[flang] Add -f[no-]associative-math and -mreassociate

Only add the option processing and store the result. No attributes are
added to FIR yet.

Clang only forwards -mreassociate
if (AssociativeMath && !SignedZeros && !TrappingMath)

Flang doesn't have -f[no-]trapping-math, so this part of the condition
has been omitted. !TrappingMath is the default.

Differential Revision: https://reviews.llvm.org/D137329

1 files changed, 6 insertions, 0 deletions

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index eeadb21..8c0bdcd 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -720,6 +720,12 @@ static bool parseFloatingPointArgs(CompilerInvocation &invoc,
     opts.NoSignedZeros = true;
   }
 
+  if (const llvm::opt::Arg *a =
+          args.getLastArg(clang::driver::options::OPT_mreassociate)) {
+    diags.Report(diagUnimplemented) << a->getOption().getName();
+    opts.AssociativeMath = true;
+  }
+
   return true;
 }