[llvm] r272730 - Reverting r272715 since it broke libcxx.
Michael Kuperstein via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 14 15:30:41 PDT 2016
Author: mkuper
Date: Tue Jun 14 17:30:41 2016
New Revision: 272730
URL: http://llvm.org/viewvc/llvm-project?rev=272730&view=rev
Log:
Reverting r272715 since it broke libcxx.
Removed:
llvm/trunk/test/Transforms/LoopVectorize/iv_outside_user.ll
Modified:
llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/trunk/test/Transforms/LoopVectorize/no_outside_user.ll
Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp?rev=272730&r1=272729&r2=272730&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Tue Jun 14 17:30:41 2016
@@ -355,12 +355,6 @@ protected:
/// Create an empty loop, based on the loop ranges of the old loop.
void createEmptyLoop();
-
- /// Set up the values of the IVs correctly when exiting the vector loop.
- void fixupIVUsers(PHINode *OrigPhi, const InductionDescriptor &II,
- Value *CountRoundDown, Value *EndValue,
- BasicBlock *MiddleBlock);
-
/// Create a new induction variable inside L.
PHINode *createInductionVariable(Loop *L, Value *Start, Value *End,
Value *Step, Instruction *DL);
@@ -1439,11 +1433,13 @@ private:
/// invariant.
void collectStridedAccess(Value *LoadOrStoreInst);
+ /// \brief Returns true if we can vectorize using this PHI node as an
+ /// induction.
+ ///
/// Updates the vectorization state by adding \p Phi to the inductions list.
/// This can set \p Phi as the main induction of the loop if \p Phi is a
/// better choice for the main induction than the existing one.
- void addInductionPhi(PHINode *Phi, InductionDescriptor ID,
- SmallPtrSetImpl<Value *> &AllowedExit);
+ bool addInductionPhi(PHINode *Phi, InductionDescriptor ID);
/// Report an analysis message to assist the user in diagnosing loops that are
/// not vectorized. These are handled as LoopAccessReport rather than
@@ -1497,7 +1493,7 @@ private:
/// Holds the widest induction type encountered.
Type *WidestIndTy;
- /// Allowed outside users. This holds the induction and reduction
+ /// Allowed outside users. This holds the reduction
/// vars which can be accessed from outside the loop.
SmallPtrSet<Value *, 4> AllowedExit;
/// This set holds the variables which are known to be uniform after
@@ -3223,9 +3219,6 @@ void InnerLoopVectorizer::createEmptyLoo
// or the value at the end of the vectorized loop.
BCResumeVal->addIncoming(EndValue, MiddleBlock);
- // Fix up external users of the induction variable.
- fixupIVUsers(OrigPhi, II, CountRoundDown, EndValue, MiddleBlock);
-
// Fix the scalar body counter (PHI node).
unsigned BlockIdx = OrigPhi->getBasicBlockIndex(ScalarPH);
@@ -3265,59 +3258,6 @@ void InnerLoopVectorizer::createEmptyLoo
Hints.setAlreadyVectorized();
}
-// Fix up external users of the induction variable. At this point, we are
-// in LCSSA form, with all external PHIs that use the IV having one input value,
-// coming from the remainder loop. We need those PHIs to also have a correct
-// value for the IV when arriving directly from the middle block.
-void InnerLoopVectorizer::fixupIVUsers(PHINode *OrigPhi,
- const InductionDescriptor &II,
- Value *CountRoundDown, Value *EndValue,
- BasicBlock *MiddleBlock) {
- // There are two kinds of external IV usages - those that use the value
- // computed in the last iteration (the PHI) and those that use the penultimate
- // value (the value that feeds into the phi from the loop latch).
- // We allow both, but they, obviously, have different values.
-
- // We only expect at most one of each kind of user. This is because LCSSA will
- // canonicalize the users to a single PHI node per exit block, and we
- // currently only vectorize loops with a single exit.
- assert(OrigLoop->getExitBlock() && "Expected a single exit block");
-
- // An external user of the last iteration's value should see the value that
- // the remainder loop uses to initialize its own IV.
- Value *PostInc = OrigPhi->getIncomingValueForBlock(OrigLoop->getLoopLatch());
- for (User *U : PostInc->users()) {
- Instruction *UI = cast<Instruction>(U);
- if (!OrigLoop->contains(UI)) {
- assert(isa<PHINode>(UI) && "Expected LCSSA form");
- cast<PHINode>(UI)->addIncoming(EndValue, MiddleBlock);
- break;
- }
- }
-
- // An external user of the penultimate value need to see EndValue - Step.
- // The simplest way to get this is to recompute it from the constituent SCEVs,
- // that is Start + (Step * (CRD - 1)).
- for (User *U : OrigPhi->users()) {
- Instruction *UI = cast<Instruction>(U);
- if (!OrigLoop->contains(UI)) {
- assert(isa<PHINode>(UI) && "Expected LCSSA form");
- const DataLayout &DL =
- OrigLoop->getHeader()->getModule()->getDataLayout();
-
- IRBuilder<> B(MiddleBlock->getTerminator());
- Value *CountMinusOne = B.CreateSub(
- CountRoundDown, ConstantInt::get(CountRoundDown->getType(), 1));
- Value *CMO = B.CreateSExtOrTrunc(CountMinusOne, II.getStep()->getType(),
- "cast.cmo");
- Value *Escape = II.transform(B, CMO, PSE.getSE(), DL);
- Escape->setName("ind.escape");
- cast<PHINode>(UI)->addIncoming(Escape, MiddleBlock);
- break;
- }
- }
-}
-
namespace {
struct CSEDenseMapInfo {
static bool canHandle(Instruction *I) {
@@ -4699,10 +4639,10 @@ static Type *getWiderType(const DataLayo
/// \brief Check that the instruction has outside loop users and is not an
/// identified reduction variable.
static bool hasOutsideLoopUser(const Loop *TheLoop, Instruction *Inst,
- SmallPtrSetImpl<Value *> &AllowedExit) {
- // Reduction and Induction instructions are allowed to have exit users. All
- // other instructions must not have external users.
- if (!AllowedExit.count(Inst))
+ SmallPtrSetImpl<Value *> &Reductions) {
+ // Reduction instructions are allowed to have exit users. All other
+ // instructions must not have external users.
+ if (!Reductions.count(Inst))
// Check that all of the users of the loop are inside the BB.
for (User *U : Inst->users()) {
Instruction *UI = cast<Instruction>(U);
@@ -4715,9 +4655,8 @@ static bool hasOutsideLoopUser(const Loo
return false;
}
-void LoopVectorizationLegality::addInductionPhi(
- PHINode *Phi, InductionDescriptor ID,
- SmallPtrSetImpl<Value *> &AllowedExit) {
+bool LoopVectorizationLegality::addInductionPhi(PHINode *Phi,
+ InductionDescriptor ID) {
Inductions[Phi] = ID;
Type *PhiTy = Phi->getType();
const DataLayout &DL = Phi->getModule()->getDataLayout();
@@ -4743,13 +4682,18 @@ void LoopVectorizationLegality::addInduc
Induction = Phi;
}
- // Both the PHI node itself, and the "post-increment" value feeding
- // back into the PHI node may have external users.
- AllowedExit.insert(Phi);
- AllowedExit.insert(Phi->getIncomingValueForBlock(TheLoop->getLoopLatch()));
-
DEBUG(dbgs() << "LV: Found an induction variable.\n");
- return;
+
+ // Until we explicitly handle the case of an induction variable with
+ // an outside loop user we have to give up vectorizing this loop.
+ if (hasOutsideLoopUser(TheLoop, Phi, AllowedExit)) {
+ emitAnalysis(VectorizationReport(Phi) <<
+ "use of induction value outside of the "
+ "loop is not handled by vectorizer");
+ return false;
+ }
+
+ return true;
}
bool LoopVectorizationLegality::canVectorizeInstrs() {
@@ -4813,7 +4757,8 @@ bool LoopVectorizationLegality::canVecto
InductionDescriptor ID;
if (InductionDescriptor::isInductionPHI(Phi, PSE, ID)) {
- addInductionPhi(Phi, ID, AllowedExit);
+ if (!addInductionPhi(Phi, ID))
+ return false;
continue;
}
@@ -4825,7 +4770,8 @@ bool LoopVectorizationLegality::canVecto
// As a last resort, coerce the PHI to a AddRec expression
// and re-try classifying it a an induction PHI.
if (InductionDescriptor::isInductionPHI(Phi, PSE, ID, true)) {
- addInductionPhi(Phi, ID, AllowedExit);
+ if (!addInductionPhi(Phi, ID))
+ return false;
continue;
}
Removed: llvm/trunk/test/Transforms/LoopVectorize/iv_outside_user.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/iv_outside_user.ll?rev=272729&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/iv_outside_user.ll (original)
+++ llvm/trunk/test/Transforms/LoopVectorize/iv_outside_user.ll (removed)
@@ -1,84 +0,0 @@
-; RUN: opt -S -loop-vectorize -force-vector-interleave=1 -force-vector-width=2 < %s | FileCheck %s
-
-; CHECK-LABEL: @postinc
-; CHECK-LABEL: scalar.ph:
-; CHECK: %bc.resume.val = phi i32 [ %n.vec, %middle.block ], [ 0, %entry ]
-; CHECK-LABEL: for.end:
-; CHECK: %[[RET:.*]] = phi i32 [ {{.*}}, %for.body ], [ %n.vec, %middle.block ]
-; CHECK: ret i32 %[[RET]]
-define i32 @postinc(i32 %k) {
-entry:
- br label %for.body
-
-for.body:
- %inc.phi = phi i32 [ 0, %entry ], [ %inc, %for.body ]
- %inc = add nsw i32 %inc.phi, 1
- %cmp = icmp eq i32 %inc, %k
- br i1 %cmp, label %for.end, label %for.body
-
-for.end:
- ret i32 %inc
-}
-
-; CHECK-LABEL: @preinc
-; CHECK-LABEL: middle.block:
-; CHECK: %3 = sub i32 %n.vec, 1
-; CHECK: %ind.escape = add i32 0, %3
-; CHECK-LABEL: scalar.ph:
-; CHECK: %bc.resume.val = phi i32 [ %n.vec, %middle.block ], [ 0, %entry ]
-; CHECK-LABEL: for.end:
-; CHECK: %[[RET:.*]] = phi i32 [ {{.*}}, %for.body ], [ %ind.escape, %middle.block ]
-; CHECK: ret i32 %[[RET]]
-define i32 @preinc(i32 %k) {
-entry:
- br label %for.body
-
-for.body:
- %inc.phi = phi i32 [ 0, %entry ], [ %inc, %for.body ]
- %inc = add nsw i32 %inc.phi, 1
- %cmp = icmp eq i32 %inc, %k
- br i1 %cmp, label %for.end, label %for.body
-
-for.end:
- ret i32 %inc.phi
-}
-
-; CHECK-LABEL: @constpre
-; CHECK-LABEL: for.end:
-; CHECK: %[[RET:.*]] = phi i32 [ {{.*}}, %for.body ], [ 2, %middle.block ]
-; CHECK: ret i32 %[[RET]]
-define i32 @constpre() {
-entry:
- br label %for.body
-
-for.body:
- %inc.phi = phi i32 [ 32, %entry ], [ %inc, %for.body ]
- %inc = sub nsw i32 %inc.phi, 2
- %cmp = icmp eq i32 %inc, 0
- br i1 %cmp, label %for.end, label %for.body
-
-for.end:
- ret i32 %inc.phi
-}
-
-; CHECK-LABEL: @geppre
-; CHECK-LABEL: middle.block:
-; CHECK: %ind.escape = getelementptr i32, i32* %ptr, i64 124
-; CHECK-LABEL: for.end:
-; CHECK: %[[RET:.*]] = phi i32* [ {{.*}}, %for.body ], [ %ind.escape, %middle.block ]
-; CHECK: ret i32* %[[RET]]
-define i32* @geppre(i32* %ptr) {
-entry:
- br label %for.body
-
-for.body:
- %inc.phi = phi i32 [ 0, %entry ], [ %inc, %for.body ]
- %ptr.phi = phi i32* [ %ptr, %entry ], [ %inc.ptr, %for.body ]
- %inc = add nsw i32 %inc.phi, 1
- %inc.ptr = getelementptr i32, i32* %ptr.phi, i32 4
- %cmp = icmp eq i32 %inc, 32
- br i1 %cmp, label %for.end, label %for.body
-
-for.end:
- ret i32* %ptr.phi
-}
Modified: llvm/trunk/test/Transforms/LoopVectorize/no_outside_user.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/no_outside_user.ll?rev=272730&r1=272729&r2=272730&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/no_outside_user.ll (original)
+++ llvm/trunk/test/Transforms/LoopVectorize/no_outside_user.ll Tue Jun 14 17:30:41 2016
@@ -1,6 +1,7 @@
; RUN: opt -S -loop-vectorize -force-vector-interleave=1 -force-vector-width=2 < %s 2>&1 | FileCheck %s
; CHECK: remark: {{.*}}: loop not vectorized: value could not be identified as an induction or reduction variable
+; CHECK: remark: {{.*}}: loop not vectorized: use of induction value outside of the loop is not handled by vectorizer
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
@@ -40,3 +41,34 @@ f1.exit.loopexit:
%.lcssa = phi i32 [ %tmp17, %bb16 ]
ret i32 %.lcssa
}
+
+; Don't vectorize this loop. Its phi node (induction variable) has an outside
+; loop user. We currently don't handle this case.
+; PR17179
+
+; CHECK-LABEL: @test2(
+; CHECK-NOT: <2 x
+
+ at x1 = common global i32 0, align 4
+ at x2 = common global i32 0, align 4
+ at x0 = common global i32 0, align 4
+
+define i32 @test2() {
+entry:
+ store i32 0, i32* @x1, align 4
+ %0 = load i32, i32* @x0, align 4
+ br label %for.cond1.preheader
+
+for.cond1.preheader:
+ %inc7 = phi i32 [ 0, %entry ], [ %inc, %for.cond1.preheader ]
+ %inc = add nsw i32 %inc7, 1
+ %cmp = icmp eq i32 %inc, 52
+ br i1 %cmp, label %for.end5, label %for.cond1.preheader
+
+for.end5:
+ %inc7.lcssa = phi i32 [ %inc7, %for.cond1.preheader ]
+ %xor = xor i32 %inc7.lcssa, %0
+ store i32 52, i32* @x1, align 4
+ store i32 1, i32* @x2, align 4
+ ret i32 %xor
+}
More information about the llvm-commits
mailing list