Commit Graph

88 Commits

Author SHA1 Message Date
Matthias Braun c7c06f158c CodeGen/LLVMTargetMachine: Refactor ISel pass construction; NFCI
- Move ISel (and pre-isel) pass construction into TargetPassConfig
- Extract AsmPrinter construction into a helper function

Putting the ISel code into TargetPassConfig seems a lot more natural and
both changes together make make it easier to build custom pipelines
involving .mir in an upcoming commit. This moves MachineModuleInfo to an
earlier place in the pass pipeline which shouldn't have any effect.

llvm-svn: 304754
2017-06-06 00:26:13 +00:00
Matthias Braun d6a36ae282 TargetMachine: Indicate whether machine verifier passes.
This adds a callback to the LLVMTargetMachine that lets target indicate
that they do not pass the machine verifier checks in all cases yet.

This is intended to be a temporary measure while the targets are fixed
allowing us to enable the machine verifier by default with
EXPENSIVE_CHECKS enabled!

Differential Revision: https://reviews.llvm.org/D33696

llvm-svn: 304320
2017-05-31 18:41:23 +00:00
Matthias Braun 5e394c3d6f TargetPassConfig: Keep a reference to an LLVMTargetMachine; NFC
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
2017-05-30 21:36:41 +00:00
Francis Visoiu Mistrih 8b61764cbb [LegacyPassManager] Remove TargetMachine constructors
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
2017-05-18 17:21:13 +00:00
Dehao Chen 02828a93e8 Only enable LiveRangeShrink for x86.
Summary: Moving LiveRangeShrink to x86 as this pass is mostly useful for archtectures with great register pressure.

Reviewers: MatzeB, qcolombet

Reviewed By: qcolombet

Subscribers: jholewinski, jyknight, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33294

llvm-svn: 303292
2017-05-17 20:18:13 +00:00
Jonas Paulsson 0f8678016f Make sure -optimize-regalloc=false is used correctly by user.
Don't allow -optimize-regalloc=false with -regalloc given for anything other
than 'fast'. The other register allocators depend on the supporting passes
added by addOptimizedRegAlloc().

Reviewers: Quentin Colombet, Matthias Braun
https://reviews.llvm.org/D33181

llvm-svn: 303238
2017-05-17 07:36:03 +00:00
Ayman Musa c5490e5a29 [X86] Relocate code of replacement of subtarget unsupported masked memory intrinsics to run also on -O0 option.
Currently, when masked load, store, gather or scatter intrinsics are used, we check in CodeGenPrepare pass if the subtarget support these intrinsics, if not we replace them with scalar code - this is a functional transformation not an optimization (not optional).

CodeGenPrepare pass does not run when the optimization level is set to CodeGenOpt::None (-O0).

Functional transformation should run with all optimization levels, so here I created a new pass which runs on all optimization levels and does no more than this transformation.

Differential Revision: https://reviews.llvm.org/D32487

llvm-svn: 303050
2017-05-15 11:30:54 +00:00
Dehao Chen 65dd23e273 Add LiveRangeShrink pass to shrink live range within BB.
Summary: LiveRangeShrink pass moves instruction right after the definition with the same BB if the instruction and its operands all have more than one use. This pass is inexpensive and guarantees optimal live-range within BB.

Reviewers: davidxl, wmi, hfinkel, MatzeB, andreadb

Reviewed By: MatzeB, andreadb

Subscribers: hiraditya, jyknight, sanjoy, skatkov, gberry, jholewinski, qcolombet, javed.absar, krytarowski, atrick, spatel, RKSimon, andreadb, MatzeB, mehdi_amini, mgorny, efriedma, davide, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32563

llvm-svn: 302938
2017-05-12 19:29:27 +00:00
Amara Emerson 836b0f48c1 Add a late IR expansion pass for the experimental reduction intrinsics.
This pass uses a new target hook to decide whether or not to expand a particular
intrinsic to the shuffevector sequence.

Differential Revision: https://reviews.llvm.org/D32245

llvm-svn: 302631
2017-05-10 09:42:49 +00:00
Matt Arsenault 7b0d947404 Allow targets to opt-in to codegen in SCC order
Decouple this setting from EnableIRPA.

To support function calls on AMDGPU, it is necessary to
report the global register usage throughout the kernel's
call graph, so callees need to be handled first.

llvm-svn: 299487
2017-04-04 23:44:46 +00:00
Jessica Paquette 596f483a5e [Outliner] Fixed Asan bot failure in r296418
Fixed the asan bot failure which led to the last commit of the outliner being reverted.
The change is in lib/CodeGen/MachineOutliner.cpp in the SuffixTree's constructor. LeafVector
is no longer initialized using reserve but just a standard constructor.

llvm-svn: 297081
2017-03-06 21:31:18 +00:00
Ahmed Bougacha 120ae22d70 [GlobalISel] Add a way for targets to enable GISel.
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
2017-03-01 23:33:08 +00:00
Nemanja Ivanovic b223cfabcc Improve scheduling with branch coalescing
This patch adds a MachineSSA pass that coalesces blocks that branch
on the same condition.

Committing on behalf of Lei Huang.

Differential Revision: https://reviews.llvm.org/D28249

llvm-svn: 296670
2017-03-01 20:29:34 +00:00
Matthias Braun 81f68ec3a9 Revert "Add MIR-level outlining pass"
Revert Machine Outliner for now, as it breaks the asan bot.

This reverts commit r296418.

llvm-svn: 296426
2017-02-28 02:24:30 +00:00
Matthias Braun d36410945f Add MIR-level outlining pass
This is a patch for the outliner described in the RFC at:
http://lists.llvm.org/pipermail/llvm-dev/2016-August/104170.html

The outliner is a code-size reduction pass which works by finding
repeated sequences of instructions in a program, and replacing them with
calls to functions. This is useful to people working in low-memory
environments, where sacrificing performance for space is acceptable.

This adds an interprocedural outliner directly before printing assembly.
For reference on how this would work, this patch also includes X86
target hooks and an X86 test.

The outliner is run like so:

clang -mno-red-zone -mllvm -enable-machine-outliner file.c

Patch by Jessica Paquette<jpaquette@apple.com>!

rdar://29166825

Differential Revision: https://reviews.llvm.org/D26872

llvm-svn: 296418
2017-02-28 00:33:32 +00:00
Kamil Rytarowski 5d2bd8dd54 Revamp llvm::once_flag to be closer to std::once_flag
Summary:
Make this interface reusable similarly to std::call_once and std::once_flag interface.

This makes porting LLDB to NetBSD easier as there was in the original approach a portable way to specify a non-static once_flag. With this change translating std::once_flag to llvm::once_flag is mechanical.

Sponsored by <The NetBSD Foundation>

Reviewers: mehdi_amini, labath, joerg

Reviewed By: mehdi_amini

Subscribers: emaste, clayborg

Differential Revision: https://reviews.llvm.org/D29566

llvm-svn: 294143
2017-02-05 21:13:06 +00:00
Nirav Dave a7c041d147 [X86] Implement -mfentry
Summary: Insert calls to __fentry__ at function entry.

Reviewers: hfinkel, craig.topper

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D28000

llvm-svn: 293648
2017-01-31 17:00:27 +00:00
Matthias Braun e2d2ead661 TargetPassConfig: Rename DisablePostRA -> DisablePostRASched; NFC
llvm-svn: 289003
2016-12-08 00:16:08 +00:00
Matthias Braun 35a024fe0f TargetPassConfig: Move addPass of IPRA RegUsageInfoProp down.
TargetPassConfig::addMachinePasses() does some housekeeping first:
Handling the -print-machineinstrs flag and doing an initial printing
"After Instruction Selection". There is no reason for RegUsageInfoProp
to run before those two steps.

llvm-svn: 285422
2016-10-28 18:05:05 +00:00
Mehdi Amini 732afdd09a Turn cl::values() (for enum) from a vararg function to using C++ variadic template
The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:

 va_start(ValueArgs, Desc);

with Desc being a StringRef.

Differential Revision: https://reviews.llvm.org/D25342

llvm-svn: 283671
2016-10-08 19:41:06 +00:00
Matthias Braun 729c989083 llc: Add -start-before/-stop-before options
Differential Revision: https://reviews.llvm.org/D23089

llvm-svn: 282302
2016-09-23 21:46:02 +00:00
Hal Finkel 40d7f5c277 Add a counter-function insertion pass
As discussed in https://reviews.llvm.org/D22666, our current mechanism to
support -pg profiling, where we insert calls to mcount(), or some similar
function, is fundamentally broken. We insert these calls in the frontend, which
means they get duplicated when inlining, and so the accumulated execution
counts for the inlined-into functions are wrong.

Because we don't want the presence of these functions to affect optimizaton,
they should be inserted in the backend. Here's a pass which would do just that.
The knowledge of the name of the counting function lives in the frontend, so
we're passing it here as a function attribute. Clang will be updated to use
this mechanism.

Differential Revision: https://reviews.llvm.org/D22825

llvm-svn: 280347
2016-09-01 09:42:39 +00:00
Quentin Colombet 1c06a73a7c [TargetPassConfig] Add a hook to tell whether GlobalISel should warm on fallback.
Thanks to this patch, we know have a way to easly see if GlobalISel
failed.

llvm-svn: 280273
2016-08-31 18:43:04 +00:00
Quentin Colombet 0de43b225f [TargetPassConfig] Add a target hook to know what GlobalISel should do on error.
By default, this hook tells GlobalISel to abort (report a fatal error)
when it encounters an error. The alternative will be to fall back on
SDISel.
This fall back will be removed when the bring-up of GlobalISel is over.

llvm-svn: 279879
2016-08-26 22:32:59 +00:00
Alex Bradbury 3447ca3f08 (Trivial) TargetPassConfig: assert when TargetMachine has no MCAsmInfo
Summary:
This is a pretty trivial, but I thought it was worth just checking that nobody feels it's completely the wrong thing to be doing.

The motivation is that when starting a new backend, you often start with a minimal stub, pretty much just FooTargetMachine and FooTargetInfo. Once that's built, you might naturally try `llc -march=foo myinput.ll` and it seems more developer-friendly if this ends up asserting due to the lack of MCAsmInfo with an informative message rather than just segfaulting.

Reviewers: MatzeB, chandlerc

Subscribers: bogner, llvm-commits

Differential Revision: https://reviews.llvm.org/D23443

llvm-svn: 279061
2016-08-18 13:08:58 +00:00
Justin Bogner b03fd12cef Replace "fallthrough" comments with LLVM_FALLTHROUGH
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

llvm-svn: 278902
2016-08-17 05:10:15 +00:00
Dean Michael Berris 52735fc435 XRay: Add entry and exit sleds
Summary:
In this patch we implement the following parts of XRay:

- Supporting a function attribute named 'function-instrument' which currently only supports 'xray-always'. We should be able to use this attribute for other instrumentation approaches.
- Supporting a function attribute named 'xray-instruction-threshold' used to determine whether a function is instrumented with a minimum number of instructions (IR instruction counts).
- X86-specific nop sleds as described in the white paper.
- A machine function pass that adds the different instrumentation marker instructions at a very late stage.
- A way of identifying which return opcode is considered "normal" for each architecture.

There are some caveats here:

1) We don't handle PATCHABLE_RET in platforms other than x86_64 yet -- this means if IR used PATCHABLE_RET directly instead of a normal ret, instruction lowering for that platform might do the wrong thing. We think this should be handled at instruction selection time to by default be unpacked for platforms where XRay is not availble yet.

2) The generated section for X86 is different from what is described from the white paper for the sole reason that LLVM allows us to do this neatly. We're taking the opportunity to deviate from the white paper from this perspective to allow us to get richer information from the runtime library.

Reviewers: sanjoy, eugenis, kcc, pcc, echristo, rnk

Subscribers: niravd, majnemer, atrick, rnk, emaste, bmakam, mcrosier, mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D19904

llvm-svn: 275367
2016-07-14 04:06:33 +00:00
Mehdi Amini cfed2564f7 Add EnableIPRA to TargetOptions, and move the cl::opt -enable-ipra to TargetMachine.cpp
Avoid exposing a cl::opt in a public header and instead promote this
option in the API.
Alternatively, we could land the cl::opt in CommandFlags.h so that
it is available to every tool, but we would still have to find an
option for clang.

llvm-svn: 275348
2016-07-13 23:39:46 +00:00
Mehdi Amini 4beea66232 [IPRA] Set callee saved registers to none for local function when IPRA is enabled.
IPRA try to optimize caller saved register by propagating register
usage information from callee to caller so it is beneficial to have
caller saved registers compare to callee saved registers when IPRA
is enabled. Please find more detailed explanation here
https://groups.google.com/d/msg/llvm-dev/XRzGhJ9wtZg/tjAJqb0eEgAJ.

This change makes local function do not have any callee preserved
register when IPRA is enabled. A simple test case is also added to
verify this change.

Patch by Vivek Pandya <vivekvpandya@gmail.com>

Differential Revision: http://reviews.llvm.org/D21561

llvm-svn: 275347
2016-07-13 23:39:34 +00:00
David Majnemer d9d02d8259 [CodeGen, TargetPassConfig] Remove a race from createRegAllocPass
The createRegAllocPass reads and writes to a global variable 'Registry'
via calls to getDefault and setDefault.  Run this under a call_once to
avoid races.

llvm-svn: 274875
2016-07-08 16:39:00 +00:00
George Burgess IV bfa401e5ad [CFLAA] Split into Anders+Steens analysis.
StratifiedSets (as implemented) is very fast, but its accuracy is also
limited. If we take a more aggressive andersens-like approach, we can be
way more accurate, but we'll also end up being slower.

So, we've decided to split CFLAA into CFLSteensAA and CFLAndersAA.

Long-term, we want to end up in a place where CFLSteens is queried
first; if it can provide an answer, great (since queries are basically
map lookups). Otherwise, we'll fall back to CFLAnders, BasicAA, etc.

This patch splits everything out so we can try to do something like
that when we get a reasonable CFLAnders implementation.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21910

llvm-svn: 274589
2016-07-06 00:26:41 +00:00
Mehdi Amini 1d396832d3 Interprocedural Register Allocation (IPRA): add a Transformation Pass
Adds a MachineFunctionPass that scans the body to find calls, and
update the register mask with the one saved by the
RegUsageInfoCollector analysis in PhysicalRegisterUsageInfo.

Patch by Vivek Pandya <vivekvpandya@gmail.com>

Differential Revision: http://reviews.llvm.org/D21180

llvm-svn: 272414
2016-06-10 18:37:21 +00:00
Mehdi Amini bbacddfe92 Interprocedural Register Allocation (IPRA) Analysis
Add an option to enable the analysis of MachineFunction register
usage to extract the list of clobbered registers.

When enabled, the CodeGen order is changed to be bottom up on the Call
Graph.

The analysis is split in two parts, RegUsageInfoCollector is the
MachineFunction Pass that runs post-RA and collect the list of
clobbered registers to produce a register mask.

An immutable pass, RegisterUsageInfo, stores the RegMask produced by
RegUsageInfoCollector, and keep them available. A future tranformation
pass will use this information to update every call-sites after
instruction selection.

Patch by Vivek Pandya <vivekvpandya@gmail.com>

Differential Revision: http://reviews.llvm.org/D20769

llvm-svn: 272403
2016-06-10 16:19:46 +00:00
Matt Arsenault 8023233afd CodeGen: Allow verifier to run after MachineBlockPlacement
No tests break with this enabled.

llvm-svn: 272340
2016-06-09 23:31:55 +00:00
Matthias Braun f9acacaa92 CodeGen: Refactor renameDisconnectedComponents() as a pass
Refactor LiveIntervals::renameDisconnectedComponents() to be a pass.
Also change the name to "RenameIndependentSubregs":

- renameDisconnectedComponents() worked on a MachineFunction at a time
  so it is a natural candidate for a machine function pass.

- The algorithm is testable with a .mir test now.

- This also fixes a problem where the lazy renaming as part of the
  MachineScheduler introduced IMPLICIT_DEF instructions after the number
  of a nodes in a region were counted leading to a mismatch.

Differential Revision: http://reviews.llvm.org/D20507

llvm-svn: 271345
2016-05-31 22:38:06 +00:00
Derek Schuff 1aaf87e91d Factor PrologEpilogInserter around spilling, frame finalization, and scavenging
PrologEpilogInserter has these 3 phases, which are related, but not
all of them are needed by all targets. This patch reorganizes PEI's
varous functions around those phases for more clear separation. It also
introduces a new TargetMachine hook, usesPhysRegsForPEI, which is true
for non-virtual targets. When it is true, all the phases operate as
before, and PEI requires the AllVRegsAllocated property on
MachineFunctions. Otherwise, CSR spilling and scavenging are skipped and
only prolog/epilog insertion/frame finalization is done.

Differential Revision: http://reviews.llvm.org/D18366

llvm-svn: 269750
2016-05-17 08:49:59 +00:00
Matthias Braun 0663b61e1a TargetPassConfig: Set PrintMachineCode even if addMachinePasses() does not run.
llvm-svn: 269013
2016-05-10 04:51:04 +00:00
Matthias Braun 31d19d43c7 CodeGen: Move TargetPassConfig from Passes.h to an own header; NFC
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
2016-05-10 03:21:59 +00:00