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

    Add options to control floating point behavior: trapping and
    exception behavior, rounding, and control of optimizations that affect
    floating point calculations. More details in UsersManual.rst.

    Reviewers: rjmccall

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

1 files changed, 30 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 46a7e39770a..195a29d7118 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3129,6 +3129,36 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
       Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val;
   }
 
+  if (Args.hasArg(OPT_frounding_math)) {
+    Opts.setFPRoundingMode(LangOptions::FPR_Dynamic);
+  }
+
+  if (Args.hasArg(OPT_fno_rounding_math)) {
+    Opts.setFPRoundingMode(LangOptions::FPR_ToNearest);
+  }
+
+  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);