Add support for ARM's specialized vector-compare-against-zero instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118453 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index fa3170c..6577a24 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -3074,7 +3074,38 @@
if (Swap)
std::swap(Op0, Op1);
- SDValue Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
+ // If one of the operands is a constant vector zero, attempt to fold the
+ // comparison to a specialized compare-against-zero form.
+ SDValue SingleOp;
+ if (ISD::isBuildVectorAllZeros(Op1.getNode()))
+ SingleOp = Op0;
+ else if (ISD::isBuildVectorAllZeros(Op0.getNode())) {
+ if (Opc == ARMISD::VCGE)
+ Opc = ARMISD::VCLEZ;
+ else if (Opc == ARMISD::VCGT)
+ Opc = ARMISD::VCLTZ;
+ SingleOp = Op1;
+ }
+
+ SDValue Result;
+ if (SingleOp.getNode()) {
+ switch (Opc) {
+ case ARMISD::VCEQ:
+ Result = DAG.getNode(ARMISD::VCEQZ, dl, VT, SingleOp); break;
+ case ARMISD::VCGE:
+ Result = DAG.getNode(ARMISD::VCGEZ, dl, VT, SingleOp); break;
+ case ARMISD::VCLEZ:
+ Result = DAG.getNode(ARMISD::VCLEZ, dl, VT, SingleOp); break;
+ case ARMISD::VCGT:
+ Result = DAG.getNode(ARMISD::VCGTZ, dl, VT, SingleOp); break;
+ case ARMISD::VCLTZ:
+ Result = DAG.getNode(ARMISD::VCLTZ, dl, VT, SingleOp); break;
+ default:
+ Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
+ }
+ } else {
+ Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
+ }
if (Invert)
Result = DAG.getNOT(dl, Result, VT);