This patch contains a pass that transforms CBZ/CBNZ/TBZ/TBNZ instructions into a
conditional branch (Bcc), when the NZCV flags can be set for "free". This is
preferred on targets that have more flexibility when scheduling Bcc
instructions as compared to CBZ/CBNZ/TBZ/TBNZ (assuming all other variables are
equal). This can reduce register pressure and is also the default behavior for
GCC.
A few examples:
add w8, w0, w1 -> cmn w0, w1 ; CMN is an alias of ADDS.
cbz w8, .LBB_2 -> b.eq .LBB0_2 ; single def/use of w8 removed.
add w8, w0, w1 -> adds w8, w0, w1 ; w8 has multiple uses.
cbz w8, .LBB1_2 -> b.eq .LBB1_2
sub w8, w0, w1 -> subs w8, w0, w1 ; w8 has multiple uses.
tbz w8, #31, .LBB6_2 -> b.ge .LBB6_2
In looking at all current sub-target machine descriptions, this transformation
appears to be either positive or neutral.
Differential Revision: https://reviews.llvm.org/D34220.
llvm-svn: 306144
TargetPassConfig is not useful for targets that do not use the CodeGen
library, so we may just as well store a pointer to an
LLVMTargetMachine instead of just to a TargetMachine.
While at it, also change the constructor to take a reference instead of a
pointer as the TM must not be nullptr.
llvm-svn: 304247
Summary:
This patch makes instruction fusion more aggressive by
* adding artificial edges between the successors of FirstSU and
SecondSU, similar to BaseMemOpClusterMutation::clusterNeighboringMemOps.
* updating PostGenericScheduler::tryCandidate to keep clusters together,
similar to GenericScheduler::tryCandidate.
This change increases the number of AES instruction pairs generated on
Cortex-A57 and Cortex-A72. This doesn't change code at all in
most benchmarks or general code, but we've seen improvement on kernels
using AESE/AESMC and AESD/AESIMC.
Reviewers: evandro, kristof.beyls, t.p.northover, silviu.baranga, atrick, rengolin, MatzeB
Reviewed By: evandro
Subscribers: aemerson, rengolin, MatzeB, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33230
llvm-svn: 303618
Summary:
This causes them to be re-computed more often than necessary but resolves
objections that were raised post-commit on r301750.
Reviewers: qcolombet, ab, t.p.northover, rovka, kristof.beyls
Reviewed By: qcolombet
Subscribers: igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D32861
llvm-svn: 303418
This provides a new way to access the TargetMachine through
TargetPassConfig, as a dependency.
The patterns replaced here are:
* Passes handling a null TargetMachine call
`getAnalysisIfAvailable<TargetPassConfig>`.
* Passes not handling a null TargetMachine
`addRequired<TargetPassConfig>` and call
`getAnalysis<TargetPassConfig>`.
* MachineFunctionPasses now use MF.getTarget().
* Remove all the TargetMachine constructors.
* Remove INITIALIZE_TM_PASS.
This fixes a crash when running `llc -start-before prologepilog`.
PEI needs StackProtector, which gets constructed without a TargetMachine
by the pass manager. The StackProtector pass doesn't handle the case
where there is no TargetMachine, so it segfaults.
Related to PR30324.
Differential Revision: https://reviews.llvm.org/D33222
llvm-svn: 303360
Summary:
Remove the AArch64AddressTypePromotion pass as we migrated all transformations
done in this pass into CGP in r299379.
Reviewers: qcolombet, jmolloy, javed.absar, mcrosier
Reviewed By: qcolombet
Subscribers: aemerson, rengolin, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D31623
llvm-svn: 302245
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
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
Summary:
Move the aarch64-type-promotion pass within the existing type promotion framework in CGP.
This change also support forking sexts when a new sext is required for promotion.
Note that change is based on D27853 and I am submitting this out early to provide a better idea on D27853.
Reviewers: jmolloy, mcrosier, javed.absar, qcolombet
Reviewed By: qcolombet
Subscribers: llvm-commits, aemerson, rengolin, mcrosier
Differential Revision: https://reviews.llvm.org/D28680
llvm-svn: 299379
Until now, we've had to use -global-isel to enable GISel. But using
that on other targets that don't support it will result in an abort, as we
can't build a full pipeline.
Additionally, we want to experiment with enabling GISel by default for
some targets: we can't just enable GISel by default, even among those
target that do have some support, because the level of support varies.
This first step adds an override for the target to explicitly define its
level of support. For AArch64, do that using
a new command-line option (I know..):
-aarch64-enable-global-isel-at-O=<N>
Where N is the opt-level below which GISel should be used.
Default that to -1, so that we still don't enable GISel anywhere.
We're not there yet!
While there, remove a couple LLVM_UNLIKELYs. Building the pipeline is
such a cold path that in practice that shouldn't matter at all.
llvm-svn: 296710
This feature enables the fusion of such operations on Cortex A57, as
recommended in its Software Optimisation Guide, sections 4.14 and 4.15.
Differential revision: https://reviews.llvm.org/D28698
llvm-svn: 293739
This patch moves the class for scheduling adjacent instructions,
MacroFusion, to the target.
In AArch64, it also expands the fusion to all instructions pairs in a
scheduling block, beyond just among the predecessors of the branch at the
end.
Differential revision: https://reviews.llvm.org/D28489
llvm-svn: 293737
Summary:
Adds a RegisterBank tablegen class that can be used to declare the register
banks and an associated tablegen pass to generate the necessary code.
Changes since first commit attempt:
* Added missing guards
* Added more missing guards
* Found and fixed a use-after-free bug involving Twine locals
Reviewers: t.p.northover, ab, rovka, qcolombet
Reviewed By: qcolombet
Subscribers: aditya_nandakumar, rengolin, kristof.beyls, vkalintiris, mgorny, dberris, llvm-commits, rovka
Differential Revision: https://reviews.llvm.org/D27338
llvm-svn: 292478
MachineLegalizer used to be the name of both the class and the member,
causing GCC errors. r276522 fixed that by renaming the member to just
'Legalizer'. The 'class' workaround isn't necessary anymore; drop it.
llvm-svn: 289848
This makes the createGenericSchedLive() function that constructs the
default scheduler available for the public API. This should help when
you want to get a scheduler and the default list of DAG mutations.
This also shrinks the list of default DAG mutations:
{Load|Store}ClusterDAGMutation and MacroFusionDAGMutation are no longer
added by default. Targets can easily add them if they need them. It also
makes it easier for targets to add alternative/custom macrofusion or
clustering mutations while staying with the default
createGenericSchedLive(). It also saves the callback back and forth in
TargetInstrInfo::enableClusterLoads()/enableClusterStores().
Differential Revision: https://reviews.llvm.org/D26986
llvm-svn: 288057
Doing this before register allocation reduces register pressure as we do
not even have to allocate a register for those dead definitions.
Differential Revision: https://reviews.llvm.org/D26111
llvm-svn: 287076
Summary:
Add relocations for AArch64 ILP32. Includes:
- Addition of definitions for R_AARCH32_*
- Definition of new -target-abi: ilp32
- Definition of data layout string
- Tests for added relocations. Not comprehensive, but matches
existing tests for 64-bit. Renames "CHECK-OBJ" to "CHECK-OBJ-LP64".
- Tests for llvm-readobj
Reviewers: zatrazz, peter.smith, echristo, t.p.northover
Subscribers: aemerson, rengolin, mehdi_amini
Differential Revision: https://reviews.llvm.org/D25159
llvm-svn: 284973
The previous names were both misleading (the MachineLegalizer actually
contained the info tables) and inconsistent with the selector & translator (in
having a "Machine") prefix. This should make everything sensible again.
The only functional change is the name of a couple of command-line options.
llvm-svn: 284287
Avoid generating indexed vector instructions for Exynos. This is needed for
fmla/fmls/fmul/fmulx. For example, the instruction
fmla v0.4s, v1.4s, v2.s[1]
is less efficient than the instructions
dup v2.4s, v2.s[1]
fmla v0.4s, v1.4s, v2.4s
Patch written by Abderrazek Zaafrani.
Differential Revision: https://reviews.llvm.org/D21571
llvm-svn: 283663
This reverts commit b7d42b0048f65346e9fa37fb65defeea7ce8c337 per request by
Eric Christopher <echristo@gmail.com> (v. http://bit.ly/2cmz6kW).
llvm-svn: 282000
Initialize all AArch64-specific passes in the TargetMachine so they can be run
by llc. This can lead to conflicts in opt with some command line options that
share the same name as the pass, so I took this opportunity to do some cleanups:
* rename all relevant command line options from "aarch64-blah" to
"aarch64-enable-blah" and update the tests accordingly
* run clang-format on their declarations
* move all these declarations to a common place (the TargetMachine) as opposed
to having them scattered around (AArch64BranchRelaxation and
AArch64AddressTypePromotion were the only offenders)
llvm-svn: 277322
This adds the actual MachineLegalizeHelper to do the work and a trivial pass
wrapper that legalizes all instructions in a MachineFunction. Currently the
only transformation supported is splitting up a vector G_ADD into one acting on
smaller vectors.
llvm-svn: 276461
The commit reinstates r273279, which was informally approved.
Original Review: http://reviews.llvm.org/D21414
This reverts commit ca632c91aaa7cafc50942f890c49f727a046ace1.
llvm-svn: 274790
Testing for specific CPUs has a number of problems, better use subtarget
features:
- When some tweak is added for a specific CPU it is often desirable for
the next version of that CPU as well, yet we often forget to add it.
- It is hard to keep track of checks scattered around the target code;
Declaring all target specifics together with the CPU in the tablegen
file is a clear representation.
- Subtarget features can be tweaked from the command line.
To discourage people from using CPU checks in the future I removed the
isCortexXX(), isCyclone(), ... functions. I added an getProcFamily()
function for exceptional circumstances but made it clear in the comment
that usage is discouraged.
Reformat feature list in AArch64.td to have 1 feature per line in
alphabetical order to simplify merging and sorting for out of tree
tweaks.
No functional change intended.
Differential Revision: http://reviews.llvm.org/D20762
llvm-svn: 271555
Having an enum member named Default is quite confusing: Is it distinct
from the others?
This patch removes that member and instead uses Optional<Reloc> in
places where we have a user input that still hasn't been maped to the
default value, which is now clear has no be one of the remaining 3
options.
llvm-svn: 269988
Many files include Passes.h but only a fraction needs to know about the
TargetPassConfig class. Move it into an own header. Also rename
Passes.cpp to TargetPassConfig.cpp while we are at it.
llvm-svn: 269011
This patch adds support for estimating the square root, its reciprocal and
division or reciprocal using the combiner generic reciprocal machinery.
llvm-svn: 268539
Rework the access to GlobalISel APIs to contain how much of
the APIs we need to access for the final executable to build when
GlobalISel is not built.
This prevents massive usage of ifdefs in various places. Now, all the
GlobalISel ifdefs will be happing only in AArch64TargetMachine.cpp.
llvm-svn: 265567
Summary:
This wires up the pass for Cyclone but keeps it off for now because we
need a few more TTIs.
The getPrefetchMinStride value is not very well tuned right now but it
works well with CFP2006/433.milc which motivated this.
Tests will be added as part of the upcoming large-stride prefetching
patch.
Reviewers: t.p.northover
Subscribers: llvm-commits, aemerson, hfinkel, rengolin
Differential Revision: http://reviews.llvm.org/D17943
llvm-svn: 263770
Summary:
This change will add a pass to remove unnecessary zero copies in target blocks
of cbz/cbnz instructions. E.g., the copy instruction in the code below can be
removed because the cbz jumps to BB1 when x0 is zero :
BB0:
cbz x0, .BB1
BB1:
mov x0, xzr
Jun
Reviewers: gberry, jmolloy, HaoLiu, MatzeB, mcrosier
Subscribers: mcrosier, mssimpso, haicheng, bmakam, llvm-commits, aemerson, rengolin
Differential Revision: http://reviews.llvm.org/D16203
llvm-svn: 261004
Chad Rosier