[LTO] Promote before performing weak resolution

[mehdi_amini]

Summary

This was reversed compared to ThinLTOCodeGenerator for some reason,
and lead to an increased code-size on my tests. I figured that the
weak resolution may internalize a linkonce function, which will be
promoted immediately (and renamed), before being internalized again.

[mehdi_amini]

I couldn't check if any gold test needs to be updated.

[tejohnson]

Will test on gold.

[tejohnson]

Test needs fix but otherwise fine.

test/ThinLTO/X86/internalize.ll

10 ↗

(On Diff #68439)

It passes only if I change the file name to "%t.o.1.2.internalize.bc"

Note there are two changes in the name: s/0/1/ and s/internalized/internalize/.

[mehdi_amini]

test/ThinLTO/X86/internalize.ll

10 ↗

(On Diff #68439)

Yes, annoyingly the suffix for the temporary names for the new API don't match the ThinLTOCodeGenerator ones. I had a local patch to correct this while I'm migrating.

llvm/trunk/lib/LTO/LTOBackend.cpp

if (!TOrErr)
     return TOrErr.takeError();
 
   std::unique_ptr<TargetMachine> TM =
       createTargetMachine(Conf, Mod.getTargetTriple(), *TOrErr);
 
   if (Conf.PreOptModuleHook && !Conf.PreOptModuleHook(Task, Mod))
     return Error();
 
-  thinLTOResolveWeakForLinkerModule(Mod, DefinedGlobals);
-
   renameModuleForThinLTO(Mod, CombinedIndex);
 
+  thinLTOResolveWeakForLinkerModule(Mod, DefinedGlobals);
+
   if (Conf.PostPromoteModuleHook && !Conf.PostPromoteModuleHook(Task, Mod))
     return Error();
 
   if (!DefinedGlobals.empty())
     thinLTOInternalizeModule(Mod, DefinedGlobals);
 
   if (Conf.PostInternalizeModuleHook &&
       !Conf.PostInternalizeModuleHook(Task, Mod))

llvm/trunk/test/ThinLTO/X86/internalize.ll

 ;; RUN: opt -module-summary %s -o %t1.bc
 ; RUN: llvm-lto -thinlto-action=thinlink -o %t.index.bc %t1.bc
 ; RUN: llvm-lto -thinlto-action=internalize -thinlto-index %t.index.bc %t1.bc -o - | llvm-dis -o - | FileCheck %s --check-prefix=REGULAR
 ; RUN: llvm-lto -thinlto-action=internalize -thinlto-index %t.index.bc %t1.bc -o -  --exported-symbol=foo | llvm-dis -o - | FileCheck %s --check-prefix=INTERNALIZE
 
+; RUN: llvm-lto2 %t1.bc -o %t.o -save-temps \
+; RUN:     -r=%t1.bc,_foo,pxl \
+; RUN:     -r=%t1.bc,_bar,pl \
+; RUN:     -r=%t1.bc,_linkonce_func,pl
+; RUN: llvm-dis < %t.o.1.2.internalize.bc | FileCheck  %s --check-prefix=INTERNALIZE
+
+
 ; REGULAR: define void @foo
 ; REGULAR: define void @bar
+; REGULAR: define linkonce void @linkonce_func()
 ; INTERNALIZE: define void @foo
 ; INTERNALIZE: define internal void @bar
+; INTERNALIZE: define internal void @linkonce_func()
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.11.0"
 
 define void @foo() {
     ret void
 }
 define void @bar() {
+    call void @linkonce_func()
+  ret void
+}
+define linkonce void @linkonce_func() {
     ret void
 }
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