[llvm] [RISCV] Add QingKe "XW" compressed opcode extension (PR #97925)

[Craig Topper via llvm-commits]

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@@ -799,6 +800,20 @@ Error RISCVISAInfo::checkDependency() {
         errc::invalid_argument,
         "'zabha' requires 'a' or 'zaamo' extension to also be specified");
 
+  if (Exts.count("xwchc") != 0) {
+    if (XLen != 32)
+      return createStringError(errc::invalid_argument,
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topperc wrote:

This needs to be rebased to use the recently introduced `getError` function.

https://github.com/llvm/llvm-project/pull/97925