Commit Graph

117 Commits

Author SHA1 Message Date
Simon Pilgrim 3842b94c4e Revert rG57ee0435bd47f23f3939f402914c231b4f65ca5e - [TII] Use optional destination and source pair as a return value; NFC
This is breaking MSVC builds: http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/20375
2019-10-31 18:00:29 +00:00
Djordje Todorovic 57ee0435bd [TII] Use optional destination and source pair as a return value; NFC
Refactor usage of isCopyInstrImpl, isCopyInstr and isAddImmediate methods
to return optional machine operand pair of destination and source
registers.

Patch by Nikola Prica

Differential Revision: https://reviews.llvm.org/D69622
2019-10-31 15:34:49 +01:00
Djordje Todorovic 532815dd5c [ARM][AArch64][DebugInfo] Improve call site instruction interpretation
Extend the describeLoadedValue() with support for target specific ARM and
AArch64 instructions interpretation. The patch provides specialization for
ADD and SUB operations that include a register and an immediate/offset
operand. Some of the instructions can operate with global string addresses
or constant pool indexes but such cases are omitted since we currently lack
flexible support for processing such operands at DWARF production stage.

Patch by Nikola Prica

Differential Revision: https://reviews.llvm.org/D67556
2019-10-30 13:58:14 +01:00
David Stenberg 74a72e6848 [DebugInfo] Stop describing imms in TargetInstrInfo's describeLoadedValue() impl
Summary:
The default implementation of the describeLoadedValue() hook uses the
MoveImm property to determine if an instruction moves an immediate. If
an instruction has that property the function returns the second
operand, assuming that that is the immediate value the instruction
moves. As far as I can tell, the MoveImm property does not imply that
the second operand is the immediate value, nor that any other operand
necessarily holds the immediate value; it just means that the
instruction moves some immediate value.

One example where the second operand is not the immediate is SystemZ's
LZER instruction, which moves a zero immediate implicitly: $f0S = LZER.

That case triggered an out-of-bound assertion when getting the operand.
I have added a test case for that instruction.

Another example is ARM's MVN instruction, which holds the logical
bitwise NOT'd value of the immediate that is moved. For the following
reproducer:

  extern void foo(int);
  int main() { foo(-11); }

an incorrect call site value would be emitted:

  $ clang --target=arm foo.c -O1 -g -Xclang -femit-debug-entry-values \
      -c -o - | ./build/bin/llvm-dwarfdump  - | \
      grep -A2 call_site_parameter

  0x00000058:       DW_TAG_GNU_call_site_parameter
                      DW_AT_location (DW_OP_reg0 R0)
                      DW_AT_GNU_call_site_value (DW_OP_lit10)

Another example is the A2_combineii instruction on Hexagon which moves
two immediates to a super-register: $d0 = A2_combineii 20, 10.

Perhaps these are rare exceptions, and most MoveImm instructions hold
the immediate in the second operand, but in my opinion the default
implementation of the hook should only describe values that it can, by
some contract, guarantee are safe to describe, rather than leaving it up
to the targets to override the exceptions, as that can silently result
in incorrect call site values.

This patch adds X86's relevant move immediate instructions to the
target's hook implementation, so this commit should be a NFC for that
target. We need to do the same for ARM and AArch64.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: vsk

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D69109
2019-10-23 11:41:29 +02:00
Reid Kleckner 0ad6c191de Prune Analysis includes from SelectionDAG.h
Only forward declarations are needed here. Follow-on to r375311.

llvm-svn: 375319
2019-10-19 01:07:48 +00:00
Nikola Prica 98603a8153 [DebugInfo][If-Converter] Update call site info during the optimization
During the If-Converter optimization pay attention when copying or
deleting call instructions in order to keep call site information in
valid state.

Reviewers: aprantl, vsk, efriedma

Reviewed By: vsk, efriedma

Differential Revision: https://reviews.llvm.org/D66955

llvm-svn: 374068
2019-10-08 15:43:12 +00:00
Djordje Todorovic eb4c98ca3d [DebugInfo] Exclude memory location values as parameter entry values
Abandon describing of loaded values due to safety concerns. Loaded
values are described as derefed memory location at caller point.
At callee we can unintentionally change that memory location which
would lead to different entry being printed value before and after
the memory location clobbering. This problem is described in
llvm.org/PR43343.

Patch by Nikola Prica

Differential Revision: https://reviews.llvm.org/D67717

llvm-svn: 373089
2019-09-27 13:52:43 +00:00
Simon Pilgrim 5f2d8b2618 [TargetInstrInfo] Let findCommutedOpIndices take const MachineInstr&
Neither the base implementation of findCommutedOpIndices nor any in-tree target modifies the instruction passed in and there is no reason why they would in the future.

Committed on behalf of @hvdijk (Harald van Dijk)

Differential Revision: https://reviews.llvm.org/D66138

llvm-svn: 372882
2019-09-25 14:55:57 +00:00
Simon Pilgrim 0d6684d7e5 TargetInstrInfo::getStackSlotRange - fix "variable used but never read" analyzer warning. NFCI.
We don't need to divide the BitSize local variable at all.

llvm-svn: 372582
2019-09-23 11:36:24 +00:00
James Molloy 8a74eca398 [MachinePipeliner] Improve the TargetInstrInfo API analyzeLoop/reduceLoopCount
Recommit: fix asan errors.

The way MachinePipeliner uses these target hooks is stateful - we reduce trip
count by one per call to reduceLoopCount. It's a little overfit for hardware
loops, where we don't have to worry about stitching a loop induction variable
across prologs and epilogs (the induction variable is implicit).

This patch introduces a new API:

  /// Analyze loop L, which must be a single-basic-block loop, and if the
  /// conditions can be understood enough produce a PipelinerLoopInfo object.
  virtual std::unique_ptr<PipelinerLoopInfo>
  analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const;

The return value is expected to be an implementation of the abstract class:

  /// Object returned by analyzeLoopForPipelining. Allows software pipelining
  /// implementations to query attributes of the loop being pipelined.
  class PipelinerLoopInfo {
  public:
    virtual ~PipelinerLoopInfo();
    /// Return true if the given instruction should not be pipelined and should
    /// be ignored. An example could be a loop comparison, or induction variable
    /// update with no users being pipelined.
    virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;

    /// Create a condition to determine if the trip count of the loop is greater
    /// than TC.
    ///
    /// If the trip count is statically known to be greater than TC, return
    /// true. If the trip count is statically known to be not greater than TC,
    /// return false. Otherwise return nullopt and fill out Cond with the test
    /// condition.
    virtual Optional<bool>
    createTripCountGreaterCondition(int TC, MachineBasicBlock &MBB,
                                 SmallVectorImpl<MachineOperand> &Cond) = 0;

    /// Modify the loop such that the trip count is
    /// OriginalTC + TripCountAdjust.
    virtual void adjustTripCount(int TripCountAdjust) = 0;

    /// Called when the loop's preheader has been modified to NewPreheader.
    virtual void setPreheader(MachineBasicBlock *NewPreheader) = 0;

    /// Called when the loop is being removed.
    virtual void disposed() = 0;
  };

The Pipeliner (ModuloSchedule.cpp) can use this object to modify the loop while
allowing the target to hold its own state across all calls. This API, in
particular the disjunction of creating a trip count check condition and
adjusting the loop, improves the code quality in ModuloSchedule.cpp.

llvm-svn: 372463
2019-09-21 08:19:41 +00:00
Mitch Phillips 72a3d8597d Revert "[MachinePipeliner] Improve the TargetInstrInfo API analyzeLoop/reduceLoopCount"
This commit broke the ASan buildbot. See comments in rL372376 for more
information.

This reverts commit 15e27b0b6d.

llvm-svn: 372425
2019-09-20 20:25:16 +00:00
James Molloy 15e27b0b6d [MachinePipeliner] Improve the TargetInstrInfo API analyzeLoop/reduceLoopCount
The way MachinePipeliner uses these target hooks is stateful - we reduce trip
count by one per call to reduceLoopCount. It's a little overfit for hardware
loops, where we don't have to worry about stitching a loop induction variable
across prologs and epilogs (the induction variable is implicit).

This patch introduces a new API:

  /// Analyze loop L, which must be a single-basic-block loop, and if the
  /// conditions can be understood enough produce a PipelinerLoopInfo object.
  virtual std::unique_ptr<PipelinerLoopInfo>
  analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const;

The return value is expected to be an implementation of the abstract class:

  /// Object returned by analyzeLoopForPipelining. Allows software pipelining
  /// implementations to query attributes of the loop being pipelined.
  class PipelinerLoopInfo {
  public:
    virtual ~PipelinerLoopInfo();
    /// Return true if the given instruction should not be pipelined and should
    /// be ignored. An example could be a loop comparison, or induction variable
    /// update with no users being pipelined.
    virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;

    /// Create a condition to determine if the trip count of the loop is greater
    /// than TC.
    ///
    /// If the trip count is statically known to be greater than TC, return
    /// true. If the trip count is statically known to be not greater than TC,
    /// return false. Otherwise return nullopt and fill out Cond with the test
    /// condition.
    virtual Optional<bool>
    createTripCountGreaterCondition(int TC, MachineBasicBlock &MBB,
                                 SmallVectorImpl<MachineOperand> &Cond) = 0;

    /// Modify the loop such that the trip count is
    /// OriginalTC + TripCountAdjust.
    virtual void adjustTripCount(int TripCountAdjust) = 0;

    /// Called when the loop's preheader has been modified to NewPreheader.
    virtual void setPreheader(MachineBasicBlock *NewPreheader) = 0;

    /// Called when the loop is being removed.
    virtual void disposed() = 0;
  };

The Pipeliner (ModuloSchedule.cpp) can use this object to modify the loop while
allowing the target to hold its own state across all calls. This API, in
particular the disjunction of creating a trip count check condition and
adjusting the loop, improves the code quality in ModuloSchedule.cpp.

llvm-svn: 372376
2019-09-20 08:57:46 +00:00
David Stenberg 8b70139e95 [NFC] Make the describeLoadedValue() hook return machine operand objects
Summary:
This changes the ParamLoadedValue pair which the describeLoadedValue()
hook returns so that MachineOperand objects are returned instead of
pointers.

When describing call site values we may need to describe operands which
are not part of the instruction. One such example is zero-materializing
XORs on x86, which I have implemented support for in a child revision.
Instead of having to return a pointer to an operand stored somewhere
outside the instruction, start returning objects directly instead, as
that simplifies the code.

The MachineOperand class only holds POD members, and on x86-64 it is 32
bytes large. That combined with copy elision means that the overhead of
returning a machine operand object from the hook does not become very
large.

I benchmarked this on a 8-thread i7-8650U machine with 32 GB RAM. The
benchmark consisted of building a clang 8.0 binary configured with:

  -DCMAKE_BUILD_TYPE=RelWithDebInfo \
  -DLLVM_TARGETS_TO_BUILD=X86 \
  -DLLVM_USE_SANITIZER=Address \
  -DCMAKE_CXX_FLAGS="-Xclang -femit-debug-entry-values -stdlib=libc++"

The average wall clock time increased by 4 seconds, from 62:05 to
62:09, which is an 0.1% increase.

Reviewers: aprantl, vsk, djtodoro, NikolaPrica

Reviewed By: vsk

Subscribers: hiraditya, ychen, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67261

llvm-svn: 371332
2019-09-08 14:05:10 +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
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
Djordje Todorovic b9973f87c6 Reland "[DwarfDebug] Dump call site debug info"
The build failure found after the rL365467 has been
resolved.

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 367446
2019-07-31 16:51:28 +00:00
Djordje Todorovic 0739ccd3b5 Revert "[DwarfDebug] Dump call site debug info"
A build failure was found on the SystemZ platform.

This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc.

llvm-svn: 365886
2019-07-12 09:45:12 +00:00
Djordje Todorovic 01eaae6dd1 [DwarfDebug] Dump call site debug info
Dump the DWARF information about call sites and call site parameters into
debug info sections.

The patch also provides an interface for the interpretation of instructions
that could load values of a call site parameters in order to generate DWARF
about the call site parameters.

([13/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 365467
2019-07-09 11:33:56 +00:00
Djordje Todorovic 71d3869f60 [Backend] Keep call site info valid through the backend
Handle call instruction replacements and deletions in order to preserve
valid state of the call site info of the MachineFunction.

NOTE: If the call site info is enabled for a new target, the assertion from
the MachineFunction::DeleteMachineInstr() should help to locate places
where the updateCallSiteInfo() should be called in order to preserve valid
state of the call site info.

([10/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D61062

llvm-svn: 364536
2019-06-27 13:10:29 +00:00
Matt Arsenault e3a676e9ad CodeGen: Introduce a class for registers
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
2019-06-24 15:50:29 +00:00
Jonas Paulsson fdc4ea34e3 [SystemZ, RegAlloc] Favor 3-address instructions during instruction selection.
This patch aims to reduce spilling and register moves by using the 3-address
versions of instructions per default instead of the 2-address equivalent
ones. It seems that both spilling and register moves are improved noticeably
generally.

Regalloc hints are passed to increase conversions to 2-address instructions
which are done in SystemZShortenInst.cpp (after regalloc).

Since the SystemZ reg/mem instructions are 2-address (dst and lhs regs are
the same), foldMemoryOperandImpl() can no longer trivially fold a spilled
source register since the reg/reg instruction is now 3-address. In order to
remedy this, new 3-address pseudo memory instructions are used to perform the
folding only when the dst and lhs virtual registers are known to be allocated
to the same physreg. In order to not let MachineCopyPropagation run and
change registers on these transformed instructions (making it 3-address), a
new target pass called SystemZPostRewrite.cpp is run just after
VirtRegRewriter, that immediately lowers the pseudo to a target instruction.

If it would have been possibe to insert a COPY instruction and change a
register operand (convert to 2-address) in foldMemoryOperandImpl() while
trusting that the caller (e.g. InlineSpiller) would update/repair the
involved LiveIntervals, the solution involving pseudo instructions would not
have been needed. This is perhaps a potential improvement (see Phabricator
post).

Common code changes:

* A new hook TargetPassConfig::addPostRewrite() is utilized to be able to run a
target pass immediately before MachineCopyPropagation.

* VirtRegMap is passed as an argument to foldMemoryOperand().

Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D60888

llvm-svn: 362868
2019-06-08 06:19:15 +00:00
Ulrich Weigand 6c5d5ce551 Allow target to handle STRICT floating-point nodes
The ISD::STRICT_ nodes used to implement the constrained floating-point
intrinsics are currently never passed to the target back-end, which makes
it impossible to handle them correctly (e.g. mark instructions are depending
on a floating-point status and control register, or mark instructions as
possibly trapping).

This patch allows the target to use setOperationAction to switch the action
on ISD::STRICT_ nodes to Legal. If this is done, the SelectionDAG common code
will stop converting the STRICT nodes to regular floating-point nodes, but
instead pass the STRICT nodes to the target using normal SelectionDAG
matching rules.

To avoid having the back-end duplicate all the floating-point instruction
patterns to handle both strict and non-strict variants, we make the MI
codegen explicitly aware of the floating-point exceptions by introducing
two new concepts:

- A new MCID flag "mayRaiseFPException" that the target should set on any
  instruction that possibly can raise FP exception according to the
  architecture definition.
- A new MI flag FPExcept that CodeGen/SelectionDAG will set on any MI
  instruction resulting from expansion of any constrained FP intrinsic.

Any MI instruction that is *both* marked as mayRaiseFPException *and*
FPExcept then needs to be considered as raising exceptions by MI-level
codegen (e.g. scheduling).

Setting those two new flags is straightforward. The mayRaiseFPException
flag is simply set via TableGen by marking all relevant instruction
patterns in the .td files.

The FPExcept flag is set in SDNodeFlags when creating the STRICT_ nodes
in the SelectionDAG, and gets inherited in the MachineSDNode nodes created
from it during instruction selection. The flag is then transfered to an
MIFlag when creating the MI from the MachineSDNode. This is handled just
like fast-math flags like no-nans are handled today.

This patch includes both common code changes required to implement the
new features, and the SystemZ implementation.

Reviewed By: andrew.w.kaylor

Differential Revision: https://reviews.llvm.org/D55506

llvm-svn: 362663
2019-06-05 22:33:10 +00:00
Matt Arsenault ca64ef2043 MC: Allow getMaxInstLength to depend on the subtarget
Keep it optional in cases this is ever needed in some global
context. Currently it's only used for getting an upper bound inline
asm code size.

For AMDGPU, gfx10 increases the maximum instruction size to
20-bytes. This avoids penalizing older subtargets when estimating code
size, and making some annoying branch relaxation test adjustments.

llvm-svn: 361405
2019-05-22 16:28:41 +00:00
Austin Kerbow 6e6480e216 [CodeGen] Rename DEBUG_TYPE for default hazard recognizer.
Summary:
The DEBUG_TYPE of the default hazard recognizer should be updated to
match the DEBUG_TYPE of the machine-scheduler pass.

Reviewers: rampitec

Reviewed By: rampitec

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61359

llvm-svn: 360198
2019-05-07 22:09:04 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Sander de Smalen c91b27d9ee Remove FrameAccess struct from hasLoadFromStackSlot
This removes the FrameAccess struct that was added to the interface
in D51537, since the PseudoValue from the MachineMemoryOperand
can be safely casted to a FixedStackPseudoSourceValue.

Reviewers: MatzeB, thegameg, javed.absar

Reviewed By: thegameg

Differential Revision: https://reviews.llvm.org/D51617

llvm-svn: 341454
2018-09-05 08:59:50 +00:00
Sander de Smalen 6cab60fa06 Extend hasStoreToStackSlot with list of FI accesses.
For instructions that spill/fill to and from multiple frame-indices
in a single instruction, hasStoreToStackSlot and hasLoadFromStackSlot
should return an array of accesses, rather than just the first encounter
of such an access.

This better describes FI accesses for AArch64 (paired) LDP/STP
instructions.

Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar, MatzeB

Reviewed By: MatzeB

Differential Revision: https://reviews.llvm.org/D51537

llvm-svn: 341301
2018-09-03 09:15:58 +00:00
Chandler Carruth c73c0307fe [MI] Change the array of `MachineMemOperand` pointers to be
a generically extensible collection of extra info attached to
a `MachineInstr`.

The primary change here is cleaning up the APIs used for setting and
manipulating the `MachineMemOperand` pointer arrays so chat we can
change how they are allocated.

Then we introduce an extra info object that using the trailing object
pattern to attach some number of MMOs but also other extra info. The
design of this is specifically so that this extra info has a fixed
necessary cost (the header tracking what extra info is included) and
everything else can be tail allocated. This pattern works especially
well with a `BumpPtrAllocator` which we use here.

I've also added the basic scaffolding for putting interesting pointers
into this, namely pre- and post-instruction symbols. These aren't used
anywhere yet, they're just there to ensure I've actually gotten the data
structure types correct. I'll flesh out support for these in
a subsequent patch (MIR dumping, parsing, the works).

Finally, I've included an optimization where we store any single pointer
inline in the `MachineInstr` to avoid the allocation overhead. This is
expected to be the overwhelmingly most common case and so should avoid
any memory usage growth due to slightly less clever / dense allocation
when dealing with >1 MMO. This did require several ergonomic
improvements to the `PointerSumType` to reasonably support the various
usage models.

This also has a side effect of freeing up 8 bits within the
`MachineInstr` which could be repurposed for something else.

The suggested direction here came largely from Hal Finkel. I hope it was
worth it. ;] It does hopefully clear a path for subsequent extensions
w/o nearly as much leg work. Lots of thanks to Reid and Justin for
careful reviews and ideas about how to do all of this.

Differential Revision: https://reviews.llvm.org/D50701

llvm-svn: 339940
2018-08-16 21:30:05 +00:00
Bjorn Pettersson c8b782cec2 [MC] Remove PhysRegSize from MCRegisterClass
Summary:
The interface to get size and spill size of a register
was moved from MCRegisterInfo to TargetRegisterInfo over
a year ago. Afaik the old interface has bee around
to give out-of-tree targets a chance to adapt to the
new interface.

One problem with the old MCRegisterClass::PhysRegSize was that
it represented the size of a register as "size in bits" / 8.
So a register had to be a multiple of eight bits wide for the
size to be correct (and the byte size for the target needed to
be eight bits).

Reviewers: kparzysz, qcolombet

Reviewed By: kparzysz

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47199

llvm-svn: 339350
2018-08-09 15:19:07 +00:00
Jun Bum Lim 47aece1344 [CodeGen] Use RegUnits to track register aliases (NFC)
Summary: Use RegUnits to track register aliases in PostRASink and AArch64LoadStoreOptimizer.

Reviewers: thegameg, mcrosier, gberry, qcolombet, sebpop, MatzeB, t.p.northover, javed.absar

Reviewed By: thegameg, sebpop

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

Differential Revision: https://reviews.llvm.org/D45695

llvm-svn: 331066
2018-04-27 18:44:37 +00:00
Jun Bum Lim 2ecb7ba4c6 [CodeGen] Add a new pass for PostRA sink
Summary:
This pass sinks COPY instructions into a successor block, if the COPY is not
used in the current block and the COPY is live-in to a single successor
(i.e., doesn't require the COPY to be duplicated).  This avoids executing the
the copy on paths where their results aren't needed.  This also exposes
additional opportunites for dead copy elimination and shrink wrapping.

These copies were either not handled by or are inserted after the MachineSink
pass. As an example of the former case, the MachineSink pass cannot sink
COPY instructions with allocatable source registers; for AArch64 these type
of copy instructions are frequently used to move function parameters (PhyReg)
into virtual registers in the entry block..

For the machine IR below, this pass will sink %w19 in the entry into its
successor (%bb.1) because %w19 is only live-in in %bb.1.

```
   %bb.0:
      %wzr = SUBSWri %w1, 1
      %w19 = COPY %w0
      Bcc 11, %bb.2
    %bb.1:
      Live Ins: %w19
      BL @fun
      %w0 = ADDWrr %w0, %w19
      RET %w0
    %bb.2:
      %w0 = COPY %wzr
      RET %w0
```
As we sink %w19 (CSR in AArch64) into %bb.1, the shrink-wrapping pass will be
able to see %bb.0 as a candidate.

With this change I observed 12% more shrink-wrapping candidate and 13% more dead copies deleted  in spec2000/2006/2017 on AArch64.

Reviewers: qcolombet, MatzeB, thegameg, mcrosier, gberry, hfinkel, john.brawn, twoh, RKSimon, sebpop, kparzysz

Reviewed By: sebpop

Subscribers: evandro, sebpop, sfertile, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D41463

llvm-svn: 328237
2018-03-22 20:06:47 +00:00
Geoff Berry d37dc77b6e [AMDGPU][X86][Mips] Make sure renamable bit not set for reserved regs
Summary:
Fix a few places that were modifying code after register
allocation to set the renamable bit correctly to avoid failing the
validation added in D42449.

llvm-svn: 323675
2018-01-29 18:47:48 +00:00
Matthias Braun ea4359e922 PeepholeOptimizer: Fix for vregs without defs
The PeepholeOptimizer would fail for vregs without a definition. If this
was caused by an undef operand abort to keep the code simple (so we
don't need to add logic everywhere to replicate the undef flag).

Differential Revision: https://reviews.llvm.org/D40763

llvm-svn: 322319
2018-01-11 22:30:43 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
David Blaikie 3f833edc7c Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647
2017-11-08 01:01:31 +00:00
David Blaikie 1be62f0327 Move TargetFrameLowering.h to CodeGen where it's implemented
This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.

This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.

llvm-svn: 317379
2017-11-03 22:32:11 +00:00
Justin Bogner fdf9bf4f16 CodeGen: Minor cleanups to use MachineInstr::getMF. NFC
Since r315388 we have a shorter way to say this, so we'll replace
MI->getParent()->getParent() with MI->getMF() in a few places.

llvm-svn: 315390
2017-10-10 23:50:49 +00:00
Sanjay Patel 232669d6b3 use range-for-loops; NFCI
llvm-svn: 314676
2017-10-02 15:02:06 +00:00
Sanjay Patel 7998d37076 remove duplicate comments, reposition related functions; NFC
llvm-svn: 314669
2017-10-02 14:03:17 +00:00
Alex Bradbury 5518cbfc41 Teach TargetInstrInfo::getInlineAsmLength to parse .space directives with integer arguments
It's currently quite difficult to test passes like branch relaxation, which
requires branches with large displacement to be generated. The .space assembler
directive makes it easy to create arbitrarily large basic blocks, but
getInlineAsmLength is not able to parse it and so the size of the block is not
correctly estimated. Other backends (AArch64, AMDGPU) introduce options just
for testing that artificially restrict the ranges of branch instructions (e.g.
aarch64-tbz-offset-bits). Although parsing a single form of the .space
directive feels inelegant, it does allow a more direct testing approach.

This patch adapts the .space parsing code from
Mips16InstrInfo::getInlineAsmLength and removes it now the extra functionality
is provided by the base implementation. I want to move this functionality to
the generic getInlineAsmLength as 1) I need the same for RISC-V, and 2) I feel
other backends will benefit from more direct testing of large branch
displacements.

Differential Revision: https://reviews.llvm.org/D37798

llvm-svn: 314393
2017-09-28 09:31:46 +00:00
Matthias Braun 55bc9b3f9e TargetInstrInfo: Change duplicate() to work on bundles.
Adds infrastructure to clone whole instruction bundles rather than just
single instructions. This fixes a bug where tail duplication would
unbundle instructions while cloning.

This should unbreak the "Clang Stage 1: cmake, RA, with expensive checks
enabled" build on greendragon. The bot broke with r311139 hitting this
pre-existing bug.

A proper testcase will come next.

llvm-svn: 311511
2017-08-22 23:56:30 +00:00
Krzysztof Parzyszek 44e25f37ae Move size and alignment information of regclass to TargetRegisterInfo
1. RegisterClass::getSize() is split into two functions:
   - TargetRegisterInfo::getRegSizeInBits(const TargetRegisterClass &RC) const;
   - TargetRegisterInfo::getSpillSize(const TargetRegisterClass &RC) const;
2. RegisterClass::getAlignment() is replaced by:
   - TargetRegisterInfo::getSpillAlignment(const TargetRegisterClass &RC) const;

This will allow making those values depend on subtarget features in the
future.

Differential Revision: https://reviews.llvm.org/D31783

llvm-svn: 301221
2017-04-24 18:55:33 +00:00
Hans Wennborg 9b9a5358dd Re-commit r301040 "X86: Don't emit zero-byte functions on Windows"
In addition to the original commit, tighten the condition for when to
pad empty functions to COFF Windows.  This avoids running into problems
when targeting e.g. Win32 AMDGPU, which caused test failures when this
was committed initially.

llvm-svn: 301047
2017-04-21 21:48:41 +00:00
Hans Wennborg 04593000d8 Revert r301040 "X86: Don't emit zero-byte functions on Windows"
This broke almost all bots. Reverting while fixing.

llvm-svn: 301041
2017-04-21 21:10:37 +00:00
Hans Wennborg cb3e810714 X86: Don't emit zero-byte functions on Windows
Empty functions can lead to duplicate entries in the Guard CF Function
Table of a binary due to multiple functions sharing the same RVA,
causing the kernel to refuse to load that binary.

We had a terrific bug due to this in Chromium.

It turns out we were already doing this for Mach-O in certain
situations. This patch expands the code for that in
AsmPrinter::EmitFunctionBody() and renames
TargetInstrInfo::getNoopForMachoTarget() to simply getNoop() since it
seems it was used for not just Mach-O anyway.

Differential Revision: https://reviews.llvm.org/D32330

llvm-svn: 301040
2017-04-21 20:58:12 +00:00
Serge Pavlov 49acf9c8eb Use methods to access data stored with frame instructions
Instructions CALLSEQ_START..CALLSEQ_END and their target dependent
counterparts keep data like frame size, stack adjustment etc. These
data are accessed by getOperand using hard coded indices. It is
error prone way. This change implements the access by special methods,
which improve readability and allow changing data representation without
massive changes of index values.

Differential Revision: https://reviews.llvm.org/D31953

llvm-svn: 300196
2017-04-13 14:10:52 +00:00
Diana Picus 116bbab4e4 [CodeGen] Rename MachineInstrBuilder::addOperand. NFC
Rename from addOperand to just add, to match the other method that has been
added to MachineInstrBuilder for adding more than just 1 operand.

See https://reviews.llvm.org/D28057 for the whole discussion.

Differential Revision: https://reviews.llvm.org/D28556

llvm-svn: 291891
2017-01-13 09:58:52 +00:00
Michael Kuperstein 47eb85a003 [X86] Allow folding of stack reloads when loading a subreg of the spilled reg
We did not support subregs in InlineSpiller:foldMemoryOperand() because targets
may not deal with them correctly.

This adds a target hook to let the spiller know that a target can handle
subregs, and actually enables it for x86 for the case of stack slot reloads.
This fixes PR30832.

Differential Revision: https://reviews.llvm.org/D26521

llvm-svn: 287792
2016-11-23 18:33:49 +00:00
Matthias Braun de8c1b3433 MachineRegisterInfo: Remove unused arg from isConstantPhysReg(); NFC
llvm-svn: 285423
2016-10-28 18:05:09 +00:00
Peter Collingbourne 5c924d7117 Target: Remove unused entities.
llvm-svn: 283690
2016-10-09 04:38:57 +00:00