diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -231,8 +231,24 @@
 def LLVM_FMulOp : LLVM_ArithmeticOp<"fmul", "CreateFMul">;
 def LLVM_FDivOp : LLVM_ArithmeticOp<"fdiv", "CreateFDiv">;
 def LLVM_FRemOp : LLVM_ArithmeticOp<"frem", "CreateFRem">;
+
+// Floating point unary operations.
 def LLVM_FNegOp : LLVM_UnaryArithmeticOp<"fneg", "CreateFNeg">;
 
+def LLVM_RsqrtOp : LLVM_Op<"rsqrt", [NoSideEffect, SameOperandsAndResultType]>,
+                   Arguments<(ins LLVM_Type:$in)>,
+                   Results<(outs LLVM_Type:$res)> {
+  let llvmBuilder = [{
+    llvm::Module *module = builder.GetInsertBlock()->getModule();
+    llvm::Function *fn = llvm::Intrinsic::getDeclaration(
+        module, llvm::Intrinsic::sqrt, {$in->getType()});
+    auto sqrt = builder.CreateCall(fn, {$in});
+    $res = builder.CreateFDiv(llvm::ConstantFP::get(sqrt->getType(), 1), sqrt);
+  }];
+  let parser = [{ return impl::parseOneResultSameOperandTypeOp(parser, result); }];
+  let printer = [{ mlir::impl::printOneResultOp(this->getOperation(), p); }];
+}
+
 // Memory-related operations.
 def LLVM_AllocaOp :
     LLVM_OneResultOp<"alloca">,
@@ -736,7 +752,7 @@
 def LLVM_FMulAddOp : LLVM_TernarySameArgsIntrinsicOp<"fmuladd">;
 def LLVM_SqrtOp : LLVM_UnaryIntrinsicOp<"sqrt">;
 
-def LLVM_LogOp : LLVM_Op<"intr.log", [NoSideEffect]>,
+def LLVM_LogOp : LLVM_Op<"intr.log", [NoSideEffect, SameOperandsAndResultType]>,
                    Arguments<(ins LLVM_Type:$in)>,
                    Results<(outs LLVM_Type:$res)> {
   let llvmBuilder = [{
diff --git a/mlir/test/Dialect/LLVMIR/roundtrip.mlir b/mlir/test/Dialect/LLVMIR/roundtrip.mlir
--- a/mlir/test/Dialect/LLVMIR/roundtrip.mlir
+++ b/mlir/test/Dialect/LLVMIR/roundtrip.mlir
@@ -97,6 +97,10 @@
 // CHECK:  %29 = llvm.fneg %arg1 : !llvm.float
   %29 = llvm.fneg %arg1 : !llvm.float
 
+// Floating point unary operations.
+// CHECK:  %30 = llvm.rsqrt %arg1 : !llvm.float
+  %30 = llvm.rsqrt %arg1 : !llvm.float
+
 // CHECK:  llvm.return
   llvm.return
 }