diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -3495,3 +3495,11 @@
   let Subjects = SubjectList<[ParmVar]>;
   let Documentation = [ReleaseHandleDocs];
 }
+
+def StrictFP : InheritableAttr {
+  // This attribute has no spellings as it is only ever created implicitly.
+  let Spellings = [];
+  let Args = [BoolArgument<"Access">];  // TODO: Add Rounding and Exceptions.
+  let Subjects = SubjectList<[Function]>;
+  let Documentation = [Undocumented];
+}
diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -1069,9 +1069,9 @@
 // - #pragma stdc unknown
 def ext_stdc_pragma_ignored : ExtWarn<"unknown pragma in STDC namespace">,
    InGroup<UnknownPragmas>;
-def warn_stdc_fenv_access_not_supported :
-   Warning<"pragma STDC FENV_ACCESS ON is not supported, ignoring pragma">,
-   InGroup<UnknownPragmas>;
+def err_pragma_stdc_fenv_access_scope : Error<
+  "'#pragma STDC FENV_ACCESS' can only appear at file scope or at the start of a "
+  "compound statement">;
 // - #pragma comment
 def err_pragma_comment_malformed : Error<
   "pragma comment requires parenthesized identifier and optional string">;
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -1286,12 +1286,12 @@
   /// should not be used elsewhere.
   void EmitCurrentDiagnostic(unsigned DiagID);
 
-  /// Records and restores the FP_CONTRACT state on entry/exit of compound
+  /// Records and restores the FPFeatures state on entry/exit of compound
   /// statements.
-  class FPContractStateRAII {
+  class FPFeaturesStateRAII {
   public:
-    FPContractStateRAII(Sema &S) : S(S), OldFPFeaturesState(S.FPFeatures) {}
-    ~FPContractStateRAII() { S.FPFeatures = OldFPFeaturesState; }
+    FPFeaturesStateRAII(Sema &S) : S(S), OldFPFeaturesState(S.FPFeatures) {}
+    ~FPFeaturesStateRAII() { S.FPFeatures = OldFPFeaturesState; }
 
   private:
     Sema& S;
@@ -4071,6 +4071,7 @@
   void ActOnFinishOfCompoundStmt();
   StmtResult ActOnCompoundStmt(SourceLocation L, SourceLocation R,
                                ArrayRef<Stmt *> Elts, bool isStmtExpr);
+  void ActOnAfterCompoundStatementLeadingPragmas();
 
   /// A RAII object to enter scope of a compound statement.
   class CompoundScopeRAII {
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -896,6 +896,10 @@
         CGM.getCodeGenOpts().StackAlignment)
       Fn->addFnAttr("stackrealign");
 
+  if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D))
+    if (const auto *FEnv = FD->getAttr<StrictFPAttr>())
+      Builder.setIsFPConstrained(FEnv->getAccess());
+
   llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);
 
   // Create a marker to make it easy to insert allocas into the entryblock
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1110,6 +1110,10 @@
   /// definition.
   void SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F);
 
+  /// Set the LLVM function attributes that represent floating point
+  /// environment.
+  void setLLVMFunctionFEnvAttributes(const FunctionDecl *D, llvm::Function *F);
+
   /// Return true iff the given type uses 'sret' when used as a return type.
   bool ReturnTypeUsesSRet(const CGFunctionInfo &FI);
 
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1644,6 +1644,15 @@
   }
 }
 
+void CodeGenModule::setLLVMFunctionFEnvAttributes(const FunctionDecl *D,
+                                                  llvm::Function *F) {
+  if (D->hasAttr<StrictFPAttr>()) {
+    llvm::AttrBuilder FuncAttrs;
+    FuncAttrs.addAttribute("strictfp");
+    F->addAttributes(llvm::AttributeList::FunctionIndex, FuncAttrs);
+  }
+}
+
 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
   const Decl *D = GD.getDecl();
   if (dyn_cast_or_null<NamedDecl>(D))
@@ -4449,9 +4458,11 @@
 
   MaybeHandleStaticInExternC(D, Fn);
 
-
   maybeSetTrivialComdat(*D, *Fn);
 
+  // Set CodeGen attributes that represent floating point environment.
+  setLLVMFunctionFEnvAttributes(D, Fn);
+
   CodeGenFunction(*this).GenerateCode(D, Fn, FI);
 
   setNonAliasAttributes(GD, Fn);
diff --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
--- a/clang/lib/Parse/ParsePragma.cpp
+++ b/clang/lib/Parse/ParsePragma.cpp
@@ -106,9 +106,6 @@
     tok::OnOffSwitch OOS;
     if (PP.LexOnOffSwitch(OOS))
      return;
-    if (OOS == tok::OOS_ON) {
-      PP.Diag(Tok, diag::warn_stdc_fenv_access_not_supported);
-    }
 
     MutableArrayRef<Token> Toks(PP.getPreprocessorAllocator().Allocate<Token>(1),
                                 1);
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -365,7 +365,8 @@
 
   case tok::annot_pragma_fenv_access:
     ProhibitAttributes(Attrs);
-    HandlePragmaFEnvAccess();
+    Diag(Tok, diag::err_pragma_stdc_fenv_access_scope);
+    ConsumeAnnotationToken();
     return StmtEmpty();
 
   case tok::annot_pragma_opencl_extension:
@@ -1014,9 +1015,9 @@
                                 Tok.getLocation(),
                                 "in compound statement ('{}')");
 
-  // Record the state of the FP_CONTRACT pragma, restore on leaving the
+  // Record the current FPFeatures, restore on leaving the
   // compound statement.
-  Sema::FPContractStateRAII SaveFPContractState(Actions);
+  Sema::FPFeaturesStateRAII SaveFPFeatures(Actions);
 
   InMessageExpressionRAIIObject InMessage(*this, false);
   BalancedDelimiterTracker T(*this, tok::l_brace);
@@ -1027,6 +1028,7 @@
 
   // Parse any pragmas at the beginning of the compound statement.
   ParseCompoundStatementLeadingPragmas();
+  Actions.ActOnAfterCompoundStatementLeadingPragmas();
 
   StmtVector Stmts;
 
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -381,6 +381,13 @@
   PopCompoundScope();
 }
 
+void Sema::ActOnAfterCompoundStatementLeadingPragmas() {
+  if (FPFeatures.allowFEnvAccess()) {
+    FunctionDecl *F = getCurFunctionDecl();
+    F->addAttr(StrictFPAttr::CreateImplicit(Context, true));
+  }
+}
+
 sema::CompoundScopeInfo &Sema::getCurCompoundScope() const {
   return getCurFunction()->CompoundScopes.back();
 }
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -9837,7 +9837,7 @@
       RHS.get() == E->getRHS())
     return E;
 
-  Sema::FPContractStateRAII FPContractState(getSema());
+  Sema::FPFeaturesStateRAII FPFeaturesState(getSema());
   getSema().FPFeatures = E->getFPFeatures();
 
   return getDerived().RebuildBinaryOperator(E->getOperatorLoc(), E->getOpcode(),
@@ -10363,7 +10363,7 @@
       (E->getNumArgs() != 2 || Second.get() == E->getArg(1)))
     return SemaRef.MaybeBindToTemporary(E);
 
-  Sema::FPContractStateRAII FPContractState(getSema());
+  Sema::FPFeaturesStateRAII FPFeaturesState(getSema());
   getSema().FPFeatures = E->getFPFeatures();
 
   return getDerived().RebuildCXXOperatorCallExpr(E->getOperator(),
diff --git a/clang/test/CodeGen/pragma-fenv_access.c b/clang/test/CodeGen/pragma-fenv_access.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/pragma-fenv_access.c
@@ -0,0 +1,62 @@
+// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm %s -o - | FileCheck %s
+
+#pragma STDC FENV_ACCESS ON
+
+float func_01(float x, float y) {
+  return x + y;
+}
+// CHECK-LABEL: @func_01
+// CHECK: call float @llvm.experimental.constrained.fadd.f32(float {{.*}}, float {{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")
+
+
+float func_02(float x, float y) {
+  #pragma STDC FENV_ACCESS OFF
+  return x + y;
+}
+// CHECK-LABEL: @func_02
+// CHECK: fadd float {{.*}}
+
+
+float func_03(float x, float y) {
+  return x + y;
+}
+// CHECK-LABEL: @func_03
+// CHECK: call float @llvm.experimental.constrained.fadd.f32(float {{.*}}, float {{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")
+
+
+#pragma STDC FENV_ACCESS OFF
+
+float func_04(float x, float y) {
+  return x + y;
+}
+// CHECK-LABEL: @func_04
+// CHECK: fadd float {{.*}}
+
+
+float func_05(float x, float y) {
+  #pragma STDC FENV_ACCESS ON
+  return x + y;
+}
+// CHECK-LABEL: @func_05
+// CHECK: call float @llvm.experimental.constrained.fadd.f32(float {{.*}}, float {{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")
+
+
+float func_06(float x, float y) {
+  return x + y;
+}
+// CHECK-LABEL: @func_06
+// CHECK: fadd float {{.*}}
+
+
+float func_07(float x, float y) {
+  x -= y;
+  if (x) {
+    #pragma STDC FENV_ACCESS ON
+    y *= 2;
+  }
+  return y + 4;
+}
+// CHECK-LABEL: @func_07
+// CHECK: call float @llvm.experimental.constrained.fsub.f32(float {{.*}}, float {{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")
+// CHECK: call float @llvm.experimental.constrained.fmul.f32(float {{.*}}, float {{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")
+// CHECK: call float @llvm.experimental.constrained.fadd.f32(float {{.*}}, float {{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")
diff --git a/clang/test/Parser/pragma-fenv_access.c b/clang/test/Parser/pragma-fenv_access.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Parser/pragma-fenv_access.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+#pragma STDC FENV_ACCESS IN_BETWEEN   // expected-warning {{expected 'ON' or 'OFF' or 'DEFAULT' in pragma}}
+
+#pragma STDC FENV_ACCESS OFF
+
+float func_04(int x, float y) {
+  if (x)
+    return y + 2;
+  #pragma STDC FENV_ACCESS ON // expected-error{{'#pragma STDC FENV_ACCESS' can only appear at file scope or at the start of a compound statement}}
+  return x + y;
+}
diff --git a/clang/test/Preprocessor/pragma_unknown.c b/clang/test/Preprocessor/pragma_unknown.c
--- a/clang/test/Preprocessor/pragma_unknown.c
+++ b/clang/test/Preprocessor/pragma_unknown.c
@@ -16,15 +16,6 @@
 // CHECK: {{^}}#pragma STDC FP_CONTRACT DEFAULT{{$}}
 // CHECK: {{^}}#pragma STDC FP_CONTRACT IN_BETWEEN{{$}}
 
-#pragma STDC FENV_ACCESS ON          // expected-warning {{pragma STDC FENV_ACCESS ON is not supported, ignoring pragma}}
-#pragma STDC FENV_ACCESS OFF
-#pragma STDC FENV_ACCESS DEFAULT
-#pragma STDC FENV_ACCESS IN_BETWEEN   // expected-warning {{expected 'ON' or 'OFF' or 'DEFAULT' in pragma}}
-// CHECK: {{^}}#pragma STDC FENV_ACCESS ON{{$}}
-// CHECK: {{^}}#pragma STDC FENV_ACCESS OFF{{$}}
-// CHECK: {{^}}#pragma STDC FENV_ACCESS DEFAULT{{$}}
-// CHECK: {{^}}#pragma STDC FENV_ACCESS IN_BETWEEN{{$}}
-
 #pragma STDC CX_LIMITED_RANGE ON
 #pragma STDC CX_LIMITED_RANGE OFF
 #pragma STDC CX_LIMITED_RANGE DEFAULT