This teaches GISel to select patterns which fold an extend plus optional shift
into the addressing mode. In particular, adds and subs.
Factor out the arith extended register ComplexPatterns in AArch64InstrFormats.td
and create GISel equivalents.
Add some equivalent functions to the ones in AArch64ISelDAGToDAG:
- `selectArithExtendedRegister`
- `narrowExtendRegIfNeeded`
- `getExtendTypeForInst`
`getExtendTypeForInst` includes the checks for loads and stores. This will be
used for WRO addressing modes in loads + stores.
Teach selectCopy to properly handle subregister copies on the same bank in
order to support `narrowExtendRegIfNeeded`. The extended register must be a
GPR32, so we need to support same-bank subregister copies.
Fix a bug in getSubRegForClass which would cause registers on things like
GPR32common to end up getting ssub. Just change the check to look for FPR32
rather than GPR32.
For tests:
- Add select-arith-extended-reg.mir
- Update addsub_ext.ll to include GlobalISel checks
Differential Revision: https://reviews.llvm.org/D66835
llvm-svn: 370410
AMDGPU uses this for some addressing mode selection patterns. The
analysis run itself doesn't do anything so it seems easier to just
always require this than adding a way to opt in.
llvm-svn: 370388
Remove manual selection code for this intrinsic and use a GISelPredicateCode
instead.
This allows us to fully select this intrinsic without any tricky custom C++
matching.
Differential Revision: https://reviews.llvm.org/D65780
llvm-svn: 370380
Add a GISelPredicateCode to ldaxr_*. This allows us to import the patterns for
@llvm.aarch64.ldaxr.*, and thus select them.
Add `isLoadStoreOfNumBytes` for the GISelPredicateCode, since each of these
intrinsics involves the same check.
Add select-ldaxr-intrin.mir, and update arm64-ldxr-stxr.ll.
Differential Revision: https://reviews.llvm.org/D66897
llvm-svn: 370377
Instead of using custom C++ in `earlySelect` for loads and stores, just import
the patterns.
Remove `earlySelectLoad`, since we can just import the work it's doing.
Some minor changes to how `ComplexRendererFns` are returned for the XRO
addressing modes. If you add immediates in two steps, sometimes they are not
imported properly and you only end up with one immediate. I'm not sure if this
is intentional.
- Update load-addressing-modes.mir to include the instructions we can now
import.
- Add a similar test, store-addressing-modes.mir to show which store opcodes we
currently import, and show that we can pull in shifts etc.
- Update arm64-fastisel-gep-promote-before-add.ll to use FastISel instead of
GISel. This test failed with GISel because GISel folds the gep into the load.
The test checks that FastISel doesn't fold non-pointer-width adds into loads.
GISel on the other hand, produces a G_CONSTANT of -128 for the add, and then
a G_GEP, which must be pointer-width.
Note that we don't get STRBRoX right now. It seems like the importer can't
handle `FPR8Op:{ *:[Untyped] }:$Rt` source operands. So, those are not currently
supported.
Differential Revision: https://reviews.llvm.org/D66679
llvm-svn: 369806
Add a GlobalISel equivalent for the logical_imm32_XFORM and logical_imm64_XFORM
SDNodeXForms in AArch64InstrFormats.td.
- Add select-logical-imm.mir, which contains tests for each imported pattern.
- Update select-pr32733.mir and select-scalar-shift-imm.mir, since they now
select instructions of this form.
Differential Revision: https://reviews.llvm.org/D66162
llvm-svn: 369465
This adds GlobalISel equivalents for the following from AArch64InstrFormats:
- arith_shifted_reg32
- arith_shifted_reg64
And partial support for
- logical_shifted_reg32
- logical_shifted_reg32
The only thing missing for the logical cases is support for rotates. Other than
the missing support, the transformation is identical for the arithmetic shifted
register and the logical shifted register.
Lots of tests here:
- Add select-arith-shifted-reg.mir to show that we correctly select add and
sub instructions which use this pattern.
- Add select-logical-shifted-reg.mir to cover patterns which are not shared
between the arithmetic and logical cases.
- Update addsub-shifted.ll to show that we correctly fold shifts into
adds/subs.
- Update eon.ll to show that we can select the eon instruction by folding xors.
Differential Revision: https://reviews.llvm.org/D66163
llvm-svn: 369460
Implement this single atomic load instruction so that we can compile stack
protector code.
Differential Revision: https://reviews.llvm.org/D66245
llvm-svn: 368923
Currently shufflemasks get emitted as any other constant, and you end
up with a bunch of virtual registers of G_CONSTANT with a
G_BUILD_VECTOR. The AArch64 selector then asserts on anything that
doesn't fit this pattern. This isn't an ideal representation, and
should avoid legalization and have fewer opportunities for a
representational error.
Rather than invent a new shuffle mask operand type, similar to what
ShuffleVectorSDNode does, just track the original IR Constant mask
operand. I don't completely like the idea of adding another link to
the IR, but MIR is already quite dependent on IR constants already,
and this will allow sharing the shuffle mask utility functions with
the IR.
llvm-svn: 368704
Currently we can't keep any state in the selector object that we get from
subtarget. As a result we have to plumb through all our variables through
multiple functions. This change makes it non-const and adds a virtual init()
method to allow further state to be captured for each target.
AArch64 makes use of this in this patch to cache a call to hasFnAttribute()
which is expensive to call, and is used on each selection of G_BRCOND.
Differential Revision: https://reviews.llvm.org/D65984
llvm-svn: 368652
All TLS access on Darwin is in the "general dynamic" form where we call
a function to resolve the address, so implementation is pretty simple.
llvm-svn: 368418
Summary:
This is tested by D61289 but has been pulled into a separate patch at
a reviewers request.
Reviewers: bogner, aditya_nandakumar, volkan, aemerson, paquette, arsenm, rovka
Reviewed By: arsenm
Subscribers: javed.absar, hiraditya, wdng, kristof.beyls, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61321
llvm-svn: 368063
These cases can come up when the extending loads combiner doesn't combine a
zext(load) to a zextload op, due to some other operation being in between, which
then gets simplified at a later stage.
Differential Revision: https://reviews.llvm.org/D65360
llvm-svn: 367723
Add an equivalent ComplexRendererFns function for SelectNegArithImmed. This
allows us to select immediate adds of -1 by turning them into subtracts.
Update select-binop.mir to show that the pattern works.
Differential Revision: https://reviews.llvm.org/D65460
llvm-svn: 367700
This makes the field wider than MachineOperand::SubReg_TargetFlags so that
we don't end up silently truncating any higher bits. We should still catch
any bits truncated from the MachineOperand field as a consequence of the
assertion in MachineOperand::setTargetFlags().
Differential Revision: https://reviews.llvm.org/D65465
llvm-svn: 367474
Add partial instruction selection for intrinsics like this:
```
declare i32 @llvm.aarch64.stlxr(i64, i32*)
```
(This only handles the case where a G_ZEXT is feeding the intrinsic.)
Also make sure that the added store instruction actually has the memory op from
the original G_STORE.
Update select-stlxr-intrin.mir and arm64-ldxr-stxr.ll.
Differential Revision: https://reviews.llvm.org/D65355
llvm-svn: 367163
Before, we weren't able to select things like this for G_GEP:
add x0, x8, #8
And instead we'd materialize the 8.
This teaches GISel to do that. It gives some considerable code size savings
on 252.eon-- about 4%!
Differential Revision: https://reviews.llvm.org/D65248
llvm-svn: 366959
If we have a G_MUL, and either the LHS or the RHS of that mul is the legal
shift value for a load addressing mode, we can fold it into the load.
This gives some code size savings on some SPEC tests. The best are around 2%
on 300.twolf and 3% on 254.gap.
Differential Revision: https://reviews.llvm.org/D65173
llvm-svn: 366954
Fix an off-by-one error which made us not look at the last element of the
zero vector. This caused a miscompile in 188.ammp.
Differential Revision: https://reviews.llvm.org/D65168
llvm-svn: 366930
We need to be able to load and store s128 for memcpy inlining, where we want to
generate Q register mem ops. Making these legal also requires that we add some
support in other instructions. Regbankselect should also know about these since
they have no GPR register class that can hold them, so need special handling to
live on the FPR bank.
Differential Revision: https://reviews.llvm.org/D65166
llvm-svn: 366857
When we select the XRO variants of loads, we can pull in very specific shifts
(of the size of an element). E.g.
```
ldr x1, [x2, x3, lsl #3]
```
This teaches GISel to handle these when they're coming from shifts
specifically.
This adds a new addressing mode function, `selectAddrModeShiftedExtendXReg`
which recognizes this pattern.
This also packs this up with `selectAddrModeRegisterOffset` into
`selectAddrModeXRO`. This is intended to be equivalent to `selectAddrModeXRO`
in AArch64ISelDAGtoDAG.
Also update load-addressing-modes to show that all of the cases here work.
Differential Revision: https://reviews.llvm.org/D65119
llvm-svn: 366819
Sometimes, you can end up with cross-bank copies between same-sized GPRs and
FPRs, which feed into G_STOREs. When these copies feed only into stores, they
aren't necessary; we can just store using the original register bank.
This provides some minor code size savings for some floating point SPEC
benchmarks. (Around 0.2% for 453.povray and 450.soplex)
This issue doesn't seem to show up due to regbankselect or anything similar. So,
this patch introduces an early select function, `contractCrossBankCopyIntoStore`
which performs the contraction when possible. The selector then continues
normally and selects the correct store opcode, eliminating needless copies
along the way.
Differential Revision: https://reviews.llvm.org/D65024
llvm-svn: 366625
Add support for folding G_GEPs into loads of the form
```
ldr reg, [base, off]
```
when possible. This can save an add before the load. Currently, this is only
supported for loads of 64 bits into 64 bit registers.
Add a new addressing mode function, `selectAddrModeRegisterOffset` which
performs this folding when it is profitable.
Also add a test for addressing modes for G_LOAD.
Differential Revision: https://reviews.llvm.org/D64944
llvm-svn: 366503
Since we have distinct types for pointers and scalars, G_INTTOPTRs can sometimes
obstruct attempts to find constant source values. These usually come about when
try to do some kind of null pointer check. Teaching getConstantVRegValWithLookThrough
about this operation allows the CBZ/CBNZ optimization to catch more cases.
This change also improves the case where we can't find a constant source at all.
Previously we would emit a cmp, cset and tbnz for that. Now we try to just emit
a cmp and conditional branch, saving an instruction.
The cumulative code size improvement of this change plus D64354 is 5.5% geomean
on arm64 CTMark -O0.
Differential Revision: https://reviews.llvm.org/D64377
llvm-svn: 365690
Some minor cleanup.
This function in Utils does the same thing as `findMIFromReg`. It also looks
through copies, which `findMIFromReg` didn't.
Delete `findMIFromReg` and use `getOpcodeDef` instead. This only happens in
`tryOptVectorDup` right now.
Update opt-shuffle-splat to show that we can look through the copies now, too.
Differential Revision: https://reviews.llvm.org/D64520
llvm-svn: 365684
There are a few places where we walk over copies throughout
AArch64InstructionSelector.cpp. In Utils, there's a function that does exactly
this which we can use instead.
Note that the utility function works with the case where we run into a COPY
from a physical register. We've run into bugs with this a couple times, so using
it should defend us from similar future bugs.
Also update opt-fold-compare.mir to show that we still handle physical registers
properly.
Differential Revision: https://reviews.llvm.org/D64513
llvm-svn: 365683
Porting over the part of `emitComparison` in AArch64ISelLowering where we use
TST to represent a compare.
- Rename `tryOptCMN` to `tryFoldIntegerCompare`, since it now also emits TSTs
when possible.
- Add a utility function for emitting a TST with register operands.
- Rename opt-fold-cmn.mir to opt-fold-compare.mir, since it now also tests the
TST fold as well.
Differential Revision: https://reviews.llvm.org/D64371
llvm-svn: 365404
Precedence was wrong in an assert added in r364961. Add braces around the
assertion condition to make it right.
See: https://reviews.llvm.org/D64084
llvm-svn: 365069
Instead of just stopping to see if we have a G_CONSTANT, instead, look through
G_TRUNCs, G_SEXTs, and G_ZEXTs.
This gives an average ~1.3% code size improvement on CINT2000 at -O3.
Differential Revision: https://reviews.llvm.org/D64108
llvm-svn: 365063
There are two main issues preventing us from generating immediate form shifts:
1) We have partial SelectionDAG imported support for G_ASHR and G_LSHR shift
immediate forms, but they currently don't work because the amount type is
expected to be an s64 constant, but we only legalize them to have homogenous
types.
To deal with this, first we introduce a custom legalizer to *only* custom legalize
s32 shifts which have a constant operand into a s64.
There is also an additional artifact combiner to fold zexts(g_constant) to a
larger G_CONSTANT if it's legal, a counterpart to the anyext version committed
in an earlier patch.
2) For G_SHL the importer can't cope with the pattern. For this I introduced an
early selection phase in the arm64 selector to select these forms manually
before the tablegen selector pessimizes it to a register-register variant.
Differential Revision: https://reviews.llvm.org/D63910
llvm-svn: 364994
This teaches `tryOptSelect` to handle folding G_ICMP, and removes the
requirement that the G_SELECT we're dealing with is floating point.
Some refactoring to make this work nicely as well:
- Factor out the scalar case from the selection code for G_ICMP into
`emitIntegerCompare`.
- Make `tryOptCMN` return a MachineInstr* instead of a bool.
- Make `tryOptCMN` not modify the instruction being selected.
- Factor out the CMN emission into `emitCMN` for readability.
By doing this this way, we can get all of the compare selection optimizations
in select emission.
Differential Revision: https://reviews.llvm.org/D64084
llvm-svn: 364961
Avoids using a plain unsigned for registers throughoug codegen.
Doesn't attempt to change every register use, just something a little
more than the set needed to build after changing the return type of
MachineOperand::getReg().
llvm-svn: 364191
On Windows ARM64, intrinsic __debugbreak is compiled into brk #0xF000 which is
mapped to llvm.debugtrap in Clang. Instruction brk #F000 is the defined break
point instruction on ARM64 which is recognized by Windows debugger and
exception handling code, so llvm.debugtrap should map to it instead of
redirecting to llvm.trap (brk #1) as the default implementation.
Differential Revision: https://reviews.llvm.org/D63635
llvm-svn: 364115
With this we can now fully code generate jump tables, which is important for code size.
Differential Revision: https://reviews.llvm.org/D63223
llvm-svn: 364086
We sometimes get poor code size because constants of types < 32b are legalized
as 32 bit G_CONSTANTs with a truncate to fit. This works but means that the
localizer can no longer sink them (although it's possible to extend it to do so).
On AArch64 however s8 and s16 constants can be selected in the same way as s32
constants, with a mov pseudo into a W register. If we make s8 and s16 constants
legal then we can avoid unnecessary truncates, they can be CSE'd, and the
localizer can sink them as normal.
There is a caveat: if the user of a smaller constant has to widen the sources,
we end up with an anyext of the smaller typed G_CONSTANT. This can cause
regressions because of the additional extend and missed pattern matching. To
remedy this, there's a new artifact combiner to generate the wider G_CONSTANT
if it's legal for the target.
Differential Revision: https://reviews.llvm.org/D63587
llvm-svn: 364075
Basically porting over the behaviour in AArch64ISelLowering to GISel. See
emitComparison for reference.
When we have something like this:
```
lhs = G_SUB 0, y
...
G_ICMP lhs, rhs
```
We can fold away the G_SUB and produce a cmn instead, given that we produce
the same value in NZCV.
Add a test showing that the transformation works, and also showing that we
don't perform the transformation when it's unsafe.
Also factor out the CSet emission into emitCSetForICMP.
Differential Revision: https://reviews.llvm.org/D63163
llvm-svn: 363596
We already get support for G_ZEXTLOAD to s32 from the importer, but it can't
deal with the SUBREG_TO_REG in the pattern. Tweaking the existing manual
selection code for G_LOAD to handle an additional SUBREG_TO_REG when dealing
with G_ZEXTLOAD isn't much work.
Also add tests to check the imported pattern selections to s32 work.
llvm-svn: 362681
Jessica Paquette