diff --git a/src/dxbc/dxbc_compiler.cpp b/src/dxbc/dxbc_compiler.cpp
index 8bcc72ac..c4d092f5 100644
--- a/src/dxbc/dxbc_compiler.cpp
+++ b/src/dxbc/dxbc_compiler.cpp
@@ -1264,6 +1264,26 @@ namespace dxvk {
           src.at(0).id, src.at(1).id);
         break;
       
+      case DxbcOpcode::CountBits:
+        dst.id = m_module.opBitCount(
+          typeId, src.at(0).id);
+        break;
+        
+      case DxbcOpcode::FirstBitLo:
+        dst.id = m_module.opFindILsb(
+          typeId, src.at(0).id);
+        break;
+        
+      case DxbcOpcode::FirstBitHi:
+        dst.id = m_module.opFindUMsb(
+          typeId, src.at(0).id);
+        break;
+        
+      case DxbcOpcode::FirstBitShi:
+        dst.id = m_module.opFindSMsb(
+          typeId, src.at(0).id);
+        break;
+      
       ///////////////////////////
       // Conversion instructions
       case DxbcOpcode::ItoF:
diff --git a/src/dxbc/dxbc_defs.cpp b/src/dxbc/dxbc_defs.cpp
index cd265a5e..8be6e7a8 100644
--- a/src/dxbc/dxbc_defs.cpp
+++ b/src/dxbc/dxbc_defs.cpp
@@ -623,13 +623,25 @@ namespace dxvk {
     /* USubb                                */
     { },
     /* CountBits                            */
-    { },
+    { 2, DxbcInstClass::VectorAlu, {
+      { DxbcOperandKind::DstReg, DxbcScalarType::Uint32 },
+      { DxbcOperandKind::SrcReg, DxbcScalarType::Uint32 },
+    } },
     /* FirstBitHi                           */
-    { },
+    { 2, DxbcInstClass::VectorAlu, {
+      { DxbcOperandKind::DstReg, DxbcScalarType::Uint32 },
+      { DxbcOperandKind::SrcReg, DxbcScalarType::Uint32 },
+    } },
     /* FirstBitLo                           */
-    { },
+    { 2, DxbcInstClass::VectorAlu, {
+      { DxbcOperandKind::DstReg, DxbcScalarType::Uint32 },
+      { DxbcOperandKind::SrcReg, DxbcScalarType::Uint32 },
+    } },
     /* FirstBitShi                          */
-    { },
+    { 2, DxbcInstClass::VectorAlu, {
+      { DxbcOperandKind::DstReg, DxbcScalarType::Uint32 },
+      { DxbcOperandKind::SrcReg, DxbcScalarType::Uint32 },
+    } },
     /* UBfe                                 */
     { 4, DxbcInstClass::BitExtract, {
       { DxbcOperandKind::DstReg, DxbcScalarType::Uint32 },