Restore lost lto opts for amdgpu (llvm#1696)

Author: ronlieb

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9464,6 +9464,28 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
           A->render(Args, LinkerArgs);
       }
 
+      if (isAMDGPU && !C.getDriver().IsFlangMode()) {
+        StringRef OOpt;
+        if (const Arg *A = Args.getLastArg(options::OPT_O_Group)) {
+          if (A->getOption().matches(options::OPT_O4) ||
+              A->getOption().matches(options::OPT_Ofast))
+            OOpt = "3";
+          else if (A->getOption().matches(options::OPT_O)) {
+            OOpt = A->getValue();
+            if (OOpt == "g")
+              OOpt = "1";
+            else if (OOpt == "s" || OOpt == "z")
+              OOpt = "2";
+          } else if (A->getOption().matches(options::OPT_O0))
+            OOpt = "0";
+        }
+
+        if (!OOpt.empty() && OOpt != "0") {
+          LinkerArgs.push_back(Args.MakeArgString(
+              "--lto-newpm-passes=default-post-link<O" + OOpt + ">"));
+        }
+      }
+
       // Forward all of these to the appropriate toolchain.
       for (StringRef Arg : CompilerArgs)
         CmdArgs.push_back(Args.MakeArgString(

llvm/include/llvm/Pass.h

@@ -83,7 +83,9 @@ enum class ThinOrFullLTOPhase {
   /// Full LTO prelink phase.
   FullLTOPreLink,
   /// Full LTO postlink (backend compile) phase.
-  FullLTOPostLink
+  FullLTOPostLink,
+  /// Custom LTO postlink (e.g. --lto-newpm-passes=...)
+  CustomLTOPostLink
 };
 
 //===----------------------------------------------------------------------===//

llvm/lib/Analysis/InlineAdvisor.cpp

@@ -562,6 +562,7 @@ static inline const char *getLTOPhase(ThinOrFullLTOPhase LTOPhase) {
     return "prelink";
   case (ThinOrFullLTOPhase::ThinLTOPostLink):
   case (ThinOrFullLTOPhase::FullLTOPostLink):
+  case (ThinOrFullLTOPhase::CustomLTOPostLink):
     return "postlink";
   }
   llvm_unreachable("unreachable");

llvm/lib/Passes/PassBuilder.cpp

@@ -488,7 +488,8 @@ static cl::opt<bool> DoFunctionSpecialize("function-specialize",
 // AOCC end
 
 static const Regex DefaultAliasRegex(
-    "^(default|thinlto-pre-link|thinlto|lto-pre-link|lto)<(O[0123sz])>$");
+    "^(default|default-post-link|thinlto-pre-link|thinlto|lto-pre-link|lto)"
+    "<(O[0123sz])>$");
 
 namespace llvm {
 cl::opt<bool> PrintPipelinePasses(
@@ -1920,6 +1921,9 @@ Error PassBuilder::parseModulePass(ModulePassManager &MPM,
 
     if (Matches[1] == "default") {
       MPM.addPass(buildPerModuleDefaultPipeline(L));
+    } else if (Matches[1] == "default-post-link") {
+      MPM.addPass(buildPerModuleDefaultPipeline(
+          L, ThinOrFullLTOPhase::CustomLTOPostLink));
     } else if (Matches[1] == "thinlto-pre-link") {
       MPM.addPass(buildThinLTOPreLinkDefaultPipeline(L));
     } else if (Matches[1] == "thinlto") {

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -414,7 +414,8 @@ static bool isLTOPreLink(ThinOrFullLTOPhase Phase) {
 // Helper to check if the current compilation phase is LTO backend
 static bool isLTOPostLink(ThinOrFullLTOPhase Phase) {
   return Phase == ThinOrFullLTOPhase::ThinLTOPostLink ||
-         Phase == ThinOrFullLTOPhase::FullLTOPostLink;
+         Phase == ThinOrFullLTOPhase::FullLTOPostLink ||
+         Phase == ThinOrFullLTOPhase::CustomLTOPostLink;
 }
 
 // Helper to wrap conditionally Coro passes.

llvm/lib/Transforms/IPO/OpenMPOpt.cpp

@@ -5822,7 +5822,8 @@ PreservedAnalyses OpenMPOptPass::run(Module &M, ModuleAnalysisManager &AM) {
 
   bool PostLink = LTOPhase == ThinOrFullLTOPhase::FullLTOPostLink ||
                   LTOPhase == ThinOrFullLTOPhase::ThinLTOPostLink ||
-                  LTOPhase == ThinOrFullLTOPhase::ThinLTOPreLink;
+                  LTOPhase == ThinOrFullLTOPhase::ThinLTOPreLink ||
+                  LTOPhase == ThinOrFullLTOPhase::CustomLTOPostLink;
   OMPInformationCache InfoCache(M, AG, Allocator, /*CGSCC*/ nullptr, PostLink);
 
   unsigned MaxFixpointIterations =
@@ -5900,7 +5901,8 @@ PreservedAnalyses OpenMPOptCGSCCPass::run(LazyCallGraph::SCC &C,
 
   bool PostLink = LTOPhase == ThinOrFullLTOPhase::FullLTOPostLink ||
                   LTOPhase == ThinOrFullLTOPhase::ThinLTOPostLink ||
-                  LTOPhase == ThinOrFullLTOPhase::ThinLTOPreLink;
+                  LTOPhase == ThinOrFullLTOPhase::ThinLTOPreLink ||
+                  LTOPhase == ThinOrFullLTOPhase::CustomLTOPostLink;
   SetVector<Function *> Functions(llvm::from_range, SCC);
   OMPInformationCache InfoCache(*(Functions.back()->getParent()), AG, Allocator,
                                 /*CGSCC*/ &Functions, PostLink);