[clang] Remove -Wexperimental-float-control.

[rupprecht]

Summary

Per D62731, the behavior of clang with -frounding-math is no worse than when the rounding flag was completely ignored, so remove this unnecessary warning.

[mibintc]

thanks for taking care of this. looks good to me

[merge_guards_bot]

Unit tests: fail. 60990 tests passed, 1 failed and 727 were skipped.

failed: lit.lit/shtest-format.py

clang-tidy: fail. Please fix clang-tidy findings.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

clang/include/clang/Basic/DiagnosticDriverKinds.td

 def warn_drv_experimental_isel_incomplete : Warning<
   "-fexperimental-isel support for the '%0' architecture is incomplete">,
   InGroup<ExperimentalISel>;
 
 def warn_drv_experimental_isel_incomplete_opt : Warning<
   "-fexperimental-isel support is incomplete for this architecture at the current optimization level">,
   InGroup<ExperimentalISel>;
 
-def warn_drv_experimental_fp_control_incomplete_opt : Warning<
-  "Support for floating point control option %0 is incomplete and experimental">,
-  InGroup<ExperimentalFloatControl>;
-
 def warn_drv_moutline_unsupported_opt : Warning<
   "The '%0' architecture does not support -moutline; flag ignored">,
   InGroup<OptionIgnored>;
 
 def warn_drv_darwin_sdk_invalid_settings : Warning<
   "SDK settings were ignored as 'SDKSettings.json' could not be parsed">,
   InGroup<DiagGroup<"darwin-sdk-settings">>;
 

clang/include/clang/Basic/DiagnosticGroups.td

 
 // A warning group for warnings about code that clang accepts when
 // compiling OpenCL C/C++ but which is not compatible with the SPIR spec.
 def SpirCompat : DiagGroup<"spir-compat">;
 
 // Warning for the experimental-isel options.
 def ExperimentalISel : DiagGroup<"experimental-isel">;
 
-// Warning for the experimental float control options.
-def ExperimentalFloatControl : DiagGroup<"experimental-float-control">;
-
 // A warning group specifically for warnings related to function
 // multiversioning.
 def FunctionMultiVersioning : DiagGroup<"function-multiversion">;
 
 def NoDeref : DiagGroup<"noderef">;
 
 // A group for cross translation unit static analysis related warnings.
 def CrossTU : DiagGroup<"ctu">;
 
 def CTADMaybeUnsupported : DiagGroup<"ctad-maybe-unsupported">;
 
 def FortifySource : DiagGroup<"fortify-source">;

clang/lib/Driver/ToolChains/Clang.cpp

static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
   }
 
   for (const Arg *A : Args) {
     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;