[flang-commits] [clang] [flang] [flang] Emit module summary for ThinLTO (PR #195999)

[Tarun Prabhu via flang-commits]

================
@@ -1060,23 +1060,20 @@ void CodeGenAction::runOptimizationPipeline(llvm::raw_pwrite_stream &os) {
 
   if (action == BackendActionTy::Backend_EmitBC ||
       action == BackendActionTy::Backend_EmitLL || opts.PrepareForFatLTO) {
-    if (opts.PrepareForThinLTO) {
-      // TODO: ThinLTO module summary support is yet to be enabled.
-      if (action == BackendActionTy::Backend_EmitBC)
-        mpm.addPass(llvm::BitcodeWriterPass(os));
-      else if (action == BackendActionTy::Backend_EmitLL)
-        mpm.addPass(llvm::PrintModulePass(os));
-    } else {
-      if (emitSummary && !llvmModule->getModuleFlag("ThinLTO"))
+
+    // If it is not ThinLTO, emits the module flag and sets it to be off.
+    if (!opts.PrepareForThinLTO) {
+      if (emitSummary && !llvmModule->getModuleFlag("ThinLTO")) {
         llvmModule->addModuleFlag(llvm::Module::Error, "ThinLTO", uint32_t(0));
-      if (action == BackendActionTy::Backend_EmitBC)
-        mpm.addPass(llvm::BitcodeWriterPass(
-            os, /*ShouldPreserveUseListOrder=*/false, emitSummary));
-      else if (action == BackendActionTy::Backend_EmitLL)
-        mpm.addPass(llvm::PrintModulePass(os, /*Banner=*/"",
-                                          /*ShouldPreserveUseListOrder=*/false,
-                                          emitSummary));
+      }
     }
+    if (action == BackendActionTy::Backend_EmitBC)
----------------
tarunprabhu wrote:

Per Flang's [style guide](https://flang.llvm.org/docs/C%2B%2Bstyle.html#layout), this should have braces. However, there is an exception for code "that makes heavy use of LLVM or MLIR API's. I am inclined to argue that this part of the code does, so we can probably leave it as it is.

https://github.com/llvm/llvm-project/pull/195999