[CHERIoT] Convert a few places from checking the subarch to checking for the XCheriot ISA feature.

Author: resistor

clang/lib/Basic/Targets/RISCV.cpp

@@ -245,7 +245,7 @@ void RISCVTargetInfo::getTargetDefines(const LangOptions &Opts,
     }
 
     // Macros for use with the set and get permissions builtins.
-    if (getTriple().getSubArch() == llvm::Triple::RISCV32SubArch_cheriot_v1) {
+    if (ISAInfo->hasExtension("xcheriot")) {
       // Expose CHERI-compatible macros for permissions that overlap with other
       // CHERI implementations.
       Builder.defineMacro("__CHERI_CAP_PERMISSION_GLOBAL__", Twine(1 << 0));
@@ -379,6 +379,7 @@ bool RISCVTargetInfo::initFeatureMap(
 
   if (getTriple().getSubArch() == llvm::Triple::RISCV32SubArch_cheriot_v1) {
     Features["xcheri"] = true;
+    Features["xcheriot"] = true;
     Features["cap-mode"] = true;
     Features["c"] = true;
     Features["e"] = true;

llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp

@@ -108,9 +108,7 @@ unsigned RISCVELFObjectWriter::getRelocType(MCContext &Ctx,
       return ELF::R_RISCV_CHERI_CJAL;
     case RISCV::fixup_riscv_ccall: {
       const auto *STI = Ctx.getSubtargetInfo();
-      if (STI->hasFeature(RISCV::FeatureVendorXCheriot) ||
-          STI->getTargetTriple().getSubArch() ==
-              Triple::RISCV32SubArch_cheriot_v1)
+      if (STI->hasFeature(RISCV::FeatureVendorXCheriot))
         return ELF::R_RISCV_CHERIOT_CCALL;
       return ELF::R_RISCV_CHERI_CCALL;
     }