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-rw-r--r--include/llvm/Analysis/ScalarEvolution.h28
-rw-r--r--lib/Analysis/ScalarEvolution.cpp370
-rw-r--r--test/Analysis/ScalarEvolution/2008-11-18-Stride1.ll4
-rw-r--r--test/Analysis/ScalarEvolution/2008-11-18-Stride2.ll5
-rw-r--r--test/Analysis/ScalarEvolution/2008-12-15-DontUseSDiv.ll1
-rw-r--r--test/Analysis/ScalarEvolution/trip-count3.ll3
-rw-r--r--test/Analysis/ScalarEvolution/trip-count9.ll10
-rw-r--r--test/Transforms/IndVarSimplify/loop_evaluate_6.ll5
-rw-r--r--test/Transforms/IndVarSimplify/no-iv-rewrite.ll9
9 files changed, 247 insertions, 188 deletions
diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 3d37651525..4915bc6af2 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -426,14 +426,6 @@ namespace llvm {
/// resolution.
void ForgetSymbolicName(Instruction *I, const SCEV *SymName);
- /// getBECount - Subtract the end and start values and divide by the step,
- /// rounding up, to get the number of times the backedge is executed. Return
- /// CouldNotCompute if an intermediate computation overflows.
- const SCEV *getBECount(const SCEV *Start,
- const SCEV *End,
- const SCEV *Step,
- bool NoWrap);
-
/// getBackedgeTakenInfo - Return the BackedgeTakenInfo for the given
/// loop, lazily computing new values if the loop hasn't been analyzed
/// yet.
@@ -498,6 +490,8 @@ namespace llvm {
/// less-than is signed.
ExitLimit HowManyLessThans(const SCEV *LHS, const SCEV *RHS,
const Loop *L, bool isSigned, bool IsSubExpr);
+ ExitLimit HowManyGreaterThans(const SCEV *LHS, const SCEV *RHS,
+ const Loop *L, bool isSigned, bool IsSubExpr);
/// getPredecessorWithUniqueSuccessorForBB - Return a predecessor of BB
/// (which may not be an immediate predecessor) which has exactly one
@@ -880,6 +874,24 @@ namespace llvm {
virtual void verifyAnalysis() const;
private:
+ /// Compute the backedge taken count knowing the interval difference, the
+ /// stride and presence of the equality in the comparison.
+ const SCEV *computeBECount(const SCEV *Delta, const SCEV *Stride,
+ bool Equality);
+
+ /// Verify if an linear IV with positive stride can overflow when in a
+ /// less-than comparison, knowing the invariant term of the comparison,
+ /// the stride and the knowledge of NSW/NUW flags on the recurrence.
+ bool doesIVOverflowOnLT(const SCEV *RHS, const SCEV *Stride,
+ bool IsSigned, bool NoWrap);
+
+ /// Verify if an linear IV with negative stride can overflow when in a
+ /// greater-than comparison, knowing the invariant term of the comparison,
+ /// the stride and the knowledge of NSW/NUW flags on the recurrence.
+ bool doesIVOverflowOnGT(const SCEV *RHS, const SCEV *Stride,
+ bool IsSigned, bool NoWrap);
+
+ private:
FoldingSet<SCEV> UniqueSCEVs;
BumpPtrAllocator SCEVAllocator;
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 227f1de129..9467823ddc 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3102,6 +3102,12 @@ const SCEV *ScalarEvolution::createNodeForPHI(PHINode *PN) {
if (isKnownPositive(getMinusSCEV(getSCEV(GEP), Ptr)))
Flags = setFlags(Flags, SCEV::FlagNUW);
}
+ } else if (const SubOperator *OBO =
+ dyn_cast<SubOperator>(BEValueV)) {
+ if (OBO->hasNoUnsignedWrap())
+ Flags = setFlags(Flags, SCEV::FlagNUW);
+ if (OBO->hasNoSignedWrap())
+ Flags = setFlags(Flags, SCEV::FlagNSW);
}
const SCEV *StartVal = getSCEV(StartValueV);
@@ -4605,25 +4611,17 @@ ScalarEvolution::ComputeExitLimitFromICmp(const Loop *L,
if (EL.hasAnyInfo()) return EL;
break;
}
- case ICmpInst::ICMP_SLT: {
- ExitLimit EL = HowManyLessThans(LHS, RHS, L, true, IsSubExpr);
- if (EL.hasAnyInfo()) return EL;
- break;
- }
- case ICmpInst::ICMP_SGT: {
- ExitLimit EL = HowManyLessThans(getNotSCEV(LHS),
- getNotSCEV(RHS), L, true, IsSubExpr);
- if (EL.hasAnyInfo()) return EL;
- break;
- }
- case ICmpInst::ICMP_ULT: {
- ExitLimit EL = HowManyLessThans(LHS, RHS, L, false, IsSubExpr);
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_ULT: { // while (X < Y)
+ bool IsSigned = Cond == ICmpInst::ICMP_SLT;
+ ExitLimit EL = HowManyLessThans(LHS, RHS, L, IsSigned, IsSubExpr);
if (EL.hasAnyInfo()) return EL;
break;
}
- case ICmpInst::ICMP_UGT: {
- ExitLimit EL = HowManyLessThans(getNotSCEV(LHS),
- getNotSCEV(RHS), L, false, IsSubExpr);
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_UGT: { // while (X > Y)
+ bool IsSigned = Cond == ICmpInst::ICMP_SGT;
+ ExitLimit EL = HowManyGreaterThans(LHS, RHS, L, IsSigned, IsSubExpr);
if (EL.hasAnyInfo()) return EL;
break;
}
@@ -6330,45 +6328,72 @@ ScalarEvolution::isImpliedCondOperandsHelper(ICmpInst::Predicate Pred,
return false;
}
-/// getBECount - Subtract the end and start values and divide by the step,
-/// rounding up, to get the number of times the backedge is executed. Return
-/// CouldNotCompute if an intermediate computation overflows.
-const SCEV *ScalarEvolution::getBECount(const SCEV *Start,
- const SCEV *End,
- const SCEV *Step,
- bool NoWrap) {
- assert(!isKnownNegative(Step) &&
- "This code doesn't handle negative strides yet!");
-
- Type *Ty = Start->getType();
-
- // When Start == End, we have an exact BECount == 0. Short-circuit this case
- // here because SCEV may not be able to determine that the unsigned division
- // after rounding is zero.
- if (Start == End)
- return getConstant(Ty, 0);
-
- const SCEV *NegOne = getConstant(Ty, (uint64_t)-1);
- const SCEV *Diff = getMinusSCEV(End, Start);
- const SCEV *RoundUp = getAddExpr(Step, NegOne);
-
- // Add an adjustment to the difference between End and Start so that
- // the division will effectively round up.
- const SCEV *Add = getAddExpr(Diff, RoundUp);
-
- if (!NoWrap) {
- // Check Add for unsigned overflow.
- // TODO: More sophisticated things could be done here.
- Type *WideTy = IntegerType::get(getContext(),
- getTypeSizeInBits(Ty) + 1);
- const SCEV *EDiff = getZeroExtendExpr(Diff, WideTy);
- const SCEV *ERoundUp = getZeroExtendExpr(RoundUp, WideTy);
- const SCEV *OperandExtendedAdd = getAddExpr(EDiff, ERoundUp);
- if (getZeroExtendExpr(Add, WideTy) != OperandExtendedAdd)
- return getCouldNotCompute();
+// Verify if an linear IV with positive stride can overflow when in a
+// less-than comparison, knowing the invariant term of the comparison, the
+// stride and the knowledge of NSW/NUW flags on the recurrence.
+bool ScalarEvolution::doesIVOverflowOnLT(const SCEV *RHS, const SCEV *Stride,
+ bool IsSigned, bool NoWrap) {
+ if (NoWrap) return false;
+
+ unsigned BitWidth = getTypeSizeInBits(RHS->getType());
+ const SCEV *One = getConstant(Stride->getType(), 1);
+
+ if (IsSigned) {
+ APInt MaxRHS = getSignedRange(RHS).getSignedMax();
+ APInt MaxValue = APInt::getSignedMaxValue(BitWidth);
+ APInt MaxStrideMinusOne = getSignedRange(getMinusSCEV(Stride, One))
+ .getSignedMax();
+
+ // SMaxRHS + SMaxStrideMinusOne > SMaxValue => overflow!
+ return (MaxValue - MaxStrideMinusOne).slt(MaxRHS);
+ }
+
+ APInt MaxRHS = getUnsignedRange(RHS).getUnsignedMax();
+ APInt MaxValue = APInt::getMaxValue(BitWidth);
+ APInt MaxStrideMinusOne = getUnsignedRange(getMinusSCEV(Stride, One))
+ .getUnsignedMax();
+
+ // UMaxRHS + UMaxStrideMinusOne > UMaxValue => overflow!
+ return (MaxValue - MaxStrideMinusOne).ult(MaxRHS);
+}
+
+// Verify if an linear IV with negative stride can overflow when in a
+// greater-than comparison, knowing the invariant term of the comparison,
+// the stride and the knowledge of NSW/NUW flags on the recurrence.
+bool ScalarEvolution::doesIVOverflowOnGT(const SCEV *RHS, const SCEV *Stride,
+ bool IsSigned, bool NoWrap) {
+ if (NoWrap) return false;
+
+ unsigned BitWidth = getTypeSizeInBits(RHS->getType());
+ const SCEV *One = getConstant(Stride->getType(), 1);
+
+ if (IsSigned) {
+ APInt MinRHS = getSignedRange(RHS).getSignedMin();
+ APInt MinValue = APInt::getSignedMinValue(BitWidth);
+ APInt MaxStrideMinusOne = getSignedRange(getMinusSCEV(Stride, One))
+ .getSignedMax();
+
+ // SMinRHS - SMaxStrideMinusOne < SMinValue => overflow!
+ return (MinValue + MaxStrideMinusOne).sgt(MinRHS);
}
- return getUDivExpr(Add, Step);
+ APInt MinRHS = getUnsignedRange(RHS).getUnsignedMin();
+ APInt MinValue = APInt::getMinValue(BitWidth);
+ APInt MaxStrideMinusOne = getUnsignedRange(getMinusSCEV(Stride, One))
+ .getUnsignedMax();
+
+ // UMinRHS - UMaxStrideMinusOne < UMinValue => overflow!
+ return (MinValue + MaxStrideMinusOne).ugt(MinRHS);
+}
+
+// Compute the backedge taken count knowing the interval difference, the
+// stride and presence of the equality in the comparison.
+const SCEV *ScalarEvolution::computeBECount(const SCEV *Delta, const SCEV *Step,
+ bool Equality) {
+ const SCEV *One = getConstant(Step->getType(), 1);
+ Delta = Equality ? getAddExpr(Delta, Step)
+ : getAddExpr(Delta, getMinusSCEV(Step, One));
+ return getUDivExpr(Delta, Step);
}
/// HowManyLessThans - Return the number of times a backedge containing the
@@ -6380,125 +6405,144 @@ const SCEV *ScalarEvolution::getBECount(const SCEV *Start,
/// a subexpression that cannot overflow before evaluating true.
ScalarEvolution::ExitLimit
ScalarEvolution::HowManyLessThans(const SCEV *LHS, const SCEV *RHS,
- const Loop *L, bool isSigned,
+ const Loop *L, bool IsSigned,
bool IsSubExpr) {
- // Only handle: "ADDREC < LoopInvariant".
- if (!isLoopInvariant(RHS, L)) return getCouldNotCompute();
+ // We handle only IV < Invariant
+ if (!isLoopInvariant(RHS, L))
+ return getCouldNotCompute();
- const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(LHS);
- if (!AddRec || AddRec->getLoop() != L)
+ const SCEVAddRecExpr *IV = dyn_cast<SCEVAddRecExpr>(LHS);
+
+ // Avoid weird loops
+ if (!IV || IV->getLoop() != L || !IV->isAffine())
return getCouldNotCompute();
- if (AddRec->isAffine()) {
- unsigned BitWidth = getTypeSizeInBits(AddRec->getType());
- const SCEV *Step = AddRec->getStepRecurrence(*this);
+ bool NoWrap = !IsSubExpr &&
+ IV->getNoWrapFlags(IsSigned ? SCEV::FlagNSW : SCEV::FlagNUW);
- if (Step->isZero())
- return getCouldNotCompute();
- if (Step->isOne()) {
- // With unit stride, the iteration never steps past the limit value.
- } else if (isKnownPositive(Step)) {
- // Test whether a positive iteration can step past the limit value and
- // past the maximum value for its type in a single step. Constant negative
- // stride should be rare because LHS > RHS comparisons are canonicalized
- // to -LHS < -RHS.
- //
- // NSW/NUW flags imply that stepping past RHS would immediately result in
- // undefined behavior. No self-wrap is not useful here because the loop
- // counter may signed or unsigned wrap but continue iterating and
- // terminate with defined behavior without ever self-wrapping.
- const SCEV *One = getConstant(Step->getType(), 1);
- if (isSigned) {
- if (!AddRec->getNoWrapFlags(SCEV::FlagNSW)) {
- APInt Max = APInt::getSignedMaxValue(BitWidth);
- if ((Max - getSignedRange(getMinusSCEV(Step, One)).getSignedMax())
- .slt(getSignedRange(RHS).getSignedMax()))
- return getCouldNotCompute();
- }
- } else if (!AddRec->getNoWrapFlags(SCEV::FlagNUW)){
- APInt Max = APInt::getMaxValue(BitWidth);
- if ((Max - getUnsignedRange(getMinusSCEV(Step, One)).getUnsignedMax())
- .ult(getUnsignedRange(RHS).getUnsignedMax()))
- return getCouldNotCompute();
- }
- } else {
- // Cannot handle variable stride.
- return getCouldNotCompute();
- }
- // We know the LHS is of the form {n,+,s} and the RHS is some loop-invariant
- // m. So, we count the number of iterations in which {n,+,s} < m is true.
- // Note that we cannot simply return max(m-n,0)/s because it's not safe to
- // treat m-n as signed nor unsigned due to overflow possibility.
-
- // First, we get the value of the LHS in the first iteration: n
- const SCEV *Start = AddRec->getOperand(0);
-
- // Determine the minimum constant start value.
- const SCEV *MinStart = getConstant(isSigned ?
- getSignedRange(Start).getSignedMin() :
- getUnsignedRange(Start).getUnsignedMin());
-
- // If we know that the condition is true in order to enter the loop,
- // then we know that it will run exactly (m-n)/s times. Otherwise, we
- // only know that it will execute (max(m,n)-n)/s times. In both cases,
- // the division must round up.
- const SCEV *End = RHS;
- if (!isLoopEntryGuardedByCond(L,
- isSigned ? ICmpInst::ICMP_SLT :
- ICmpInst::ICMP_ULT,
- getMinusSCEV(Start, Step), RHS))
- End = isSigned ? getSMaxExpr(RHS, Start)
- : getUMaxExpr(RHS, Start);
-
- // Determine the maximum constant end value.
- const SCEV *MaxEnd = getConstant(isSigned ?
- getSignedRange(End).getSignedMax() :
- getUnsignedRange(End).getUnsignedMax());
-
- // If MaxEnd is within a step of the maximum integer value in its type,
- // adjust it down to the minimum value which would produce the same effect.
- // This allows the subsequent ceiling division of (N+(step-1))/step to
- // compute the correct value.
- const SCEV *StepMinusOne = getMinusSCEV(Step,
- getConstant(Step->getType(), 1));
- MaxEnd = isSigned ?
- getSMinExpr(MaxEnd,
- getMinusSCEV(getConstant(APInt::getSignedMaxValue(BitWidth)),
- StepMinusOne)) :
- getUMinExpr(MaxEnd,
- getMinusSCEV(getConstant(APInt::getMaxValue(BitWidth)),
- StepMinusOne));
-
- // If the loop counter does not self-wrap, then the trip count may be
- // computed by dividing the distance by the step. This is independent of
- // signed or unsigned wrap.
- bool NoWrap = false;
- if (!IsSubExpr) {
- NoWrap = AddRec->getNoWrapFlags(
- (SCEV::NoWrapFlags)(((isSigned ? SCEV::FlagNSW : SCEV::FlagNUW))
- | SCEV::FlagNW));
- }
- // Finally, we subtract these two values and divide, rounding up, to get
- // the number of times the backedge is executed.
- const SCEV *BECount = getBECount(Start, End, Step, NoWrap);
+ const SCEV *Stride = IV->getStepRecurrence(*this);
- // The maximum backedge count is similar, except using the minimum start
- // value and the maximum end value.
- // If we already have an exact constant BECount, use it instead.
- const SCEV *MaxBECount = isa<SCEVConstant>(BECount) ? BECount
- : getBECount(MinStart, MaxEnd, Step, NoWrap);
+ // Avoid negative or zero stride values
+ if (!isKnownPositive(Stride))
+ return getCouldNotCompute();
- // If the stride is nonconstant, and NoWrap == true, then
- // getBECount(MinStart, MaxEnd) may not compute. This would result in an
- // exact BECount and invalid MaxBECount, which should be avoided to catch
- // more optimization opportunities.
- if (isa<SCEVCouldNotCompute>(MaxBECount))
- MaxBECount = BECount;
+ // Avoid proven overflow cases: this will ensure that the backedge taken count
+ // will not generate any unsigned overflow. Relaxed no-overflow conditions
+ // exploit NoWrapFlags, allowing to optimize in presence of undefined
+ // behaviors like the case of C language.
+ if (!Stride->isOne() && doesIVOverflowOnLT(RHS, Stride, IsSigned, NoWrap))
+ return getCouldNotCompute();
- return ExitLimit(BECount, MaxBECount);
- }
+ ICmpInst::Predicate Cond = IsSigned ? ICmpInst::ICMP_SLT
+ : ICmpInst::ICMP_ULT;
+ const SCEV *Start = IV->getStart();
+ const SCEV *End = RHS;
+ if (!isLoopEntryGuardedByCond(L, Cond, getMinusSCEV(Start, Stride), RHS))
+ End = IsSigned ? getSMaxExpr(RHS, Start)
+ : getUMaxExpr(RHS, Start);
- return getCouldNotCompute();
+ const SCEV *BECount = computeBECount(getMinusSCEV(End, Start), Stride, false);
+
+ APInt MinStart = IsSigned ? getSignedRange(Start).getSignedMin()
+ : getUnsignedRange(Start).getUnsignedMin();
+
+ APInt MinStride = IsSigned ? getSignedRange(Stride).getSignedMin()
+ : getUnsignedRange(Stride).getUnsignedMin();
+
+ unsigned BitWidth = getTypeSizeInBits(LHS->getType());
+ APInt Limit = IsSigned ? APInt::getSignedMaxValue(BitWidth) - (MinStride - 1)
+ : APInt::getMaxValue(BitWidth) - (MinStride - 1);
+
+ // Although End can be a MAX expression we estimate MaxEnd considering only
+ // the case End = RHS. This is safe because in the other case (End - Start)
+ // is zero, leading to a zero maximum backedge taken count.
+ APInt MaxEnd =
+ IsSigned ? APIntOps::smin(getSignedRange(RHS).getSignedMax(), Limit)
+ : APIntOps::umin(getUnsignedRange(RHS).getUnsignedMax(), Limit);
+
+ const SCEV *MaxBECount = getCouldNotCompute();
+ if (isa<SCEVConstant>(BECount))
+ MaxBECount = BECount;
+ else
+ MaxBECount = computeBECount(getConstant(MaxEnd - MinStart),
+ getConstant(MinStride), false);
+
+ if (isa<SCEVCouldNotCompute>(MaxBECount))
+ MaxBECount = BECount;
+
+ return ExitLimit(BECount, MaxBECount);
+}
+
+ScalarEvolution::ExitLimit
+ScalarEvolution::HowManyGreaterThans(const SCEV *LHS, const SCEV *RHS,
+ const Loop *L, bool IsSigned,
+ bool IsSubExpr) {
+ // We handle only IV > Invariant
+ if (!isLoopInvariant(RHS, L))
+ return getCouldNotCompute();
+
+ const SCEVAddRecExpr *IV = dyn_cast<SCEVAddRecExpr>(LHS);
+
+ // Avoid weird loops
+ if (!IV || IV->getLoop() != L || !IV->isAffine())
+ return getCouldNotCompute();
+
+ bool NoWrap = !IsSubExpr &&
+ IV->getNoWrapFlags(IsSigned ? SCEV::FlagNSW : SCEV::FlagNUW);
+
+ const SCEV *Stride = getNegativeSCEV(IV->getStepRecurrence(*this));
+
+ // Avoid negative or zero stride values
+ if (!isKnownPositive(Stride))
+ return getCouldNotCompute();
+
+ // Avoid proven overflow cases: this will ensure that the backedge taken count
+ // will not generate any unsigned overflow. Relaxed no-overflow conditions
+ // exploit NoWrapFlags, allowing to optimize in presence of undefined
+ // behaviors like the case of C language.
+ if (!Stride->isOne() && doesIVOverflowOnGT(RHS, Stride, IsSigned, NoWrap))
+ return getCouldNotCompute();
+
+ ICmpInst::Predicate Cond = IsSigned ? ICmpInst::ICMP_SGT
+ : ICmpInst::ICMP_UGT;
+
+ const SCEV *Start = IV->getStart();
+ const SCEV *End = RHS;
+ if (!isLoopEntryGuardedByCond(L, Cond, getAddExpr(Start, Stride), RHS))
+ End = IsSigned ? getSMinExpr(RHS, Start)
+ : getUMinExpr(RHS, Start);
+
+ const SCEV *BECount = computeBECount(getMinusSCEV(Start, End), Stride, false);
+
+ APInt MaxStart = IsSigned ? getSignedRange(Start).getSignedMax()
+ : getUnsignedRange(Start).getUnsignedMax();
+
+ APInt MinStride = IsSigned ? getSignedRange(Stride).getSignedMin()
+ : getUnsignedRange(Stride).getUnsignedMin();
+
+ unsigned BitWidth = getTypeSizeInBits(LHS->getType());
+ APInt Limit = IsSigned ? APInt::getSignedMinValue(BitWidth) + (MinStride - 1)
+ : APInt::getMinValue(BitWidth) + (MinStride - 1);
+
+ // Although End can be a MIN expression we estimate MinEnd considering only
+ // the case End = RHS. This is safe because in the other case (Start - End)
+ // is zero, leading to a zero maximum backedge taken count.
+ APInt MinEnd =
+ IsSigned ? APIntOps::smax(getSignedRange(RHS).getSignedMin(), Limit)
+ : APIntOps::umax(getUnsignedRange(RHS).getUnsignedMin(), Limit);
+
+
+ const SCEV *MaxBECount = getCouldNotCompute();
+ if (isa<SCEVConstant>(BECount))
+ MaxBECount = BECount;
+ else
+ MaxBECount = computeBECount(getConstant(MaxStart - MinEnd),
+ getConstant(MinStride), false);
+
+ if (isa<SCEVCouldNotCompute>(MaxBECount))
+ MaxBECount = BECount;
+
+ return ExitLimit(BECount, MaxBECount);
}
/// getNumIterationsInRange - Return the number of iterations of this loop that
diff --git a/test/Analysis/ScalarEvolution/2008-11-18-Stride1.ll b/test/Analysis/ScalarEvolution/2008-11-18-Stride1.ll
index 74698795ca..7acf90c733 100644
--- a/test/Analysis/ScalarEvolution/2008-11-18-Stride1.ll
+++ b/test/Analysis/ScalarEvolution/2008-11-18-Stride1.ll
@@ -1,6 +1,8 @@
; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
-; CHECK: Loop %bb: Unpredictable backedge-taken count.
+; CHECK: Loop %bb: backedge-taken count is ((-5 + %x) /u 3)
+; CHECK: Loop %bb: max backedge-taken count is 1431655764
+
; ScalarEvolution can't compute a trip count because it doesn't know if
; dividing by the stride will have a remainder. This could theoretically
diff --git a/test/Analysis/ScalarEvolution/2008-11-18-Stride2.ll b/test/Analysis/ScalarEvolution/2008-11-18-Stride2.ll
index 0ee69c6d30..2b2296a3a2 100644
--- a/test/Analysis/ScalarEvolution/2008-11-18-Stride2.ll
+++ b/test/Analysis/ScalarEvolution/2008-11-18-Stride2.ll
@@ -1,7 +1,8 @@
; RUN: opt < %s -analyze -scalar-evolution 2>&1 | FileCheck %s
-; XFAIL: *
-; CHECK: /u 3
+; CHECK: Loop %bb: backedge-taken count is ((999 + (-1 * %x)) /u 3)
+; CHECK: Loop %bb: max backedge-taken count is 334
+
; This is a tricky testcase for unsigned wrap detection which ScalarEvolution
; doesn't yet know how to do.
diff --git a/test/Analysis/ScalarEvolution/2008-12-15-DontUseSDiv.ll b/test/Analysis/ScalarEvolution/2008-12-15-DontUseSDiv.ll
index d40044e7f8..70588bc057 100644
--- a/test/Analysis/ScalarEvolution/2008-12-15-DontUseSDiv.ll
+++ b/test/Analysis/ScalarEvolution/2008-12-15-DontUseSDiv.ll
@@ -1,5 +1,4 @@
; RUN: opt < %s -analyze -scalar-evolution 2>&1 | FileCheck %s
-; XFAIL: *
; CHECK: /u 5
diff --git a/test/Analysis/ScalarEvolution/trip-count3.ll b/test/Analysis/ScalarEvolution/trip-count3.ll
index 32c51bfc45..850e035e7c 100644
--- a/test/Analysis/ScalarEvolution/trip-count3.ll
+++ b/test/Analysis/ScalarEvolution/trip-count3.ll
@@ -4,7 +4,8 @@
; dividing by the stride will have a remainder. This could theoretically
; be teaching it how to use a more elaborate trip count computation.
-; CHECK: Loop %bb3.i: Unpredictable backedge-taken count.
+; CHECK: Loop %bb3.i: backedge-taken count is ((64 + (-64 smax (-1 + (-1 * %0))) + %0) /u 64)
+; CHECK: Loop %bb3.i: max backedge-taken count is 33554431
%struct.FILE = type { i32, i8*, i8*, i8*, i8*, i8*, i8*, i8*, i8*, i8*, i8*, i8*, %struct._IO_marker*, %struct.FILE*, i32, i32, i64, i16, i8, [1 x i8], i8*, i64, i8*, i8*, i8*, i8*, i64, i32, [20 x i8] }
%struct.SHA_INFO = type { [5 x i32], i32, i32, [16 x i32] }
diff --git a/test/Analysis/ScalarEvolution/trip-count9.ll b/test/Analysis/ScalarEvolution/trip-count9.ll
index 85d4050249..9a080b3474 100644
--- a/test/Analysis/ScalarEvolution/trip-count9.ll
+++ b/test/Analysis/ScalarEvolution/trip-count9.ll
@@ -228,7 +228,7 @@ exit:
}
; CHECK: Determining loop execution counts for: @even_step2
-; CHECK: Loop %loop: Unpredictable backedge-taken count.
+; CHECK: Loop %loop: backedge-taken count is ((-1 + (2 * %n)) /u 2)
; CHECK: Loop %loop: max backedge-taken count is 2
define void @even_step2(i4 %n) {
entry:
@@ -262,7 +262,7 @@ exit:
}
; CHECK: Determining loop execution counts for: @even_start1_step2
-; CHECK: Loop %loop: Unpredictable backedge-taken count.
+; CHECK: Loop %loop: backedge-taken count is ((-2 + (3 smax (2 * %n))) /u 2)
; CHECK: Loop %loop: max backedge-taken count is 2
define void @even_start1_step2(i4 %n) {
entry:
@@ -280,7 +280,7 @@ exit:
; CHECK: Determining loop execution counts for: @even_startx
; CHECK: Loop %loop: backedge-taken count is (-1 + (-1 * %x) + ((1 + %x) smax (2 * %n)))
-; CHECK: Loop %loop: max backedge-taken count is -1
+; CHECK: Loop %loop: max backedge-taken count is -2
define void @even_startx(i4 %n, i4 %x) {
entry:
%m = shl i4 %n, 1
@@ -296,7 +296,7 @@ exit:
}
; CHECK: Determining loop execution counts for: @even_startx_step2
-; CHECK: Loop %loop: Unpredictable backedge-taken count.
+; CHECK: Loop %loop: backedge-taken count is ((-1 + (-1 * %x) + ((2 + %x) smax (2 * %n))) /u 2)
; CHECK: Loop %loop: max backedge-taken count is 7
define void @even_startx_step2(i4 %n, i4 %x) {
entry:
@@ -382,7 +382,7 @@ exit:
; CHECK: Determining loop execution counts for: @even_nsw_startx
; CHECK: Loop %loop: backedge-taken count is (-1 + (-1 * %x) + ((1 + %x) smax (2 * %n)))
-; CHECK: Loop %loop: max backedge-taken count is -1
+; CHECK: Loop %loop: max backedge-taken count is -2
define void @even_nsw_startx(i4 %n, i4 %x) {
entry:
%m = shl i4 %n, 1
diff --git a/test/Transforms/IndVarSimplify/loop_evaluate_6.ll b/test/Transforms/IndVarSimplify/loop_evaluate_6.ll
index da38de538f..af01fe5386 100644
--- a/test/Transforms/IndVarSimplify/loop_evaluate_6.ll
+++ b/test/Transforms/IndVarSimplify/loop_evaluate_6.ll
@@ -1,9 +1,4 @@
; RUN: opt < %s -indvars -loop-deletion -S | grep phi | count 1
-; XFAIL: *
-
-; Indvars can't evaluate this loop, because ScalarEvolution can't compute
-; an exact trip count, because it doesn't know if dividing by the stride will
-; have a remainder. It could be done with more aggressive VRP though.
define i32 @test(i32 %x_offs) nounwind readnone {
entry:
diff --git a/test/Transforms/IndVarSimplify/no-iv-rewrite.ll b/test/Transforms/IndVarSimplify/no-iv-rewrite.ll
index 507f695e67..057669277c 100644
--- a/test/Transforms/IndVarSimplify/no-iv-rewrite.ll
+++ b/test/Transforms/IndVarSimplify/no-iv-rewrite.ll
@@ -223,13 +223,18 @@ entry:
%halfLim = ashr i32 %limit, 2
br label %loop
-; Test cloning an or, which is not an OverflowBinaryOperator.
+; This test originally checked that the OR instruction was cloned. Now the
+; ScalarEvolution is able to understand the loop evolution and that '%iv' at the
+; end of the loop is an even value. Thus '%val' is computed at the end of the
+; loop and the OR instruction is replaced by an ADD keeping the result
+; equivalent.
;
; CHECK: loop:
; CHECK: phi i64
; CHECK-NOT: sext
-; CHECK: or i64
+; CHECK: icmp slt i32
; CHECK: exit:
+; CHECK: add i64
loop:
%iv = phi i32 [ 0, %entry], [ %iv.next, %loop ]
%t1 = sext i32 %iv to i64
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-12 11:59:39 +0000