems a little nicer than having to know about how intrinsic instructions
are structured.

Differential Revision: https://reviews.llvm.org/D100398
2021-04-19 10:47:49 -07:00
Matt Arsenault b24436ac96 GlobalISel: Lower funnel shifts 2021-03-23 09:11:17 -04:00
Matt Arsenault 9fdfd8dd52 GlobalISel: Add utility function to constant fold FP ops 2021-03-22 14:38:17 -04:00
Matt Arsenault c34819afe3 GlobalISel: Handle G_BUILD_VECTOR in isKnownToBeAPowerOfTwo 2021-03-22 14:20:35 -04:00
Matt Arsenault b9a0384983 GlobalISel: Preserve source value information for outgoing byval args
Pass through the original argument IR value in order to preserve the
aliasing information in the memcpy memory operands.
2021-03-18 09:16:54 -04:00
Amara Emerson 28963d895b [GlobalISel] Don't DCE LIFETIME_START/LIFETIME_END markers.
These are pseudos without any users, so DCE was killing them in the combiner.

Marking them as having side effects doesn't seem quite right since they don't.

Gives a nice 0.3% geomean size win on CTMark -Os.

Differential Revision: https://reviews.llvm.org/D98811
2021-03-17 18:02:08 -07:00
Jessica Paquette 5c26be214d [AArch64][GlobalISel] Lower G_BUILD_VECTOR -> G_DUP
If we have

```
%vec = G_BUILD_VECTOR %reg, %reg, ..., %reg
```

Then lower it to

```
%vec = G_DUP %reg
```

Also update the selector to handle constant splats on G_DUP.

This will not combine when the splat is all zeros or ones. Tablegen-imported
patterns rely on these being G_BUILD_VECTOR.

Minor code size improvements on CTMark at -Os.

Also adds some utility functions to make it a bit easier to recognize splats,
and an AArch64-specific splat helper.

Differential Revision: https://reviews.llvm.org/D97731
2021-03-08 13:01:10 -08:00
Amara Emerson 8a316045ed [AArch64][GlobalISel] Enable use of the optsize predicate in the selector.
To do this while supporting the existing functionality in SelectionDAG of using
PGO info, we add the ProfileSummaryInfo and LazyBlockFrequencyInfo analysis
dependencies to the instruction selector pass.

Then, use the predicate to generate constant pool loads for f32 materialization,
if we're targeting optsize/minsize.

Differential Revision: https://reviews.llvm.org/D97732
2021-03-02 12:55:51 -08:00
Petar Avramovic f0d65f4096 AMDGPU/GlobalISel: Calculate isKnownNeverNaN for fminnum and fmaxnum
Implements same logis as in SelectionDAG.
G_FMINNUM_IEEE and G_FMAXNUM_IEEE are never SNaN by definition and
never NaN when one operand is known non-NaN and other known non-SNaN.
G_FMINNUM and G_FMAXNUM are never NaN/SNaN when one of the operands
is known non-NaN/SNaN.

Differential Revision: https://reviews.llvm.org/D91716
2021-02-12 17:14:34 +01:00
Petar Avramovic 122c649c98 AMDGPU/GlobalISel: Check values of constants in isKnownNeverNaN
Differential Revision: https://reviews.llvm.org/D91714
2021-02-12 17:14:34 +01:00
Jessica Paquette daffab1985 Recommit "[GlobalISel] Walk through hints in getDefIgnoringCopies et al"
Recommit of 4580acf675

`Opc = DefMI->getOpcode()` was in the wrong place.
2021-01-28 14:43:00 -08:00
Jessica Paquette dcb5b5f1f2 Revert "[GlobalISel] Walk through hints in getDefIgnoringCopies et al"
This reverts commit 4580acf675.

Reverting while looking into some test failures.
2021-01-28 14:37:57 -08:00
Jessica Paquette 4580acf675 [GlobalISel] Walk through hints in getDefIgnoringCopies et al
Treat hint instructions like G_ASSERT_ZEXT like COPY instructions in helpers
which walk through copies.

This ensures that instructions like G_ASSERT_ZEXT won't impact any optimizations
that rely on these helpers.

Differential Revision: https://reviews.llvm.org/D95577
2021-01-28 14:27:00 -08:00
Mirko Brkusanin a6a72dfdf2 [AMDGPU][GlobalISel] Avoid selecting S_PACK with constants
If constants are hidden behind G_ANYEXT we can treat them same way as G_SEXT.
For that purpose we extend getConstantVRegValWithLookThrough with option
to handle G_ANYEXT same way as G_SEXT.

Differential Revision: https://reviews.llvm.org/D92219
2021-01-20 11:54:53 +01:00
Gabriel Hjort Åkerlund 2aeaaf841b [GlobalISel] Add missing operand update when copy is required
When constraining an operand register using constrainOperandRegClass(),
the function may emit a COPY in case the provided register class does
not match the current operand register class. However, the operand
itself is not updated to make use of the COPY, thereby resulting in
incorrect code. This patch fixes that bug by updating the machine
operand accordingly.

Reviewed By: dsanders

Differential Revision: https://reviews.llvm.org/D91244
2021-01-20 10:32:52 +01:00
Matt Arsenault a427f15d60 GlobalISel: Add isKnownToBeAPowerOfTwo helper function 2021-01-05 12:59:08 -05:00
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
Jessica Paquette b184a2eccf [GlobalISel] Add matchers for specific constants and a matcher for negations
It's fairly common to need matchers for a specific constant value, or for
common idioms like finding a negated register.

Add

- `m_SpecificICst`, which returns true when matching a specific value..
- `m_ZeroInt`, which returns true when an integer 0 is matched.
- `m_Neg`, which returns when a register is negated.

Also update a few places which use idioms related to the new matchers.

Differential Revision: https://reviews.llvm.org/D91397
2020-11-13 09:24:54 -08:00
Matt Arsenault c67e1a985f GlobalISel: Directly expose getDefSrcRegIgnoringCopies utility
It's useful to get both the instruction and register at the same time.
2020-11-13 11:07:04 -05:00
Petar Avramovic 6e2a86ed5a AMDGPU/GlobalISel Check for NoNaNsFPMath in isKnownNeverSNaN
Check for NoNaNsFPMath function attribute in isKnownNeverSNaN.
Function attributes are in held in 'TargetMachine.Options'.
Among other things, this allows selection of some patterns imported
in D87351 since G_FCANONICALIZE is not generated when isKnownNeverSNaN
returns true in lowerFMinNumMaxNum.

However we notice some incorrect results since function attributes are
not correctly written in TargetMachine.Options when next function is
processed. Take a look at @v_test_no_global_nnans_med3_f32_pat0_srcmod0,
it has "no-nans-fp-math"="false" but TargetMachine.Options still has it
set to true since first function in test file had this attribute set to
true. This will be fixed in D87511.

Differential Revision: https://reviews.llvm.org/D87456
2020-09-14 12:11:00 +02:00
Amara Emerson cc76da7ada [GlobalISel] Rewrite the elide-br-by-swapping-icmp-ops combine to do less.
This combine previously tried to take sequences like:
  %cond = G_ICMP pred, a, b
  G_BRCOND %cond, %truebb
  G_BR %falsebb
%truebb:
  ...
%falsebb:
  ...

and by inverting the compare predicate and swapping branch targets, delete the
G_BR and instead have a single conditional branch to the falsebb. Since in an
earlier patch we have a combine to fold not(icmp) into just an inverted icmp,
we don't need this combine to do as much. This patch instead generalizes the
combine by just looking for:
  G_BRCOND %cond, %truebb
  G_BR %falsebb
%truebb:
  ...
%falsebb:
  ...

and then inverting the condition using a not (xor). The xor can be folded away
in a separate combine. This change also lets us avoid some optimization code
in the IRTranslator.

I also think that deleting G_BRs in the combiner is unnecessary. That's
something that targets can decide to do at selection time and could simplify
generic code in future.

Differential Revision: https://reviews.llvm.org/D86664
2020-09-09 13:08:16 -07:00
Simon Pilgrim 898e42db93 GlobalISel/Utils.h - remove unused includes. NFCI.
Twine is unused, and TargetLowering can be reduced to a forward declaration and moved to Utils.cpp
2020-09-03 15:59:12 +01:00
Amara Emerson 520ab710fb Revert "Revert "[GlobalISel] Fold xor(cmp(pred, _, _), 1) -> cmp(inverse(pred), _, _)" (and dependent patch "Optimize away a Not feeding a brcond by using tbz instead of tbnz.")"
This reverts commit 8693ddc743.

Re-committing with the test requiring asserts.
2020-09-01 14:29:04 -07:00
Jordan Rupprecht 8693ddc743 Revert "[GlobalISel] Fold xor(cmp(pred, _, _), 1) -> cmp(inverse(pred), _, _)" (and dependent patch "Optimize away a Not feeding a brcond by using tbz instead of tbnz.")
This reverts commit 8ad8f484b6. It causes crashes when running `ninja check-llvm-codegen-aarch64-globalisel`, e.g.
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/24132/steps/test-stage1-compiler/logs/stdio.
Note that the crash does not seem to reproduce in debug builds.

5ded444252 depends on this, so revert that too.
2020-09-01 13:31:57 -07:00
Amara Emerson 8ad8f484b6 [GlobalISel] Fold xor(cmp(pred, _, _), 1) -> cmp(inverse(pred), _, _)
This is needed for an upcoming change to how we translate conditional branches
which might generate these.

Differential Revision: https://reviews.llvm.org/D86383
2020-09-01 10:57:17 -07:00
Matt Arsenault 924f31bc3c GlobalISel: Remove unnecessary check for copy type
COPY isn't allowed to change the type, but can mix no type with type.
2020-08-17 09:19:25 -04:00
Matt Arsenault 04a288f0f0 GlobalISel: Remove unnecessary llvm:: 2020-08-15 12:12:50 -04:00
Matt Arsenault 5c5e6d951e TableGen/GlobalISel: Partially handle immAllOnesV/immAllZerosV
These should really match either G_BUILD_VECTOR or
G_BUILD_VECTOR_TRUNC, but there doesn't seem to be an existing
mechanism for matching alternative opcodes. There is GIM_SwitchOpcode,
but it seems to assume it's oly only used for matcher optimization.

I could also omit any opcode check and rely on the matcher directly
checking the opcode, but the table optimizer currently assumes there
has to be an opcode check.

Also doesn't try to handle undef elements like the DAG version.
2020-08-14 13:55:30 -04:00
Matt Arsenault f8fb7835d6 GlobalISel: Add utilty for getting function argument live ins
Get the argument register and ensure there's a copy to the virtual
register. AMDGPU and AArch64 have similarish code to get the livein
value, and I also want to use this in multiple places.

This is a bit more aggressive about setting the register class than
the original function, but that's probably OK.

I think we're missing a few verifier checks for function live ins. I
noticed AArch64's calling convention code is not actually adding
liveins to functions, only the entry block (which apparently might not
matter that much?). There should probably be a verifier check that
entry block live ins are also live into the function. We also might
need a verifier check that the copy to the livein virtual register is
in the entry block.
2020-08-04 16:55:55 -04:00
Matt Arsenault 3e16e2152c GlobalISel: Handle llvm.localescape
This one is pretty easy and shrinks the list of unhandled
intrinsics. I'm not sure how relevant the insert point is. Using the
insert position of EntryBuilder will place this after
constants. SelectionDAG seems to end up emitting these after argument
copies and before anything else, but I don't think it really
matters. This also ends up emitting these in the opposite order from
SelectionDAG, but I don't think that matters either.

This also needs a fix to stop the later passes dropping this as a dead
instruction. DeadMachineInstructionElim's version of isDead special
cases LOCAL_ESCAPE for some reason, and I'm not sure why it's excluded
from MachineInstr::isLabel (or why isDead doesn't check it).

I also noticed DeadMachineInstructionElim never considers inline asm
as dead, but GlobalISel will drop asm with no constraints.
2020-08-04 15:19:02 -04:00
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
Matt Arsenault 1ef3ed0eb4 GlobalISel: Rewrite getLCMType
Try to make the behavior more consistent with getGCDType, and bias
towards returning something closer to the source type whenever there's
an ambiguity.
2020-07-20 21:06:30 -04:00
Matt Arsenault 12d5bec8c7 GlobalISel: Handle more cases in getGCDType
Try harder to find a canonical unmerge type when trying to cover the
desired target type. Handle finding a compatible unmerge type for two
vectors with different element types. This will return the largest
multiple of the source vector element that will evenly divide the
target vector type.

Also make the handling mixing scalars and vectors, and prefer the
source element type as the unmerge target type.
2020-07-20 20:53:35 -04:00
Matt Arsenault 8a3340d25d GlobalISel: Use early return and reduce indentation 2020-06-16 14:47:08 -04:00
Matt Arsenault 5f7e38d8f4 GlobalISel: Use Register 2020-06-08 10:15:53 -04:00
Daniel Sanders 7c6ca18fff [globalisel] Allow backends to report an issue without triggering fallback. NFC
Summary:
This will allow us to fix the issue where the lost locations
verifier causes CodeGen changes on lost locations because it
falls back on DAGISel

Reviewers: qcolombet, bogner, aprantl, vsk, paquette

Subscribers: rovka, hiraditya, volkan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78261
2020-04-16 10:43:35 -07:00
Guillaume Chatelet d2d6c9f591 [Alignment][NFC] GlobalIsel Utils inferAlignFromPtrInfo
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: rovka, hiraditya, volkan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77079
2020-03-31 06:58:57 +00:00
Matt Arsenault b71203a751 GlobalISel: Move some legalizer functions to utils 2020-03-04 16:40:00 -05:00
Matt Arsenault fb0c35fa34 GlobalISel: Set alignment on function argument stack load/store 2020-03-04 16:38:46 -05:00
Aditya Nandakumar b91d9ec0bb [GlobalISel]: Fix some non determinism exposed in CSE due to not notifying observers about mutations + add verification for CSE
https://reviews.llvm.org/D67133

While investigating some non determinism (CSE doesn't produce wrong
code, it just doesn't CSE some times) in GISel CSE on an out of tree
target, I realized that the core issue was that there were lots of code
that mutates (setReg, setRegClass etc), but doesn't notify observers
(CSE in this case but this could be any other observer). In order to
make the Observer be available in various parts of code and to avoid
having to thread it through various API, the MachineFunction now has the
observer as field. This allows it to be easily used in helper functions
such as constrainOperandRegClass.
Also added some invariant verification method in CSEInfo which can
catch these issues (when CSE is enabled).
2020-02-18 14:54:57 -08:00
Matt Arsenault 3bb0ff8341 GlobalISel: Remove unused function argument 2020-02-14 15:57:39 -08:00
Volkan Keles 187686a22f [GlobalISel] LegalizationArtifactCombiner: Fix a bug in tryCombineMerges
Like COPY instructions explained in D70616, we don't check the constraints
when combining G_UNMERGE_VALUES. Use the same logic used in D70616 to check
if registers can be replaced, or a COPY instruction needs to be built.

https://reviews.llvm.org/D70564
2020-02-14 10:45:58 -08:00
Shu-Chun Weng ce9633633c [GlobalISel][AArch64] Fix contract cross-bank copies with SIMD instructions
contractCrossBankCopyIntoStore() finds the instruction defines the
source register and uses its output to replace the register. There are,
however, instructions that have multiple outputs, e.g. G_UNMERGE_VALUES.
Current implementation hardcodes to operand 0 and has no way of knowing
which output should be used.

This change adds another function to directly return the register that
is the source of the register and use that for folding.

This fixes https://bugs.llvm.org/show_bug.cgi?id=44783

Differential Revision: https://reviews.llvm.org/D74005
2020-02-05 10:38:35 -08:00
Matt Arsenault eb7f74e300 CodeGen: Use Register 2020-01-30 15:01:56 -08:00
Matt Arsenault 595ac8c46e GlobalISel: Move getLLTForMVT/getMVTForLLT
As an intermediate step, some TLI functions can be converted to using
LLT instead of MVT. Move this somewhere out of GlobalISel so DAG
functions can use these.
2020-01-09 16:32:51 -05:00
Marcello Maggioni a064edf55e [GISel] Simplifying return from else in function. NFC
Forgot to integrate this little change in previous commit

llvm-svn: 374463
2019-10-10 21:51:30 +00:00
Marcello Maggioni 0112123eea [GISel] Allow getConstantVRegVal() to return G_FCONSTANT values.
In GISel we have both G_CONSTANT and G_FCONSTANT, but because
in GISel we don't really have a concept of Float vs Int value
the only difference between the two is where the data originates
from.

What both G_CONSTANT and G_FCONSTANT return is just a bag of bits
with the constant representation in it.

By making getConstantVRegVal() return G_FCONSTANTs bit representation
as well we allow ConstantFold and other things to operate with
G_FCONSTANT.

Adding tests that show ConstantFolding to work on mixed G_CONSTANT
and G_FCONSTANT sources.

Differential Revision: https://reviews.llvm.org/D68739

llvm-svn: 374458
2019-10-10 21:46:26 +00:00
Amara Emerson fbaf425b79 [GlobalISel][CallLowering] Add support for splitting types according to calling conventions.
On AArch64, s128 types have to be split into s64 GPRs when passed as arguments.
This change adds the generic support in call lowering for dealing with multiple
registers, for incoming and outgoing args.

Support for splitting for return types not yet implemented.

Differential Revision: https://reviews.llvm.org/D66180

llvm-svn: 370822
2019-09-03 21:42:28 +00:00
Daniel Sanders 0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
2019-08-15 19:22:08 +00:00