Commit Graph

185 Commits

Author SHA1 Message Date
Nikita Popov 0529e2e018 [InstrInfo] Use 64-bit immediates for analyzeCompare() (NFCI)
The backend generally uses 64-bit immediates (e.g. what
MachineOperand::getImm() returns), so use that for analyzeCompare()
and optimizeCompareInst() as well. This avoids truncation for
targets that support immediates larger 32-bit. In particular, we
can avoid the bugprone value normalization hack in the AArch64
target.

This is a followup to D108076.

Differential Revision: https://reviews.llvm.org/D108875
2021-08-30 19:46:04 +02:00
Kai Luo 1c450c3d7e [PowerPC] Export 16 byte load-store instructions
Export `lq`, `stq`, `lqarx` and `stqcx.` in preparation for implementing 16-byte lock free atomic operations on AIX.
Add a new register class `g8prc` for these instructions, since these instructions require even-odd register pair.

Reviewed By: nemanjai, jsji, #powerpc

Differential Revision: https://reviews.llvm.org/D103010
2021-06-15 01:56:10 +00:00
Fangrui Song 5d44c92bf8 Change void getNoop(MCInst &NopInst) to MCInst getNop()
Prefer (self-documenting) return values to output parameters (which are
liable to be used).
While here, rename Noop to Nop which is more widely used and improves
consistency with hasEmitNops/setEmitNops/emitNop/etc.
2021-03-15 12:05:34 -07:00
Chen Zheng 0ed4cf4bf3 [PowerPC] support register pressure reduction in machine combiner.
Reassociating some patterns to generate more fma instructions to
reduce register pressure.

Reviewed By: jsji

Differential Revision: https://reviews.llvm.org/D92071
2021-01-24 21:28:21 -05:00
Tres Popp 3bd24574c7 Revert "[PowerPC] support register pressure reduction in machine combiner."
This reverts commit 26a396c4ef.

See https://reviews.llvm.org/D92071 for a description of the issue.
2021-01-18 12:01:57 +01:00
Chen Zheng 26a396c4ef [PowerPC] support register pressure reduction in machine combiner.
Reassociating some patterns to generate more fma instructions to
reduce register pressure.

Reviewed By: jsji

Differential Revision: https://reviews.llvm.org/D92071
2021-01-17 23:56:13 -05:00
Esme-Yi 2ea7210e39 Revert "[PowerPC] Extend folding RLWINM + RLWINM to post-RA."
This reverts commit 1c0941e152.
2020-12-16 17:12:24 +00:00
Chen Zheng 4830d458dd [MachineCombiner][NFC] Add MustReduceRegisterPressure goal
add a new goal MustReduceRegisterPressure for machine combiner pass.

PowerPC will use this new goal to do some register pressure related optimization.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D92068
2020-12-14 00:02:42 -05:00
Esme-Yi 1c0941e152 [PowerPC] Extend folding RLWINM + RLWINM to post-RA.
Summary: We have the patterns to fold 2 RLWINMs before RA, while some RLWINM will be generated after RA, for example rGc4690b007743. If the RLWINM generated after RA followed by another RLWINM, we expect to perform the optimization too.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D89855
2020-11-22 07:37:24 +00:00
Baptiste Saleil 37c4ac8545 [PowerPC] Accumulator/Unprimed Accumulator register copy, spill and restore
This patch adds support for accumulator/unprimed accumulator
register copy, spill and restore for MMA.

Authored By: Baptiste Saleil

Reviewed By: #powerpc, bsaleil, amyk

Differential Revision: https://reviews.llvm.org/D90616
2020-11-11 16:23:45 -06:00
Esme-Yi 5053eab890 Revert "[PowerPC] Extend folding RLWINM + RLWINM to post-RA."
This reverts commit 119ab2181e.
2020-11-03 16:34:02 +00:00
Esme-Yi 119ab2181e [PowerPC] Extend folding RLWINM + RLWINM to post-RA.
Summary: This patch depends on D89846. We have the patterns to fold 2 RLWINMs in ppc-mi-peephole, while some RLWINM will be generated after RA, for example rGc4690b007743. If the RLWINM generated after RA followed by another RLWINM, we expect to perform the optimization after RA, too.

Reviewed By: shchenz, steven.zhang

Differential Revision: https://reviews.llvm.org/D89855
2020-11-03 07:44:11 +00:00
Esme-Yi b969dfe26f [NFC][PowerPC] Move the folding RLWINMs from ppc-mi-peephole to PPCInstrInfo.
Summary: We have the patterns to fold 2 RLWINMs in ppc-mi-peephole, while some RLWINM will be generated after RA, for example D88274. If the RLWINM generated after RA followed by another RLWINM, we expect to perform the optimization after RA, too.
This is a NFC patch to move the folding patterns to PPCInstrInfo, and the follow-up works will be calling it in pre-emit-peephole and expand the patterns to handle more cases.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D89846
2020-11-03 06:28:56 +00:00
Nicholas Guy 9a2d2bedb7 Add "SkipDead" parameter to TargetInstrInfo::DefinesPredicate
Some instructions may be removable through processes such as IfConversion,
however DefinesPredicate can not be made aware of when this should be considered.
This parameter allows DefinesPredicate to distinguish these removable instructions
on a per-call basis, allowing for more fine-grained control from processes like
ifConversion.

Renames DefinesPredicate to ClobbersPredicate, to better reflect it's purpose

Differential Revision: https://reviews.llvm.org/D88494
2020-10-21 11:52:47 +01:00
Sean Fertile dfb717da1f [PowerPC] Remove support for VRSAVE save/restore/update.
After removal of Darwin as a PowerPC subtarget, the VRSAVE
save/restore/spill/update code is no longer needed by any supported
subtarget, so remove it while keeping support for vrsave and related instruction
aliases for inline asm. I've pre-commited tests to document the existing vrsave
handling in relation to @llvm.eh.unwind.init and inline asm usage, as
well as a test which shows a beahviour change on AIX related to
returning vector type as we were wrongly emiting VRSAVE_UPDATE on AIX.
2020-09-30 10:05:53 -04:00
David Blaikie ce89eeee16 PPCInstrInfo: Fix readability-inconsistent-declaration-parameter-name clang-tidy warning
Reduces the chance of confusion when calling the function with
autocomplete (will show the more accurate/informative variable name),
etc.
2020-09-13 13:08:17 -07:00
Qiu Chaofan bec81dc67d Reland "[PowerPC] Implement instruction clustering for stores"
Commit 3c0b3250 introduced store fusion for PowerPC target, but it
brought failure under UB sanitizer and was reverted. This patch fixes
them.
2020-09-13 19:51:01 +08:00
Qiu Chaofan 8d9c13f37d Revert "[PowerPC] Implement instruction clustering for stores"
This reverts commit 3c0b325023, (along
with ea795304 and bb39eb9e) since it breaks test with UB sanitizer.
2020-09-08 17:24:08 +08:00
Qiu Chaofan 3c0b325023 [PowerPC] Implement instruction clustering for stores
On Power10, it's profitable to schedule some stores with adjacent target
address together. This patch implements this feature.

Reviewed By: steven.zhang

Differential Revision: https://reviews.llvm.org/D86754
2020-09-08 11:03:09 +08:00
Chen Zheng 4d52ebb9b9 [PowerPC] Make StartMI ignore COPY like instructions.
Reviewed By: lkail

Differential Revision: https://reviews.llvm.org/D85659
2020-08-17 02:12:30 -04:00
Qiu Chaofan dbcfbffc7a [PowerPC] Add intrinsic to read or set FPSCR register
This patch introduces two intrinsics: llvm.ppc.setflm and
llvm.ppc.readflm. They read from or write to FPSCR register
(floating-point status & control) which contains rounding mode and
exception status.

To ensure correctness of program, we need to prevent FP operations from
being moved across these intrinsics (mffs/mtfsf instruction), so here I
set them as scheduling boundaries. We can relax such restriction if
FPSCR is modeled well in the future.

Reviewed By: steven.zhang

Differential Revision: https://reviews.llvm.org/D84914
2020-08-10 18:27:45 +08:00
Jinsong Ji d28f86723f Re-land "[PowerPC] Remove QPX/A2Q BGQ/BGP CNK support"
This reverts commit bf544fa1c3.

Fixed the typo in PPCInstrInfo.cpp.
2020-07-28 14:00:11 +00:00
Jinsong Ji bf544fa1c3 Revert "[PowerPC] Remove QPX/A2Q BGQ/BGP CNK support"
This reverts commit adffce7153.

This is breaking test-suite, revert while investigation.
2020-07-27 21:07:00 +00:00
Jinsong Ji adffce7153 [PowerPC] Remove QPX/A2Q BGQ/BGP CNK support
Per RFC http://lists.llvm.org/pipermail/llvm-dev/2020-April/141295.html
no one is making use of QPX/A2Q/BGQ/BGP CNK anymore.

This patch remove the support of QPX/A2Q in llvm, BGQ/BGP in clang,
CNK support in openmp/polly.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D83915
2020-07-27 19:24:39 +00:00
Chen Zheng 36f9fe2d34 [PowerPC] fixupIsDeadOrKill start and end in different block fixing
In fixupIsDeadOrKill, we assume StartMI and EndMI not exist in same
basic block, so we add an assertion in that function. This is wrong
before RA, as before RA the true definition may exist in another
block through copy like instructions.

Reviewed By: nemanjai

Differential Revision: https://reviews.llvm.org/D83365
2020-07-22 06:27:13 -04:00
Chen Zheng 7ab05d9a60 [PowerPC] fold addi's imm operand to its imm form consumer's displacement
This patch adds a function to do following transformation:

%0:g8rc_and_g8rc_nox0 = ADDI8 %5:g8rc_and_g8rc_nox0, 144
STD killed %7:g8rc, 16, %0:g8rc_and_g8rc_nox0 :: (store 8 into %ir.8)

------>

STD killed %7:g8rc, 160, %5:g8rc_and_g8rc_nox0 :: (store 8 into %ir.8)

Reviewed By: steven.zhang

Differential Revision: https://reviews.llvm.org/D81723
2020-06-23 06:28:18 -04:00
Chen Zheng bd7096b977 [PowerPC] fma chain break to expose more ILP
This patch tries to reassociate two patterns related to FMA to expose
more ILP on PowerPC.

// Pattern 1:
//   A =  FADD X,  Y          (Leaf)
//   B =  FMA  A,  M21,  M22  (Prev)
//   C =  FMA  B,  M31,  M32  (Root)
// -->
//   A =  FMA  X,  M21,  M22
//   B =  FMA  Y,  M31,  M32
//   C =  FADD A,  B

// Pattern 2:
//   A =  FMA  X,  M11,  M12  (Leaf)
//   B =  FMA  A,  M21,  M22  (Prev)
//   C =  FMA  B,  M31,  M32  (Root)
// -->
//   A =  FMUL M11,  M12
//   B =  FMA  X,  M21,  M22
//   D =  FMA  A,  M31,  M32
//   C =  FADD B,  D

Reviewed By: jsji

Differential Revision: https://reviews.llvm.org/D80175
2020-06-15 00:00:04 -04:00
Chen Zheng 9b6e86a1a5 [PowerPC] refactor convertToImmediateForm - NFC
This is a NFC patch to make convertToImmediateForm a light wrapper
for converting xform and imm form instructions on PowerPC.

Reviewed By: Steven.zhang

Differential Revision: https://reviews.llvm.org/D80907
2020-06-12 03:57:54 -04:00
Lei Huang 2e6e27583c [PowerPC][NFC] Cleanup load/store spilling code
Summary: Cleanup and commonize code used for spilling to the stack.

Reviewers: stefanp, nemanjai, #powerpc, kamaub

Reviewed By: nemanjai, #powerpc, kamaub

Subscribers: kamaub, hiraditya, wuzish, shchenz, llvm-commits, kbarton

Tags: #llvm, #powerpc

Differential Revision: https://reviews.llvm.org/D79736
2020-05-19 14:57:32 -05:00
Chen Zheng 9971839942 fix build failure due to commit rGddcb3cf213e8 2020-05-18 21:47:40 -04:00
Kamau Bridgeman cd83333fc8 [PowerPC] Fold redundant load immediates of zero and delete if possible
This patch folds redundant load immediates into a zero for instructions
which recognise this as the value zero and not the register. If the load
immediate is no longer in use it is then deleted.

This is already done in earlier passes but the ppc-mi-peephole allows for
a more general implementation.

Differential Revision: https://reviews.llvm.org/D69168
2020-05-12 13:15:06 -05:00
Nick Desaulniers 1b9fdec1f6 [TII] remove overrides of isUnpredicatedTerminator
Summary:
They all match the base implementation in
TargetInstrInfo::isUnpredicatedTerminator.

Follow up to D62749.

Reviewers: echristo, MaskRay, hfinkel

Reviewed By: echristo

Subscribers: wuzish, nemanjai, hiraditya, kbarton, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78976
2020-04-28 08:47:28 -07:00
Chen Zheng 45d92806ea [PowerPC] use inst-level fast-math-flags to drive MachineCombiner
Currently, on PowerPC target, it uses function scope UnsafeFPMath
option to drive Machine Combiner pass.

This is not accurate in two ways:
1: the scope is not accurate. Machine Combiner pass only requires
   instruction-level flags instead of the function scope.
2: the float point flag is not accurate. Machine Combiner pass
   only requires float point flags reassoc and nsz.

Reviewed By: steven.zhang

Differential Revision: https://reviews.llvm.org/D78183
2020-04-28 03:31:12 -04:00
Matt Arsenault 30ebafaa56 CodeGen: Convert some TII hooks to use Register 2020-04-03 14:52:54 -04:00
Nemanja Ivanovic 26bf877ec5 [PowerPC] Fix spilling of vector registers in PEI of EH aware functions
On little endian targets prior to Power9, we spill vector registers using a
swapping store (i.e. stdxvd2x saves the vector with the two doublewords in
big endian order regardless of endianness). This is generally not a problem
since we restore them using the corresponding swapping load (lxvd2x). However
if the restore is done by the unwinder, the vector register contains data in
the incorrect order.

This patch fixes that by using Altivec loads/stores for vector saves and
restores in PEI (which keep the order correct) under those specific conditions:
- EH aware function
- Subtarget requires swaps for VSX memops (Little Endian prior to Power9)

Differential revision: https://reviews.llvm.org/D73692
2020-02-07 14:41:52 -06:00
Simon Moll 5c8ba508b2 [NFC] unsigned->Register in storeRegTo/loadRegFromStack
Summary:
This patch makes progress on the 'unsigned -> Register' rewrite for
`TargetInstrInfo::loadRegFromStack` and `TII::storeRegToStack`.

Reviewers: arsenm, craig.topper, uweigand, jpienaar, atanasyan, venkatra, robertlytton, dylanmckay, t.p.northover, kparzysz, tstellar, k-ishizaka

Reviewed By: arsenm

Subscribers: wuzish, merge_guards_bot, jyknight, sdardis, nemanjai, jvesely, wdng, nhaehnle, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73870
2020-02-03 14:22:16 +01:00
Stefan Pintilie f00be8da62 [PowerPC][Future] Prefixed Instructions 64 Byte Boundary Support
A known limitation for Future CPU is that the new prefixed instructions may
not cross 64 Byte boundaries.

All instructions are already 4 byte aligned so the only situation where this
can occur is when the prefix is in one 64 byte block and the instruction that
is prefixed is at the top of the next 64 byte block. To fix this case
PPCELFStreamer was added to intercept EmitInstruction. When a prefixed
instruction is emitted we try to align it to 64 Bytes by adding a maximum of
4 bytes. If the prefixed instruction crosses the 64 Byte boundary then the
alignment would trigger and a 4 byte nop would be added to push the
instruction into the next 64 byte block.

Differential Revision: https://reviews.llvm.org/D72570
2020-01-30 06:52:30 -06:00
Victor Huang 5cee34013c [PowerPC][Future] Add prefixed instruction paddi to future CPU
Future CPU will include support for prefixed instructions.
These prefixed instructions are formed by a 4 byte prefix
immediately followed by a 4 byte instruction effectively
making an 8 byte instruction. The new instruction paddi
is a prefixed form of addi.

This patch adds paddi and all of the support required
for that instruction. The majority of the patch deals with
supporting the new prefixed instructions. The addition of
paddi is mainly to allow for testing.

Differential Revision: https://reviews.llvm.org/D72569
2020-01-24 07:27:25 -06:00
Amara Emerson 67a8775322 [AArch64] Don't generate gpr CSEL instructions in early-ifcvt if regclasses aren't compatible.
In GlobalISel we may in some unfortunate circumstances generate PHIs with
operands that are on separate banks. If-conversion doesn't currently check for
that case and ends up generating a CSEL on AArch64 with incorrect register
operands.

Differential Revision: https://reviews.llvm.org/D72961
2020-01-21 16:51:31 -08:00
Jinsong Ji d7032bc3c0 [PowerPC][NFC] Reclaim TSFlags bit 6
We removed UseVSXReg flag in https://reviews.llvm.org/D58685
But we did not reclain the bit 6 it was assigned,
this will become confusing and a hole later..
We should reclaim it as early as possible before new bits.

Reviewed By: sfertile

Differential Revision: https://reviews.llvm.org/D72649
2020-01-21 15:04:05 +00:00
Qiu Chaofan 45c4b08d82 [NFC] [PowerPC] Add isPredicable for basic instrs
PowerPC uses a dedicated method to check if the machine instr is
predicable by opcode. However, there's a bit `isPredicable` in instr
definition. This patch removes the method and set the bit only to
opcodes referenced in it.

Differential Revision: https://reviews.llvm.org/D71921
2020-01-10 16:48:44 +08:00
Matt Arsenault e6c9a9af39 Use MCRegister in copyPhysReg 2019-11-11 14:42:33 +05:30
czhengsz 822059147b [PowerPC] [Peephole] fold frame offset by using index form to save add.
renamable $x6 = ADDI8 $x1, -80      ;;; 0 is replaced with -80
renamable $x6 = ADD8 killed renamable $x6, renamable $x5
STW killed renamable $r3, 4, killed renamable $x6 :: (store 4 into %ir.14, !tbaa !2)

After PEI there is a peephole opt opportunity to combine above -80 in ADDI8 with 4 in the STW to eliminate unnecessary ADD8.

Expected result:
renamable $x6 = ADDI8 $x1, -76
STWX killed renamable $r3, renamable $x5, killed renamable $x6 :: (store 4 into %ir.6, !tbaa !2)

Reviewed by: stefanp

Differential Revision: https://reviews.llvm.org/D66329
2019-10-25 04:13:30 -04:00
Reid Kleckner 1d7b41361f Prune two MachineInstr.h includes, fix up deps
MachineInstr.h included AliasAnalysis.h, which includes a world of IR
constructs mostly unneeded in CodeGen. Prune it. Same for
DebugInfoMetadata.h.

Noticed with -ftime-trace.

llvm-svn: 375311
2019-10-19 00:22:07 +00:00
Changpeng Fang f5524f0451 Remove the AliasAnalysis argument in function areMemAccessesTriviallyDisjoint
Reviewers:
  arsenm

Differential Revision:
  https://reviews.llvm.org/D58360

llvm-svn: 373024
2019-09-26 22:53:44 +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
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
Kai Luo 985e52a4c1 [PowerPC][NFC] Make `getDefMIPostRA` public
llvm-svn: 366995
2019-07-25 08:36:44 +00:00