Commit Graph

107 Commits

Author SHA1 Message Date
Amara Emerson d5785775f8 [AArch64][GlobalISel] Add isel support for global values in the large code model.
Fixes PR35958.

Differential Revision: https://reviews.llvm.org/D42175

llvm-svn: 322878
2018-01-18 19:21:27 +00:00
Aditya Nandakumar 18b3f9d384 [GISel] Make constrainSelectedInstRegOperands() available to the legalizer. NFC
https://reviews.llvm.org/D42149

llvm-svn: 322743
2018-01-17 19:31:33 +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
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 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
David Blaikie 6265130054 InstructionSelectorImpl.h: Modularize/remove ODR violations by using a static member function to expose the debug name
llvm-svn: 316715
2017-10-26 23:39:54 +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 01805b6747 [aarch64][globalisel] Fix a crash in selectAddrModeIndexed() caused by incorrect G_FRAME_INDEX handling
The wrong operand was being rendered to the result instruction.

The crash was detected by Bitcode/simd_ops/AArch64_halide_runtime.bc

llvm-svn: 315890
2017-10-16 05:39:30 +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 ce72d611af Revert r315885: [globalisel][tblgen] Add support for iPTR and implement am_unscaled* and am_indexed*
MSVC doesn't like one of the constructors.

llvm-svn: 315886
2017-10-16 02:15:39 +00:00
Daniel Sanders 6735ea86cd [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.

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: 315885
2017-10-16 01:16:35 +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
Daniel Sanders b95b867dd8 [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

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: 315863
2017-10-15 17:03:36 +00:00
Daniel Sanders 11300cead8 [globalisel][tablegen] Add support for fpimm and import of APInt/APFloat based ImmLeaf.
Summary:
There's only a tablegen testcase for IntImmLeaf and not a CodeGen one
because the relevant rules are rejected for other reasons at the moment.
On AArch64, it's because there's an SDNodeXForm attached to the operand.
On X86, it's because the rule either emits multiple instructions or has
another predicate using PatFrag which cannot easily be supported at the
same time.

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

Reviewed By: qcolombet

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

Differential Revision: https://reviews.llvm.org/D36569

llvm-svn: 315761
2017-10-13 21:28:03 +00:00
Ahmed Bougacha 106dd035a8 [AArch64][GlobalISel] Select all fpexts.
Tablegen already can select these: mark them as legal, remove the
c++ code, and add tests for all types.

llvm-svn: 313074
2017-09-12 21:04:11 +00:00
Ahmed Bougacha a7aa2a9fb1 [AArch64][GlobalISel] Select all fptruncs.
We already support these in tablegen, but we're matching the wrong
operator (libm ftrunc).  Fix that.

While there, drop the c++ code, support COPYs of FPR16, and add tests
for the other types.

llvm-svn: 313073
2017-09-12 21:04:10 +00:00
Aditya Nandakumar efd8a84cd5 [GISEl]: Translate phi into G_PHI
G_PHI has the same semantics as PHI but also has types.
This lets us verify that the types in the G_PHI are consistent.
This also allows specifying legalization actions for G_PHIs.

https://reviews.llvm.org/D36990

llvm-svn: 311596
2017-08-23 20:45:48 +00:00
Daniel Sanders edd0784be6 Re-commit: [globalisel][tablegen] Support zero-instruction emission.
Summary:
Support the case where an operand of a pattern is also the whole of the
result pattern. In this case the original result and all its uses must be
replaced by the operand. However, register class restrictions can require
a COPY. This patch handles both cases by always emitting the copy and
leaving it for the register allocator to optimize.

The previous commit failed on Windows machines due to a flaw in the sort
predicate which allowed both A < B < C and B == C to be satisfied
simultaneously. The cause of this was some sloppiness in the priority order of
G_CONSTANT instructions compared to other instructions. These had equal priority
because it makes no difference, however there were operands had higher priority
than G_CONSTANT but lower priority than any other instruction. As a result, a
priority order between G_CONSTANT and other instructions must be enforced to
ensure the predicate defines a strict weak order.

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

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

Differential Revision: https://reviews.llvm.org/D36084

llvm-svn: 311076
2017-08-17 09:26:14 +00:00
Daniel Sanders eb2f5f3256 Revert r310919 - [globalisel][tablegen] Support zero-instruction emission.
As expected, this failed on the windows bots but the instrumentation showed
something interesting. The ADD8ri and INC8r rules are never directly compared
on the windows machines. That implies that the issue lies in transitivity of
the Compare predicate. I believe I've already verified that but maybe I missed
something.

llvm-svn: 310922
2017-08-15 15:10:31 +00:00
Daniel Sanders 16e6dd3cd6 Re-commit with some instrumentation: [globalisel][tablegen] Support zero-instruction emission.
Summary:
Support the case where an operand of a pattern is also the whole of the
result pattern. In this case the original result and all its uses must be
replaced by the operand. However, register class restrictions can require
a COPY. This patch handles both cases by always emitting the copy and
leaving it for the register allocator to optimize.

The previous commit failed on the windows bots and this one is likely to fail
on those same bots. However, the added instrumentation should reveal a particular
isHigherPriorityThan() evaluation which I'm expecting to expose that
these machines are weighing priority of two rules differently from the
non-windows machines.

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

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

Differential Revision: https://reviews.llvm.org/D36084

llvm-svn: 310919
2017-08-15 13:50:09 +00:00
Daniel Sanders e6c216ed5b Revert r310716 (and r310735): [globalisel][tablegen] Support zero-instruction emission.
Two of the Windows bots are failing test\CodeGen\X86\GlobalISel\select-inc.mir
which should not have been affected by the change. Reverting while I investigate.

Also reverted r310735 because it builds on r310716.

llvm-svn: 310745
2017-08-11 19:19:21 +00:00
Daniel Sanders 1fb1ce0c87 [globalisel][tablegen] Support zero-instruction emission.
Summary:
Support the case where an operand of a pattern is also the whole of the
result pattern. In this case the original result and all its uses must be
replaced by the operand. However, register class restrictions can require
a COPY. This patch handles both cases by always emitting the copy and
leaving it for the register allocator to optimize.

Depends on D35833

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

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

Differential Revision: https://reviews.llvm.org/D36084

llvm-svn: 310716
2017-08-11 15:40:32 +00:00
Daniel Sanders 0554004698 [globalisel][tablegen] Add support for importing 'imm' operands.
Summary:
This patch enables the import of rules containing 'imm' operands that do not
constrain the acceptable values using predicates. Support for ImmLeaf will
arrive in a later patch.

Depends on D35681

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

Reviewed By: rovka

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

Differential Revision: https://reviews.llvm.org/D35833

llvm-svn: 310343
2017-08-08 10:44:31 +00:00
Quentin Colombet 250e050a50 [GlobalISel] Make GlobalISel a non-optional library.
With this change, the GlobalISel library gets always built. In
particular, this is not possible to opt GlobalISel out of the build
using the LLVM_BUILD_GLOBAL_ISEL variable any more.

llvm-svn: 309990
2017-08-03 21:52:25 +00:00
Aditya Nandakumar 02c602e18c [GISel]: Support Widening G_ICMP's destination operand.
Updated AArch64 to widen destination to s32.
https://reviews.llvm.org/D35737

Reviewed by Tim

llvm-svn: 309579
2017-07-31 17:00:16 +00:00
Tim Northover 7b6d66c0c9 Recommit: GlobalISel: select G_EXTRACT and G_INSERT instructions on AArch64.
It revealed a bug in the Localizer pass which has now been fixed.

This includes the fix for SUBREG_TO_REG committed separately last time.

llvm-svn: 308688
2017-07-20 22:58:38 +00:00
Diana Picus 7534b28291 Revert "GlobalISel: select G_EXTRACT and G_INSERT instructions on AArch64."
This reverts commit 36c6a2ea9669bc3bb695928529a85d12d1d3e3f9 because it
broke the test-suite on the GlobalISel bot.

llvm-svn: 308603
2017-07-20 11:36:03 +00:00
Tim Northover 967d4aa7a0 GlobalISel: partially revert r308540.
An unfinished and untested implementation of ISel for G_UNMERGE_VALUES crept in
by mistake.

llvm-svn: 308542
2017-07-19 22:11:08 +00:00
Tim Northover 0e0b3c97dd GlobalISel: fix SUBREG_TO_REG implementation.
The first argument needs to be an immediate rather than a register. Should fix
some crashes in the verifier bot.

llvm-svn: 308540
2017-07-19 22:08:08 +00:00
Tim Northover d59fbec8e2 GlobalISel: select G_EXTRACT and G_INSERT instructions on AArch64.
llvm-svn: 308493
2017-07-19 16:47:07 +00:00
Justin Bogner 4fc696635d GlobalISel: Handle selection of G_IMPLICIT_DEF in AArch64
A generic variant of IMPLICIT_DEF was added in r306875, but this
survives to selection and hits a `Cannot Select`. Add handling that
converts the note to a regular IMPLICIT_DEF.

llvm-svn: 307817
2017-07-12 17:32:32 +00:00
Simon Pilgrim 9e90152363 [AArch64] Fix -Wimplicit-fallthrough warnings. NFCI.
Add breaks - doesn't affect results as both GPR/FPU both check for 32/64 bit sizes. So will still default to GenericOps in the same way.

llvm-svn: 307484
2017-07-08 19:28:24 +00:00
Daniel Sanders 6ab0daade8 [globalisel][tablegen] Partially fix compile-time regressions by converting matcher to state-machine(s)
Summary:
Replace the matcher if-statements for each rule with a state-machine. This
significantly reduces compile time, memory allocations, and cumulative memory
allocation when compiling AArch64InstructionSelector.cpp.o after r303259 is
recommitted.

The following patches will expand on this further to fully fix the regressions.

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

Reviewed By: ab

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

Differential Revision: https://reviews.llvm.org/D33758

llvm-svn: 307079
2017-07-04 14:35:06 +00:00
Daniel Sanders cc36dbf55d [globalisel][tablegen] Add support for EXTRACT_SUBREG.
Summary:
After this patch, we finally have test cases that require multiple
instruction emission.

Depends on D33590

Reviewers: ab, qcolombet, t.p.northover, rovka, kristof.beyls

Subscribers: javed.absar, llvm-commits, igorb

Differential Revision: https://reviews.llvm.org/D33596

llvm-svn: 306388
2017-06-27 10:11:39 +00:00
Daniel Sanders e9fdba39e0 [globalisel][tablegen] Compute available feature bits correctly.
Summary:
Predicate<> now has a field to indicate how often it must be recomputed.
Currently, there are two frequencies, per-module (RecomputePerFunction==0)
and per-function (RecomputePerFunction==1). Per-function predicates are
currently recomputed more frequently than necessary since the only predicate
in this category is cheap to test. Per-module predicates are now computed in
getSubtargetImpl() while per-function predicates are computed in selectImpl().

Tablegen now manages the PredicateBitset internally. It should only be
necessary to add the required includes.

Also fixed a problem revealed by the test case where
constrainSelectedInstRegOperands() would attempt to tie operands that
BuildMI had already tied.

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

Reviewed By: rovka

Subscribers: kristof.beyls, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D32491

llvm-svn: 301750
2017-04-29 17:30:09 +00:00
Daniel Sanders 2deea1878e [globalisel][tablegen] Revise API for ComplexPattern operands to improve flexibility.
Summary:
Some targets need to be able to do more complex rendering than just adding an
operand or two to an instruction. For example, it may need to insert an
instruction to extract a subreg first, or it may need to perform an operation
on the operand.

In SelectionDAG, targets would create SDNode's to achieve the desired effect
during the complex pattern predicate. This worked because SelectionDAG had a
form of garbage collection that would take care of SDNode's that were created
but not used due to a later predicate rejecting a match. This doesn't translate
well to GlobalISel and the churn was wasteful.

The API changes in this patch enable GlobalISel to accomplish the same thing
without the waste. The API is now:
	InstructionSelector::OptionalComplexRendererFn selectArithImmed(MachineOperand &Root) const;
where Root is the root of the match. The return value can be omitted to
indicate that the predicate failed to match, or a function with the signature
ComplexRendererFn can be returned. For example:
	return OptionalComplexRendererFn(
	       [=](MachineInstrBuilder &MIB) { MIB.addImm(Immed).addImm(ShVal); });
adds two immediate operands to the rendered instruction. Immed and ShVal are
captured from the predicate function.

As an added bonus, this also reduces the amount of information we need to
provide to GIComplexOperandMatcher.

Depends on D31418

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

Reviewed By: ab

Subscribers: dberris, kristof.beyls, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D31761

llvm-svn: 301079
2017-04-22 15:11:04 +00:00
Daniel Sanders e7b0d66080 [globalisel][tablegen] Import SelectionDAG's rule predicates and support the equivalent in GIRule.
Summary:
The SelectionDAG importer now imports rules with Predicate's attached via
Requires, PredicateControl, etc. These predicates are implemented as
bitset's to allow multiple predicates to be tested together. However,
unlike the MC layer subtarget features, each target only pays for it's own
predicates (e.g. AArch64 doesn't have 192 feature bits just because X86
needs a lot).

Both AArch64 and X86 derive at least one predicate from the MachineFunction
or Function so they must re-initialize AvailableFeatures before each
function. They also declare locals in <Target>InstructionSelector so that
computeAvailableFeatures() can use the code from SelectionDAG without
modification.

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

Reviewed By: rovka

Subscribers: aemerson, rengolin, dberris, kristof.beyls, llvm-commits, igorb

Differential Revision: https://reviews.llvm.org/D31418

llvm-svn: 300993
2017-04-21 15:59:56 +00:00
Daniel Sanders 419efdd55b Revert r300964 + r300970 - [globalisel][tablegen] Import SelectionDAG's rule predicates and support the equivalent in GIRule.
It's causing llvm-clang-x86_64-expensive-checks-win to fail to compile and I
haven't worked out why. Reverting to make it green while I figure it out.

llvm-svn: 300978
2017-04-21 14:09:20 +00:00
Daniel Sanders 279d03527e [globalisel][tablegen] Import SelectionDAG's rule predicates and support the equivalent in GIRule.
Summary:
The SelectionDAG importer now imports rules with Predicate's attached via
Requires, PredicateControl, etc. These predicates are implemented as
bitset's to allow multiple predicates to be tested together. However,
unlike the MC layer subtarget features, each target only pays for it's own
predicates (e.g. AArch64 doesn't have 192 feature bits just because X86
needs a lot).

Both AArch64 and X86 derive at least one predicate from the MachineFunction
or Function so they must re-initialize AvailableFeatures before each
function. They also declare locals in <Target>InstructionSelector so that
computeAvailableFeatures() can use the code from SelectionDAG without
modification.

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

Reviewed By: rovka

Subscribers: aemerson, rengolin, dberris, kristof.beyls, llvm-commits, igorb

Differential Revision: https://reviews.llvm.org/D31418

llvm-svn: 300964
2017-04-21 10:27:20 +00:00
Aditya Nandakumar 75ad9ccbfa [GISEL]: Move getConstantVReg to Utils
NFCI

llvm-svn: 300751
2017-04-19 20:48:50 +00:00
Daniel Sanders 0b5293f6ae [globalisel][tablegen] Move <Target>InstructionSelector declarations to anonymous namespaces
Summary: This resolves the issue of tablegen-erated includes in the headers for non-GlobalISel builds in a simpler way than before.

Reviewers: qcolombet, ab

Reviewed By: ab

Subscribers: igorb, ab, mgorny, dberris, rovka, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D30998

llvm-svn: 299637
2017-04-06 09:49:34 +00:00
Daniel Sanders bee5739a7c [tablegen][globalisel] Add support for nested instruction matching.
Summary:
Lift the restrictions that prevented the tree walking introduced in the
previous change and add support for patterns like:
  (G_ADD (G_MUL (G_SEXT $src1), (G_SEXT $src2)), $src3) -> SMADDWrrr $dst, $src1, $src2, $src3
Also adds support for G_SEXT and G_ZEXT to support these cases.

One particular aspect of this that I should draw attention to is that I've
tried to be overly conservative in determining the safety of matches that
involve non-adjacent instructions and multiple basic blocks. This is intended
to be used as a cheap initial check and we may add a more expensive check in
the future. The current rules are:
* Reject if any instruction may load/store (we'd need to check for intervening
  memory operations.
* Reject if any instruction has implicit operands.
* Reject if any instruction has unmodelled side-effects.
See isObviouslySafeToFold().

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

Reviewed By: ab

Subscribers: igorb, dberris, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D30539

llvm-svn: 299430
2017-04-04 13:25:23 +00:00
Ahmed Bougacha f0b22c471b [GlobalISel][AArch64] Extract a variable out of an NDEBUG block. NFC.
r298863 used PtrReg, but that's never defined in release builds. Fix it.

llvm-svn: 298869
2017-03-27 18:14:20 +00:00
Ahmed Bougacha f75782f9dc [GlobalISel][AArch64] Fold FI into LDR/STR ui addressing mode.
A majority of loads and stores at O0 access an alloca.

It's trivial to fold the G_FRAME_INDEX into the instruction; do it.

llvm-svn: 298864
2017-03-27 17:31:56 +00:00
Ahmed Bougacha 8a654085d0 [GlobalISel][AArch64] Fold G_GEP into LDR/STR ui addressing mode.
We're not to the point of supporting the load/store patterns yet
(because they extensively use PatFrags).

But in the meantime, we can implement some of the simplest addressing
modes.

llvm-svn: 298863
2017-03-27 17:31:52 +00:00
Ahmed Bougacha 85a66a6d9f [GlobalISel][AArch64] Select store of zero to WZR/XZR.
These occur very frequently, and are quite trivial to catch.

llvm-svn: 298862
2017-03-27 17:31:48 +00:00
Ahmed Bougacha 641cb203b6 [GlobalISel][AArch64] Select CBZ.
CBZ/CBNZ represent a substantial portion of all conditional branches.
Look through G_ICMP to select them.

We can't use tablegen yet because the existing patterns match an
AArch64ISD node.

llvm-svn: 298856
2017-03-27 16:35:31 +00:00
Daniel Sanders 0e64202871 [globalisel] Correct G_CONSTANT path of selectArithImmed()
Earlier stages of GlobalISel always use ConstantInt in G_CONSTANT so that's
what we should check for.

This fixes a crash introduced in r297782.

llvm-svn: 297968
2017-03-16 18:04:50 +00:00