[llvm] 6ecc67f - [Exegesis] CPU selection, when native arch and target mismatch (#131014)

[via llvm-commits]

Author: AnastasiyaChernikova
Date: 2025-03-26T19:00:06+03:00
New Revision: 6ecc67fb3223fbc641560596a4811da371dc6c4b

URL: https://github.com/llvm/llvm-project/commit/6ecc67fb3223fbc641560596a4811da371dc6c4b
DIFF: https://github.com/llvm/llvm-project/commit/6ecc67fb3223fbc641560596a4811da371dc6c4b.diff

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

Added: 
    llvm/test/tools/llvm-exegesis/X86/mcpu_not_set_during_cross_compilation.s

Modified: 
    llvm/tools/llvm-exegesis/lib/LlvmState.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/test/tools/llvm-exegesis/X86/mcpu_not_set_during_cross_compilation.s b/llvm/test/tools/llvm-exegesis/X86/mcpu_not_set_during_cross_compilation.s
new file mode 100644
index 0000000000000..f2a4e51552eb1
--- /dev/null
+++ b/llvm/test/tools/llvm-exegesis/X86/mcpu_not_set_during_cross_compilation.s
@@ -0,0 +1,3 @@
+# RUN: not llvm-exegesis -mtriple=riscv64-unknown-linux-gnu -mode=latency --benchmark-phase=assemble-measured-code -opcode-name=ADD 2>&1 | FileCheck %s
+
+# CHECK: llvm-exegesis error: A CPU must be explicitly specified when cross compiling. To see all possible options for riscv64-unknown-linux-gnu triple use -mcpu=help

diff  --git a/llvm/tools/llvm-exegesis/lib/LlvmState.cpp b/llvm/tools/llvm-exegesis/lib/LlvmState.cpp
index 9502cae993f67..88c0d67694afb 100644
--- a/llvm/tools/llvm-exegesis/lib/LlvmState.cpp
+++ b/llvm/tools/llvm-exegesis/lib/LlvmState.cpp
@@ -42,8 +42,17 @@ Expected<LLVMState> LLVMState::Create(std::string TripleName,
   // Update Triple with the updated triple from the target lookup.
   TripleName = TheTriple.str();
 
-  if (CpuName == "native")
+  if (CpuName == "native") {
+    // case for cross generating, when native arch and target mismatch
+    if ((Triple(sys::getProcessTriple()).getArch() !=
+         Triple(TripleName).getArch()))
+      return make_error<StringError>(
+          "A CPU must be explicitly specified when cross compiling. To see all "
+          "possible options for " +
+              TripleName + " triple use -mcpu=help",
+          inconvertibleErrorCode());
     CpuName = std::string(sys::getHostCPUName());
+  }
 
   std::unique_ptr<MCSubtargetInfo> STI(
       TheTarget->createMCSubtargetInfo(TripleName, CpuName, ""));