lower sra_parts on the dag, implementing it for the dag isel, and exposing
the ops to dag optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23176 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index fd9233f..c6511e8 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -71,6 +71,9 @@
// PowerPC wants to turn select_cc of FP into fsel when possible.
setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
+
+ // PowerPC wants to expand SRA_PARTS into SELECT_CC and stuff.
+ setOperationAction(ISD::SRA, MVT::i64, Custom);
// PowerPC does not have BRCOND* which requires SetCC
setOperationAction(ISD::BRCOND, MVT::Other, Expand);
@@ -161,6 +164,31 @@
}
}
break;
+ case ISD::SRA:
+ assert(Op.getValueType() == MVT::i64 &&
+ Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SRA!");
+ // The generic code does a fine job expanding shift by a constant.
+ if (isa<ConstantSDNode>(Op.getOperand(1))) break;
+
+ // Otherwise, expand into a bunch of logical ops, followed by a select_cc.
+ SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
+ DAG.getConstant(0, MVT::i32));
+ SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
+ DAG.getConstant(1, MVT::i32));
+ SDOperand Amt = Op.getOperand(1);
+
+ SDOperand Tmp1 = DAG.getNode(ISD::SUB, MVT::i32,
+ DAG.getConstant(32, MVT::i32), Amt);
+ SDOperand Tmp2 = DAG.getNode(ISD::SRL, MVT::i32, Lo, Amt);
+ SDOperand Tmp3 = DAG.getNode(ISD::SHL, MVT::i32, Hi, Tmp1);
+ SDOperand Tmp4 = DAG.getNode(ISD::OR , MVT::i32, Tmp2, Tmp3);
+ SDOperand Tmp5 = DAG.getNode(ISD::ADD, MVT::i32, Amt,
+ DAG.getConstant(-32U, MVT::i32));
+ SDOperand Tmp6 = DAG.getNode(ISD::SRA, MVT::i32, Hi, Tmp5);
+ SDOperand OutHi = DAG.getNode(ISD::SRA, MVT::i32, Hi, Amt);
+ SDOperand OutLo = DAG.getSelectCC(Tmp5, DAG.getConstant(0, MVT::i32),
+ Tmp4, Tmp6, ISD::SETLE);
+ return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
}
return SDOperand();
}