Run verifier during LLVM code generation (#2211)

src/codegen/llvm/llvm_common.h

@@ -26,6 +26,7 @@
 #include <llvm/IR/Type.h>
 #include <llvm/IR/Intrinsics.h>
 #include <llvm/IR/MDBuilder.h>
+#include <llvm/IR/Verifier.h>
 
 #include <llvm/IR/LegacyPassManager.h>
 #include <llvm/Transforms/Utils/Cloning.h>

src/codegen/llvm/llvm_module.cc

@@ -168,6 +168,11 @@ class LLVMModuleNode final : public runtime::ModuleNode {
     }
     cg->AddMainFunction(funcs[0]->name);
     module_ = cg->Finish();
+    std::string verify_errors_storage;
+    llvm::raw_string_ostream verify_errors(verify_errors_storage);
+    LOG_IF(FATAL, llvm::verifyModule(*module_, &verify_errors))
+        << "LLVM module verification failed with the following errors: \n"
+        << verify_errors.str();
     module_->addModuleFlag(
         llvm::Module::Warning, "tvm_target",
         llvm::MDString::get(*ctx_, target));