[flang] Add -f[no-]signed-zeros

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

Differential Revision: https://reviews.llvm.org/D137328

Author: tblah

clang/include/clang/Driver/Options.td

@@ -1902,7 +1902,7 @@ defm finite_math_only : BoolFOption<"finite-math-only",
   NegFlag<SetFalse>>;
 defm signed_zeros : BoolFOption<"signed-zeros",
   LangOpts<"NoSignedZero">, DefaultFalse,
-  NegFlag<SetTrue, [CC1Option], "Allow optimizations that ignore the sign of floating point zeros",
+  NegFlag<SetTrue, [CC1Option, FC1Option, FlangOption], "Allow optimizations that ignore the sign of floating point zeros",
             [cl_no_signed_zeros.KeyPath, funsafe_math_optimizations.KeyPath]>,
   PosFlag<SetFalse>>;
 def fhonor_nans : Flag<["-"], "fhonor-nans">, Group<f_Group>;

clang/lib/Driver/ToolChains/Flang.cpp

@@ -86,6 +86,7 @@ static void addFloatingPointOptions(const Driver &D, const ArgList &Args,
   bool HonorINFs = true;
   bool HonorNaNs = true;
   bool ApproxFunc = false;
+  bool SignedZeros = true;
 
   if (const Arg *A = Args.getLastArg(options::OPT_ffp_contract)) {
     const StringRef Val = A->getValue();
@@ -129,6 +130,12 @@ static void addFloatingPointOptions(const Driver &D, const ArgList &Args,
     case options::OPT_fno_approx_func:
       ApproxFunc = false;
       break;
+    case options::OPT_fsigned_zeros:
+      SignedZeros = true;
+      break;
+    case options::OPT_fno_signed_zeros:
+      SignedZeros = false;
+      break;
     }
 
     // If we handled this option claim it
@@ -146,6 +153,9 @@ static void addFloatingPointOptions(const Driver &D, const ArgList &Args,
 
   if (ApproxFunc)
     CmdArgs.push_back("-fapprox-func");
+
+  if (!SignedZeros)
+    CmdArgs.push_back("-fno-signed-zeros");
 }
 
 void Flang::ConstructJob(Compilation &C, const JobAction &JA,

flang/include/flang/Frontend/LangOptions.def

@@ -27,6 +27,8 @@ LANGOPT(NoHonorInfs, 1, false)
 LANGOPT(NoHonorNaNs, 1, false)
 /// Allow math functions to be replaced with an approximately equivalent calculation
 LANGOPT(ApproxFunc, 1, false)
+/// Allow optimizations that ignore the sign of floating point zeros
+LANGOPT(NoSignedZeros, 1, false)
 
 #undef LANGOPT
 #undef ENUM_LANGOPT

flang/lib/Frontend/CompilerInvocation.cpp

@@ -714,6 +714,12 @@ static bool parseFloatingPointArgs(CompilerInvocation &invoc,
     opts.ApproxFunc = true;
   }
 
+  if (const llvm::opt::Arg *a =
+          args.getLastArg(clang::driver::options::OPT_fno_signed_zeros)) {
+    diags.Report(diagUnimplemented) << a->getOption().getName();
+    opts.NoSignedZeros = true;
+  }
+
   return true;
 }
 

flang/test/Driver/driver-help-hidden.f90

@@ -45,6 +45,7 @@
 ! CHECK-NEXT: -fno-automatic         Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE
 ! CHECK-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
 ! CHECK-NEXT: -fno-integrated-as     Disable the integrated assembler
+! CHECK-NEXT: -fno-signed-zeros      Allow optimizations that ignore the sign of floating point zeros
 ! CHECK-NEXT: -fopenacc              Enable OpenACC
 ! CHECK-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! CHECK-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages

flang/test/Driver/driver-help.f90

@@ -43,6 +43,7 @@
 ! HELP-NEXT: -fno-automatic         Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE
 ! HELP-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
 ! HELP-NEXT: -fno-integrated-as      Disable the integrated assembler
+! HELP-NEXT: -fno-signed-zeros      Allow optimizations that ignore the sign of floating point zeros
 ! HELP-NEXT: -fopenacc              Enable OpenACC
 ! HELP-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! HELP-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages
@@ -124,6 +125,7 @@
 ! HELP-FC1-NEXT: -fno-automatic         Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE
 ! HELP-FC1-NEXT: -fno-debug-pass-manager Disables debug printing for the new pass manager
 ! HELP-FC1-NEXT: -fno-reformat          Dump the cooked character stream in -E mode
+! HELP-FC1-NEXT: -fno-signed-zeros      Allow optimizations that ignore the sign of floating point zeros
 ! HELP-FC1-NEXT: -fopenacc              Enable OpenACC
 ! HELP-FC1-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! HELP-FC1-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages

flang/test/Driver/flang_fp_opts.f90

@@ -5,8 +5,10 @@
 ! RUN:      -menable-no-infs \
 ! RUN:      -menable-no-nans \
 ! RUN:      -fapprox-func \
+! RUN:      -fno-signed-zeros \
 ! RUN:      %s 2>&1 | FileCheck %s
 ! CHECK: ffp-contract= is not currently implemented
 ! CHECK: menable-no-infs is not currently implemented
 ! CHECK: menable-no-nans is not currently implemented
 ! CHECK: fapprox-func is not currently implemented
+! CHECK: fno-signed-zeros is not currently implemented

flang/test/Driver/frontend-forwarding.f90

@@ -12,6 +12,7 @@
 ! RUN:     -fno-honor-infinities \
 ! RUN:     -fno-honor-nans \
 ! RUN:     -fapprox-func \
+! RUN:     -fno-signed-zeros \
 ! RUN:     -mllvm -print-before-all\
 ! RUN:     -P \
 ! RUN:   | FileCheck %s
@@ -26,5 +27,6 @@
 ! CHECK: "-menable-no-infs"
 ! CHECK: "-menable-no-nans"
 ! CHECK: "-fapprox-func"
+! CHECK: "-fno-signed-zeros"
 ! CHECK: "-fconvert=little-endian"
 ! CHECK:  "-mllvm" "-print-before-all"