[lld][COFF] Add command line options for LTO with new pass manager

[dmajor]

Summary

This is more or less a port of rL329598 (D45275) to the COFF linker. Since there were already LTO-related settings under -opt:, I added them there instead of new flags.

[dmajor]

Oh, I didn't realize that Rui was inactive... trying rnk instead, based on recent commits under lld/COFF/.

[rnk]

lgtm

lld/COFF/Config.h

struct Configuration {
   // Used for /opt:lldltopartitions=N
   unsigned ltoPartitions = 1;
 
   // Used for /opt:lldltocache=path
   StringRef ltoCache;
   // Used for /opt:lldltocachepolicy=policy
   llvm::CachePruningPolicy ltoCachePolicy;
 
+  // Used for /opt:[no]ltonewpassmanager
+  bool ltoNewPassManager = false;
+  // Used for /opt:[no]ltodebugpassmanager
+  bool ltoDebugPassManager = false;
+
   // Used for /merge:from=to (e.g. /merge:.rdata=.text)
   std::map<StringRef, StringRef> merge;
 
   // Used for /section=.name,{DEKPRSW} to set section attributes.
   std::map<StringRef, uint32_t> section;
 
   // Options for manifest files.
   ManifestKind manifest = No;

lld/COFF/Driver.cpp

void LinkerDriver::link(ArrayRef<const char *> argsArr) {
   if (auto *arg = args.getLastArg(OPT_implib))
     config->implib = arg->getValue();
 
   // Handle /opt.
   bool doGC = debug == DebugKind::None || args.hasArg(OPT_profile);
   unsigned icfLevel =
       args.hasArg(OPT_profile) ? 0 : 1; // 0: off, 1: limited, 2: on
   unsigned tailMerge = 1;
+  bool ltoNewPM = false;
+  bool ltoDebugPM = false;
   for (auto *arg : args.filtered(OPT_opt)) {
     std::string str = StringRef(arg->getValue()).lower();
     SmallVector<StringRef, 1> vec;
     StringRef(str).split(vec, ',');
     for (StringRef s : vec) {
       if (s == "ref") {
         doGC = true;
       } else if (s == "noref") {
         doGC = false;
       } else if (s == "icf" || s.startswith("icf=")) {
         icfLevel = 2;
       } else if (s == "noicf") {
         icfLevel = 0;
       } else if (s == "lldtailmerge") {
         tailMerge = 2;
       } else if (s == "nolldtailmerge") {
         tailMerge = 0;
+      } else if (s == "ltonewpassmanager") {
+        ltoNewPM = true;
+      } else if (s == "noltonewpassmanager") {
+        ltoNewPM = false;
+      } else if (s == "ltodebugpassmanager") {
+        ltoDebugPM = true;
+      } else if (s == "noltodebugpassmanager") {
+        ltoDebugPM = false;
       } else if (s.startswith("lldlto=")) {
         StringRef optLevel = s.substr(7);
         if (optLevel.getAsInteger(10, config->ltoo) || config->ltoo > 3)
           error("/opt:lldlto: invalid optimization level: " + optLevel);
       } else if (s.startswith("lldltojobs=")) {
         StringRef jobs = s.substr(11);
         if (!get_threadpool_strategy(jobs))
           error("/opt:lldltojobs: invalid job count: " + jobs);
void LinkerDriver::link(ArrayRef<const char *> argsArr) {
   // FIXME: LLD only implements "limited" ICF, i.e. it only merges identical
   // code. If the user passes /OPT:ICF explicitly, LLD should merge identical
   // comdat readonly data.
   if (icfLevel == 1 && !doGC)
     icfLevel = 0;
   config->doGC = doGC;
   config->doICF = icfLevel > 0;
   config->tailMerge = (tailMerge == 1 && config->doICF) || tailMerge == 2;
+  config->ltoNewPassManager = ltoNewPM;
+  config->ltoDebugPassManager = ltoDebugPM;
 
   // Handle /lldsavetemps
   if (args.hasArg(OPT_lldsavetemps))
     config->saveTemps = true;
 
   // Handle /kill-at
   if (args.hasArg(OPT_kill_at))
     config->killAt = true;

lld/COFF/LTO.cpp

else
     c.RelocModel = Reloc::PIC_;
   c.DisableVerify = true;
   c.DiagHandler = diagnosticHandler;
   c.OptLevel = config->ltoo;
   c.CPU = getCPUStr();
   c.MAttrs = getMAttrs();
   c.CGOptLevel = args::getCGOptLevel(config->ltoo);
   c.AlwaysEmitRegularLTOObj = !config->ltoObjPath.empty();
+  c.UseNewPM = config->ltoNewPassManager;
+  c.DebugPassManager = config->ltoDebugPassManager;
 
   if (config->saveTemps)
     checkError(c.addSaveTemps(std::string(config->outputFile) + ".",
                               /*UseInputModulePath*/ true));
   return c;
 }
 
 BitcodeCompiler::BitcodeCompiler() {

lld/test/COFF/lto-new-pass-manager.ll

+; REQUIRES: x86
+; RUN: llvm-as %s -o %s.obj
+
+; RUN: lld-link %s.obj -entry:main -opt:ltonewpassmanager -opt:ltodebugpassmanager 2>&1 | FileCheck %s --check-prefix=ENABLED
+; ENABLED: Starting llvm::Module pass manager run.
+; ENABLED: Finished llvm::Module pass manager run.
+
+; Passing -time just to avoid empty FileCheck input
+; RUN: lld-link %s.obj -entry:main -time -opt:ltonewpassmanager -opt:ltodebugpassmanager -opt:noltonewpassmanager 2>&1 | FileCheck %s --check-prefix=DISABLED
+; RUN: lld-link %s.obj -entry:main -time -opt:ltonewpassmanager -opt:ltodebugpassmanager -opt:noltodebugpassmanager 2>&1 | FileCheck %s --check-prefix=DISABLED
+; DISABLED-NOT: Starting llvm::Module pass manager run.
+; DISABLED-NOT: Finished llvm::Module pass manager run.
+
+target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.11.0"
+
+define dso_local i32 @main(i32 %argc, i8** nocapture readnone %0) local_unnamed_addr {
+entry:
+  ret i32 %argc
+}