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

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

1 files changed, 28 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 74831e7..198ae69b7 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);