[llvm] r265388 - Adds the ability to use an epilog remainder loop during loop unrolling and makes
Mikhail Zolotukhin via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 21 11:57:51 PDT 2016
> On Jul 21, 2016, at 11:36 AM, Evgeny Stupachenko <evstupac at gmail.com> wrote:
>
> Hi Michael,
Hi Evgeny,
>
> Turning back to default will decrease LSR positive effect.
When the LSR changes are committed, we certainly can switch it back.
> As for the test itself. It does not represent a real case.
I won't argue that, though the "real case" is a very vague term. What matters is that this test is currently in the testsuite.
> Global arrays with big amount of data are not ok.
> If we switch to malloc instead, the regression disappears.
The problem here is that we have a big regression with this change, and it's not addressed so far. It might be a test issue or an LSR issue, but whatever it is, we need to address it, and if it takes too long, turn it back off until it's fixed.
Thanks,
Michael
> I'd better modify the test or exclude it.
>
> Thanks,
> Evgeny
>
> On Wed, Jul 20, 2016 at 1:06 PM, Michael Zolotukhin
> <mzolotukhin at apple.com> wrote:
>> Hi Evgeny,
>>
>> Thanks for the detailed update! After a second thought - can we please switch the default to the previous value while you’re working on the patch? Generally, it’s bad to have such a big regression even though your original patch just exposed an issue in another place.
>>
>> Thanks,
>> Michael
>>> On Jul 11, 2016, at 9:08 PM, Evgeny Stupachenko <evstupac at gmail.com> wrote:
>>>
>>> Hi Michael,
>>>
>>> The patch is under internal review. It changes a lot. I plan to send
>>> it here this month or in August.
>>> The patch fixes addressing, but not the regression.
>>> We looked into the regression itself on simulator. It appears that the
>>> big issue is branch misprediction.
>>>
>>> Regarding addresses.
>>> When we have prolog (with unroll on 2):
>>>
>>> for_body
>>> i = phi [i.next, i0]; //i0 is 0 or 1 depending on the prolog execution
>>> x = *(array + i);
>>> ...
>>> cmp i, N
>>> br for_body
>>>
>>> LSR is trying to simplify ind vars to one.
>>> lsr.i = phi [lsr.i.next, 0];
>>> or
>>> lsr.i = phi [lsr.i.next, -N];
>>> That way array access will have base: “array + i0” or “array + i0 - N”
>>> which is not static even if array is static.
>>>
>>> x = *((array + i0) + lsr.i);
>>>
>>> So it will require a register inside loop. Right now number of
>>> registers has the highest priority in LSR when it chooses a solution.
>>>
>>> When we have epilog, the same access is without “i0”
>>>
>>> x = *(array + lsr.i);
>>>
>>> If array is static we do not need an additional register.
>>> In the test where regression occurred the array is static and N is constant.
>>>
>>> However if we have enough registers we can use register instead of
>>> constant address. The patch should address this.
>>>
>>> Thanks,
>>> Evgeny
>>>
>>> On Mon, Jul 11, 2016 at 6:04 PM, Michael Zolotukhin
>>> <mzolotukhin at apple.com> wrote:
>>>>
>>>>> On Apr 22, 2016, at 11:35 AM, Michael Zolotukhin <mzolotukhin at apple.com> wrote:
>>>>>
>>>>>
>>>>>> On Apr 20, 2016, at 4:43 PM, Evgeny Stupachenko <evstupac at gmail.com> wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> Yes if the test is that important. However I believe that the
>>>>>> regression caused randomly, but not by epilog unrolling.
>>>>>> On my Corei7 "I was able to reproduce it only in 32 bit mode, 64 bit
>>>>>> mode epilog is ~30% faster.".
>>>>>> The analysis showed no critical changes in the hottest loop.
>>>>>>
>>>>>> As for LSR issue.
>>>>>> Sorry for missing your request for posting PR. I'm preparing LSR patch
>>>>>> fixing the issue. And issue itself is related to already filed PR23384
>>>>>> (on an inefficient x86 LSR transformation).
>>>> Hi Evgeny,
>>>>
>>>> Is there any progress with the LSR patch? Or is there something blocking you?
>>>>
>>>> Thanks,
>>>> Michael
>>>>> Hi Evgeny,
>>>>>
>>>>> It’s fine with me to keep it on, I just want to make sure we address the regression. So, if you’re working on the patch, there are no concerns from my side.
>>>>>
>>>>> Thanks,
>>>>> Michael
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Evgeny
>>>>>>
>>>>>> On Wed, Apr 20, 2016 at 11:41 AM, Michael Zolotukhin
>>>>>> <mzolotukhin at apple.com> wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Could we change the default value to the original one until this 90%
>>>>>>> regression is addressed?
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Michael
>>>>>>>
>>>>>>> On Apr 15, 2016, at 12:37 PM, Mikhail Zolotukhin <mzolotukhin at apple.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>> On Apr 8, 2016, at 5:39 PM, Evgeny Stupachenko <evstupac at gmail.com> wrote:
>>>>>>>
>>>>>>> Investigation showed that the regression is most likely LSR related,
>>>>>>> but not loop unroll.
>>>>>>> I was able to reproduce it only in 32 bit mode, 64 bit mode epilog is
>>>>>>> ~30% faster.
>>>>>>>
>>>>>>> Going back to the changes in the test. Epilog variant has 1 move more
>>>>>>> in the hottest loop (which is redundant and should be deleted) and use
>>>>>>> constant address in moves inside the loop. However manual deleting of
>>>>>>> the move does not give any significant performance gain.
>>>>>>> The different behavior of LSR comes from additional inductive variable
>>>>>>> in unrolled loop. For Epilog case we add "k" (supposed to be
>>>>>>> eliminated after LSR):
>>>>>>>
>>>>>>> k = n - n % (unroll factor));
>>>>>>> ...
>>>>>>> access a[i];
>>>>>>> i++;
>>>>>>> k--;
>>>>>>> if (!k) break;
>>>>>>>
>>>>>>> Moving code of the loop modifying "palign" before loop showed up to 2
>>>>>>> times perf difference. So most likely epilog unroll itself does not
>>>>>>> influence on performance here.
>>>>>>> However, the fact that LSR leave constant address inside the loop
>>>>>>> moves (making them much longer), should be addressed to LSR. I'll
>>>>>>> submit a bug report on this.
>>>>>>>
>>>>>>> Hi Evgeny,
>>>>>>>
>>>>>>> Could you please post the PR number here as well?
>>>>>>>
>>>>>>> Michael
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Apr 8, 2016 at 2:09 PM, Evgeny Stupachenko <evstupac at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>> Hi Michael,
>>>>>>>
>>>>>>> Yes I do have the data.
>>>>>>> There were ~10% improvements on some EEMBC tests; spec2000 performance
>>>>>>> was almost flat (within 2%).
>>>>>>>
>>>>>>> Let me look into BubbleSort case and come back with analysis and
>>>>>>> possible improvement.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Evgeny
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Apr 8, 2016 at 1:23 PM, Michael Zolotukhin via llvm-commits
>>>>>>> <llvm-commits at lists.llvm.org> wrote:
>>>>>>>
>>>>>>> Hi Evgeny,
>>>>>>>
>>>>>>> We’ve found several performance regressions on LLVM testsuite caused by this
>>>>>>> patch. Do you have a data from your performance experiments to back-up the
>>>>>>> decision to make epilogues the default strategy?
>>>>>>>
>>>>>>> One of the biggest regressions we see is 89% on
>>>>>>> SingleSource/Benchmarks/Stanford/Bubblesort (on x86), while the biggest gain
>>>>>>> is only 30%.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Michael
>>>>>>>
>>>>>>>
>>>>>>> On Apr 5, 2016, at 5:19 AM, David L Kreitzer via llvm-commits
>>>>>>> <llvm-commits at lists.llvm.org> wrote:
>>>>>>>
>>>>>>> Author: dlkreitz
>>>>>>> Date: Tue Apr 5 07:19:35 2016
>>>>>>> New Revision: 265388
>>>>>>>
>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=265388&view=rev
>>>>>>> Log:
>>>>>>> Adds the ability to use an epilog remainder loop during loop unrolling and
>>>>>>> makes
>>>>>>> this the default behavior.
>>>>>>>
>>>>>>> Patch by Evgeny Stupachenko (evstupac at gmail.com).
>>>>>>>
>>>>>>> Differential Revision: http://reviews.llvm.org/D18158
>>>>>>>
>>>>>>> Modified:
>>>>>>> llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h
>>>>>>> llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp
>>>>>>> llvm/trunk/lib/Transforms/Utils/LoopUnrollRuntime.cpp
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/AArch64/runtime-loop.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/PowerPC/a2-unrolling.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/X86/mmx.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/runtime-loop.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/runtime-loop1.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/runtime-loop2.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/runtime-loop4.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/runtime-loop5.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/tripcount-overflow.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/unroll-cleanup.ll
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas.ll
>>>>>>>
>>>>>>> Modified: llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h (original)
>>>>>>> +++ llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -34,10 +34,11 @@ bool UnrollLoop(Loop *L, unsigned Count,
>>>>>>> LoopInfo *LI, ScalarEvolution *SE, DominatorTree *DT,
>>>>>>> AssumptionCache *AC, bool PreserveLCSSA);
>>>>>>>
>>>>>>> -bool UnrollRuntimeLoopProlog(Loop *L, unsigned Count,
>>>>>>> - bool AllowExpensiveTripCount, LoopInfo *LI,
>>>>>>> - ScalarEvolution *SE, DominatorTree *DT,
>>>>>>> - bool PreserveLCSSA);
>>>>>>> +bool UnrollRuntimeLoopRemainder(Loop *L, unsigned Count,
>>>>>>> + bool AllowExpensiveTripCount,
>>>>>>> + bool UseEpilogRemainder, LoopInfo *LI,
>>>>>>> + ScalarEvolution *SE, DominatorTree *DT,
>>>>>>> + bool PreserveLCSSA);
>>>>>>>
>>>>>>> MDNode *GetUnrollMetadata(MDNode *LoopID, StringRef Name);
>>>>>>> }
>>>>>>>
>>>>>>> Modified: llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp (original)
>>>>>>> +++ llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp Tue Apr 5 07:19:35 2016
>>>>>>> @@ -44,6 +44,11 @@ using namespace llvm;
>>>>>>> STATISTIC(NumCompletelyUnrolled, "Number of loops completely unrolled");
>>>>>>> STATISTIC(NumUnrolled, "Number of loops unrolled (completely or
>>>>>>> otherwise)");
>>>>>>>
>>>>>>> +static cl::opt<bool>
>>>>>>> +UnrollRuntimeEpilog("unroll-runtime-epilog", cl::init(true), cl::Hidden,
>>>>>>> + cl::desc("Allow runtime unrolled loops to be unrolled "
>>>>>>> + "with epilog instead of prolog."));
>>>>>>> +
>>>>>>> /// Convert the instruction operands from referencing the current values
>>>>>>> into
>>>>>>> /// those specified by VMap.
>>>>>>> static inline void remapInstruction(Instruction *I,
>>>>>>> @@ -288,12 +293,13 @@ bool llvm::UnrollLoop(Loop *L, unsigned
>>>>>>> "convergent "
>>>>>>> "operation.");
>>>>>>> });
>>>>>>> - // Don't output the runtime loop prolog if Count is a multiple of
>>>>>>> - // TripMultiple. Such a prolog is never needed, and is unsafe if the
>>>>>>> loop
>>>>>>> + // Don't output the runtime loop remainder if Count is a multiple of
>>>>>>> + // TripMultiple. Such a remainder is never needed, and is unsafe if the
>>>>>>> loop
>>>>>>> // contains a convergent instruction.
>>>>>>> if (RuntimeTripCount && TripMultiple % Count != 0 &&
>>>>>>> - !UnrollRuntimeLoopProlog(L, Count, AllowExpensiveTripCount, LI, SE,
>>>>>>> DT,
>>>>>>> - PreserveLCSSA))
>>>>>>> + !UnrollRuntimeLoopRemainder(L, Count, AllowExpensiveTripCount,
>>>>>>> + UnrollRuntimeEpilog, LI, SE, DT,
>>>>>>> + PreserveLCSSA))
>>>>>>> return false;
>>>>>>>
>>>>>>> // Notify ScalarEvolution that the loop will be substantially changed,
>>>>>>>
>>>>>>> Modified: llvm/trunk/lib/Transforms/Utils/LoopUnrollRuntime.cpp
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopUnrollRuntime.cpp?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/lib/Transforms/Utils/LoopUnrollRuntime.cpp (original)
>>>>>>> +++ llvm/trunk/lib/Transforms/Utils/LoopUnrollRuntime.cpp Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -16,8 +16,8 @@
>>>>>>> // case, we need to generate code to execute these 'left over' iterations.
>>>>>>> //
>>>>>>> // The current strategy generates an if-then-else sequence prior to the
>>>>>>> -// unrolled loop to execute the 'left over' iterations. Other strategies
>>>>>>> -// include generate a loop before or after the unrolled loop.
>>>>>>> +// unrolled loop to execute the 'left over' iterations before or after the
>>>>>>> +// unrolled loop.
>>>>>>> //
>>>>>>> //===----------------------------------------------------------------------===//
>>>>>>>
>>>>>>> @@ -60,33 +60,35 @@ STATISTIC(NumRuntimeUnrolled,
>>>>>>> /// than the unroll factor.
>>>>>>> ///
>>>>>>> static void ConnectProlog(Loop *L, Value *BECount, unsigned Count,
>>>>>>> - BasicBlock *LastPrologBB, BasicBlock *PrologEnd,
>>>>>>> - BasicBlock *OrigPH, BasicBlock *NewPH,
>>>>>>> - ValueToValueMapTy &VMap, DominatorTree *DT,
>>>>>>> - LoopInfo *LI, bool PreserveLCSSA) {
>>>>>>> + BasicBlock *PrologExit, BasicBlock *PreHeader,
>>>>>>> + BasicBlock *NewPreHeader, ValueToValueMapTy
>>>>>>> &VMap,
>>>>>>> + DominatorTree *DT, LoopInfo *LI, bool
>>>>>>> PreserveLCSSA) {
>>>>>>> BasicBlock *Latch = L->getLoopLatch();
>>>>>>> assert(Latch && "Loop must have a latch");
>>>>>>> + BasicBlock *PrologLatch = cast<BasicBlock>(VMap[Latch]);
>>>>>>>
>>>>>>> // Create a PHI node for each outgoing value from the original loop
>>>>>>> // (which means it is an outgoing value from the prolog code too).
>>>>>>> // The new PHI node is inserted in the prolog end basic block.
>>>>>>> - // The new PHI name is added as an operand of a PHI node in either
>>>>>>> + // The new PHI node value is added as an operand of a PHI node in either
>>>>>>> // the loop header or the loop exit block.
>>>>>>> - for (succ_iterator SBI = succ_begin(Latch), SBE = succ_end(Latch);
>>>>>>> - SBI != SBE; ++SBI) {
>>>>>>> - for (BasicBlock::iterator BBI = (*SBI)->begin();
>>>>>>> - PHINode *PN = dyn_cast<PHINode>(BBI); ++BBI) {
>>>>>>> -
>>>>>>> + for (BasicBlock *Succ : successors(Latch)) {
>>>>>>> + for (Instruction &BBI : *Succ) {
>>>>>>> + PHINode *PN = dyn_cast<PHINode>(&BBI);
>>>>>>> + // Exit when we passed all PHI nodes.
>>>>>>> + if (!PN)
>>>>>>> + break;
>>>>>>> // Add a new PHI node to the prolog end block and add the
>>>>>>> // appropriate incoming values.
>>>>>>> - PHINode *NewPN = PHINode::Create(PN->getType(), 2,
>>>>>>> PN->getName()+".unr",
>>>>>>> - PrologEnd->getTerminator());
>>>>>>> + PHINode *NewPN = PHINode::Create(PN->getType(), 2, PN->getName() +
>>>>>>> ".unr",
>>>>>>> + PrologExit->getFirstNonPHI());
>>>>>>> // Adding a value to the new PHI node from the original loop preheader.
>>>>>>> // This is the value that skips all the prolog code.
>>>>>>> if (L->contains(PN)) {
>>>>>>> - NewPN->addIncoming(PN->getIncomingValueForBlock(NewPH), OrigPH);
>>>>>>> + NewPN->addIncoming(PN->getIncomingValueForBlock(NewPreHeader),
>>>>>>> + PreHeader);
>>>>>>> } else {
>>>>>>> - NewPN->addIncoming(UndefValue::get(PN->getType()), OrigPH);
>>>>>>> + NewPN->addIncoming(UndefValue::get(PN->getType()), PreHeader);
>>>>>>> }
>>>>>>>
>>>>>>> Value *V = PN->getIncomingValueForBlock(Latch);
>>>>>>> @@ -97,22 +99,22 @@ static void ConnectProlog(Loop *L, Value
>>>>>>> }
>>>>>>> // Adding a value to the new PHI node from the last prolog block
>>>>>>> // that was created.
>>>>>>> - NewPN->addIncoming(V, LastPrologBB);
>>>>>>> + NewPN->addIncoming(V, PrologLatch);
>>>>>>>
>>>>>>> // Update the existing PHI node operand with the value from the
>>>>>>> // new PHI node. How this is done depends on if the existing
>>>>>>> // PHI node is in the original loop block, or the exit block.
>>>>>>> if (L->contains(PN)) {
>>>>>>> - PN->setIncomingValue(PN->getBasicBlockIndex(NewPH), NewPN);
>>>>>>> + PN->setIncomingValue(PN->getBasicBlockIndex(NewPreHeader), NewPN);
>>>>>>> } else {
>>>>>>> - PN->addIncoming(NewPN, PrologEnd);
>>>>>>> + PN->addIncoming(NewPN, PrologExit);
>>>>>>> }
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> // Create a branch around the original loop, which is taken if there are no
>>>>>>> // iterations remaining to be executed after running the prologue.
>>>>>>> - Instruction *InsertPt = PrologEnd->getTerminator();
>>>>>>> + Instruction *InsertPt = PrologExit->getTerminator();
>>>>>>> IRBuilder<> B(InsertPt);
>>>>>>>
>>>>>>> assert(Count != 0 && "nonsensical Count!");
>>>>>>> @@ -126,25 +128,152 @@ static void ConnectProlog(Loop *L, Value
>>>>>>> BasicBlock *Exit = L->getUniqueExitBlock();
>>>>>>> assert(Exit && "Loop must have a single exit block only");
>>>>>>> // Split the exit to maintain loop canonicalization guarantees
>>>>>>> - SmallVector<BasicBlock*, 4> Preds(pred_begin(Exit), pred_end(Exit));
>>>>>>> + SmallVector<BasicBlock*, 4> Preds(predecessors(Exit));
>>>>>>> SplitBlockPredecessors(Exit, Preds, ".unr-lcssa", DT, LI,
>>>>>>> PreserveLCSSA);
>>>>>>> // Add the branch to the exit block (around the unrolled loop)
>>>>>>> - B.CreateCondBr(BrLoopExit, Exit, NewPH);
>>>>>>> + B.CreateCondBr(BrLoopExit, Exit, NewPreHeader);
>>>>>>> + InsertPt->eraseFromParent();
>>>>>>> +}
>>>>>>> +
>>>>>>> +/// Connect the unrolling epilog code to the original loop.
>>>>>>> +/// The unrolling epilog code contains code to execute the
>>>>>>> +/// 'extra' iterations if the run-time trip count modulo the
>>>>>>> +/// unroll count is non-zero.
>>>>>>> +///
>>>>>>> +/// This function performs the following:
>>>>>>> +/// - Update PHI nodes at the unrolling loop exit and epilog loop exit
>>>>>>> +/// - Create PHI nodes at the unrolling loop exit to combine
>>>>>>> +/// values that exit the unrolling loop code and jump around it.
>>>>>>> +/// - Update PHI operands in the epilog loop by the new PHI nodes
>>>>>>> +/// - Branch around the epilog loop if extra iters (ModVal) is zero.
>>>>>>> +///
>>>>>>> +static void ConnectEpilog(Loop *L, Value *ModVal, BasicBlock *NewExit,
>>>>>>> + BasicBlock *Exit, BasicBlock *PreHeader,
>>>>>>> + BasicBlock *EpilogPreHeader, BasicBlock
>>>>>>> *NewPreHeader,
>>>>>>> + ValueToValueMapTy &VMap, DominatorTree *DT,
>>>>>>> + LoopInfo *LI, bool PreserveLCSSA) {
>>>>>>> + BasicBlock *Latch = L->getLoopLatch();
>>>>>>> + assert(Latch && "Loop must have a latch");
>>>>>>> + BasicBlock *EpilogLatch = cast<BasicBlock>(VMap[Latch]);
>>>>>>> +
>>>>>>> + // Loop structure should be the following:
>>>>>>> + //
>>>>>>> + // PreHeader
>>>>>>> + // NewPreHeader
>>>>>>> + // Header
>>>>>>> + // ...
>>>>>>> + // Latch
>>>>>>> + // NewExit (PN)
>>>>>>> + // EpilogPreHeader
>>>>>>> + // EpilogHeader
>>>>>>> + // ...
>>>>>>> + // EpilogLatch
>>>>>>> + // Exit (EpilogPN)
>>>>>>> +
>>>>>>> + // Update PHI nodes at NewExit and Exit.
>>>>>>> + for (Instruction &BBI : *NewExit) {
>>>>>>> + PHINode *PN = dyn_cast<PHINode>(&BBI);
>>>>>>> + // Exit when we passed all PHI nodes.
>>>>>>> + if (!PN)
>>>>>>> + break;
>>>>>>> + // PN should be used in another PHI located in Exit block as
>>>>>>> + // Exit was split by SplitBlockPredecessors into Exit and NewExit
>>>>>>> + // Basicaly it should look like:
>>>>>>> + // NewExit:
>>>>>>> + // PN = PHI [I, Latch]
>>>>>>> + // ...
>>>>>>> + // Exit:
>>>>>>> + // EpilogPN = PHI [PN, EpilogPreHeader]
>>>>>>> + //
>>>>>>> + // There is EpilogPreHeader incoming block instead of NewExit as
>>>>>>> + // NewExit was spilt 1 more time to get EpilogPreHeader.
>>>>>>> + assert(PN->hasOneUse() && "The phi should have 1 use");
>>>>>>> + PHINode *EpilogPN = cast<PHINode> (PN->use_begin()->getUser());
>>>>>>> + assert(EpilogPN->getParent() == Exit && "EpilogPN should be in Exit
>>>>>>> block");
>>>>>>> +
>>>>>>> + // Add incoming PreHeader from branch around the Loop
>>>>>>> + PN->addIncoming(UndefValue::get(PN->getType()), PreHeader);
>>>>>>> +
>>>>>>> + Value *V = PN->getIncomingValueForBlock(Latch);
>>>>>>> + Instruction *I = dyn_cast<Instruction>(V);
>>>>>>> + if (I && L->contains(I))
>>>>>>> + // If value comes from an instruction in the loop add VMap value.
>>>>>>> + V = VMap[I];
>>>>>>> + // For the instruction out of the loop, constant or undefined value
>>>>>>> + // insert value itself.
>>>>>>> + EpilogPN->addIncoming(V, EpilogLatch);
>>>>>>> +
>>>>>>> + assert(EpilogPN->getBasicBlockIndex(EpilogPreHeader) >= 0 &&
>>>>>>> + "EpilogPN should have EpilogPreHeader incoming block");
>>>>>>> + // Change EpilogPreHeader incoming block to NewExit.
>>>>>>> +
>>>>>>> EpilogPN->setIncomingBlock(EpilogPN->getBasicBlockIndex(EpilogPreHeader),
>>>>>>> + NewExit);
>>>>>>> + // Now PHIs should look like:
>>>>>>> + // NewExit:
>>>>>>> + // PN = PHI [I, Latch], [undef, PreHeader]
>>>>>>> + // ...
>>>>>>> + // Exit:
>>>>>>> + // EpilogPN = PHI [PN, NewExit], [VMap[I], EpilogLatch]
>>>>>>> + }
>>>>>>> +
>>>>>>> + // Create PHI nodes at NewExit (from the unrolling loop Latch and
>>>>>>> PreHeader).
>>>>>>> + // Update corresponding PHI nodes in epilog loop.
>>>>>>> + for (BasicBlock *Succ : successors(Latch)) {
>>>>>>> + // Skip this as we already updated phis in exit blocks.
>>>>>>> + if (!L->contains(Succ))
>>>>>>> + continue;
>>>>>>> + for (Instruction &BBI : *Succ) {
>>>>>>> + PHINode *PN = dyn_cast<PHINode>(&BBI);
>>>>>>> + // Exit when we passed all PHI nodes.
>>>>>>> + if (!PN)
>>>>>>> + break;
>>>>>>> + // Add new PHI nodes to the loop exit block and update epilog
>>>>>>> + // PHIs with the new PHI values.
>>>>>>> + PHINode *NewPN = PHINode::Create(PN->getType(), 2, PN->getName() +
>>>>>>> ".unr",
>>>>>>> + NewExit->getFirstNonPHI());
>>>>>>> + // Adding a value to the new PHI node from the unrolling loop
>>>>>>> preheader.
>>>>>>> + NewPN->addIncoming(PN->getIncomingValueForBlock(NewPreHeader),
>>>>>>> PreHeader);
>>>>>>> + // Adding a value to the new PHI node from the unrolling loop latch.
>>>>>>> + NewPN->addIncoming(PN->getIncomingValueForBlock(Latch), Latch);
>>>>>>> +
>>>>>>> + // Update the existing PHI node operand with the value from the new
>>>>>>> PHI
>>>>>>> + // node. Corresponding instruction in epilog loop should be PHI.
>>>>>>> + PHINode *VPN = cast<PHINode>(VMap[&BBI]);
>>>>>>> + VPN->setIncomingValue(VPN->getBasicBlockIndex(EpilogPreHeader),
>>>>>>> NewPN);
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + Instruction *InsertPt = NewExit->getTerminator();
>>>>>>> + IRBuilder<> B(InsertPt);
>>>>>>> + Value *BrLoopExit = B.CreateIsNotNull(ModVal);
>>>>>>> + assert(Exit && "Loop must have a single exit block only");
>>>>>>> + // Split the exit to maintain loop canonicalization guarantees
>>>>>>> + SmallVector<BasicBlock*, 4> Preds(predecessors(Exit));
>>>>>>> + SplitBlockPredecessors(Exit, Preds, ".epilog-lcssa", DT, LI,
>>>>>>> + PreserveLCSSA);
>>>>>>> + // Add the branch to the exit block (around the unrolling loop)
>>>>>>> + B.CreateCondBr(BrLoopExit, EpilogPreHeader, Exit);
>>>>>>> InsertPt->eraseFromParent();
>>>>>>> }
>>>>>>>
>>>>>>> /// Create a clone of the blocks in a loop and connect them together.
>>>>>>> -/// If UnrollProlog is true, loop structure will not be cloned, otherwise a
>>>>>>> new
>>>>>>> -/// loop will be created including all cloned blocks, and the iterator of
>>>>>>> it
>>>>>>> -/// switches to count NewIter down to 0.
>>>>>>> +/// If CreateRemainderLoop is false, loop structure will not be cloned,
>>>>>>> +/// otherwise a new loop will be created including all cloned blocks, and
>>>>>>> the
>>>>>>> +/// iterator of it switches to count NewIter down to 0.
>>>>>>> +/// The cloned blocks should be inserted between InsertTop and InsertBot.
>>>>>>> +/// If loop structure is cloned InsertTop should be new preheader,
>>>>>>> InsertBot
>>>>>>> +/// new loop exit.
>>>>>>> ///
>>>>>>> -static void CloneLoopBlocks(Loop *L, Value *NewIter, const bool
>>>>>>> UnrollProlog,
>>>>>>> +static void CloneLoopBlocks(Loop *L, Value *NewIter,
>>>>>>> + const bool CreateRemainderLoop,
>>>>>>> + const bool UseEpilogRemainder,
>>>>>>> BasicBlock *InsertTop, BasicBlock *InsertBot,
>>>>>>> + BasicBlock *Preheader,
>>>>>>> std::vector<BasicBlock *> &NewBlocks,
>>>>>>> LoopBlocksDFS &LoopBlocks, ValueToValueMapTy
>>>>>>> &VMap,
>>>>>>> LoopInfo *LI) {
>>>>>>> - BasicBlock *Preheader = L->getLoopPreheader();
>>>>>>> + StringRef suffix = UseEpilogRemainder ? "epil" : "prol";
>>>>>>> BasicBlock *Header = L->getHeader();
>>>>>>> BasicBlock *Latch = L->getLoopLatch();
>>>>>>> Function *F = Header->getParent();
>>>>>>> @@ -152,7 +281,7 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> LoopBlocksDFS::RPOIterator BlockEnd = LoopBlocks.endRPO();
>>>>>>> Loop *NewLoop = nullptr;
>>>>>>> Loop *ParentLoop = L->getParentLoop();
>>>>>>> - if (!UnrollProlog) {
>>>>>>> + if (CreateRemainderLoop) {
>>>>>>> NewLoop = new Loop();
>>>>>>> if (ParentLoop)
>>>>>>> ParentLoop->addChildLoop(NewLoop);
>>>>>>> @@ -163,7 +292,7 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> // For each block in the original loop, create a new copy,
>>>>>>> // and update the value map with the newly created values.
>>>>>>> for (LoopBlocksDFS::RPOIterator BB = BlockBegin; BB != BlockEnd; ++BB) {
>>>>>>> - BasicBlock *NewBB = CloneBasicBlock(*BB, VMap, ".prol", F);
>>>>>>> + BasicBlock *NewBB = CloneBasicBlock(*BB, VMap, "." + suffix, F);
>>>>>>> NewBlocks.push_back(NewBB);
>>>>>>>
>>>>>>> if (NewLoop)
>>>>>>> @@ -179,16 +308,17 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> }
>>>>>>>
>>>>>>> if (Latch == *BB) {
>>>>>>> - // For the last block, if UnrollProlog is true, create a direct jump
>>>>>>> to
>>>>>>> - // InsertBot. If not, create a loop back to cloned head.
>>>>>>> + // For the last block, if CreateRemainderLoop is false, create a
>>>>>>> direct
>>>>>>> + // jump to InsertBot. If not, create a loop back to cloned head.
>>>>>>> VMap.erase((*BB)->getTerminator());
>>>>>>> BasicBlock *FirstLoopBB = cast<BasicBlock>(VMap[Header]);
>>>>>>> BranchInst *LatchBR = cast<BranchInst>(NewBB->getTerminator());
>>>>>>> IRBuilder<> Builder(LatchBR);
>>>>>>> - if (UnrollProlog) {
>>>>>>> + if (!CreateRemainderLoop) {
>>>>>>> Builder.CreateBr(InsertBot);
>>>>>>> } else {
>>>>>>> - PHINode *NewIdx = PHINode::Create(NewIter->getType(), 2,
>>>>>>> "prol.iter",
>>>>>>> + PHINode *NewIdx = PHINode::Create(NewIter->getType(), 2,
>>>>>>> + suffix + ".iter",
>>>>>>> FirstLoopBB->getFirstNonPHI());
>>>>>>> Value *IdxSub =
>>>>>>> Builder.CreateSub(NewIdx, ConstantInt::get(NewIdx->getType(), 1),
>>>>>>> @@ -207,9 +337,15 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> // cloned loop.
>>>>>>> for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) {
>>>>>>> PHINode *NewPHI = cast<PHINode>(VMap[&*I]);
>>>>>>> - if (UnrollProlog) {
>>>>>>> - VMap[&*I] = NewPHI->getIncomingValueForBlock(Preheader);
>>>>>>> - cast<BasicBlock>(VMap[Header])->getInstList().erase(NewPHI);
>>>>>>> + if (!CreateRemainderLoop) {
>>>>>>> + if (UseEpilogRemainder) {
>>>>>>> + unsigned idx = NewPHI->getBasicBlockIndex(Preheader);
>>>>>>> + NewPHI->setIncomingBlock(idx, InsertTop);
>>>>>>> + NewPHI->removeIncomingValue(Latch, false);
>>>>>>> + } else {
>>>>>>> + VMap[&*I] = NewPHI->getIncomingValueForBlock(Preheader);
>>>>>>> + cast<BasicBlock>(VMap[Header])->getInstList().erase(NewPHI);
>>>>>>> + }
>>>>>>> } else {
>>>>>>> unsigned idx = NewPHI->getBasicBlockIndex(Preheader);
>>>>>>> NewPHI->setIncomingBlock(idx, InsertTop);
>>>>>>> @@ -254,7 +390,7 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> -/// Insert code in the prolog code when unrolling a loop with a
>>>>>>> +/// Insert code in the prolog/epilog code when unrolling a loop with a
>>>>>>> /// run-time trip-count.
>>>>>>> ///
>>>>>>> /// This method assumes that the loop unroll factor is total number
>>>>>>> @@ -266,6 +402,7 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> /// instruction in SimplifyCFG.cpp. Then, the backend decides how code for
>>>>>>> /// the switch instruction is generated.
>>>>>>> ///
>>>>>>> +/// ***Prolog case***
>>>>>>> /// extraiters = tripcount % loopfactor
>>>>>>> /// if (extraiters == 0) jump Loop:
>>>>>>> /// else jump Prol
>>>>>>> @@ -277,17 +414,35 @@ static void CloneLoopBlocks(Loop *L, Val
>>>>>>> /// ...
>>>>>>> /// End:
>>>>>>> ///
>>>>>>> -bool llvm::UnrollRuntimeLoopProlog(Loop *L, unsigned Count,
>>>>>>> - bool AllowExpensiveTripCount, LoopInfo
>>>>>>> *LI,
>>>>>>> - ScalarEvolution *SE, DominatorTree *DT,
>>>>>>> - bool PreserveLCSSA) {
>>>>>>> - // For now, only unroll loops that contain a single exit.
>>>>>>> +/// ***Epilog case***
>>>>>>> +/// extraiters = tripcount % loopfactor
>>>>>>> +/// if (extraiters == tripcount) jump LoopExit:
>>>>>>> +/// unroll_iters = tripcount - extraiters
>>>>>>> +/// Loop: LoopBody; (executes unroll_iter times);
>>>>>>> +/// unroll_iter -= 1
>>>>>>> +/// if (unroll_iter != 0) jump Loop:
>>>>>>> +/// LoopExit:
>>>>>>> +/// if (extraiters == 0) jump EpilExit:
>>>>>>> +/// Epil: LoopBody; (executes extraiters times)
>>>>>>> +/// extraiters -= 1 // Omitted if unroll factor is
>>>>>>> 2.
>>>>>>> +/// if (extraiters != 0) jump Epil: // Omitted if unroll factor is
>>>>>>> 2.
>>>>>>> +/// EpilExit:
>>>>>>> +
>>>>>>> +bool llvm::UnrollRuntimeLoopRemainder(Loop *L, unsigned Count,
>>>>>>> + bool AllowExpensiveTripCount,
>>>>>>> + bool UseEpilogRemainder,
>>>>>>> + LoopInfo *LI, ScalarEvolution *SE,
>>>>>>> + DominatorTree *DT, bool
>>>>>>> PreserveLCSSA) {
>>>>>>> + // for now, only unroll loops that contain a single exit
>>>>>>> if (!L->getExitingBlock())
>>>>>>> return false;
>>>>>>>
>>>>>>> // Make sure the loop is in canonical form, and there is a single
>>>>>>> // exit block only.
>>>>>>> - if (!L->isLoopSimplifyForm() || !L->getUniqueExitBlock())
>>>>>>> + if (!L->isLoopSimplifyForm())
>>>>>>> + return false;
>>>>>>> + BasicBlock *Exit = L->getUniqueExitBlock(); // successor out of loop
>>>>>>> + if (!Exit)
>>>>>>> return false;
>>>>>>>
>>>>>>> // Use Scalar Evolution to compute the trip count. This allows more loops to
>>>>>>> @@ -311,8 +466,8 @@ bool llvm::UnrollRuntimeLoopProlog(Loop
>>>>>>> return false;
>>>>>>>
>>>>>>> BasicBlock *Header = L->getHeader();
>>>>>>> - BasicBlock *PH = L->getLoopPreheader();
>>>>>>> - BranchInst *PreHeaderBR = cast<BranchInst>(PH->getTerminator());
>>>>>>> + BasicBlock *PreHeader = L->getLoopPreheader();
>>>>>>> + BranchInst *PreHeaderBR = cast<BranchInst>(PreHeader->getTerminator());
>>>>>>> const DataLayout &DL = Header->getModule()->getDataLayout();
>>>>>>> SCEVExpander Expander(*SE, DL, "loop-unroll");
>>>>>>> if (!AllowExpensiveTripCount &&
>>>>>>> @@ -330,26 +485,75 @@ bool llvm::UnrollRuntimeLoopProlog(Loop
>>>>>>> SE->forgetLoop(ParentLoop);
>>>>>>>
>>>>>>> BasicBlock *Latch = L->getLoopLatch();
>>>>>>> - // It helps to split the original preheader twice, one for the end of the
>>>>>>> - // prolog code and one for a new loop preheader.
>>>>>>> - BasicBlock *PEnd = SplitEdge(PH, Header, DT, LI);
>>>>>>> - BasicBlock *NewPH = SplitBlock(PEnd, PEnd->getTerminator(), DT, LI);
>>>>>>> - PreHeaderBR = cast<BranchInst>(PH->getTerminator());
>>>>>>>
>>>>>>> + // Loop structure is the following:
>>>>>>> + //
>>>>>>> + // PreHeader
>>>>>>> + // Header
>>>>>>> + // ...
>>>>>>> + // Latch
>>>>>>> + // Exit
>>>>>>> +
>>>>>>> + BasicBlock *NewPreHeader;
>>>>>>> + BasicBlock *NewExit = nullptr;
>>>>>>> + BasicBlock *PrologExit = nullptr;
>>>>>>> + BasicBlock *EpilogPreHeader = nullptr;
>>>>>>> + BasicBlock *PrologPreHeader = nullptr;
>>>>>>> +
>>>>>>> + if (UseEpilogRemainder) {
>>>>>>> + // If epilog remainder
>>>>>>> + // Split PreHeader to insert a branch around loop for unrolling.
>>>>>>> + NewPreHeader = SplitBlock(PreHeader, PreHeader->getTerminator(), DT,
>>>>>>> LI);
>>>>>>> + NewPreHeader->setName(PreHeader->getName() + ".new");
>>>>>>> + // Split Exit to create phi nodes from branch above.
>>>>>>> + SmallVector<BasicBlock*, 4> Preds(predecessors(Exit));
>>>>>>> + NewExit = SplitBlockPredecessors(Exit, Preds, ".unr-lcssa",
>>>>>>> + DT, LI, PreserveLCSSA);
>>>>>>> + // Split NewExit to insert epilog remainder loop.
>>>>>>> + EpilogPreHeader = SplitBlock(NewExit, NewExit->getTerminator(), DT,
>>>>>>> LI);
>>>>>>> + EpilogPreHeader->setName(Header->getName() + ".epil.preheader");
>>>>>>> + } else {
>>>>>>> + // If prolog remainder
>>>>>>> + // Split the original preheader twice to insert prolog remainder loop
>>>>>>> + PrologPreHeader = SplitEdge(PreHeader, Header, DT, LI);
>>>>>>> + PrologPreHeader->setName(Header->getName() + ".prol.preheader");
>>>>>>> + PrologExit = SplitBlock(PrologPreHeader,
>>>>>>> PrologPreHeader->getTerminator(),
>>>>>>> + DT, LI);
>>>>>>> + PrologExit->setName(Header->getName() + ".prol.loopexit");
>>>>>>> + // Split PrologExit to get NewPreHeader.
>>>>>>> + NewPreHeader = SplitBlock(PrologExit, PrologExit->getTerminator(), DT,
>>>>>>> LI);
>>>>>>> + NewPreHeader->setName(PreHeader->getName() + ".new");
>>>>>>> + }
>>>>>>> + // Loop structure should be the following:
>>>>>>> + // Epilog Prolog
>>>>>>> + //
>>>>>>> + // PreHeader PreHeader
>>>>>>> + // *NewPreHeader *PrologPreHeader
>>>>>>> + // Header *PrologExit
>>>>>>> + // ... *NewPreHeader
>>>>>>> + // Latch Header
>>>>>>> + // *NewExit ...
>>>>>>> + // *EpilogPreHeader Latch
>>>>>>> + // Exit Exit
>>>>>>> +
>>>>>>> + // Calculate conditions for branch around loop for unrolling
>>>>>>> + // in epilog case and around prolog remainder loop in prolog case.
>>>>>>> // Compute the number of extra iterations required, which is:
>>>>>>> - // extra iterations = run-time trip count % (loop unroll factor + 1)
>>>>>>> + // extra iterations = run-time trip count % loop unroll factor
>>>>>>> + PreHeaderBR = cast<BranchInst>(PreHeader->getTerminator());
>>>>>>> Value *TripCount = Expander.expandCodeFor(TripCountSC,
>>>>>>> TripCountSC->getType(),
>>>>>>> PreHeaderBR);
>>>>>>> Value *BECount = Expander.expandCodeFor(BECountSC, BECountSC->getType(),
>>>>>>> PreHeaderBR);
>>>>>>> -
>>>>>>> IRBuilder<> B(PreHeaderBR);
>>>>>>> Value *ModVal;
>>>>>>> // Calculate ModVal = (BECount + 1) % Count.
>>>>>>> // Note that TripCount is BECount + 1.
>>>>>>> if (isPowerOf2_32(Count)) {
>>>>>>> + // When Count is power of 2 we don't BECount for epilog case, however
>>>>>>> we'll
>>>>>>> + // need it for a branch around unrolling loop for prolog case.
>>>>>>> ModVal = B.CreateAnd(TripCount, Count - 1, "xtraiter");
>>>>>>> - // 1. There are no iterations to be run in the prologue loop.
>>>>>>> + // 1. There are no iterations to be run in the prolog/epilog loop.
>>>>>>> // OR
>>>>>>> // 2. The addition computing TripCount overflowed.
>>>>>>> //
>>>>>>> @@ -371,18 +575,18 @@ bool llvm::UnrollRuntimeLoopProlog(Loop
>>>>>>> ConstantInt::get(BECount->getType(), Count),
>>>>>>> "xtraiter");
>>>>>>> }
>>>>>>> - Value *BranchVal = B.CreateIsNotNull(ModVal, "lcmp.mod");
>>>>>>> -
>>>>>>> - // Branch to either the extra iterations or the cloned/unrolled loop.
>>>>>>> - // We will fix up the true branch label when adding loop body copies.
>>>>>>> - B.CreateCondBr(BranchVal, PEnd, PEnd);
>>>>>>> - assert(PreHeaderBR->isUnconditional() &&
>>>>>>> - PreHeaderBR->getSuccessor(0) == PEnd &&
>>>>>>> - "CFG edges in Preheader are not correct");
>>>>>>> + Value *CmpOperand =
>>>>>>> + UseEpilogRemainder ? TripCount :
>>>>>>> + ConstantInt::get(TripCount->getType(), 0);
>>>>>>> + Value *BranchVal = B.CreateICmpNE(ModVal, CmpOperand, "lcmp.mod");
>>>>>>> + BasicBlock *FirstLoop = UseEpilogRemainder ? NewPreHeader :
>>>>>>> PrologPreHeader;
>>>>>>> + BasicBlock *SecondLoop = UseEpilogRemainder ? NewExit : PrologExit;
>>>>>>> + // Branch to either remainder (extra iterations) loop or unrolling loop.
>>>>>>> + B.CreateCondBr(BranchVal, FirstLoop, SecondLoop);
>>>>>>> PreHeaderBR->eraseFromParent();
>>>>>>> Function *F = Header->getParent();
>>>>>>> // Get an ordered list of blocks in the loop to help with the ordering of
>>>>>>> the
>>>>>>> - // cloned blocks in the prolog code.
>>>>>>> + // cloned blocks in the prolog/epilog code
>>>>>>> LoopBlocksDFS LoopBlocks(L);
>>>>>>> LoopBlocks.perform(LI);
>>>>>>>
>>>>>>> @@ -394,17 +598,38 @@ bool llvm::UnrollRuntimeLoopProlog(Loop
>>>>>>> std::vector<BasicBlock *> NewBlocks;
>>>>>>> ValueToValueMapTy VMap;
>>>>>>>
>>>>>>> - bool UnrollPrologue = Count == 2;
>>>>>>> + // For unroll factor 2 remainder loop will have 1 iterations.
>>>>>>> + // Do not create 1 iteration loop.
>>>>>>> + bool CreateRemainderLoop = (Count != 2);
>>>>>>>
>>>>>>> // Clone all the basic blocks in the loop. If Count is 2, we don't clone
>>>>>>> // the loop, otherwise we create a cloned loop to execute the extra
>>>>>>> // iterations. This function adds the appropriate CFG connections.
>>>>>>> - CloneLoopBlocks(L, ModVal, UnrollPrologue, PH, PEnd, NewBlocks,
>>>>>>> LoopBlocks,
>>>>>>> - VMap, LI);
>>>>>>> + BasicBlock *InsertBot = UseEpilogRemainder ? Exit : PrologExit;
>>>>>>> + BasicBlock *InsertTop = UseEpilogRemainder ? EpilogPreHeader :
>>>>>>> PrologPreHeader;
>>>>>>> + CloneLoopBlocks(L, ModVal, CreateRemainderLoop, UseEpilogRemainder,
>>>>>>> InsertTop,
>>>>>>> + InsertBot, NewPreHeader, NewBlocks, LoopBlocks, VMap,
>>>>>>> LI);
>>>>>>> +
>>>>>>> + // Insert the cloned blocks into the function.
>>>>>>> + F->getBasicBlockList().splice(InsertBot->getIterator(),
>>>>>>> + F->getBasicBlockList(),
>>>>>>> + NewBlocks[0]->getIterator(),
>>>>>>> + F->end());
>>>>>>>
>>>>>>> - // Insert the cloned blocks into the function just before the original
>>>>>>> loop.
>>>>>>> - F->getBasicBlockList().splice(PEnd->getIterator(),
>>>>>>> F->getBasicBlockList(),
>>>>>>> - NewBlocks[0]->getIterator(), F->end());
>>>>>>> + // Loop structure should be the following:
>>>>>>> + // Epilog Prolog
>>>>>>> + //
>>>>>>> + // PreHeader PreHeader
>>>>>>> + // NewPreHeader PrologPreHeader
>>>>>>> + // Header PrologHeader
>>>>>>> + // ... ...
>>>>>>> + // Latch PrologLatch
>>>>>>> + // NewExit PrologExit
>>>>>>> + // EpilogPreHeader NewPreHeader
>>>>>>> + // EpilogHeader Header
>>>>>>> + // ... ...
>>>>>>> + // EpilogLatch Latch
>>>>>>> + // Exit Exit
>>>>>>>
>>>>>>> // Rewrite the cloned instruction operands to use the values created when
>>>>>>> the
>>>>>>> // clone is created.
>>>>>>> @@ -415,11 +640,38 @@ bool llvm::UnrollRuntimeLoopProlog(Loop
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> - // Connect the prolog code to the original loop and update the
>>>>>>> - // PHI functions.
>>>>>>> - BasicBlock *LastLoopBB = cast<BasicBlock>(VMap[Latch]);
>>>>>>> - ConnectProlog(L, BECount, Count, LastLoopBB, PEnd, PH, NewPH, VMap, DT,
>>>>>>> LI,
>>>>>>> - PreserveLCSSA);
>>>>>>> + if (UseEpilogRemainder) {
>>>>>>> + // Connect the epilog code to the original loop and update the
>>>>>>> + // PHI functions.
>>>>>>> + ConnectEpilog(L, ModVal, NewExit, Exit, PreHeader,
>>>>>>> + EpilogPreHeader, NewPreHeader, VMap, DT, LI,
>>>>>>> + PreserveLCSSA);
>>>>>>> +
>>>>>>> + // Update counter in loop for unrolling.
>>>>>>> + // I should be multiply of Count.
>>>>>>> + IRBuilder<> B2(NewPreHeader->getTerminator());
>>>>>>> + Value *TestVal = B2.CreateSub(TripCount, ModVal, "unroll_iter");
>>>>>>> + BranchInst *LatchBR = cast<BranchInst>(Latch->getTerminator());
>>>>>>> + B2.SetInsertPoint(LatchBR);
>>>>>>> + PHINode *NewIdx = PHINode::Create(TestVal->getType(), 2, "niter",
>>>>>>> + Header->getFirstNonPHI());
>>>>>>> + Value *IdxSub =
>>>>>>> + B2.CreateSub(NewIdx, ConstantInt::get(NewIdx->getType(), 1),
>>>>>>> + NewIdx->getName() + ".nsub");
>>>>>>> + Value *IdxCmp;
>>>>>>> + if (LatchBR->getSuccessor(0) == Header)
>>>>>>> + IdxCmp = B2.CreateIsNotNull(IdxSub, NewIdx->getName() + ".ncmp");
>>>>>>> + else
>>>>>>> + IdxCmp = B2.CreateIsNull(IdxSub, NewIdx->getName() + ".ncmp");
>>>>>>> + NewIdx->addIncoming(TestVal, NewPreHeader);
>>>>>>> + NewIdx->addIncoming(IdxSub, Latch);
>>>>>>> + LatchBR->setCondition(IdxCmp);
>>>>>>> + } else {
>>>>>>> + // Connect the prolog code to the original loop and update the
>>>>>>> + // PHI functions.
>>>>>>> + ConnectProlog(L, BECount, Count, PrologExit, PreHeader, NewPreHeader,
>>>>>>> + VMap, DT, LI, PreserveLCSSA);
>>>>>>> + }
>>>>>>> NumRuntimeUnrolled++;
>>>>>>> return true;
>>>>>>> }
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/AArch64/runtime-loop.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/AArch64/runtime-loop.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/AArch64/runtime-loop.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/AArch64/runtime-loop.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -1,13 +1,21 @@
>>>>>>> -; RUN: opt < %s -S -loop-unroll -mtriple aarch64 -mcpu=cortex-a57 |
>>>>>>> FileCheck %s
>>>>>>> +; RUN: opt < %s -S -loop-unroll -mtriple aarch64 -mcpu=cortex-a57 |
>>>>>>> FileCheck %s -check-prefix=EPILOG
>>>>>>> +; RUN: opt < %s -S -loop-unroll -mtriple aarch64 -mcpu=cortex-a57
>>>>>>> -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
>>>>>>>
>>>>>>> ; Tests for unrolling loops with run-time trip counts
>>>>>>>
>>>>>>> -; CHECK: %xtraiter = and i32 %n
>>>>>>> -; CHECK: %lcmp.mod = icmp ne i32 %xtraiter, 0
>>>>>>> -; CHECK: br i1 %lcmp.mod, label %for.body.prol, label
>>>>>>> %for.body.preheader.split
>>>>>>> +; EPILOG: %xtraiter = and i32 %n
>>>>>>> +; EPILOG: %lcmp.mod = icmp ne i32 %xtraiter, %n
>>>>>>> +; EPILOG: br i1 %lcmp.mod, label %for.body.preheader.new, label
>>>>>>> %for.end.loopexit.unr-lcssa
>>>>>>>
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: for.body:
>>>>>>> +; PROLOG: %xtraiter = and i32 %n
>>>>>>> +; PROLOG: %lcmp.mod = icmp ne i32 %xtraiter, 0
>>>>>>> +; PROLOG: br i1 %lcmp.mod, label %for.body.prol.preheader, label
>>>>>>> %for.body.prol.loopexit
>>>>>>> +
>>>>>>> +; EPILOG: for.body:
>>>>>>> +; EPILOG: for.body.epil:
>>>>>>> +
>>>>>>> +; PROLOG: for.body.prol:
>>>>>>> +; PROLOG: for.body:
>>>>>>>
>>>>>>> define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly {
>>>>>>> entry:
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/PowerPC/a2-unrolling.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/PowerPC/a2-unrolling.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/PowerPC/a2-unrolling.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/PowerPC/a2-unrolling.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -1,4 +1,5 @@
>>>>>>> -; RUN: opt < %s -S -mtriple=powerpc64-unknown-linux-gnu -mcpu=a2
>>>>>>> -loop-unroll | FileCheck %s
>>>>>>> +; RUN: opt < %s -S -mtriple=powerpc64-unknown-linux-gnu -mcpu=a2
>>>>>>> -loop-unroll | FileCheck %s -check-prefix=EPILOG
>>>>>>> +; RUN: opt < %s -S -mtriple=powerpc64-unknown-linux-gnu -mcpu=a2
>>>>>>> -loop-unroll -unroll-runtime-epilog=false | FileCheck %s
>>>>>>> -check-prefix=PROLOG
>>>>>>> define void @unroll_opt_for_size() nounwind optsize {
>>>>>>> entry:
>>>>>>> br label %loop
>>>>>>> @@ -13,11 +14,17 @@ exit:
>>>>>>> ret void
>>>>>>> }
>>>>>>>
>>>>>>> -; CHECK-LABEL: @unroll_opt_for_size
>>>>>>> -; CHECK: add
>>>>>>> -; CHECK-NEXT: add
>>>>>>> -; CHECK-NEXT: add
>>>>>>> -; CHECK: icmp
>>>>>>> +; EPILOG-LABEL: @unroll_opt_for_size
>>>>>>> +; EPILOG: add
>>>>>>> +; EPILOG-NEXT: add
>>>>>>> +; EPILOG-NEXT: add
>>>>>>> +; EPILOG: icmp
>>>>>>> +
>>>>>>> +; PROLOG-LABEL: @unroll_opt_for_size
>>>>>>> +; PROLOG: add
>>>>>>> +; PROLOG-NEXT: add
>>>>>>> +; PROLOG-NEXT: add
>>>>>>> +; PROLOG: icmp
>>>>>>>
>>>>>>> define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly {
>>>>>>> entry:
>>>>>>> @@ -40,8 +47,13 @@ for.end:
>>>>>>> ret i32 %sum.0.lcssa
>>>>>>> }
>>>>>>>
>>>>>>> -; CHECK-LABEL: @test
>>>>>>> -; CHECK: for.body.prol{{.*}}:
>>>>>>> -; CHECK: for.body:
>>>>>>> -; CHECK: br i1 %exitcond.7, label %for.end.loopexit{{.*}}, label %for.body
>>>>>>> +; EPILOG-LABEL: @test
>>>>>>> +; EPILOG: for.body:
>>>>>>> +; EPILOG: br i1 %niter.ncmp.7, label %for.end.loopexit{{.*}}, label
>>>>>>> %for.body
>>>>>>> +; EPILOG: for.body.epil{{.*}}:
>>>>>>> +
>>>>>>> +; PROLOG-LABEL: @test
>>>>>>> +; PROLOG: for.body.prol{{.*}}:
>>>>>>> +; PROLOG: for.body:
>>>>>>> +; PROLOG: br i1 %exitcond.7, label %for.end.loopexit{{.*}}, label %for.body
>>>>>>>
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/X86/mmx.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/X86/mmx.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/X86/mmx.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/X86/mmx.ll Tue Apr 5 07:19:35
>>>>>>> 2016
>>>>>>> @@ -14,9 +14,9 @@ for.body:
>>>>>>>
>>>>>>> exit: ; preds = %for.body
>>>>>>> %ret = phi x86_mmx [ undef, %for.body ]
>>>>>>> - ; CHECK: %[[ret_unr:.*]] = phi x86_mmx [ undef,
>>>>>>> - ; CHECK: %[[ret_ph:.*]] = phi x86_mmx [ undef,
>>>>>>> - ; CHECK: %[[ret:.*]] = phi x86_mmx [ %[[ret_unr]], {{.*}} ], [
>>>>>>> %[[ret_ph]]
>>>>>>> + ; CHECK: %[[ret_ph:.*]] = phi x86_mmx [ undef, %entry
>>>>>>> + ; CHECK: %[[ret_ph1:.*]] = phi x86_mmx [ undef,
>>>>>>> + ; CHECK: %[[ret:.*]] = phi x86_mmx [ %[[ret_ph]], {{.*}} ], [
>>>>>>> %[[ret_ph1]],
>>>>>>> ; CHECK: ret x86_mmx %[[ret]]
>>>>>>> ret x86_mmx %ret
>>>>>>> }
>>>>>>>
>>>>>>> Modified:
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> ---
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll
>>>>>>> (original)
>>>>>>> +++
>>>>>>> llvm/trunk/test/Transforms/LoopUnroll/high-cost-trip-count-computation.ll
>>>>>>> Tue Apr 5 07:19:35 2016
>>>>>>> @@ -34,7 +34,7 @@ define i32 @test2(i64* %loc, i64 %conv7)
>>>>>>> ; CHECK: udiv
>>>>>>> ; CHECK: udiv
>>>>>>> ; CHECK-NOT: udiv
>>>>>>> -; CHECK-LABEL: for.body.prol
>>>>>>> +; CHECK-LABEL: for.body
>>>>>>> entry:
>>>>>>> %rem0 = load i64, i64* %loc, align 8
>>>>>>> %ExpensiveComputation = udiv i64 %rem0, 42 ; <<< Extra computations are
>>>>>>> added to the trip-count expression
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/runtime-loop.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/runtime-loop.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/runtime-loop.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/runtime-loop.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -1,18 +1,30 @@
>>>>>>> -; RUN: opt < %s -S -loop-unroll -unroll-runtime=true | FileCheck %s
>>>>>>> +; RUN: opt < %s -S -loop-unroll -unroll-runtime=true | FileCheck %s
>>>>>>> -check-prefix=EPILOG
>>>>>>> +; RUN: opt < %s -S -loop-unroll -unroll-runtime=true
>>>>>>> -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
>>>>>>>
>>>>>>> target datalayout =
>>>>>>> "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
>>>>>>>
>>>>>>> ; Tests for unrolling loops with run-time trip counts
>>>>>>>
>>>>>>> -; CHECK: %xtraiter = and i32 %n
>>>>>>> -; CHECK: %lcmp.mod = icmp ne i32 %xtraiter, 0
>>>>>>> -; CHECK: br i1 %lcmp.mod, label %for.body.prol, label
>>>>>>> %for.body.preheader.split
>>>>>>> -
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: %indvars.iv.prol = phi i64 [ %indvars.iv.next.prol, %for.body.prol
>>>>>>> ], [ 0, %for.body.preheader ]
>>>>>>> -; CHECK: %prol.iter.sub = sub i32 %prol.iter, 1
>>>>>>> -; CHECK: %prol.iter.cmp = icmp ne i32 %prol.iter.sub, 0
>>>>>>> -; CHECK: br i1 %prol.iter.cmp, label %for.body.prol, label
>>>>>>> %for.body.preheader.split, !llvm.loop !0
>>>>>>> +; EPILOG: %xtraiter = and i32 %n
>>>>>>> +; EPILOG: %lcmp.mod = icmp ne i32 %xtraiter, %n
>>>>>>> +; EPILOG: br i1 %lcmp.mod, label %for.body.preheader.new, label
>>>>>>> %for.end.loopexit.unr-lcssa
>>>>>>> +
>>>>>>> +; PROLOG: %xtraiter = and i32 %n
>>>>>>> +; PROLOG: %lcmp.mod = icmp ne i32 %xtraiter, 0
>>>>>>> +; PROLOG: br i1 %lcmp.mod, label %for.body.prol.preheader, label
>>>>>>> %for.body.prol.loopexit
>>>>>>> +
>>>>>>> +; EPILOG: for.body.epil:
>>>>>>> +; EPILOG: %indvars.iv.epil = phi i64 [ %indvars.iv.next.epil,
>>>>>>> %for.body.epil ], [ %indvars.iv.unr, %for.body.epil.preheader ]
>>>>>>> +; EPILOG: %epil.iter.sub = sub i32 %epil.iter, 1
>>>>>>> +; EPILOG: %epil.iter.cmp = icmp ne i32 %epil.iter.sub, 0
>>>>>>> +; EPILOG: br i1 %epil.iter.cmp, label %for.body.epil, label
>>>>>>> %for.end.loopexit.epilog-lcssa, !llvm.loop !0
>>>>>>> +
>>>>>>> +; PROLOG: for.body.prol:
>>>>>>> +; PROLOG: %indvars.iv.prol = phi i64 [ %indvars.iv.next.prol,
>>>>>>> %for.body.prol ], [ 0, %for.body.prol.preheader ]
>>>>>>> +; PROLOG: %prol.iter.sub = sub i32 %prol.iter, 1
>>>>>>> +; PROLOG: %prol.iter.cmp = icmp ne i32 %prol.iter.sub, 0
>>>>>>> +; PROLOG: br i1 %prol.iter.cmp, label %for.body.prol, label
>>>>>>> %for.body.prol.loopexit, !llvm.loop !0
>>>>>>> +
>>>>>>>
>>>>>>> define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly {
>>>>>>> entry:
>>>>>>> @@ -39,8 +51,11 @@ for.end:
>>>>>>> ; Still try to completely unroll loops with compile-time trip counts
>>>>>>> ; even if the -unroll-runtime is specified
>>>>>>>
>>>>>>> -; CHECK: for.body:
>>>>>>> -; CHECK-NOT: for.body.prol:
>>>>>>> +; EPILOG: for.body:
>>>>>>> +; EPILOG-NOT: for.body.epil:
>>>>>>> +
>>>>>>> +; PROLOG: for.body:
>>>>>>> +; PROLOG-NOT: for.body.prol:
>>>>>>>
>>>>>>> define i32 @test1(i32* nocapture %a) nounwind uwtable readonly {
>>>>>>> entry:
>>>>>>> @@ -64,7 +79,8 @@ for.end:
>>>>>>> ; This is test 2007-05-09-UnknownTripCount.ll which can be unrolled now
>>>>>>> ; if the -unroll-runtime option is turned on
>>>>>>>
>>>>>>> -; CHECK: bb72.2:
>>>>>>> +; EPILOG: bb72.2:
>>>>>>> +; PROLOG: bb72.2:
>>>>>>>
>>>>>>> define void @foo(i32 %trips) {
>>>>>>> entry:
>>>>>>> @@ -86,8 +102,11 @@ cond_true138:
>>>>>>>
>>>>>>> ; Test run-time unrolling for a loop that counts down by -2.
>>>>>>>
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: br i1 %prol.iter.cmp, label %for.body.prol, label
>>>>>>> %for.body.preheader.split
>>>>>>> +; EPILOG: for.body.epil:
>>>>>>> +; EPILOG: br i1 %epil.iter.cmp, label %for.body.epil, label
>>>>>>> %for.cond.for.end_crit_edge.epilog-lcssa
>>>>>>> +
>>>>>>> +; PROLOG: for.body.prol:
>>>>>>> +; PROLOG: br i1 %prol.iter.cmp, label %for.body.prol, label
>>>>>>> %for.body.prol.loopexit
>>>>>>>
>>>>>>> define zeroext i16 @down(i16* nocapture %p, i32 %len) nounwind uwtable
>>>>>>> readonly {
>>>>>>> entry:
>>>>>>> @@ -116,8 +135,11 @@ for.end:
>>>>>>> }
>>>>>>>
>>>>>>> ; Test run-time unrolling disable metadata.
>>>>>>> -; CHECK: for.body:
>>>>>>> -; CHECK-NOT: for.body.prol:
>>>>>>> +; EPILOG: for.body:
>>>>>>> +; EPILOG-NOT: for.body.epil:
>>>>>>> +
>>>>>>> +; PROLOG: for.body:
>>>>>>> +; PROLOG-NOT: for.body.prol:
>>>>>>>
>>>>>>> define zeroext i16 @test2(i16* nocapture %p, i32 %len) nounwind uwtable
>>>>>>> readonly {
>>>>>>> entry:
>>>>>>> @@ -148,6 +170,8 @@ for.end:
>>>>>>> !0 = distinct !{!0, !1}
>>>>>>> !1 = !{!"llvm.loop.unroll.runtime.disable"}
>>>>>>>
>>>>>>> -; CHECK: !0 = distinct !{!0, !1}
>>>>>>> -; CHECK: !1 = !{!"llvm.loop.unroll.disable"}
>>>>>>> +; EPILOG: !0 = distinct !{!0, !1}
>>>>>>> +; EPILOG: !1 = !{!"llvm.loop.unroll.disable"}
>>>>>>>
>>>>>>> +; PROLOG: !0 = distinct !{!0, !1}
>>>>>>> +; PROLOG: !1 = !{!"llvm.loop.unroll.disable"}
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/runtime-loop1.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/runtime-loop1.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/runtime-loop1.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/runtime-loop1.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -1,19 +1,35 @@
>>>>>>> -; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-count=2 | FileCheck
>>>>>>> %s
>>>>>>> +; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-count=2 | FileCheck
>>>>>>> %s -check-prefix=EPILOG
>>>>>>> +; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-count=2
>>>>>>> -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
>>>>>>>
>>>>>>> ; This tests that setting the unroll count works
>>>>>>>
>>>>>>> -; CHECK: for.body.preheader:
>>>>>>> -; CHECK: br {{.*}} label %for.body.prol, label %for.body.preheader.split,
>>>>>>> !dbg [[PH_LOC:![0-9]+]]
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: br label %for.body.preheader.split, !dbg [[BODY_LOC:![0-9]+]]
>>>>>>> -; CHECK: for.body.preheader.split:
>>>>>>> -; CHECK: br {{.*}} label %for.end.loopexit, label
>>>>>>> %for.body.preheader.split.split, !dbg [[PH_LOC]]
>>>>>>> -; CHECK: for.body:
>>>>>>> -; CHECK: br i1 %exitcond.1, label %for.end.loopexit.unr-lcssa, label
>>>>>>> %for.body, !dbg [[BODY_LOC]]
>>>>>>> -; CHECK-NOT: br i1 %exitcond.4, label %for.end.loopexit{{.*}}, label
>>>>>>> %for.body
>>>>>>>
>>>>>>> -; CHECK-DAG: [[PH_LOC]] = !DILocation(line: 101, column: 1, scope: !{{.*}})
>>>>>>> -; CHECK-DAG: [[BODY_LOC]] = !DILocation(line: 102, column: 1, scope:
>>>>>>> !{{.*}})
>>>>>>> +; EPILOG: for.body.preheader:
>>>>>>> +; EPILOG: br i1 %lcmp.mod, label %for.body.preheader.new, label
>>>>>>> %for.end.loopexit.unr-lcssa, !dbg [[PH_LOC:![0-9]+]]
>>>>>>> +; EPILOG: for.body:
>>>>>>> +; EPILOG: br i1 %niter.ncmp.1, label
>>>>>>> %for.end.loopexit.unr-lcssa.loopexit, label %for.body, !dbg
>>>>>>> [[BODY_LOC:![0-9]+]]
>>>>>>> +; EPILOG-NOT: br i1 %niter.ncmp.2, label %for.end.loopexit{{.*}}, label
>>>>>>> %for.body
>>>>>>> +; EPILOG: for.body.epil.preheader:
>>>>>>> +; EPILOG: br label %for.body.epil, !dbg [[EXIT_LOC:![0-9]+]]
>>>>>>> +; EPILOG: for.body.epil:
>>>>>>> +; EPILOG: br label %for.end.loopexit.epilog-lcssa, !dbg
>>>>>>> [[BODY_LOC:![0-9]+]]
>>>>>>> +
>>>>>>> +; EPILOG-DAG: [[PH_LOC]] = !DILocation(line: 101, column: 1, scope:
>>>>>>> !{{.*}})
>>>>>>> +; EPILOG-DAG: [[BODY_LOC]] = !DILocation(line: 102, column: 1, scope:
>>>>>>> !{{.*}})
>>>>>>> +; EPILOG-DAG: [[EXIT_LOC]] = !DILocation(line: 103, column: 1, scope:
>>>>>>> !{{.*}})
>>>>>>> +
>>>>>>> +; PROLOG: for.body.preheader:
>>>>>>> +; PROLOG: br {{.*}} label %for.body.prol.preheader, label
>>>>>>> %for.body.prol.loopexit, !dbg [[PH_LOC:![0-9]+]]
>>>>>>> +; PROLOG: for.body.prol:
>>>>>>> +; PROLOG: br label %for.body.prol.loopexit, !dbg [[BODY_LOC:![0-9]+]]
>>>>>>> +; PROLOG: for.body.prol.loopexit:
>>>>>>> +; PROLOG: br {{.*}} label %for.end.loopexit, label
>>>>>>> %for.body.preheader.new, !dbg [[PH_LOC]]
>>>>>>> +; PROLOG: for.body:
>>>>>>> +; PROLOG: br i1 %exitcond.1, label %for.end.loopexit.unr-lcssa, label
>>>>>>> %for.body, !dbg [[BODY_LOC]]
>>>>>>> +; PROLOG-NOT: br i1 %exitcond.4, label %for.end.loopexit{{.*}}, label
>>>>>>> %for.body
>>>>>>> +
>>>>>>> +; PROLOG-DAG: [[PH_LOC]] = !DILocation(line: 101, column: 1, scope:
>>>>>>> !{{.*}})
>>>>>>> +; PROLOG-DAG: [[BODY_LOC]] = !DILocation(line: 102, column: 1, scope:
>>>>>>> !{{.*}})
>>>>>>>
>>>>>>> define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly !dbg
>>>>>>> !6 {
>>>>>>> entry:
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/runtime-loop2.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/runtime-loop2.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/runtime-loop2.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/runtime-loop2.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -1,12 +1,18 @@
>>>>>>> -; RUN: opt < %s -S -loop-unroll -unroll-threshold=25 -unroll-runtime
>>>>>>> -unroll-count=8 | FileCheck %s
>>>>>>> +; RUN: opt < %s -S -loop-unroll -unroll-threshold=25 -unroll-runtime
>>>>>>> -unroll-count=8 | FileCheck %s -check-prefix=EPILOG
>>>>>>> +; RUN: opt < %s -S -loop-unroll -unroll-threshold=25 -unroll-runtime
>>>>>>> -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
>>>>>>>
>>>>>>> ; Choose a smaller, power-of-two, unroll count if the loop is too large.
>>>>>>> ; This test makes sure we're not unrolling 'odd' counts
>>>>>>>
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: for.body:
>>>>>>> -; CHECK: br i1 %exitcond.3, label %for.end.loopexit{{.*}}, label %for.body
>>>>>>> -; CHECK-NOT: br i1 %exitcond.4, label %for.end.loopexit{{.*}}, label
>>>>>>> %for.body
>>>>>>> +; EPILOG: for.body:
>>>>>>> +; EPILOG: br i1 %niter.ncmp.3, label
>>>>>>> %for.end.loopexit.unr-lcssa.loopexit{{.*}}, label %for.body
>>>>>>> +; EPILOG-NOT: br i1 %niter.ncmp.4, label
>>>>>>> %for.end.loopexit.unr-lcssa.loopexit{{.*}}, label %for.body
>>>>>>> +; EPILOG: for.body.epil:
>>>>>>> +
>>>>>>> +; PROLOG: for.body.prol:
>>>>>>> +; PROLOG: for.body:
>>>>>>> +; PROLOG: br i1 %exitcond.3, label %for.end.loopexit{{.*}}, label %for.body
>>>>>>> +; PROLOG-NOT: br i1 %exitcond.4, label %for.end.loopexit{{.*}}, label
>>>>>>> %for.body
>>>>>>>
>>>>>>> define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly {
>>>>>>> entry:
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/runtime-loop4.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/runtime-loop4.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/runtime-loop4.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/runtime-loop4.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -1,13 +1,21 @@
>>>>>>> -; RUN: opt < %s -S -O2 -unroll-runtime=true | FileCheck %s
>>>>>>> +; RUN: opt < %s -S -O2 -unroll-runtime=true | FileCheck %s
>>>>>>> -check-prefix=EPILOG
>>>>>>> +; RUN: opt < %s -S -O2 -unroll-runtime=true -unroll-runtime-epilog=false |
>>>>>>> FileCheck %s -check-prefix=PROLOG
>>>>>>>
>>>>>>> ; Check runtime unrolling prologue can be promoted by LICM pass.
>>>>>>>
>>>>>>> -; CHECK: entry:
>>>>>>> -; CHECK: %xtraiter
>>>>>>> -; CHECK: %lcmp.mod
>>>>>>> -; CHECK: loop1:
>>>>>>> -; CHECK: br i1 %lcmp.mod
>>>>>>> -; CHECK: loop2.prol:
>>>>>>> +; EPILOG: entry:
>>>>>>> +; EPILOG: %xtraiter
>>>>>>> +; EPILOG: %lcmp.mod
>>>>>>> +; EPILOG: loop1:
>>>>>>> +; EPILOG: br i1 %lcmp.mod
>>>>>>> +; EPILOG: loop2.epil:
>>>>>>> +
>>>>>>> +; PROLOG: entry:
>>>>>>> +; PROLOG: %xtraiter
>>>>>>> +; PROLOG: %lcmp.mod
>>>>>>> +; PROLOG: loop1:
>>>>>>> +; PROLOG: br i1 %lcmp.mod
>>>>>>> +; PROLOG: loop2.prol:
>>>>>>>
>>>>>>> define void @unroll(i32 %iter, i32* %addr1, i32* %addr2) nounwind {
>>>>>>> entry:
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/runtime-loop5.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/runtime-loop5.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/runtime-loop5.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/runtime-loop5.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -11,9 +11,6 @@ entry:
>>>>>>> %cmp1 = icmp eq i3 %n, 0
>>>>>>> br i1 %cmp1, label %for.end, label %for.body
>>>>>>>
>>>>>>> -; UNROLL-16-NOT: for.body.prol:
>>>>>>> -; UNROLL-4: for.body.prol:
>>>>>>> -
>>>>>>> for.body: ; preds = %for.body,
>>>>>>> %entry
>>>>>>> ; UNROLL-16-LABEL: for.body:
>>>>>>> ; UNROLL-4-LABEL: for.body:
>>>>>>> @@ -39,6 +36,10 @@ for.body:
>>>>>>>
>>>>>>> ; UNROLL-16-LABEL: for.end
>>>>>>> ; UNROLL-4-LABEL: for.end
>>>>>>> +
>>>>>>> +; UNROLL-16-NOT: for.body.epil:
>>>>>>> +; UNROLL-4: for.body.epil:
>>>>>>> +
>>>>>>> for.end: ; preds = %for.body,
>>>>>>> %entry
>>>>>>> %sum.0.lcssa = phi i3 [ 0, %entry ], [ %add, %for.body ]
>>>>>>> ret i3 %sum.0.lcssa
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/tripcount-overflow.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/tripcount-overflow.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/tripcount-overflow.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/tripcount-overflow.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -13,13 +13,13 @@ target datalayout = "e-m:o-i64:64-f80:12
>>>>>>> ; CHECK: entry:
>>>>>>> ; CHECK-NEXT: %0 = add i32 %N, 1
>>>>>>> ; CHECK-NEXT: %xtraiter = and i32 %0, 1
>>>>>>> -; CHECK-NEXT: %lcmp.mod = icmp ne i32 %xtraiter, 0
>>>>>>> -; CHECK-NEXT: br i1 %lcmp.mod, label %while.body.prol, label %entry.split
>>>>>>> +; CHECK-NEXT: %lcmp.mod = icmp ne i32 %xtraiter, %0
>>>>>>> +; CHECK-NEXT: br i1 %lcmp.mod, label %entry.new, label %while.end.unr-lcssa
>>>>>>>
>>>>>>> -; CHECK: while.body.prol:
>>>>>>> -; CHECK: br label %entry.split
>>>>>>> +; CHECK: while.body.epil:
>>>>>>> +; CHECK: br label %while.end.epilog-lcssa
>>>>>>>
>>>>>>> -; CHECK: entry.split:
>>>>>>> +; CHECK: while.end.epilog-lcssa:
>>>>>>>
>>>>>>> ; Function Attrs: nounwind readnone ssp uwtable
>>>>>>> define i32 @foo(i32 %N) {
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/unroll-cleanup.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/unroll-cleanup.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/unroll-cleanup.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/unroll-cleanup.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -4,14 +4,14 @@
>>>>>>> ; RUN: opt < %s -O2 -S | FileCheck %s
>>>>>>>
>>>>>>> ; After loop unroll:
>>>>>>> -; %dec18 = add nsw i32 %dec18.in, -1
>>>>>>> +; %niter.nsub = add nsw i32 %niter, -1
>>>>>>> ; ...
>>>>>>> -; %dec18.1 = add nsw i32 %dec18, -1
>>>>>>> +; %niter.nsub.1 = add nsw i32 %niter.nsub, -1
>>>>>>> ; should be merged to:
>>>>>>> -; %dec18.1 = add nsw i32 %dec18.in, -2
>>>>>>> +; %dec18.1 = add nsw i32 %niter, -2
>>>>>>> ;
>>>>>>> ; CHECK-LABEL: @_Z3fn1v(
>>>>>>> -; CHECK: %dec18.1 = add nsw i32 %dec18.in, -2
>>>>>>> +; CHECK: %niter.nsub.1 = add i32 %niter, -2
>>>>>>>
>>>>>>> ; ModuleID = '<stdin>'
>>>>>>> target triple = "x86_64-unknown-linux-gnu"
>>>>>>>
>>>>>>> Modified: llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas.ll
>>>>>>> URL:
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas.ll?rev=265388&r1=265387&r2=265388&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas.ll (original)
>>>>>>> +++ llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas.ll Tue Apr 5
>>>>>>> 07:19:35 2016
>>>>>>> @@ -171,10 +171,6 @@ for.end:
>>>>>>> ; should be duplicated (original and 4x unrolled).
>>>>>>> ;
>>>>>>> ; CHECK-LABEL: @runtime_loop_with_count4(
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: store
>>>>>>> -; CHECK-NOT: store
>>>>>>> -; CHECK: br i1
>>>>>>> ; CHECK: for.body
>>>>>>> ; CHECK: store
>>>>>>> ; CHECK: store
>>>>>>> @@ -182,6 +178,10 @@ for.end:
>>>>>>> ; CHECK: store
>>>>>>> ; CHECK-NOT: store
>>>>>>> ; CHECK: br i1
>>>>>>> +; CHECK: for.body.epil:
>>>>>>> +; CHECK: store
>>>>>>> +; CHECK-NOT: store
>>>>>>> +; CHECK: br i1
>>>>>>> define void @runtime_loop_with_count4(i32* nocapture %a, i32 %b) {
>>>>>>> entry:
>>>>>>> %cmp3 = icmp sgt i32 %b, 0
>>>>>>> @@ -287,10 +287,6 @@ for.end:
>>>>>>> ; (original and 8x).
>>>>>>> ;
>>>>>>> ; CHECK-LABEL: @runtime_loop_with_enable(
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: store
>>>>>>> -; CHECK-NOT: store
>>>>>>> -; CHECK: br i1
>>>>>>> ; CHECK: for.body:
>>>>>>> ; CHECK: store i32
>>>>>>> ; CHECK: store i32
>>>>>>> @@ -302,6 +298,10 @@ for.end:
>>>>>>> ; CHECK: store i32
>>>>>>> ; CHECK-NOT: store i32
>>>>>>> ; CHECK: br i1
>>>>>>> +; CHECK: for.body.epil:
>>>>>>> +; CHECK: store
>>>>>>> +; CHECK-NOT: store
>>>>>>> +; CHECK: br i1
>>>>>>> define void @runtime_loop_with_enable(i32* nocapture %a, i32 %b) {
>>>>>>> entry:
>>>>>>> %cmp3 = icmp sgt i32 %b, 0
>>>>>>> @@ -328,16 +328,16 @@ for.end:
>>>>>>> ; should be duplicated (original and 3x unrolled).
>>>>>>> ;
>>>>>>> ; CHECK-LABEL: @runtime_loop_with_count3(
>>>>>>> -; CHECK: for.body.prol:
>>>>>>> -; CHECK: store
>>>>>>> -; CHECK-NOT: store
>>>>>>> -; CHECK: br i1
>>>>>>> ; CHECK: for.body
>>>>>>> ; CHECK: store
>>>>>>> ; CHECK: store
>>>>>>> ; CHECK: store
>>>>>>> ; CHECK-NOT: store
>>>>>>> ; CHECK: br i1
>>>>>>> +; CHECK: for.body.epil:
>>>>>>> +; CHECK: store
>>>>>>> +; CHECK-NOT: store
>>>>>>> +; CHECK: br i1
>>>>>>> define void @runtime_loop_with_count3(i32* nocapture %a, i32 %b) {
>>>>>>> entry:
>>>>>>> %cmp3 = icmp sgt i32 %b, 0
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> llvm-commits mailing list
>>>>>>> llvm-commits at lists.llvm.org
>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> llvm-commits mailing list
>>>>>>> llvm-commits at lists.llvm.org
>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>>>>
>>>>>>>
>>>>>
>>>>
>>
More information about the llvm-commits
mailing list