Index: flang/include/flang/Common/MathOptionsBase.h
===================================================================
--- /dev/null
+++ flang/include/flang/Common/MathOptionsBase.h
@@ -0,0 +1,44 @@
+//===- MathOptionsBase.h - Math options config ------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Options controlling mathematical computations generated in FIR.
+/// This is intended to be header-only implementation without extra
+/// dependencies so that multiple components can use it to exchange
+/// math configuration.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_COMMON_MATHOPTIONSBASE_H
+#define FORTRAN_COMMON_MATHOPTIONSBASE_H
+
+namespace Fortran::common {
+
+class MathOptionsBase {
+public:
+#define ENUM_MATHOPT(Name, Type, Bits, Default) \
+  Type get##Name() const { return static_cast<Type>(Name); } \
+  MathOptionsBase &set##Name(Type Value) { \
+    Name = static_cast<unsigned>(Value); \
+    return *this; \
+  }
+#include "flang/Common/MathOptionsBase.def"
+
+  MathOptionsBase() {
+#define ENUM_MATHOPT(Name, Type, Bits, Default) set##Name(Default);
+#include "flang/Common/MathOptionsBase.def"
+  }
+
+private:
+#define ENUM_MATHOPT(Name, Type, Bits, Default) unsigned Name : Bits;
+#include "flang/Common/MathOptionsBase.def"
+};
+
+} // namespace Fortran::common
+
+#endif // FORTRAN_COMMON_MATHOPTIONSBASE_H
Index: flang/include/flang/Common/MathOptionsBase.def
===================================================================
--- /dev/null
+++ flang/include/flang/Common/MathOptionsBase.def
@@ -0,0 +1,25 @@
+//===--- MathOptionsBase.def - Math options config ---------------- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file defines math options. Users of this file must define
+/// ENUM_MATHOPT macro to make use of this information.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef ENUM_MATHOPT
+#  error Define the ENUM_MATHOPT macro to handle lowering options
+#endif
+
+/// Allow fusing FP operations (e.g. create FMAs from mul/add).
+ENUM_MATHOPT(FPContractEnabled, unsigned, 1, 0)
+
+/// Permit floating point optimizations without regard to infinities.
+ENUM_MATHOPT(NoHonorInfs, unsigned, 1, 0)
+
+#undef ENUM_MATHOPT
Index: flang/include/flang/Lower/LoweringOptions.h
===================================================================
--- flang/include/flang/Lower/LoweringOptions.h
+++ flang/include/flang/Lower/LoweringOptions.h
@@ -15,6 +15,8 @@
 #ifndef FLANG_LOWER_LOWERINGOPTIONS_H
 #define FLANG_LOWER_LOWERINGOPTIONS_H
 
+#include "flang/Common/MathOptionsBase.h"
+
 namespace Fortran::lower {
 
 class LoweringOptionsBase {
@@ -42,6 +44,16 @@
 #include "flang/Lower/LoweringOptions.def"
 
   LoweringOptions();
+
+  const Fortran::common::MathOptionsBase &getMathOptions() const {
+    return MathOptions;
+  }
+
+  Fortran::common::MathOptionsBase &getMathOptions() { return MathOptions; }
+
+private:
+  /// Options for handling/optimizing mathematical computations.
+  Fortran::common::MathOptionsBase MathOptions;
 };
 
 } // namespace Fortran::lower
Index: flang/include/flang/Optimizer/Builder/FIRBuilder.h
===================================================================
--- flang/include/flang/Optimizer/Builder/FIRBuilder.h
+++ flang/include/flang/Optimizer/Builder/FIRBuilder.h
@@ -16,6 +16,7 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 
+#include "flang/Common/MathOptionsBase.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Support/KindMapping.h"
@@ -409,6 +410,10 @@
     fastMathFlags = flags;
   }
 
+  /// Set default FastMathFlags value from the passed MathOptionsBase
+  /// config.
+  void setFastMathFlags(Fortran::common::MathOptionsBase options);
+
   /// Dump the current function. (debug)
   LLVM_DUMP_METHOD void dumpFunc();
 
Index: flang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- flang/lib/Frontend/CompilerInvocation.cpp
+++ flang/lib/Frontend/CompilerInvocation.cpp
@@ -914,8 +914,18 @@
 /// Set \p loweringOptions controlling lowering behavior based
 /// on the \p optimizationLevel.
 void CompilerInvocation::setLoweringOptions() {
-  const auto &codegenOpts = getCodeGenOpts();
+  const CodeGenOptions &codegenOpts = getCodeGenOpts();
 
   // Lower TRANSPOSE as a runtime call under -O0.
   loweringOpts.setOptimizeTranspose(codegenOpts.OptimizationLevel > 0);
+
+  const LangOptions &langOptions = getLangOpts();
+  Fortran::common::MathOptionsBase &mathOpts = loweringOpts.getMathOptions();
+  // TODO: when LangOptions are finalized, we can represent
+  //       the math related options using Fortran::commmon::MathOptionsBase,
+  //       so that we can just copy it into LoweringOptions.
+  mathOpts
+      .setFPContractEnabled(langOptions.getFPContractMode() ==
+                            LangOptions::FPM_Fast)
+      .setNoHonorInfs(langOptions.NoHonorInfs);
 }
Index: flang/lib/Lower/Bridge.cpp
===================================================================
--- flang/lib/Lower/Bridge.cpp
+++ flang/lib/Lower/Bridge.cpp
@@ -2884,6 +2884,7 @@
     mlir::func::FuncOp func = callee.addEntryBlockAndMapArguments();
     builder = new fir::FirOpBuilder(func, bridge.getKindMap());
     assert(builder && "FirOpBuilder did not instantiate");
+    builder->setFastMathFlags(bridge.getLoweringOptions().getMathOptions());
     builder->setInsertionPointToStart(&func.front());
     func.setVisibility(mlir::SymbolTable::Visibility::Public);
 
@@ -3087,6 +3088,8 @@
         mlir::FunctionType::get(context, llvm::None, llvm::None));
     func.addEntryBlock();
     builder = new fir::FirOpBuilder(func, bridge.getKindMap());
+    assert(builder && "FirOpBuilder did not instantiate");
+    builder->setFastMathFlags(bridge.getLoweringOptions().getMathOptions());
     createGlobals();
     if (mlir::Region *region = func.getCallableRegion())
       region->dropAllReferences();
Index: flang/lib/Lower/LoweringOptions.cpp
===================================================================
--- flang/lib/Lower/LoweringOptions.cpp
+++ flang/lib/Lower/LoweringOptions.cpp
@@ -14,7 +14,7 @@
 
 namespace Fortran::lower {
 
-LoweringOptions::LoweringOptions() {
+LoweringOptions::LoweringOptions() : MathOptions{} {
 #define LOWERINGOPT(Name, Bits, Default) Name = Default;
 #define ENUM_LOWERINGOPT(Name, Type, Bits, Default) set##Name(Default);
 #include "flang/Lower/LoweringOptions.def"
Index: flang/lib/Optimizer/Builder/FIRBuilder.cpp
===================================================================
--- flang/lib/Optimizer/Builder/FIRBuilder.cpp
+++ flang/lib/Optimizer/Builder/FIRBuilder.cpp
@@ -583,6 +583,18 @@
                                       op->getContext(), fastMathFlags));
 }
 
+void fir::FirOpBuilder::setFastMathFlags(
+    Fortran::common::MathOptionsBase options) {
+  mlir::arith::FastMathFlags arithFMF{};
+  if (options.getFPContractEnabled()) {
+    arithFMF = arithFMF | mlir::arith::FastMathFlags::contract;
+  }
+  if (options.getNoHonorInfs()) {
+    arithFMF = arithFMF | mlir::arith::FastMathFlags::ninf;
+  }
+  setFastMathFlags(arithFMF);
+}
+
 //===--------------------------------------------------------------------===//
 // ExtendedValue inquiry helper implementation
 //===--------------------------------------------------------------------===//
Index: flang/test/Lower/fast-math-arithmetic.f90
===================================================================
--- /dev/null
+++ flang/test/Lower/fast-math-arithmetic.f90
@@ -0,0 +1,13 @@
+! RUN: %flang_fc1 -emit-fir -ffp-contract=fast %s -o - 2>&1 | FileCheck --check-prefixes=CONTRACT,ALL %s
+! RUN: %flang_fc1 -emit-fir -menable-no-infs %s -o - 2>&1 | FileCheck --check-prefixes=NINF,ALL %s
+
+! ALL-LABEL: func.func @_QPtest
+subroutine test(x)
+  real x
+! CONTRACT: arith.mulf{{.*}}, {{.*}} fastmath<[[ATTRS:contract]]> : f32
+! NINF: arith.mulf{{.*}}, {{.*}} fastmath<[[ATTRS:ninf]]> : f32
+! ALL: arith.divf{{.*}}, {{.*}} fastmath<[[ATTRS]]> : f32
+! ALL: arith.addf{{.*}}, {{.*}} fastmath<[[ATTRS]]> : f32
+! ALL: arith.subf{{.*}}, {{.*}} fastmath<[[ATTRS]]> : f32
+  x = x * x + x / x - x
+end subroutine test