diff --git a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
--- a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
+++ b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -762,11 +762,247 @@
 
     switch (Instr.getPrimaryOperand(Var).getExplicitOperandInfo().OperandType) {
     default:
-      // We don't wish to explicitly explore this variable.
-      Choices.emplace_back(); // But add invalid MCOperand to simplify logic.
-      continue;
+      break;
+    case MCOI::OperandType::OPERAND_IMMEDIATE: {
+      int NumElts = 0;
+      switch (Instr.Description.getOpcode()) {
+      default:
+        break;
+      // Extract Byte from XMM
+      case X86::PEXTRBmr:
+      case X86::PEXTRBrr:
+      case X86::VPEXTRBZmr:
+      case X86::VPEXTRBZrr:
+      case X86::VPEXTRBmr:
+      case X86::VPEXTRBrr:
+      // Insert Byte into XMM
+      case X86::PINSRBrm:
+      case X86::PINSRBrr:
+      case X86::VPINSRBZrm:
+      case X86::VPINSRBZrr:
+      case X86::VPINSRBrm:
+      case X86::VPINSRBrr:
+        NumElts = 128 / 8;
+        break;
+
+      // Extract Word from XMM
+      case X86::PEXTRWmr:
+      case X86::PEXTRWrr:
+      case X86::VPEXTRWZmr:
+      case X86::VPEXTRWZrr:
+      case X86::VPEXTRWmr:
+      case X86::VPEXTRWrr:
+      // Insert Word into XMM
+      case X86::PINSRWrm:
+      case X86::PINSRWrr:
+      case X86::VPINSRWZrm:
+      case X86::VPINSRWZrr:
+      case X86::VPINSRWrm:
+      case X86::VPINSRWrr:
+        NumElts = 128 / 16;
+        break;
+
+      // Extract Double-Word from XMM
+      case X86::PEXTRDmr:
+      case X86::PEXTRDrr:
+      case X86::VPEXTRDZmr:
+      case X86::VPEXTRDZrr:
+      case X86::VPEXTRDmr:
+      case X86::VPEXTRDrr:
+      // Insert Double-Word into XMM
+      case X86::PINSRDrm:
+      case X86::PINSRDrr:
+      case X86::VPINSRDZrm:
+      case X86::VPINSRDZrr:
+      case X86::VPINSRDrm:
+      case X86::VPINSRDrr:
+        NumElts = 128 / 32;
+        break;
+
+      // Extract Quad-Word from XMM
+      case X86::PEXTRQmr:
+      case X86::PEXTRQrr:
+      case X86::VPEXTRQZmr:
+      case X86::VPEXTRQZrr:
+      case X86::VPEXTRQmr:
+      case X86::VPEXTRQrr:
+      // Insert Quad-Word into XMM
+      case X86::PINSRQrm:
+      case X86::PINSRQrr:
+      case X86::VPINSRQZrm:
+      case X86::VPINSRQZrr:
+      case X86::VPINSRQrm:
+      case X86::VPINSRQrr:
+        NumElts = 128 / 64;
+        break;
+
+      // Extract Scalar Single-Precision Floating-Point Value from XMM
+      case X86::EXTRACTPSmr:
+      case X86::EXTRACTPSrr:
+      case X86::VEXTRACTPSZmr:
+      case X86::VEXTRACTPSZrr:
+      case X86::VEXTRACTPSmr:
+      case X86::VEXTRACTPSrr:
+      // Insert Scalar Single-Precision Floating-Point Value into XMM
+      case X86::INSERTPSrm:
+      case X86::INSERTPSrr:
+      case X86::VINSERTPSZrm:
+      case X86::VINSERTPSZrr:
+      case X86::VINSERTPSrm:
+      case X86::VINSERTPSrr:
+        NumElts = 128 / 32;
+        break;
+
+      // Extract XMM from YMM
+      case X86::VEXTRACTF128mr:
+      case X86::VEXTRACTF128rr:
+      case X86::VEXTRACTF32x4Z256mr:
+      case X86::VEXTRACTF32x4Z256mrk:
+      case X86::VEXTRACTF32x4Z256rr:
+      case X86::VEXTRACTF32x4Z256rrk:
+      case X86::VEXTRACTF32x4Z256rrkz:
+      case X86::VEXTRACTF64x2Z256mr:
+      case X86::VEXTRACTF64x2Z256mrk:
+      case X86::VEXTRACTF64x2Z256rr:
+      case X86::VEXTRACTF64x2Z256rrk:
+      case X86::VEXTRACTF64x2Z256rrkz:
+      case X86::VEXTRACTI128mr:
+      case X86::VEXTRACTI128rr:
+      case X86::VEXTRACTI32x4Z256mr:
+      case X86::VEXTRACTI32x4Z256mrk:
+      case X86::VEXTRACTI32x4Z256rr:
+      case X86::VEXTRACTI32x4Z256rrk:
+      case X86::VEXTRACTI32x4Z256rrkz:
+      case X86::VEXTRACTI64x2Z256mr:
+      case X86::VEXTRACTI64x2Z256mrk:
+      case X86::VEXTRACTI64x2Z256rr:
+      case X86::VEXTRACTI64x2Z256rrk:
+      case X86::VEXTRACTI64x2Z256rrkz:
+      // Insert XMM into YMM
+      case X86::VINSERTF128rm:
+      case X86::VINSERTF128rr:
+      case X86::VINSERTF32x4Z256rm:
+      case X86::VINSERTF32x4Z256rmk:
+      case X86::VINSERTF32x4Z256rr:
+      case X86::VINSERTF32x4Z256rrk:
+      case X86::VINSERTF32x4Z256rrkz:
+      case X86::VINSERTF64x2Z256rm:
+      case X86::VINSERTF64x2Z256rmk:
+      case X86::VINSERTF64x2Z256rr:
+      case X86::VINSERTF64x2Z256rrk:
+      case X86::VINSERTF64x2Z256rrkz:
+      case X86::VINSERTI128rm:
+      case X86::VINSERTI128rr:
+      case X86::VINSERTI32x4Z256rm:
+      case X86::VINSERTI32x4Z256rmk:
+      case X86::VINSERTI32x4Z256rr:
+      case X86::VINSERTI32x4Z256rrk:
+      case X86::VINSERTI32x4Z256rrkz:
+      case X86::VINSERTI64x2Z256rm:
+      case X86::VINSERTI64x2Z256rmk:
+      case X86::VINSERTI64x2Z256rr:
+      case X86::VINSERTI64x2Z256rrk:
+      case X86::VINSERTI64x2Z256rrkz:
+        NumElts = 256 / 128;
+        break;
+
+      // Extract XMM from ZMM
+      case X86::VEXTRACTF32x4Zmr:
+      case X86::VEXTRACTF32x4Zmrk:
+      case X86::VEXTRACTF32x4Zrr:
+      case X86::VEXTRACTF32x4Zrrk:
+      case X86::VEXTRACTF32x4Zrrkz:
+      case X86::VEXTRACTF64x2Zmr:
+      case X86::VEXTRACTF64x2Zmrk:
+      case X86::VEXTRACTF64x2Zrr:
+      case X86::VEXTRACTF64x2Zrrk:
+      case X86::VEXTRACTF64x2Zrrkz:
+      case X86::VEXTRACTI32x4Zmr:
+      case X86::VEXTRACTI32x4Zmrk:
+      case X86::VEXTRACTI32x4Zrr:
+      case X86::VEXTRACTI32x4Zrrk:
+      case X86::VEXTRACTI32x4Zrrkz:
+      case X86::VEXTRACTI64x2Zmr:
+      case X86::VEXTRACTI64x2Zmrk:
+      case X86::VEXTRACTI64x2Zrr:
+      case X86::VEXTRACTI64x2Zrrk:
+      case X86::VEXTRACTI64x2Zrrkz:
+      // Insert XMM into ZMM
+      case X86::VINSERTF32x4Zrm:
+      case X86::VINSERTF32x4Zrmk:
+      case X86::VINSERTF32x4Zrr:
+      case X86::VINSERTF32x4Zrrk:
+      case X86::VINSERTF32x4Zrrkz:
+      case X86::VINSERTF64x2Zrm:
+      case X86::VINSERTF64x2Zrmk:
+      case X86::VINSERTF64x2Zrr:
+      case X86::VINSERTF64x2Zrrk:
+      case X86::VINSERTF64x2Zrrkz:
+      case X86::VINSERTI32x4Zrm:
+      case X86::VINSERTI32x4Zrmk:
+      case X86::VINSERTI32x4Zrr:
+      case X86::VINSERTI32x4Zrrk:
+      case X86::VINSERTI32x4Zrrkz:
+      case X86::VINSERTI64x2Zrm:
+      case X86::VINSERTI64x2Zrmk:
+      case X86::VINSERTI64x2Zrr:
+      case X86::VINSERTI64x2Zrrk:
+      case X86::VINSERTI64x2Zrrkz:
+        NumElts = 512 / 128;
+        break;
+
+      // Extract YMM from ZMM
+      case X86::VEXTRACTF32x8Zmr:
+      case X86::VEXTRACTF32x8Zmrk:
+      case X86::VEXTRACTF32x8Zrr:
+      case X86::VEXTRACTF32x8Zrrk:
+      case X86::VEXTRACTF32x8Zrrkz:
+      case X86::VEXTRACTF64x4Zmr:
+      case X86::VEXTRACTF64x4Zmrk:
+      case X86::VEXTRACTF64x4Zrr:
+      case X86::VEXTRACTF64x4Zrrk:
+      case X86::VEXTRACTF64x4Zrrkz:
+      case X86::VEXTRACTI32x8Zmr:
+      case X86::VEXTRACTI32x8Zmrk:
+      case X86::VEXTRACTI32x8Zrr:
+      case X86::VEXTRACTI32x8Zrrk:
+      case X86::VEXTRACTI32x8Zrrkz:
+      case X86::VEXTRACTI64x4Zmr:
+      case X86::VEXTRACTI64x4Zmrk:
+      case X86::VEXTRACTI64x4Zrr:
+      case X86::VEXTRACTI64x4Zrrk:
+      case X86::VEXTRACTI64x4Zrrkz:
+      // Insert YMM into ZMM
+      case X86::VINSERTF32x8Zrm:
+      case X86::VINSERTF32x8Zrr:
+      case X86::VINSERTF32x8Zrmk:
+      case X86::VINSERTF32x8Zrrk:
+      case X86::VINSERTF32x8Zrrkz:
+      case X86::VINSERTF64x4Zrm:
+      case X86::VINSERTF64x4Zrr:
+      case X86::VINSERTF64x4Zrmk:
+      case X86::VINSERTF64x4Zrrk:
+      case X86::VINSERTF64x4Zrrkz:
+      case X86::VINSERTI32x8Zrm:
+      case X86::VINSERTI32x8Zrr:
+      case X86::VINSERTI32x8Zrmk:
+      case X86::VINSERTI32x8Zrrk:
+      case X86::VINSERTI32x8Zrrkz:
+      case X86::VINSERTI64x4Zrm:
+      case X86::VINSERTI64x4Zrr:
+      case X86::VINSERTI64x4Zrmk:
+      case X86::VINSERTI64x4Zrrk:
+      case X86::VINSERTI64x4Zrrkz:
+        NumElts = 512 / 256;
+        break;
+      }
+      auto Indexes = seq(0, NumElts);
+      Choices.reserve(std::distance(Indexes.begin(), Indexes.end()));
+      for (int CondCode : Indexes)
+        Choices.emplace_back(MCOperand::createImm(CondCode));
+      break;
+    }
     case X86::OperandType::OPERAND_COND_CODE: {
-      Exploration = true;
       auto CondCodes = seq((int)X86::CondCode::COND_O,
                            1 + (int)X86::CondCode::LAST_VALID_COND);
       Choices.reserve(std::distance(CondCodes.begin(), CondCodes.end()));
@@ -775,6 +1011,12 @@
       break;
     }
     }
+
+    // We don't wish to explicitly explore this variable.
+    if (Choices.empty())
+      Choices.emplace_back(); // But add invalid MCOperand to simplify logic.
+    else
+      Exploration = true;
   }
 
   // If we don't wish to explore any variables, defer to the baseline method.