}
/// \brief Get splat value if the input is a splat vector or return nullptr.
-/// The value may be extracted from a splat constants vector or from
-/// a sequence of instructions that broadcast a single value into a vector.
+/// This function is not fully general. It checks only 2 cases:
+/// the input value is (1) a splat constants vector or (2) a sequence
+/// of instructions that broadcast a single value into a vector.
+///
llvm::Value *llvm::getSplatValue(Value *V) {
- llvm::ConstantDataVector *CV = dyn_cast<llvm::ConstantDataVector>(V);
- if (CV)
+ if (auto *CV = dyn_cast<ConstantDataVector>(V))
return CV->getSplatValue();
- llvm::ShuffleVectorInst *ShuffleInst = dyn_cast<llvm::ShuffleVectorInst>(V);
+
+ auto *ShuffleInst = dyn_cast<ShuffleVectorInst>(V);
if (!ShuffleInst)
return nullptr;
- // All-zero (our undef) shuffle mask elements.
- for (int i : ShuffleInst->getShuffleMask())
- if (i != 0 && i != -1)
+ // All-zero (or undef) shuffle mask elements.
+ for (int MaskElt : ShuffleInst->getShuffleMask())
+ if (MaskElt != 0 && MaskElt != -1)
return nullptr;
// The first shuffle source is 'insertelement' with index 0.
- llvm::InsertElementInst *InsertEltInst =
- dyn_cast<llvm::InsertElementInst>(ShuffleInst->getOperand(0));
+ auto *InsertEltInst =
+ dyn_cast<InsertElementInst>(ShuffleInst->getOperand(0));
if (!InsertEltInst || !isa<ConstantInt>(InsertEltInst->getOperand(2)) ||
!cast<ConstantInt>(InsertEltInst->getOperand(2))->isNullValue())
return nullptr;