1 files changed, 3 insertions, 42 deletions

diff --git a/contrib/llvm-project/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp b/contrib/llvm-project/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
index f3ea0f597eec..4759aa951664 100644
--- a/contrib/llvm-project/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
+++ b/contrib/llvm-project/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
@@ -1832,57 +1832,18 @@ ParseStatus RISCVAsmParser::parseCSRSystemRegister(OperandVector &Operands) {
     if (getParser().parseIdentifier(Identifier))
       return ParseStatus::Failure;
 
-    // Check for CSR names conflicts.
-    // Custom CSR names might conflict with CSR names in privileged spec.
-    // E.g. - SiFive mnscratch(0x350) and privileged spec mnscratch(0x740).
-    auto CheckCSRNameConflict = [&]() {
-      if (!(RISCVSysReg::lookupSysRegByName(Identifier))) {
-        Error(S, "system register use requires an option to be enabled");
-        return true;
-      }
-      return false;
-    };
-
-    // First check for vendor specific CSRs.
-    auto SiFiveReg = RISCVSysReg::lookupSiFiveRegByName(Identifier);
-    if (SiFiveReg) {
-      if (SiFiveReg->haveVendorRequiredFeatures(getSTI().getFeatureBits())) {
-        Operands.push_back(
-            RISCVOperand::createSysReg(Identifier, S, SiFiveReg->Encoding));
-        return ParseStatus::Success;
-      }
-      if (CheckCSRNameConflict())
-        return ParseStatus::Failure;
-    }
-
     auto SysReg = RISCVSysReg::lookupSysRegByName(Identifier);
     if (!SysReg)
+      SysReg = RISCVSysReg::lookupSysRegByAltName(Identifier);
+    if (!SysReg)
       if ((SysReg = RISCVSysReg::lookupSysRegByDeprecatedName(Identifier)))
         Warning(S, "'" + Identifier + "' is a deprecated alias for '" +
                        SysReg->Name + "'");
 
-    // Check for CSR encoding conflicts.
-    // Custom CSR encoding might conflict with CSR encoding in privileged spec.
-    // E.g. - SiFive mnscratch(0x350) and privileged spec miselect(0x350).
-    auto CheckCSREncodingConflict = [&]() {
-      auto Reg = RISCVSysReg::lookupSiFiveRegByEncoding(SysReg->Encoding);
-      if (Reg && Reg->haveVendorRequiredFeatures(getSTI().getFeatureBits())) {
-        Warning(S, "'" + Identifier + "' CSR is not available on the current " +
-                       "subtarget. Instead '" + Reg->Name +
-                       "' CSR will be used.");
-        Operands.push_back(
-            RISCVOperand::createSysReg(Reg->Name, S, Reg->Encoding));
-        return true;
-      }
-      return false;
-    };
-
-    // Accept a named SysReg if the required features are present.
+    // Accept a named Sys Reg if the required features are present.
     if (SysReg) {
       if (!SysReg->haveRequiredFeatures(getSTI().getFeatureBits()))
         return Error(S, "system register use requires an option to be enabled");
-      if (CheckCSREncodingConflict())
-        return ParseStatus::Success;
       Operands.push_back(
           RISCVOperand::createSysReg(Identifier, S, SysReg->Encoding));
       return ParseStatus::Success;