[clang] [RISCV][NFC] Use RISCVISAInfo instead of string comparison (PR #76387)

[Craig Topper via cfe-commits]

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@@ -670,10 +671,18 @@ static llvm::Triple computeTargetTriple(const Driver &D,
     if (Args.hasArg(options::OPT_march_EQ) ||
         Args.hasArg(options::OPT_mcpu_EQ)) {
       StringRef ArchName = tools::riscv::getRISCVArch(Args, Target);
-      if (ArchName.starts_with_insensitive("rv32"))
-        Target.setArch(llvm::Triple::riscv32);
-      else if (ArchName.starts_with_insensitive("rv64"))
-        Target.setArch(llvm::Triple::riscv64);
+      auto ISAInfo = llvm::RISCVISAInfo::parseArchString(
+          ArchName, /*EnableExperimentalExtensions=*/true);
+      if (!ISAInfo) {
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topperc wrote:

Use `errorToBool` to avoid the call to consumeError?

https://github.com/llvm/llvm-project/pull/76387