[clang] [llvm] [RISCV] Add Qualcomm uC Xqcicsr (CSR) extension (PR #117169)

[Craig Topper via cfe-commits]

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@@ -0,0 +1,44 @@
+//===---------------- RISCVInstrInfoXQci.td ----------------*- tablegen -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the vendor extensions defined by QUALCOMM.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Operand and SDNode transformation definitions.
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Instruction Formats
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Instruction Class Templates
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Instructions
+//===----------------------------------------------------------------------===//
+
+let Predicates = [HasVendorXqcicsr, IsRV32], DecoderNamespace = "Xqcicsr" in {
+let hasSideEffects = 0, mayLoad = 0, mayStore = 0 in {
+  def QC_CSRRWR : RVInstR<0b1000110, 0b000, OPC_SYSTEM, (outs GPR:$rd),
+                          (ins GPR:$rs1, GPRNoX0:$rs2), "qc.csrrwr",
+                          "$rd, $rs1, $rs2">;
+
+  def QC_CSRRWRI : RVInstRBase<0b000, OPC_SYSTEM, (outs GPR:$rd),
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topperc wrote:

I think you can just use `RVInstR` if you use `uimm5:$rs1`. It's what `CSR_ii` does for the standard CSR instructions.

https://github.com/llvm/llvm-project/pull/117169