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
@@ -28,14 +28,17 @@
 def FMFcontract : I32BitEnumAttrCaseBit<"contract", 4>;
 def FMFafn      : I32BitEnumAttrCaseBit<"afn", 5>;
 def FMFreassoc  : I32BitEnumAttrCaseBit<"reassoc", 6>;
-def FMFfast     : I32BitEnumAttrCaseBit<"fast", 7>;
+def FMFfast     : I32BitEnumAttrCaseGroup<"fast",
+  [ FMFnnan, FMFninf, FMFnsz, FMFarcp, FMFcontract, FMFafn, FMFreassoc]>;
 
 def FastmathFlags : I32BitEnumAttr<
     "FastmathFlags",
     "LLVM fastmath flags",
     [FMFnnan, FMFninf, FMFnsz, FMFarcp, FMFcontract, FMFafn, FMFreassoc, FMFfast
     ]> {
+  let separator = ",";
   let cppNamespace = "::mlir::LLVM";
+  let printBitEnumPrimaryGroups = 1;
 }
 
 def LLVM_FMFAttr : DialectAttr<
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -2839,26 +2839,9 @@
          op->hasTrait<OpTrait::IsIsolatedFromAbove>();
 }
 
-static constexpr const FastmathFlags fastmathFlagsList[] = {
-    // clang-format off
-    FastmathFlags::nnan,
-    FastmathFlags::ninf,
-    FastmathFlags::nsz,
-    FastmathFlags::arcp,
-    FastmathFlags::contract,
-    FastmathFlags::afn,
-    FastmathFlags::reassoc,
-    FastmathFlags::fast,
-    // clang-format on
-};
-
 void FMFAttr::print(AsmPrinter &printer) const {
   printer << "<";
-  auto flags = llvm::make_filter_range(fastmathFlagsList, [&](auto flag) {
-    return bitEnumContains(this->getFlags(), flag);
-  });
-  llvm::interleaveComma(flags, printer,
-                        [&](auto flag) { printer << stringifyEnum(flag); });
+  printer << stringifyFastmathFlags(this->getFlags());
   printer << ">";
 }
 
diff --git a/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp
--- a/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp
@@ -157,7 +157,6 @@
       {FastmathFlags::contract, &llvmFMF::setAllowContract},
       {FastmathFlags::afn,      &llvmFMF::setApproxFunc},
       {FastmathFlags::reassoc,  &llvmFMF::setAllowReassoc},
-      {FastmathFlags::fast,     &llvmFMF::setFast},
       // clang-format on
   };
   llvm::FastMathFlags ret;
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
@@ -444,7 +444,7 @@
 
 // CHECK: {{.*}} = llvm.fadd %arg0, %arg1 : f32
   %8 = llvm.fadd %arg0, %arg1 {fastmathFlags = #llvm.fastmath<>} : f32
-// CHECK: {{.*}} = llvm.fadd %arg0, %arg1 {fastmathFlags = #llvm.fastmath<nnan, ninf>} : f32
+// CHECK: {{.*}} = llvm.fadd %arg0, %arg1 {fastmathFlags = #llvm.fastmath<nnan,ninf>} : f32
   %9 = llvm.fadd %arg0, %arg1 {fastmathFlags = #llvm.fastmath<nnan, ninf>} : f32
 
 // CHECK: {{.*}} = llvm.fneg %arg0 : f32