+ case Intrinsic::ppc_altivec_vperm:
+ // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
+ if (ConstantPacked *Mask = dyn_cast<ConstantPacked>(II->getOperand(3))) {
+ assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!");
+
+ // Check that all of the elements are integer constants or undefs.
+ bool AllEltsOk = true;
+ for (unsigned i = 0; i != 16; ++i) {
+ if (!isa<ConstantInt>(Mask->getOperand(i)) &&
+ !isa<UndefValue>(Mask->getOperand(i))) {
+ AllEltsOk = false;
+ break;
+ }
+ }
+
+ if (AllEltsOk) {
+ // Cast the input vectors to byte vectors.
+ Value *Op0 = InsertCastBefore(II->getOperand(1), Mask->getType(), CI);
+ Value *Op1 = InsertCastBefore(II->getOperand(2), Mask->getType(), CI);
+ Value *Result = UndefValue::get(Op0->getType());
+
+ // Only extract each element once.
+ Value *ExtractedElts[32];
+ memset(ExtractedElts, 0, sizeof(ExtractedElts));
+
+ for (unsigned i = 0; i != 16; ++i) {
+ if (isa<UndefValue>(Mask->getOperand(i)))
+ continue;
+ unsigned Idx =cast<ConstantInt>(Mask->getOperand(i))->getRawValue();
+ Idx &= 31; // Match the hardware behavior.
+
+ if (ExtractedElts[Idx] == 0) {
+ Instruction *Elt =
+ new ExtractElementInst(Idx < 16 ? Op0 : Op1,
+ ConstantUInt::get(Type::UIntTy, Idx&15),
+ "tmp");
+ InsertNewInstBefore(Elt, CI);
+ ExtractedElts[Idx] = Elt;
+ }
+
+ // Insert this value into the result vector.
+ Result = new InsertElementInst(Result, ExtractedElts[Idx],
+ ConstantUInt::get(Type::UIntTy, i),
+ "tmp");
+ InsertNewInstBefore(cast<Instruction>(Result), CI);
+ }
+ return new CastInst(Result, CI.getType());
+ }
+ }
+ break;
+