[clang][cli] Remove -f[no-]trapping-math from -cc1 command line

[jansvoboda11]

Summary

This patch removes the -f[no-]trapping-math flags from the -cc1 command line. They are currently ignored in the command line parser anyways.

This does not remove -f[no-]trapping-math from the driver command line. The driver flags are being used and affect the compilation.

[jansvoboda11]

clang/lib/Frontend/CompilerInvocation.cpp

3080

The parsing of OPT_ftrapping_math and OPT_fno_trapping_math is immediately overwritten here.

[jansvoboda11]

Tagging @SjoerdMeijer, as these flags were pulled into the -cc1 command-line in his patch: D23840.

[Bigcheese]

This looks fine to be as that code is definitely dead. I would wait for @SjoerdMeijer in case there's a bug in the existing code.

[SjoerdMeijer]

clang/lib/Frontend/CompilerInvocation.cpp

3080

Yeah, I did some work in this area some years ago, but that's a few years ago, and then in addition to that, we are talking about option handling in Clang which I always find very confusing... Just saying I can't remember too many details at this point.

But starting with a first observation, you're saying that things are overwritten here, but they are different options. I.e., the deleted part honours OPT_ftrapping_math, and here exception modes are set based on OPT_ffp_exception_behavior. So, looks like there is some interaction here... Do we know how this should work?

[jansvoboda11]

@SjoerdMeijer If you're not comfortable reviewing this, do you know of anyone who might want to take a look?

clang/lib/Frontend/CompilerInvocation.cpp

3080

I see. The thing is, before this patch, we call Opts.setFPExceptionMode whenever we see either OPT_ftrapping_math or OPT_fno_trapping_math.

But then, we unconditionally call Opts.setFPExceptionMode(FPEB) again here. That always overwrites what we previously did for OPT_f[no_]trapping_math, making that a dead code.

Opts.setFPExceptionMode() doesn't do anything fancy, just assigns the argument to the Opts.FPExceptionModel member.

[SjoerdMeijer]

clang/lib/Frontend/CompilerInvocation.cpp

3080

Ah yes, I actually missed that we always set Opts.setFPExceptionMode(FPEB) here! So that's clear now.

But looks like my previous question is still relevant how these options should work together? I now see that
-ffp-exception-behavior is a intel/microsoft special introduced in D62731.

And while currently we ignore -fftrapping-math here, but that just seems like a bug, it looks like we actually need to handle it here too?

[dexonsmith]

LGTM. I've just done a careful audit myself, and I'm now confident this patch is correct and that there is no latent bug -- that it's correct to ignore -f*trapping-math on the -cc1 command-line since -fp-exception-mode will always have a value matching / superseding -f*trapping-math.

@SjoerdMeijer , please confirm you agree as well.

clang/lib/Driver/ToolChains/Clang.cpp

2598–2601

FPExceptionBehavior and TrappingMath are set together here (in lock step).

2626–2647

Note this handling of -ftrapping-math in the driver, which uses it to set FPExceptionBehaviour correctly.

2698–2717

Note that -ffp-exception-behaviour also sets FPExceptionBehaviour (and TrappingMath).

2732–2733

This will override FPExceptionBehavior, (wiping out any effect of -ftrapping-math), but that seems intentional and TrappingMath is set the same way.

2739–2740

FPExceptionBehavior and TrappingMath are also set together here.

2829–2832

Note: given the above, this assertion seems sufficient for confirming -ftrapping-math is effectively passed to -cc1.

clang/lib/Frontend/CompilerInvocation.cpp

3068–3075

As long as -cc1 always contains -ffp-exception-behavior (which includes any adjustment from -ftrapping-math), then it seems correct to drop this as this patch is doing.

3080

I just did an audit (see my other comments), and it looks like -ftrapping-math's behaviour is fully handled by the -ffp-exception-mode option in -cc1.

[dexonsmith]

Please also update the commit message to explain why this is safe (that -fp-exception-behavior fully encapsulates the semantics for -cc1) rather than just saying the options were ignored (which sounds like a bug).

[SjoerdMeijer]

Thanks for getting to the bottom of this. Agreed, and also LGTM.

clang/include/clang/Driver/Options.td

 def fno_honor_infinities : Flag<["-"], "fno-honor-infinities">, Group<f_Group>;
 // This option was originally misspelt "infinites" [sic].
 def : Flag<["-"], "fhonor-infinites">, Alias<fhonor_infinities>;
 def : Flag<["-"], "fno-honor-infinites">, Alias<fno_honor_infinities>;
 def frounding_math : Flag<["-"], "frounding-math">, Group<f_Group>, Flags<[CC1Option]>,
   MarshallingInfoFlag<"LangOpts->FPRoundingMode", "llvm::RoundingMode::NearestTiesToEven">,
   Normalizer<"makeFlagToValueNormalizer(llvm::RoundingMode::Dynamic)">;
 def fno_rounding_math : Flag<["-"], "fno-rounding-math">, Group<f_Group>, Flags<[CC1Option]>;
-def ftrapping_math : Flag<["-"], "ftrapping-math">, Group<f_Group>, Flags<[CC1Option]>;
-def fno_trapping_math : Flag<["-"], "fno-trapping-math">, Group<f_Group>, Flags<[CC1Option]>;
+def ftrapping_math : Flag<["-"], "ftrapping-math">, Group<f_Group>;
+def fno_trapping_math : Flag<["-"], "fno-trapping-math">, Group<f_Group>;
 def ffp_contract : Joined<["-"], "ffp-contract=">, Group<f_Group>,
   Flags<[CC1Option]>, HelpText<"Form fused FP ops (e.g. FMAs):"
   " fast (fuses across statements disregarding pragmas)"
   " | on (only fuses in the same statement unless dictated by pragmas)"
   " | off (never fuses)"
   " | fast-honor-pragmas (fuses across statements unless diectated by pragmas)."
   " Default is 'fast' for CUDA, 'fast-honor-pragmas' for HIP, and 'on' otherwise.">,
   Values<"fast,on,off,fast-honor-pragmas">;

clang/lib/Driver/ToolChains/Clang.cpp

 //===-- Clang.cpp - Clang+LLVM ToolChain Implementations --------*- 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
 //
 //===----------------------------------------------------------------------===//
 
case options::OPT_ffp_model_EQ: {
       } 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;
         FPContract = "off";
         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;
 
     // Options controlling individual features
     case options::OPT_fhonor_infinities:    HonorINFs = true;         break;
     case options::OPT_fno_honor_infinities: HonorINFs = false;        break;
     case options::OPT_fhonor_nans:          HonorNaNs = true;         break;
     case options::OPT_fno_honor_nans:       HonorNaNs = false;        break;
     case options::OPT_fmath_errno:          MathErrno = true;         break;
     case options::OPT_fno_math_errno:       MathErrno = false;        break;
     case options::OPT_fassociative_math:    AssociativeMath = true;   break;
     case options::OPT_fno_associative_math: AssociativeMath = false;  break;
     case options::OPT_freciprocal_math:     ReciprocalMath = true;    break;
     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:
       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;
for (const Arg *A : Args) {
 
     // 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;
     }
 
     case options::OPT_ffinite_math_only:
       HonorINFs = false;
       HonorNaNs = false;
       break;
     case options::OPT_fno_finite_math_only:
       HonorINFs = true;
       HonorNaNs = true;
       break;
 
     case options::OPT_funsafe_math_optimizations:
       AssociativeMath = true;
       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";
 
       // The target may have opted to flush by default, so force IEEE.
       DenormalFPMath = llvm::DenormalMode::getIEEE();
       DenormalFP32Math = llvm::DenormalMode::getIEEE();
       break;
 
     case options::OPT_Ofast:
       // If -Ofast is the optimization level, then -ffast-math should be enabled
if (!SignedZeros)
     CmdArgs.push_back("-fno-signed-zeros");
 
   if (AssociativeMath && !SignedZeros && !TrappingMath)
     CmdArgs.push_back("-mreassociate");
 
   if (ReciprocalMath)
     CmdArgs.push_back("-freciprocal-math");
 
   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");
+  }
 
   // The default is IEEE.
   if (DenormalFPMath != llvm::DenormalMode::getIEEE()) {
     llvm::SmallString<64> DenormFlag;
     llvm::raw_svector_ostream ArgStr(DenormFlag);
     ArgStr << "-fdenormal-fp-math=" << DenormalFPMath;
     CmdArgs.push_back(Args.MakeArgString(ArgStr.str()));
   }

clang/lib/Frontend/CompilerInvocation.cpp

 //===- CompilerInvocation.cpp ---------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
if (Arg *A = Args.getLastArg(OPT_ffp_contract)) {
     else if (Val == "off")
       Opts.setDefaultFPContractMode(LangOptions::FPM_Off);
     else if (Val == "fast-honor-pragmas")
       Opts.setDefaultFPContractMode(LangOptions::FPM_FastHonorPragmas);
     else
       Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val;
   }
 
-  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);
 
   unsigned SSP = getLastArgIntValue(Args, OPT_stack_protector, 0, Diags);
   switch (SSP) {
   default:
     Diags.Report(diag::err_drv_invalid_value)
       << Args.getLastArg(OPT_stack_protector)->getAsString(Args) << SSP;
     break;
   case 0: Opts.setStackProtector(LangOptions::SSPOff); break;

clang/test/CodeGen/fpconstrained.c

-// RUN: %clang_cc1 -ftrapping-math -frounding-math -ffp-exception-behavior=strict -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=FPMODELSTRICT
+// RUN: %clang_cc1 -frounding-math -ffp-exception-behavior=strict -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=FPMODELSTRICT
 // RUN: %clang_cc1 -ffp-contract=fast -emit-llvm -o - %s | FileCheck %s -check-prefix=PRECISE
 // RUN: %clang_cc1 -ffast-math -ffp-contract=fast -emit-llvm -o - %s | FileCheck %s -check-prefix=FAST
 // RUN: %clang_cc1 -ffast-math -emit-llvm -o - %s | FileCheck %s -check-prefix=FASTNOCONTRACT
 // RUN: %clang_cc1 -ffast-math -ffp-contract=fast -ffp-exception-behavior=ignore -emit-llvm -o - %s | FileCheck %s -check-prefix=FAST
 // RUN: %clang_cc1 -ffast-math -ffp-contract=fast -ffp-exception-behavior=strict -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=EXCEPT
 // RUN: %clang_cc1 -ffast-math -ffp-contract=fast -ffp-exception-behavior=maytrap -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=MAYTRAP
-
+
 float f0, f1, f2;
 
 void foo() {
   // CHECK-LABEL: define {{.*}}void @foo()
 
   // MAYTRAP: llvm.experimental.constrained.fadd.f32(float %{{.*}}, float %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.maytrap")
   // EXCEPT: llvm.experimental.constrained.fadd.f32(float %{{.*}}, float %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
   // FPMODELSTRICT: llvm.experimental.constrained.fadd.f32(float %{{.*}}, float %{{.*}}, metadata !"round.dynamic", metadata !"fpexcept.strict")

clang/test/CodeGen/fpconstrained.cpp

-// RUN: %clang_cc1 -x c++ -ftrapping-math -fexceptions -fcxx-exceptions -frounding-math -ffp-exception-behavior=strict -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=FPMODELSTRICT
+// RUN: %clang_cc1 -x c++ -fexceptions -fcxx-exceptions -frounding-math -ffp-exception-behavior=strict -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=FPMODELSTRICT
 // RUN: %clang_cc1 -x c++ -ffp-contract=fast -fexceptions -fcxx-exceptions -emit-llvm -o - %s | FileCheck %s -check-prefix=PRECISE
 // RUN: %clang_cc1 -x c++ -ffast-math -fexceptions -fcxx-exceptions -ffp-contract=fast -emit-llvm -o - %s | FileCheck %s -check-prefix=FAST
 // RUN: %clang_cc1 -x c++ -ffast-math -fexceptions -fcxx-exceptions -emit-llvm -o - %s | FileCheck %s -check-prefix=FASTNOCONTRACT
 // RUN: %clang_cc1 -x c++ -ffast-math -fexceptions -fcxx-exceptions -ffp-contract=fast -ffp-exception-behavior=ignore -emit-llvm -o - %s | FileCheck %s -check-prefix=FAST
 // RUN: %clang_cc1 -x c++ -ffast-math -fexceptions -fcxx-exceptions -ffp-contract=fast -ffp-exception-behavior=strict -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=EXCEPT
 // RUN: %clang_cc1 -x c++ -ffast-math -fexceptions -fcxx-exceptions -ffp-contract=fast -ffp-exception-behavior=maytrap -fexperimental-strict-floating-point -emit-llvm -o - %s | FileCheck %s -check-prefix=MAYTRAP
-
+
 float f0, f1, f2;
 
   template <class>
   class aaaa {
    public:
     ~aaaa();
     void b();
   };

clang/test/CodeGen/noexceptionsfpmath.c

-// RUN: %clang_cc1 -S -fno-trapping-math %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -S %s -emit-llvm -o - | FileCheck %s
 
 // CHECK-LABEL: main
 // CHECK: attributes #0 = {{.*}}"no-trapping-math"="true"{{.*}}
 
 int main() {
   return 0;
 }

clang/test/CodeGenCUDA/propagate-metadata.cu

 // Check that when we link a bitcode module into a file using
 // -mlink-builtin-bitcode, we apply the same attributes to the functions in that
 // bitcode module as we apply to functions we generate.
 //
 // In particular, we check that ftz and unsafe-math are propagated into the
 // bitcode library as appropriate.
-//
-// In addition, we set -ftrapping-math on the bitcode library, but then set
-// -fno-trapping-math on the main compilations, and ensure that the latter flag
-// overrides the flag on the bitcode library.
 
 // Build the bitcode library.  This is not built in CUDA mode, otherwise it
 // might have incompatible attributes.  This mirrors how libdevice is built.
-// RUN: %clang_cc1 -x c++ -fconvergent-functions -emit-llvm-bc -ftrapping-math -DLIB \
+// RUN: %clang_cc1 -x c++ -fconvergent-functions -emit-llvm-bc -DLIB \
 // RUN:   %s -o %t.bc -triple nvptx-unknown-unknown
 
 // RUN: %clang_cc1 -x cuda %s -emit-llvm -mlink-builtin-bitcode %t.bc -o - \
-// RUN:   -fno-trapping-math -fcuda-is-device -triple nvptx-unknown-unknown \
+// RUN:   -fcuda-is-device -triple nvptx-unknown-unknown \
 // RUN: | FileCheck %s --check-prefix=CHECK --check-prefix=NOFTZ --check-prefix=NOFAST
 
 // RUN: %clang_cc1 -x cuda %s -emit-llvm -mlink-builtin-bitcode %t.bc \
-// RUN:   -fno-trapping-math -fdenormal-fp-math-f32=preserve-sign -o - \
+// RUN:   -fdenormal-fp-math-f32=preserve-sign -o - \
 // RUN:   -fcuda-is-device -triple nvptx-unknown-unknown \
 // RUN: | FileCheck %s --check-prefix=CHECK --check-prefix=FTZ \
 // RUN:   --check-prefix=NOFAST
 
 // RUN: %clang_cc1 -x cuda %s -emit-llvm -mlink-builtin-bitcode %t.bc \
-// RUN:   -fno-trapping-math -fdenormal-fp-math-f32=preserve-sign -o - \
+// RUN:   -fdenormal-fp-math-f32=preserve-sign -o - \
 // RUN:   -fcuda-is-device -menable-unsafe-fp-math -triple nvptx-unknown-unknown \
 // RUN: | FileCheck %s --check-prefix=CHECK --check-prefix=FAST
 
 // Wrap everything in extern "C" so we don't have to worry about name mangling
 // in the IR.
 extern "C" {
 #ifdef LIB
 

clang/test/Driver/fast-math.c

 
 // CHECK-NO-REASSOC-NO-UNSAFE-MATH: "-cc1"
 // CHECK-NO-REASSOC-NO-UNSAFE-MATH-NOT: "-menable-unsafe-fp-math"
 // CHECK-NO-REASSOC-NO_UNSAFE-MATH-NOT: "-mreassociate"
 // CHECK-NO-REASSOC-NO-UNSAFE-MATH-NOT: "-menable-unsafe-fp-math"
 // CHECK-NO-REASSOC-NO-UNSAFE-MATH: "-o"
 
 
-// RUN: %clang -### -ftrapping-math -fno-trapping-math -c %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=CHECK-NO-TRAPPING-MATH %s
-// CHECK-NO-TRAPPING-MATH: "-fno-trapping-math"
-
 // This isn't fast-math, but the option is handled in the same place as other FP params.
 // Last option wins, and strict behavior is assumed by default. 
 
 // RUN: %clang -### -fno-strict-float-cast-overflow -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-FPOV-WORKAROUND %s
 // CHECK-FPOV-WORKAROUND: "-cc1"
 // CHECK-FPOV-WORKAROUND: "-fno-strict-float-cast-overflow"
 

clang/test/Driver/fp-model.c

 // RUN: %clang -### -frounding-math -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-ROUND --implicit-check-not ffp-exception-behavior=strict %s
 // CHECK-ROUND: "-cc1"
 // CHECK-ROUND: "-frounding-math"
 
 // RUN: %clang -### -ftrapping-math -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-TRAP %s
 // CHECK-TRAP: "-cc1"
-// CHECK-TRAP: "-ftrapping-math"
 // CHECK-TRAP: "-ffp-exception-behavior=strict"
 
 // RUN: %clang -### -nostdinc -ffp-model=fast -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-FPM-FAST %s
 // CHECK-FPM-FAST: "-cc1"
 // CHECK-FPM-FAST: "-menable-no-infs"
 // CHECK-FPM-FAST: "-menable-no-nans"
 // CHECK-FPM-FAST: "-menable-unsafe-fp-math"

 // RUN:   | FileCheck --check-prefix=CHECK-FPM-PRECISE %s
 // CHECK-FPM-PRECISE: "-cc1"
 // CHECK-FPM-PRECISE: "-ffp-contract=fast"
 // CHECK-FPM-PRECISE: "-fno-rounding-math"
 
 // RUN: %clang -### -nostdinc -ffp-model=strict -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-FPM-STRICT %s
 // CHECK-FPM-STRICT: "-cc1"
-// CHECK-FPM-STRICT: "-ftrapping-math"
 // CHECK-FPM-STRICT: "-frounding-math"
 // CHECK-FPM-STRICT: "-ffp-exception-behavior=strict"
 
-// RUN: %clang -### -nostdinc -ftrapping-math -ffp-exception-behavior=ignore -c %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=CHECK-TRAP-IGNORE %s
-// CHECK-TRAP-IGNORE: "-cc1"
-// CHECK-TRAP-IGNORE: "-fno-rounding-math"
-// CHECK-TRAP-IGNORE: "-ffp-exception-behavior=ignore"
-
 
 // RUN: %clang -### -nostdinc -ffp-exception-behavior=strict -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-FEB-STRICT %s
 // CHECK-FEB-STRICT: "-cc1"
 // CHECK-FEB-STRICT: "-fno-rounding-math"
 // CHECK-FEB-STRICT: "-ffp-exception-behavior=strict"
 
 // RUN: %clang -### -nostdinc -ffp-exception-behavior=maytrap -c %s 2>&1 \

clang/test/Parser/fp-floatcontrol-syntax.cpp

 #pragma float_control(pop)                    // expected-error {{can only appear at file scope or namespace scope}}
 #pragma float_control(precise, on, push)      // expected-error {{can only appear at file scope or namespace scope}}
 #pragma float_control(except, on, push)       // expected-error {{can only appear at file scope or namespace scope}}
 #pragma float_control(except, on, push, junk) // expected-error {{float_control is malformed}}
   return;
 }
 #endif
 
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -fdenormal-fp-math=preserve-sign,preserve-sign -ftrapping-math -fsyntax-only %s -DDEFAULT -verify
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fdenormal-fp-math=preserve-sign,preserve-sign -fsyntax-only %s -DDEFAULT -verify
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only %s -ffp-contract=fast -DPRECISE -verify
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only %s -ftrapping-math -ffp-contract=off -frounding-math -ffp-exception-behavior=strict -DSTRICT -verify
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only %s -ffp-contract=off -frounding-math -ffp-exception-behavior=strict -DSTRICT -verify
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -menable-no-infs -menable-no-nans -menable-unsafe-fp-math -fno-signed-zeros -mreassociate -freciprocal-math -ffp-contract=fast -ffast-math -ffinite-math-only -fsyntax-only %s -DFAST -verify
 double a = 0.0;
 double b = 1.0;
 
 #ifdef STRICT
 #pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
 #else
 #ifndef FAST