[llvm] [Exegesis] CPU selection, when native arch and target mismatch (PR #131014)

[via llvm-commits]

https://github.com/AnastasiyaChernikova updated https://github.com/llvm/llvm-project/pull/131014

>From ff1a11cd4572afc32ce901bfac15ece3073f1582 Mon Sep 17 00:00:00 2001
From: Anastasiya Chernikova <anastasiya.chernikova at syntacore.com>
Date: Wed, 19 Mar 2025 16:17:36 +0300
Subject: [PATCH] [Exegesis] Output error if mcpu flag is missing or incorrect
 when cross compiling

---
 llvm/tools/llvm-exegesis/llvm-exegesis.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
index babcffeb9666a..ab88798ce4cae 100644
--- a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
+++ b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
@@ -44,6 +44,7 @@
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/TargetParser/Host.h"
+#include "llvm/TargetParser/Triple.h"
 #include <algorithm>
 #include <string>
 
@@ -479,6 +480,12 @@ void benchmarkMain() {
 #endif
   }
 
+  // case for cross generating, when native arch and target mismatch
+  if ((Triple(sys::getProcessTriple()).getArch() !=
+       Triple(TripleName).getArch()) &&
+      (MCPU == "native"))
+    ExitWithError("Incorrect cpu. To see all possible options use -mcpu=help");
+
   InitializeAllExegesisTargets();
 #define LLVM_EXEGESIS(TargetName)                                              \
   LLVMInitialize##TargetName##AsmPrinter();                                    \