Reapply af57dbf12e54 "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="

        Patch was reverted because https://bugs.llvm.org/show_bug.cgi?id=44048
        The original patch is modified to set the strictfp IR attribute
        explicitly in CodeGen instead of as a side effect of IRBuilder.
        In the 2nd attempt to reapply there was a windows lit test fail, the
        tests were fixed to use wildcard matching.

        Differential Revision: https://reviews.llvm.org/D62731

9 files changed, 306 insertions, 9 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index bfcf7926861..0301110b706 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2793,6 +2793,7 @@ FunctionDecl::FunctionDecl(Kind DK, ASTContext &C, DeclContext *DC,
   FunctionDeclBits.ConstexprKind = ConstexprKind;
   FunctionDeclBits.InstantiationIsPending = false;
   FunctionDeclBits.UsesSEHTry = false;
+  FunctionDeclBits.UsesFPIntrin = false;
   FunctionDeclBits.HasSkippedBody = false;
   FunctionDeclBits.WillHaveBody = false;
   FunctionDeclBits.IsMultiVersion = false;
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index ca6b1d409c2..657c9260e6e 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4336,6 +4336,13 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
                              Callee.getAbstractInfo(), Attrs, CallingConv,
                              /*AttrOnCallSite=*/true);
 
+  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl))
+    if (FD->usesFPIntrin())
+      // All calls within a strictfp function are marked strictfp
+      Attrs =
+        Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
+                           llvm::Attribute::StrictFP);
+
   // Apply some call-site-specific attributes.
   // TODO: work this into building the attribute set.
 
@@ -4385,6 +4392,13 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   SmallVector<llvm::OperandBundleDef, 1> BundleList =
       getBundlesForFunclet(CalleePtr);
 
+  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl))
+    if (FD->usesFPIntrin())
+      // All calls within a strictfp function are marked strictfp
+      Attrs =
+        Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
+                           llvm::Attribute::StrictFP);
+
   // Emit the actual call/invoke instruction.
   llvm::CallBase *CI;
   if (!InvokeDest) {
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 7f3be896a7b..fd3020835a4 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -33,6 +33,8 @@
 #include "clang/Frontend/FrontendDiagnostic.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Dominators.h"
+#include "llvm/IR/FPEnv.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/Operator.h"
@@ -87,6 +89,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
     FMF.setAllowReassoc();
   }
   Builder.setFastMathFlags(FMF);
+  SetFPModel();
 }
 
 CodeGenFunction::~CodeGenFunction() {
@@ -102,6 +105,51 @@ CodeGenFunction::~CodeGenFunction() {
     CGM.getOpenMPRuntime().functionFinished(*this);
 }
 
+// Map the LangOption for rounding mode into
+// the corresponding enum in the IR.
+static llvm::fp::RoundingMode ToConstrainedRoundingMD(
+  LangOptions::FPRoundingModeKind Kind) {
+
+  switch (Kind) {
+  case LangOptions::FPR_ToNearest:  return llvm::fp::rmToNearest;
+  case LangOptions::FPR_Downward:   return llvm::fp::rmDownward;
+  case LangOptions::FPR_Upward:     return llvm::fp::rmUpward;
+  case LangOptions::FPR_TowardZero: return llvm::fp::rmTowardZero;
+  case LangOptions::FPR_Dynamic:    return llvm::fp::rmDynamic;
+  }
+  llvm_unreachable("Unsupported FP RoundingMode");
+}
+
+// Map the LangOption for exception behavior into
+// the corresponding enum in the IR.
+static llvm::fp::ExceptionBehavior ToConstrainedExceptMD(
+  LangOptions::FPExceptionModeKind Kind) {
+
+  switch (Kind) {
+  case LangOptions::FPE_Ignore:  return llvm::fp::ebIgnore;
+  case LangOptions::FPE_MayTrap: return llvm::fp::ebMayTrap;
+  case LangOptions::FPE_Strict:  return llvm::fp::ebStrict;
+  }
+  llvm_unreachable("Unsupported FP Exception Behavior");
+}
+
+void CodeGenFunction::SetFPModel() {
+  auto fpRoundingMode = ToConstrainedRoundingMD(
+                          getLangOpts().getFPRoundingMode());
+  auto fpExceptionBehavior = ToConstrainedExceptMD(
+                               getLangOpts().getFPExceptionMode());
+
+  if (fpExceptionBehavior == llvm::fp::ebIgnore &&
+      fpRoundingMode == llvm::fp::rmToNearest)
+    // Constrained intrinsics are not used.
+    ;
+  else {
+    Builder.setIsFPConstrained(true);
+    Builder.setDefaultConstrainedRounding(fpRoundingMode);
+    Builder.setDefaultConstrainedExcept(fpExceptionBehavior);
+  }
+}
+
 CharUnits CodeGenFunction::getNaturalPointeeTypeAlignment(QualType T,
                                                     LValueBaseInfo *BaseInfo,
                                                     TBAAAccessInfo *TBAAInfo) {
@@ -823,6 +871,10 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
       if (FD->isMain())
         Fn->addFnAttr(llvm::Attribute::NoRecurse);
 
+  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
+    if (FD->usesFPIntrin())
+      Fn->addFnAttr(llvm::Attribute::StrictFP);
+
   // If a custom alignment is used, force realigning to this alignment on
   // any main function which certainly will need it.
   if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 7a2627ccf58..8f99b090b81 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -4169,6 +4169,9 @@ public:
   /// point operation, expressed as the maximum relative error in ulp.
   void SetFPAccuracy(llvm::Value *Val, float Accuracy);
 
+  /// SetFPModel - Control floating point behavior via fp-model settings.
+  void SetFPModel();
+
 private:
   llvm::MDNode *getRangeForLoadFromType(QualType Ty);
   void EmitReturnOfRValue(RValue RV, QualType Ty);
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 03a6de81204..5f8c0cb8a2c 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2302,9 +2302,18 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
   bool AssociativeMath = false;
   bool ReciprocalMath = false;
   bool SignedZeros = true;
-  bool TrappingMath = true;
+  bool TrappingMath = false; // Implemented via -ffp-exception-behavior
+  bool TrappingMathPresent = false; // Is trapping-math in args, and not
+                                    // overriden by ffp-exception-behavior?
+  bool RoundingFPMath = false;
+  bool RoundingMathPresent = false; // Is rounding-math in args?
+  // -ffp-model values: strict, fast, precise
+  StringRef FPModel = "";
+  // -ffp-exception-behavior options: strict, maytrap, ignore
+  StringRef FPExceptionBehavior = "";
   StringRef DenormalFPMath = "";
   StringRef FPContract = "";
+  bool StrictFPModel = false;
 
   if (const Arg *A = Args.getLastArg(options::OPT_flimited_precision_EQ)) {
     CmdArgs.push_back("-mlimit-float-precision");
@@ -2312,7 +2321,73 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
   }
 
   for (const Arg *A : Args) {
-    switch (A->getOption().getID()) {
+    auto optID = A->getOption().getID();
+    bool PreciseFPModel = false;
+    switch (optID) {
+    default:
+      break;
+    case options::OPT_frounding_math:
+    case options::OPT_ftrapping_math:
+    case options::OPT_ffp_exception_behavior_EQ:
+      D.Diag(clang::diag::warn_drv_experimental_fp_control_incomplete_opt)
+          << A->getOption().getName();
+      break;
+    case options::OPT_ffp_model_EQ: {
+      D.Diag(clang::diag::warn_drv_experimental_fp_control_incomplete_opt)
+          << A->getOption().getName();
+      // If -ffp-model= is seen, reset to fno-fast-math
+      HonorINFs = true;
+      HonorNaNs = true;
+      // Turning *off* -ffast-math restores the toolchain default.
+      MathErrno = TC.IsMathErrnoDefault();
+      AssociativeMath = false;
+      ReciprocalMath = false;
+      SignedZeros = true;
+      // -fno_fast_math restores default denormal and fpcontract handling
+      DenormalFPMath = "";
+      FPContract = "";
+      StringRef Val = A->getValue();
+      if (OFastEnabled && !Val.equals("fast")) {
+          // Only -ffp-model=fast is compatible with OFast, ignore.
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+          << Args.MakeArgString("-ffp-model=" + Val)
+          << "-Ofast";
+        break;
+      }
+      StrictFPModel = false;
+      PreciseFPModel = true;
+      // ffp-model= is a Driver option, it is entirely rewritten into more
+      // granular options before being passed into cc1.
+      // Use the gcc option in the switch below.
+      if (!FPModel.empty() && !FPModel.equals(Val)) {
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+          << Args.MakeArgString("-ffp-model=" + FPModel)
+          << Args.MakeArgString("-ffp-model=" + Val);
+        FPContract = "";
+      }
+      if (Val.equals("fast")) {
+        optID = options::OPT_ffast_math;
+        FPModel = Val;
+        FPContract = "fast";
+      } else if (Val.equals("precise")) {
+        optID = options::OPT_ffp_contract;
+        FPModel = Val;
+        FPContract = "fast";
+        PreciseFPModel = true;
+      } else if (Val.equals("strict")) {
+        StrictFPModel = true;
+        optID = options::OPT_frounding_math;
+        FPExceptionBehavior = "strict";
+        FPModel = Val;
+        TrappingMath = true;
+      } else
+        D.Diag(diag::err_drv_unsupported_option_argument)
+            << A->getOption().getName() << Val;
+      break;
+      }
+    }
+
+    switch (optID) {
     // If this isn't an FP option skip the claim below
     default: continue;
 
@@ -2329,20 +2404,83 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
     case options::OPT_fno_reciprocal_math:  ReciprocalMath = false;   break;
     case options::OPT_fsigned_zeros:        SignedZeros = true;       break;
     case options::OPT_fno_signed_zeros:     SignedZeros = false;      break;
-    case options::OPT_ftrapping_math:       TrappingMath = true;      break;
-    case options::OPT_fno_trapping_math:    TrappingMath = false;     break;
+    case options::OPT_ftrapping_math:
+      if (!TrappingMathPresent && !FPExceptionBehavior.empty() &&
+          !FPExceptionBehavior.equals("strict"))
+        // Warn that previous value of option is overridden.
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+          << Args.MakeArgString("-ffp-exception-behavior=" + FPExceptionBehavior)
+          << "-ftrapping-math";
+      TrappingMath = true;
+      TrappingMathPresent = true;
+      FPExceptionBehavior = "strict";
+      break;
+    case options::OPT_fno_trapping_math:
+      if (!TrappingMathPresent && !FPExceptionBehavior.empty() &&
+          !FPExceptionBehavior.equals("ignore"))
+        // Warn that previous value of option is overridden.
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+          << Args.MakeArgString("-ffp-exception-behavior=" + FPExceptionBehavior)
+          << "-fno-trapping-math";
+      TrappingMath = false;
+      TrappingMathPresent = true;
+      FPExceptionBehavior = "ignore";
+      break;
+
+    case options::OPT_frounding_math:
+      RoundingFPMath = true;
+      RoundingMathPresent = true;
+      break;
+
+    case options::OPT_fno_rounding_math:
+      RoundingFPMath = false;
+      RoundingMathPresent = false;
+      break;
 
     case options::OPT_fdenormal_fp_math_EQ:
       DenormalFPMath = A->getValue();
       break;
 
-    // Validate and pass through -fp-contract option.
+    // Validate and pass through -ffp-contract option.
     case options::OPT_ffp_contract: {
       StringRef Val = A->getValue();
-      if (Val == "fast" || Val == "on" || Val == "off")
+      if (PreciseFPModel) {
+        // -ffp-model=precise enables ffp-contract=fast as a side effect
+        // the FPContract value has already been set to a string literal
+        // and the Val string isn't a pertinent value.
+        ;
+      } else if (Val.equals("fast") || Val.equals("on") || Val.equals("off"))
         FPContract = Val;
       else
         D.Diag(diag::err_drv_unsupported_option_argument)
+           << A->getOption().getName() << Val;
+      break;
+    }
+
+    // Validate and pass through -ffp-model option.
+    case options::OPT_ffp_model_EQ:
+      // This should only occur in the error case
+      // since the optID has been replaced by a more granular
+      // floating point option.
+      break;
+
+    // Validate and pass through -ffp-exception-behavior option.
+    case options::OPT_ffp_exception_behavior_EQ: {
+      StringRef Val = A->getValue();
+      if (!TrappingMathPresent && !FPExceptionBehavior.empty() &&
+          !FPExceptionBehavior.equals(Val))
+        // Warn that previous value of option is overridden.
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+          << Args.MakeArgString("-ffp-exception-behavior=" + FPExceptionBehavior)
+          << Args.MakeArgString("-ffp-exception-behavior=" + Val);
+      TrappingMath = TrappingMathPresent = false;
+      if (Val.equals("ignore") || Val.equals("maytrap"))
+        FPExceptionBehavior = Val;
+      else if (Val.equals("strict")) {
+        FPExceptionBehavior = Val;
+        TrappingMath = TrappingMathPresent = true;
+      } else
+        D.Diag(diag::err_drv_unsupported_option_argument)
             << A->getOption().getName() << Val;
       break;
     }
@@ -2361,12 +2499,14 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
       ReciprocalMath = true;
       SignedZeros = false;
       TrappingMath = false;
+      FPExceptionBehavior = "";
       break;
     case options::OPT_fno_unsafe_math_optimizations:
       AssociativeMath = false;
       ReciprocalMath = false;
       SignedZeros = true;
       TrappingMath = true;
+      FPExceptionBehavior = "strict";
       // -fno_unsafe_math_optimizations restores default denormal handling
       DenormalFPMath = "";
       break;
@@ -2384,6 +2524,7 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
       ReciprocalMath = true;
       SignedZeros = false;
       TrappingMath = false;
+      RoundingFPMath = false;
       // If fast-math is set then set the fp-contract mode to fast.
       FPContract = "fast";
       break;
@@ -2397,12 +2538,31 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
       AssociativeMath = false;
       ReciprocalMath = false;
       SignedZeros = true;
-      TrappingMath = true;
+      TrappingMath = false;
+      RoundingFPMath = false;
       // -fno_fast_math restores default denormal and fpcontract handling
       DenormalFPMath = "";
       FPContract = "";
       break;
     }
+    if (StrictFPModel) {
+      // If -ffp-model=strict has been specified on command line but
+      // subsequent options conflict then emit warning diagnostic.
+      if (HonorINFs && HonorNaNs &&
+        !AssociativeMath && !ReciprocalMath &&
+        SignedZeros && TrappingMath && RoundingFPMath &&
+        DenormalFPMath.empty() && FPContract.empty())
+        // OK: Current Arg doesn't conflict with -ffp-model=strict
+        ;
+      else {
+        StrictFPModel = false;
+        FPModel = "";
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+            << "-ffp-model=strict" <<
+            ((A->getNumValues() == 0) ?  A->getSpelling()
+            : Args.MakeArgString(A->getSpelling() + A->getValue()));
+      }
+    }
 
     // If we handled this option claim it
     A->claim();
@@ -2430,7 +2590,11 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
   if (ReciprocalMath)
     CmdArgs.push_back("-freciprocal-math");
 
-  if (!TrappingMath)
+  if (TrappingMath) {
+    // FP Exception Behavior is also set to strict
+    assert(FPExceptionBehavior.equals("strict"));
+    CmdArgs.push_back("-ftrapping-math");
+  } else if (TrappingMathPresent)
     CmdArgs.push_back("-fno-trapping-math");
 
   if (!DenormalFPMath.empty())
@@ -2440,14 +2604,37 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
   if (!FPContract.empty())
     CmdArgs.push_back(Args.MakeArgString("-ffp-contract=" + FPContract));
 
+  if (!RoundingFPMath)
+    CmdArgs.push_back(Args.MakeArgString("-fno-rounding-math"));
+
+  if (RoundingFPMath && RoundingMathPresent)
+    CmdArgs.push_back(Args.MakeArgString("-frounding-math"));
+
+  if (!FPExceptionBehavior.empty())
+    CmdArgs.push_back(Args.MakeArgString("-ffp-exception-behavior=" +
+                      FPExceptionBehavior));
+
   ParseMRecip(D, Args, CmdArgs);
 
   // -ffast-math enables the __FAST_MATH__ preprocessor macro, but check for the
   // individual features enabled by -ffast-math instead of the option itself as
   // that's consistent with gcc's behaviour.
   if (!HonorINFs && !HonorNaNs && !MathErrno && AssociativeMath &&
-      ReciprocalMath && !SignedZeros && !TrappingMath)
+      ReciprocalMath && !SignedZeros && !TrappingMath && !RoundingFPMath) {
     CmdArgs.push_back("-ffast-math");
+    if (FPModel.equals("fast")) {
+      if (FPContract.equals("fast"))
+        // All set, do nothing.
+        ;
+      else if (FPContract.empty())
+        // Enable -ffp-contract=fast
+        CmdArgs.push_back(Args.MakeArgString("-ffp-contract=fast"));
+      else
+        D.Diag(clang::diag::warn_drv_overriding_flag_option)
+          << "-ffp-model=fast"
+          << Args.MakeArgString("-ffp-contract=" + FPContract);
+    }
+  }
 
   // Handle __FINITE_MATH_ONLY__ similarly.
   if (!HonorINFs && !HonorNaNs)
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 74831e78d8c..198ae69b765 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3145,6 +3145,34 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
       Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val;
   }
 
+  LangOptions::FPRoundingModeKind FPRM = LangOptions::FPR_ToNearest;
+  if (Args.hasArg(OPT_frounding_math)) {
+    FPRM = LangOptions::FPR_Dynamic;
+  }
+  Opts.setFPRoundingMode(FPRM);
+
+  if (Args.hasArg(OPT_ftrapping_math)) {
+    Opts.setFPExceptionMode(LangOptions::FPE_Strict);
+  }
+
+  if (Args.hasArg(OPT_fno_trapping_math)) {
+    Opts.setFPExceptionMode(LangOptions::FPE_Ignore);
+  }
+
+  LangOptions::FPExceptionModeKind FPEB = LangOptions::FPE_Ignore;
+  if (Arg *A = Args.getLastArg(OPT_ffp_exception_behavior_EQ)) {
+    StringRef Val = A->getValue();
+    if (Val.equals("ignore"))
+      FPEB = LangOptions::FPE_Ignore;
+    else if (Val.equals("maytrap"))
+      FPEB = LangOptions::FPE_MayTrap;
+    else if (Val.equals("strict"))
+      FPEB = LangOptions::FPE_Strict;
+    else
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val;
+  }
+  Opts.setFPExceptionMode(FPEB);
+
   Opts.RetainCommentsFromSystemHeaders =
       Args.hasArg(OPT_fretain_comments_from_system_headers);
 
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 7bbda127a54..c53a4b789be 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -13037,6 +13037,16 @@ ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc,
   if (ResultTy.isNull() || LHS.isInvalid() || RHS.isInvalid())
     return ExprError();
 
+  if (ResultTy->isRealFloatingType() &&
+      (getLangOpts().getFPRoundingMode() != LangOptions::FPR_ToNearest ||
+       getLangOpts().getFPExceptionMode() != LangOptions::FPE_Ignore))
+    // Mark the current function as usng floating point constrained intrinsics
+    if (FunctionDecl *F = dyn_cast<FunctionDecl>(CurContext))
+{
+      F->setUsesFPIntrin(true);
+      printf("Enclosing function uses fp intrinsics\n");
+}
+
   // Some of the binary operations require promoting operands of half vector to
   // float vectors and truncating the result back to half vector. For now, we do
   // this only when HalfArgsAndReturn is set (that is, when the target is arm or
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 3f7a1ed7fd5..d989f46c4ab 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -886,6 +886,7 @@ void ASTDeclReader::VisitFunctionDecl(FunctionDecl *FD) {
 
   FD->ODRHash = Record.readInt();
   FD->setHasODRHash(true);
+  FD->setUsesFPIntrin(Record.readInt());
 
   switch ((FunctionDecl::TemplatedKind)Record.readInt()) {
   case FunctionDecl::TK_NonTemplate:
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 51902a607ca..38eb64e52e4 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -559,6 +559,7 @@ void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
   Record.AddSourceLocation(D->getEndLoc());
 
   Record.push_back(D->getODRHash());
+  Record.push_back(D->usesFPIntrin());
 
   Record.push_back(D->getTemplatedKind());
   switch (D->getTemplatedKind()) {