[lld] fe08e9c - [lld-macho] Add support for LTO optimization level

[Nico Weber via llvm-commits]

Author: Leonard Grey
Date: 2021-07-01T15:01:59-04:00
New Revision: fe08e9c4871e8842dc5c8f75a4796a86029c1ebe

URL: https://github.com/llvm/llvm-project/commit/fe08e9c4871e8842dc5c8f75a4796a86029c1ebe
DIFF: https://github.com/llvm/llvm-project/commit/fe08e9c4871e8842dc5c8f75a4796a86029c1ebe.diff

LOG: [lld-macho] Add support for LTO optimization level

Everything (including test) modified from ELF/COFF. Using the same syntax
(--lto-O3, etc) as ELF.

Differential Revision: https://reviews.llvm.org/D105223

Added: 
    

Modified: 
    lld/MachO/Config.h
    lld/MachO/Driver.cpp
    lld/MachO/LTO.cpp
    lld/MachO/Options.td

Removed: 
    


################################################################################
diff  --git a/lld/MachO/Config.h b/lld/MachO/Config.h
index 722b19f712531..ee4d49bd135a0 100644
--- a/lld/MachO/Config.h
+++ b/lld/MachO/Config.h
@@ -126,6 +126,7 @@ struct Configuration {
   llvm::StringRef outputFile;
   llvm::StringRef ltoObjPath;
   llvm::StringRef thinLTOJobs;
+  uint32_t ltoo = 2;
   bool deadStripDylibs = false;
   bool demangle = false;
   bool deadStrip = false;

diff  --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index 59f764f8c1d2c..23b505d7b9477 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -1082,6 +1082,9 @@ bool macho::link(ArrayRef<const char *> argsArr, bool canExitEarly,
   config->ltoNewPassManager =
       args.hasFlag(OPT_no_lto_legacy_pass_manager, OPT_lto_legacy_pass_manager,
                    LLVM_ENABLE_NEW_PASS_MANAGER);
+  config->ltoo = args::getInteger(args, OPT_lto_O, 2);
+  if (config->ltoo > 3)
+    error("--lto-O: invalid optimization level: " + Twine(config->ltoo));
   config->runtimePaths = args::getStrings(args, OPT_rpath);
   config->allLoad = args.hasArg(OPT_all_load);
   config->forceLoadObjC = args.hasArg(OPT_ObjC);

diff  --git a/lld/MachO/LTO.cpp b/lld/MachO/LTO.cpp
index 55e155e1a7dd6..3fa7fe4e32e59 100644
--- a/lld/MachO/LTO.cpp
+++ b/lld/MachO/LTO.cpp
@@ -13,6 +13,7 @@
 #include "Symbols.h"
 #include "Target.h"
 
+#include "lld/Common/Args.h"
 #include "lld/Common/ErrorHandler.h"
 #include "lld/Common/Strings.h"
 #include "lld/Common/TargetOptionsCommandFlags.h"
@@ -40,6 +41,8 @@ static lto::Config createConfig() {
   };
   c.TimeTraceEnabled = config->timeTraceEnabled;
   c.TimeTraceGranularity = config->timeTraceGranularity;
+  c.OptLevel = config->ltoo;
+  c.CGOptLevel = args::getCGOptLevel(config->ltoo);
   if (config->saveTemps)
     checkError(c.addSaveTemps(config->outputFile.str() + ".",
                               /*UseInputModulePath=*/true));

diff  --git a/lld/MachO/Options.td b/lld/MachO/Options.td
index ebff0d5813a02..515053a64cf10 100644
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -64,6 +64,10 @@ def icf_eq: Joined<["--"], "icf=">,
     HelpText<"Set level for identical code folding (default: none)">,
     MetaVarName<"[none,safe,all]">,
     Group<grp_lld>;
+def lto_O: Joined<["--"], "lto-O">,
+    HelpText<"Set optimization level for LTO (default: 2)">,
+    MetaVarName<"<opt-level>">,
+    Group<grp_lld>;
 
 // This is a complete Options.td compiled from Apple's ld(1) manpage
 // dated 2018-03-07 and cross checked with ld64 source code in repo