From 6098b2f5199c90ac36fda3cf6f049b72aacee27d Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Thu, 26 Jun 2014 03:02:19 +0000 Subject: [PATCH] GlobalOpt: Don't optimize thread_local for initializers Folding a reference to a thread_local variable into another global variable's initializer is very problematic, there is no relocation that exists to represent such an access. llvm-svn: 211762 --- llvm/lib/Transforms/IPO/GlobalOpt.cpp | 5 +++-- llvm/test/Transforms/GlobalOpt/constantfold-initializers.ll | 12 +++++++++++- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp index 75c1878..36c04f0 100644 --- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp +++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp @@ -1980,9 +1980,10 @@ isSimpleEnoughValueToCommit(Constant *C, static bool isSimpleEnoughValueToCommitHelper(Constant *C, SmallPtrSet &SimpleConstants, const DataLayout *DL) { - // Simple global addresses are supported, do not allow dllimport globals. + // Simple global addresses are supported, do not allow dllimport or + // thread-local globals. if (auto *GV = dyn_cast(C)) - return !GV->hasDLLImportStorageClass(); + return !GV->hasDLLImportStorageClass() && !GV->isThreadLocal(); // Simple integer, undef, constant aggregate zero, etc are all supported. if (C->getNumOperands() == 0 || isa(C)) diff --git a/llvm/test/Transforms/GlobalOpt/constantfold-initializers.ll b/llvm/test/Transforms/GlobalOpt/constantfold-initializers.ll index 53e8465..8fc1330 100644 --- a/llvm/test/Transforms/GlobalOpt/constantfold-initializers.ll +++ b/llvm/test/Transforms/GlobalOpt/constantfold-initializers.ll @@ -72,9 +72,19 @@ entry: ret void } +@threadlocalptr = global i32* null, align 4 +; CHECK: @threadlocalptr = global i32* null, align 4 +@threadlocalvar = external thread_local global i32 +define internal void @test5() { +entry: + store i32* @threadlocalvar, i32** @threadlocalptr, align 4 + ret void +} + @llvm.global_ctors = appending constant - [4 x { i32, void ()* }] + [5 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @test1 }, { i32, void ()* } { i32 65535, void ()* @test2 }, { i32, void ()* } { i32 65535, void ()* @test3 }, + { i32, void ()* } { i32 65535, void ()* @test4 }, { i32, void ()* } { i32 65535, void ()* @test4 }] -- 2.7.4