Add support of RDSEED defined in AVX2 extension



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178314 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index e0f87c0..b312765 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -10914,16 +10914,23 @@
   switch (IntNo) {
   default: return SDValue();    // Don't custom lower most intrinsics.
 
-  // RDRAND intrinsics.
+  // RDRAND/RDSEED intrinsics.
   case Intrinsic::x86_rdrand_16:
   case Intrinsic::x86_rdrand_32:
-  case Intrinsic::x86_rdrand_64: {
+  case Intrinsic::x86_rdrand_64:
+  case Intrinsic::x86_rdseed_16:
+  case Intrinsic::x86_rdseed_32:
+  case Intrinsic::x86_rdseed_64: {
+    unsigned Opcode = (IntNo == Intrinsic::x86_rdseed_16 ||
+                       IntNo == Intrinsic::x86_rdseed_32 ||
+                       IntNo == Intrinsic::x86_rdseed_64) ? X86ISD::RDSEED :
+                                                            X86ISD::RDRAND;
     // Emit the node with the right value type.
     SDVTList VTs = DAG.getVTList(Op->getValueType(0), MVT::Glue, MVT::Other);
-    SDValue Result = DAG.getNode(X86ISD::RDRAND, dl, VTs, Op.getOperand(0));
+    SDValue Result = DAG.getNode(Opcode, dl, VTs, Op.getOperand(0));
 
-    // If the value returned by RDRAND was valid (CF=1), return 1. Otherwise
-    // return the value from Rand, which is always 0, casted to i32.
+    // If the value returned by RDRAND/RDSEED was valid (CF=1), return 1.
+    // Otherwise return the value from Rand, which is always 0, casted to i32.
     SDValue Ops[] = { DAG.getZExtOrTrunc(Result, dl, Op->getValueType(1)),
                       DAG.getConstant(1, Op->getValueType(1)),
                       DAG.getConstant(X86::COND_B, MVT::i32),
@@ -12781,6 +12788,7 @@
   case X86ISD::WIN_FTOL:           return "X86ISD::WIN_FTOL";
   case X86ISD::SAHF:               return "X86ISD::SAHF";
   case X86ISD::RDRAND:             return "X86ISD::RDRAND";
+  case X86ISD::RDSEED:             return "X86ISD::RDSEED";
   case X86ISD::FMADD:              return "X86ISD::FMADD";
   case X86ISD::FMSUB:              return "X86ISD::FMSUB";
   case X86ISD::FNMADD:             return "X86ISD::FNMADD";
@@ -15847,8 +15855,10 @@
       if (Op.getOpcode() == ISD::ZERO_EXTEND ||
           Op.getOpcode() == ISD::TRUNCATE)
         Op = Op.getOperand(0);
-      // A special case for rdrand, where 0 is set if false cond is found.
-      if (Op.getOpcode() != X86ISD::RDRAND || Op.getResNo() != 0)
+      // A special case for rdrand/rdseed, where 0 is set if false cond is
+      // found.
+      if ((Op.getOpcode() != X86ISD::RDRAND &&
+           Op.getOpcode() != X86ISD::RDSEED) || Op.getResNo() != 0)
         return SDValue();
     }
     // Quit if false value is not the constant 0 or 1.