[lld] r283787 - [LTO/Thin] Make the number of threads to run in the BE configurable.

[Davide Italiano via llvm-commits]

Author: davide
Date: Mon Oct 10 13:12:53 2016
New Revision: 283787

URL: http://llvm.org/viewvc/llvm-project?rev=283787&view=rev
Log:
[LTO/Thin] Make the number of threads to run in the BE configurable.

Before the default was whatever number hardware_concurrency() returned.
Users can specify the number of threads via --lto-jobs=X option.

Added:
    lld/trunk/test/ELF/lto/Inputs/thinlto.ll
    lld/trunk/test/ELF/lto/thinlto.ll
Modified:
    lld/trunk/ELF/LTO.cpp

Modified: lld/trunk/ELF/LTO.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.cpp?rev=283787&r1=283786&r2=283787&view=diff
==============================================================================
--- lld/trunk/ELF/LTO.cpp (original)
+++ lld/trunk/ELF/LTO.cpp Mon Oct 10 13:12:53 2016
@@ -49,7 +49,6 @@ static void checkError(Error E) {
 
 static std::unique_ptr<lto::LTO> createLTO() {
   lto::Config Conf;
-  lto::ThinBackend Backend;
 
   // LLD supports the new relocations.
   Conf.Options = InitTargetOptionsFromCodeGenFlags();
@@ -68,6 +67,9 @@ static std::unique_ptr<lto::LTO> createL
     checkError(Conf.addSaveTemps(std::string(Config->OutputFile) + ".",
                             /*UseInputModulePath*/ true));
 
+  lto::ThinBackend Backend;
+  if (Config->LtoJobs)
+    Backend = lto::createInProcessThinBackend(Config->LtoJobs);
   return llvm::make_unique<lto::LTO>(std::move(Conf), Backend, Config->LtoJobs);
 }
 

Added: lld/trunk/test/ELF/lto/Inputs/thinlto.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/Inputs/thinlto.ll?rev=283787&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/Inputs/thinlto.ll (added)
+++ lld/trunk/test/ELF/lto/Inputs/thinlto.ll Mon Oct 10 13:12:53 2016
@@ -0,0 +1,7 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @g() {
+entry:
+  ret void
+}

Added: lld/trunk/test/ELF/lto/thinlto.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/thinlto.ll?rev=283787&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/thinlto.ll (added)
+++ lld/trunk/test/ELF/lto/thinlto.ll Mon Oct 10 13:12:53 2016
@@ -0,0 +1,29 @@
+; Basic ThinLTO tests.
+; RUN: llvm-as %s -o %t.o
+; RUN: llvm-as %p/Inputs/thinlto.ll -o %t2.o
+
+; First force single-threaded mode
+; RUN: ld.lld -save-temps --lto-jobs=1 -shared %t.o %t2.o -o %t
+; RUN: llvm-nm %t.lto.o | FileCheck %s --check-prefix=NM
+
+; NM: T f
+; NM: T g
+
+; Next force multi-threaded mode
+; RUN: ld.lld -save-temps --lto-jobs=2 -shared %t.o %t2.o -o %t2
+; RUN: llvm-nm %t20.lto.o | FileCheck %s --check-prefix=NM1
+; RUN: llvm-nm %t21.lto.o | FileCheck %s --check-prefix=NM2
+
+; NM1: T g
+; NM2: T f
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare void @g(...)
+
+define void @f() {
+entry:
+  call void (...) @g()
+  ret void
+}