[RISCV] Rename FeatureRVE to FeatureStdExtE. NFC (#89174)

Planning to declare all extensions in tablegen so we can generate the
tables for RISCVISAInfo.cpp. This requires making "e" consistent with
other extensions.

Author: topperc

llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp

@@ -83,7 +83,7 @@ class RISCVAsmParser : public MCTargetAsmParser {
 
   SMLoc getLoc() const { return getParser().getTok().getLoc(); }
   bool isRV64() const { return getSTI().hasFeature(RISCV::Feature64Bit); }
-  bool isRVE() const { return getSTI().hasFeature(RISCV::FeatureRVE); }
+  bool isRVE() const { return getSTI().hasFeature(RISCV::FeatureStdExtE); }
 
   RISCVTargetStreamer &getTargetStreamer() {
     assert(getParser().getStreamer().getTargetStreamer() &&

llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp

@@ -64,7 +64,7 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVDisassembler() {
 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, uint32_t RegNo,
                                            uint64_t Address,
                                            const MCDisassembler *Decoder) {
-  bool IsRVE = Decoder->getSubtargetInfo().hasFeature(RISCV::FeatureRVE);
+  bool IsRVE = Decoder->getSubtargetInfo().hasFeature(RISCV::FeatureStdExtE);
 
   if (RegNo >= 32 || (IsRVE && RegNo >= 16))
     return MCDisassembler::Fail;

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

@@ -40,7 +40,7 @@ ABI computeTargetABI(const Triple &TT, const FeatureBitset &FeatureBits,
                      StringRef ABIName) {
   auto TargetABI = getTargetABI(ABIName);
   bool IsRV64 = TT.isArch64Bit();
-  bool IsRVE = FeatureBits[RISCV::FeatureRVE];
+  bool IsRVE = FeatureBits[RISCV::FeatureStdExtE];
 
   if (!ABIName.empty() && TargetABI == ABI_Unknown) {
     errs()

llvm/lib/Target/RISCV/RISCVFeatures.td

@@ -16,6 +16,10 @@ def FeatureStdExtI
     : SubtargetFeature<"i", "HasStdExtI", "true",
                        "'I' (Base Integer Instruction Set)">;
 
+def FeatureStdExtE
+    : SubtargetFeature<"e", "HasStdExtE", "true",
+                       "Implements RV{32,64}E (provides 16 rather than 32 GPRs)">;
+
 def FeatureStdExtZic64b
     : SubtargetFeature<"zic64b", "HasStdExtZic64b", "true",
                        "'Zic64b' (Cache Block Size Is 64 Bytes)">;
@@ -1162,10 +1166,6 @@ def IsRV32 : Predicate<"!Subtarget->is64Bit()">,
 defvar RV32 = DefaultMode;
 def RV64           : HwMode<"+64bit", [IsRV64]>;
 
-def FeatureRVE
-    : SubtargetFeature<"e", "IsRVE", "true",
-                       "Implements RV{32,64}E (provides 16 rather than 32 GPRs)">;
-
 def FeatureRelax
     : SubtargetFeature<"relax", "EnableLinkerRelax", "true",
                        "Enable Linker relaxation.">;

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -18951,7 +18951,7 @@ SDValue RISCVTargetLowering::LowerFormalArguments(
   case CallingConv::RISCV_VectorCall:
     break;
   case CallingConv::GHC:
-    if (Subtarget.isRVE())
+    if (Subtarget.hasStdExtE())
       report_fatal_error("GHC calling convention is not supported on RVE!");
     if (!Subtarget.hasStdExtFOrZfinx() || !Subtarget.hasStdExtDOrZdinx())
       report_fatal_error("GHC calling convention requires the (Zfinx/F) and "
@@ -19189,7 +19189,7 @@ SDValue RISCVTargetLowering::LowerCall(CallLoweringInfo &CLI,
   CCState ArgCCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext());
 
   if (CallConv == CallingConv::GHC) {
-    if (Subtarget.isRVE())
+    if (Subtarget.hasStdExtE())
       report_fatal_error("GHC calling convention is not supported on RVE!");
     ArgCCInfo.AnalyzeCallOperands(Outs, RISCV::CC_RISCV_GHC);
   } else

llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp

@@ -65,10 +65,10 @@ RISCVRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
     if (Subtarget.hasStdExtD())
       return CSR_XLEN_F64_Interrupt_SaveList;
     if (Subtarget.hasStdExtF())
-      return Subtarget.isRVE() ? CSR_XLEN_F32_Interrupt_RVE_SaveList
-                               : CSR_XLEN_F32_Interrupt_SaveList;
-    return Subtarget.isRVE() ? CSR_Interrupt_RVE_SaveList
-                             : CSR_Interrupt_SaveList;
+      return Subtarget.hasStdExtE() ? CSR_XLEN_F32_Interrupt_RVE_SaveList
+                                    : CSR_XLEN_F32_Interrupt_SaveList;
+    return Subtarget.hasStdExtE() ? CSR_Interrupt_RVE_SaveList
+                                  : CSR_Interrupt_SaveList;
   }
 
   bool HasVectorCSR =
@@ -126,7 +126,7 @@ BitVector RISCVRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   markSuperRegs(Reserved, RISCV::DUMMY_REG_PAIR_WITH_X0);
 
   // There are only 16 GPRs for RVE.
-  if (Subtarget.isRVE())
+  if (Subtarget.hasStdExtE())
     for (MCPhysReg Reg = RISCV::X16; Reg <= RISCV::X31; Reg++)
       markSuperRegs(Reserved, Reg);
 
@@ -145,7 +145,7 @@ BitVector RISCVRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   markSuperRegs(Reserved, RISCV::VCIX_STATE);
 
   if (MF.getFunction().getCallingConv() == CallingConv::GRAAL) {
-    if (Subtarget.isRVE())
+    if (Subtarget.hasStdExtE())
       report_fatal_error("Graal reserved registers do not exist in RVE");
     markSuperRegs(Reserved, RISCV::X23);
     markSuperRegs(Reserved, RISCV::X27);