[LTO] Discard names for values that are not global by default.

Rafael reported on the mailing list that this reduces peak memory usage while linking llvm-as by 15%. It makes sense to make it the default, and introduce an inverse knob -lto-no-discard-value-names for those who want to restore the old behavior. llvm-svn: 267020
llvm · Apr 21, 2016 · 5abcb3c · 5abcb3c
1 parent 3ac0718
commit 5abcb3c
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Showing 4 changed files with 5 additions and 5 deletions.
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
@@ -289,7 +289,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->Demangle = !Args.hasArg(OPT_no_demangle);
   Config->DisableVerify = Args.hasArg(OPT_disable_verify);
   Config->DiscardAll = Args.hasArg(OPT_discard_all);
-  Config->DiscardValueNames = Args.hasArg(OPT_lto_discard_value_names);
+  Config->DiscardValueNames = !Args.hasArg(OPT_lto_no_discard_value_names);
   Config->DiscardLocals = Args.hasArg(OPT_discard_locals);
   Config->DiscardNone = Args.hasArg(OPT_discard_none);
   Config->EhFrameHdr = Args.hasArg(OPT_eh_frame_hdr);

diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
@@ -238,7 +238,7 @@ def G : Separate<["-"], "G">;
 def alias_version_script_version_script : Joined<["--"], "version-script=">, Alias<version_script>;
 
 // LTO-related options.
-def lto_discard_value_names : Flag<["-"], "lto-discard-value-names">;
+def lto_no_discard_value_names : Flag<["-"], "lto-no-discard-value-names">;
 def lto_jobs : Joined<["--"], "lto-jobs=">,
   HelpText<"Number of threads to run codegen">;
 def disable_verify : Flag<["-"], "disable-verify">;

diff --git a/lld/test/ELF/lto/discard-value-names.ll b/lld/test/ELF/lto/discard-value-names.ll
@@ -1,9 +1,9 @@
 ; RUN: llvm-as %s -o %t.o
 
-; RUN: ld.lld -m elf_x86_64 -shared -save-temps %t.o -o %t2.o
+; RUN: ld.lld -m elf_x86_64 -lto-no-discard-value-names -shared -save-temps %t.o -o %t2.o
 ; RUN: llvm-dis < %t2.o.lto.bc | FileCheck %s
 
-; RUN: ld.lld -m elf_x86_64 -lto-discard-value-names -shared -save-temps %t.o -o %t2.o
+; RUN: ld.lld -m elf_x86_64 -shared -save-temps %t.o -o %t2.o
 ; RUN: llvm-dis < %t2.o.lto.bc | FileCheck --check-prefix=NONAME %s
 
 ; CHECK: @GlobalValueName

diff --git a/lld/test/ELF/lto/type-merge2.ll b/lld/test/ELF/lto/type-merge2.ll
@@ -1,6 +1,6 @@
 ; RUN: llvm-as %s -o %t.o
 ; RUN: llvm-as %p/Inputs/type-merge2.ll -o %t2.o
-; RUN: ld.lld -m elf_x86_64 %t.o %t2.o -o %t.so -shared -save-temps
+; RUN: ld.lld -m elf_x86_64 %t.o %t2.o -o %t.so -shared -save-temps -lto-no-discard-value-names
 ; RUN: llvm-dis %t.so.lto.bc -o - | FileCheck %s
 
 target triple = "x86_64-unknown-linux-gnu"