Pull in r263301 from upstream llvm trunk (by Ahmed Bougacha):

[AArch64] Don't blindly lower f16/f128 FCCMPs.

  Instead, extend f16 (like we do when lowering a standalone SETCC),
  and let f128 be legalized to the RT calls.

  Fixes PR26803.

This fixes a fatal "Cannot select" backend error when building the
net/freerdp port for AArch64.

PR:		214380
MFC after:	3 days
This commit is contained in:
Dimitry Andric 2016-11-10 19:40:14 +00:00
parent 2fd47dea4e
commit 0ef0edf2bb

View File

@ -1177,8 +1177,14 @@ static SDValue emitComparison(SDValue LHS, SDValue RHS, ISD::CondCode CC,
SDLoc dl, SelectionDAG &DAG) {
EVT VT = LHS.getValueType();
if (VT.isFloatingPoint())
if (VT.isFloatingPoint()) {
assert(VT != MVT::f128);
if (VT == MVT::f16) {
LHS = DAG.getNode(ISD::FP_EXTEND, dl, MVT::f32, LHS);
RHS = DAG.getNode(ISD::FP_EXTEND, dl, MVT::f32, RHS);
}
return DAG.getNode(AArch64ISD::FCMP, dl, VT, LHS, RHS);
}
// The CMP instruction is just an alias for SUBS, and representing it as
// SUBS means that it's possible to get CSE with subtract operations.
@ -1261,9 +1267,14 @@ static SDValue emitConditionalComparison(SDValue LHS, SDValue RHS,
SDValue Condition, unsigned NZCV,
SDLoc DL, SelectionDAG &DAG) {
unsigned Opcode = 0;
if (LHS.getValueType().isFloatingPoint())
if (LHS.getValueType().isFloatingPoint()) {
assert(LHS.getValueType() != MVT::f128);
if (LHS.getValueType() == MVT::f16) {
LHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, LHS);
RHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, RHS);
}
Opcode = AArch64ISD::FCCMP;
else if (RHS.getOpcode() == ISD::SUB) {
} else if (RHS.getOpcode() == ISD::SUB) {
SDValue SubOp0 = RHS.getOperand(0);
if (isNullConstant(SubOp0) && (CC == ISD::SETEQ || CC == ISD::SETNE)) {
// See emitComparison() on why we can only do this for SETEQ and SETNE.
@ -1290,6 +1301,8 @@ static bool isConjunctionDisjunctionTree(const SDValue Val, bool &CanPushNegate,
return false;
unsigned Opcode = Val->getOpcode();
if (Opcode == ISD::SETCC) {
if (Val->getOperand(0).getValueType() == MVT::f128)
return false;
CanPushNegate = true;
return true;
}