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
@@ -768,17 +768,22 @@
 // Misc operations.
 def LLVM_SelectOp
     : LLVM_Op<"select",
-          [Pure, AllTypesMatch<["trueValue", "falseValue", "res"]>]>,
+          [Pure, AllTypesMatch<["trueValue", "falseValue", "res"]>,
+           DeclareOpInterfaceMethods<FastmathFlagsInterface>]>,
       LLVM_Builder<
           "$res = builder.CreateSelect($condition, $trueValue, $falseValue);"> {
   let arguments = (ins LLVM_ScalarOrVectorOf<I1>:$condition,
-                   LLVM_Type:$trueValue, LLVM_Type:$falseValue);
+                   LLVM_Type:$trueValue, LLVM_Type:$falseValue,
+                   DefaultValuedAttr<LLVM_FastmathFlagsAttr,
+                                     "{}">:$fastmathFlags);
   let results = (outs LLVM_Type:$res);
   let assemblyFormat = "operands attr-dict `:` type($condition) `,` type($res)";
   string llvmInstName = "Select";
   string mlirBuilder = [{
-    $res = $_builder.create<LLVM::SelectOp>(
+    auto op = $_builder.create<LLVM::SelectOp>(
       $_location, $_resultType, $condition, $trueValue, $falseValue);
+    moduleImport.setFastmathFlagsAttr(inst, op);
+    $res = op;
   }];
 }
 def LLVM_FreezeOp : LLVM_Op<"freeze", [SameOperandsAndResultType]> {
diff --git a/mlir/test/Target/LLVMIR/llvmir.mlir b/mlir/test/Target/LLVMIR/llvmir.mlir
--- a/mlir/test/Target/LLVMIR/llvmir.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir.mlir
@@ -1911,6 +1911,10 @@
   %19 = "llvm.intr.powi"(%arg0, %exp) {fastmathFlags = #llvm.fastmath<fast>} : (f32, i32) -> f32
 // CHECK: call afn float @llvm.powi.f32.i32(float {{.*}}, i32 {{.*}})
   %20 = "llvm.intr.powi"(%arg0, %exp) {fastmathFlags = #llvm.fastmath<afn>} : (f32, i32) -> f32
+
+  %21 = llvm.mlir.constant(true) : i1
+// CHECK: select contract i1
+  %22 = llvm.select %21, %arg0, %20 {fastmathFlags = #llvm.fastmath<contract>} : i1, f32
   llvm.return
 }