Removal of microMIPS64R6

[abeserminji]

Summary

When target is micromips64r6, errors are printed.

This is Clang part of patch. LLVM part of patch can be found here: https://reviews.llvm.org/D35625

[sdardis]

Comments inlined. This also requires a test.

Basic/Targets.cpp

8537–8539

Since we only support microMIPS for O32 and mips(32) targets, rather than checking for the exact cpu "mips64r6", we should reject the combinations of mips64(el) and IsMicromips, and ABI =="n32" || ABI == "n64".

clang/Basic/DiagnosticCommonKinds.td

188

Line is too long. Break the line after the opening < of Error and put the error string indented two spaces on the line after.

[sdardis]

Also, this need to be posted to cfe-commits.

[abeserminji]

Comments resolved

[abeserminji]

Comments resolved and patch adapted to current revision.

[sdardis]

One nit inlined, you can address it when committing.

Basic/Targets/Mips.cpp

206 ↗

(On Diff #108067)

Add a comment here stating that the microMIPS64R6 backend was removed.

[abeserminji]

Comment addressed.

[sdardis]

lib/Basic/Targets/Mips.cpp

209 ↗

(On Diff #126331)

"was removed."

Basic/Targets.cpp

ArrayRef<TargetInfo::GCCRegAlias> getGCCRegAliases() const override {
     return llvm::makeArrayRef(NewABIRegAliases);
   }
 
   bool hasInt128Type() const override {
     return ABI == "n32" || ABI == "n64";
   }
 
   bool validateTarget(DiagnosticsEngine &Diags) const override {
+    if ((getTriple().getArch() == llvm::Triple::mips64 ||
+         getTriple().getArch() == llvm::Triple::mips64el) &&
+         IsMicromips && CPU == "mips64r6") {
+      Diags.Report(diag::err_target_unsupported_cpu_for_micromips) << CPU;
+      return false;
+    }
+
     // FIXME: It's valid to use O32 on a 64-bit CPU but the backend can't handle
     //        this yet. It's better to fail here than on the backend assertion.
     if (processorSupportsGPR64() && ABI == "o32") {
       Diags.Report(diag::err_target_unsupported_abi) << ABI << CPU;
       return false;
     }
 
     // 64-bit ABI's require 64-bit CPU's.

clang/Basic/DiagnosticCommonKinds.td

 def note_invalid_subexpr_in_const_expr : Note<
   "subexpression not valid in a constant expression">;
 
 // Targets
 
 def err_target_unknown_triple : Error<
   "unknown target triple '%0', please use -triple or -arch">;
 def err_target_unknown_cpu : Error<"unknown target CPU '%0'">;
+def err_target_unsupported_cpu_for_micromips : Error<"micromips is not supported for target CPU '%0'">;
 def err_target_unknown_abi : Error<"unknown target ABI '%0'">;
 def err_target_unsupported_abi : Error<"ABI '%0' is not supported on CPU '%1'">;
 def err_target_unsupported_abi_for_triple : Error<
   "ABI '%0' is not supported for '%1'">;
 def err_target_unknown_fpmath : Error<"unknown FP unit '%0'">;
 def err_target_unsupported_fpmath : Error<
     "the '%0' unit is not supported with this instruction set">;
 def err_target_unsupported_unaligned : Error<