diff options
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 68549efad50..792542eab25 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -2207,6 +2207,25 @@ static uint64_t Choose(uint64_t n, uint64_t k, bool &Overflow) { return r; } +/// Determine if any of the operands in this SCEV are a constant or if +/// any of the add or multiply expressions in this SCEV contain a constant. +static bool containsConstantSomewhere(const SCEV *StartExpr) { + SmallVector<const SCEV *, 4> Ops; + Ops.push_back(StartExpr); + while (!Ops.empty()) { + const SCEV *CurrentExpr = Ops.pop_back_val(); + if (isa<SCEVConstant>(*CurrentExpr)) + return true; + + if (isa<SCEVAddExpr>(*CurrentExpr) || isa<SCEVMulExpr>(*CurrentExpr)) { + const auto *CurrentNAry = cast<SCEVNAryExpr>(CurrentExpr); + for (const SCEV *Operand : CurrentNAry->operands()) + Ops.push_back(Operand); + } + } + return false; +} + /// getMulExpr - Get a canonical multiply expression, or something simpler if /// possible. const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops, @@ -2246,11 +2265,13 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops, // C1*(C2+V) -> C1*C2 + C1*V if (Ops.size() == 2) - if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Ops[1])) - if (Add->getNumOperands() == 2 && - isa<SCEVConstant>(Add->getOperand(0))) - return getAddExpr(getMulExpr(LHSC, Add->getOperand(0)), - getMulExpr(LHSC, Add->getOperand(1))); + if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Ops[1])) + // If any of Add's ops are Adds or Muls with a constant, + // apply this transformation as well. + if (Add->getNumOperands() == 2) + if (containsConstantSomewhere(Add)) + return getAddExpr(getMulExpr(LHSC, Add->getOperand(0)), + getMulExpr(LHSC, Add->getOperand(1))); ++Idx; while (const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(Ops[Idx])) { |
