[Driver][ARM] Disable bf16 when hardware FP support is missing

[chill]

Is this patch needed anymore?

[vhscampos]

Not really. Closing it

clang/lib/Driver/ToolChains/Arch/ARM.cpp

return llvm::any_of(
         Split, [](const StringRef &Extension) { return Extension == "nofp"; });
   };
 
   if (ABI == arm::FloatABI::Soft) {
     llvm::ARM::getFPUFeatures(llvm::ARM::FK_NONE, Features);
 
     // Disable all features relating to hardware FP, not already disabled by the
     // above call.
-    Features.insert(Features.end(),
-                    {"-dotprod", "-fp16fml", "-mve", "-mve.fp", "-fpregs"});
+    Features.insert(Features.end(), {"-dotprod", "-fp16fml", "-bf16", "-mve",
+                                     "-mve.fp", "-fpregs"});
   } else if (FPUID == llvm::ARM::FK_NONE ||
              checkFPDisabledInArchName(ArchName)) {
     // -mfpu=none or -march=armvX+nofp is *very* similar to -mfloat-abi=soft,
     // only that it should not disable MVE-I.
-    Features.insert(Features.end(), {"-dotprod", "-fp16fml", "-mve.fp"});
+    Features.insert(Features.end(),
+                    {"-dotprod", "-fp16fml", "-bf16", "-mve.fp"});
     if (!hasIntegerMVE(Features)) {
       Features.emplace_back("-fpregs");
     }
   }
 }
 
 void arm::getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                                const ArgList &Args, ArgStringList &CmdArgs,

clang/test/CodeGen/arm-bf16-softfloat.c

-// RUN: not %clang -o %t.out -target arm-arm-eabi -march=armv8-a+bf16 -mfloat-abi=soft -c %s 2>&1 | FileCheck %s
+// RUN: not %clang -target arm-arm-none-eabi -march=armv8-a+bf16 -mfloat-abi=soft -c %s -o %t 2>&1 | FileCheck %s
+// RUN: not %clang -target arm-arm-none-eabi -march=armv8-a+bf16 -mfpu=none -c %s -o %t 2>&1 | FileCheck %s
+// RUN: not %clang -target arm-arm-none-eabi -march=armv8-a+bf16+nofp -c %s -o %t 2>&1 | FileCheck %s
 
 // CHECK: error: __bf16 is not supported on this target
 extern __bf16 var;