llvm/test/Transforms/GlobalOpt/tls.ll
Chih-Hung Hsieh dc73dc09f1 Implement target independent TLS compatible with glibc's emutls.c.
The 'common' section TLS is not implemented.
Current C/C++ TLS variables are not placed in common section.
DWARF debug info to get the address of TLS variables is not generated yet.

clang and driver changes in http://reviews.llvm.org/D10524

  Added -femulated-tls flag to select the emulated TLS model,
  which will be used for old targets like Android that do not
  support ELF TLS models.

Added TargetLowering::LowerToTLSEmulatedModel as a target-independent
function to convert a SDNode of TLS variable address to a function call
to __emutls_get_address.

Added into lib/Target/*/*ISelLowering.cpp to call LowerToTLSEmulatedModel
for TLSModel::Emulated. Although all targets supporting ELF TLS models are
enhanced, emulated TLS model has been tested only for Android ELF targets.
Modified AsmPrinter.cpp to print the emutls_v.* and emutls_t.* variables for
emulated TLS variables.
Modified DwarfCompileUnit.cpp to skip some DIE for emulated TLS variabls.

TODO: Add proper DIE for emulated TLS variables.
      Added new unit tests with emulated TLS.

Differential Revision: http://reviews.llvm.org/D10522


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243438 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-28 16:24:05 +00:00

55 lines
1.6 KiB
LLVM

; RUN: opt < %s -globalopt -S | FileCheck %s
; RUN: opt -emulated-tls < %s -globalopt -S | FileCheck %s
declare void @wait()
declare void @signal()
declare void @start_thread(void ()*)
@x = internal thread_local global [100 x i32] zeroinitializer, align 16
@ip = internal global i32* null, align 8
; PR14309: GlobalOpt would think that the value of @ip is always the address of
; x[1]. However, that address is different for different threads so @ip cannot
; be replaced with a constant.
define i32 @f() {
entry:
; Set @ip to point to x[1] for thread 1.
store i32* getelementptr inbounds ([100 x i32], [100 x i32]* @x, i64 0, i64 1), i32** @ip, align 8
; Run g on a new thread.
tail call void @start_thread(void ()* @g) nounwind
tail call void @wait() nounwind
; Reset x[1] for thread 1.
store i32 0, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @x, i64 0, i64 1), align 4
; Read the value of @ip, which now points at x[1] for thread 2.
%0 = load i32*, i32** @ip, align 8
%1 = load i32, i32* %0, align 4
ret i32 %1
; CHECK-LABEL: @f(
; Make sure that the load from @ip hasn't been removed.
; CHECK: load i32*, i32** @ip
; CHECK: ret
}
define internal void @g() nounwind uwtable {
entry:
; Set @ip to point to x[1] for thread 2.
store i32* getelementptr inbounds ([100 x i32], [100 x i32]* @x, i64 0, i64 1), i32** @ip, align 8
; Store 50 in x[1] for thread 2.
store i32 50, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @x, i64 0, i64 1), align 4
tail call void @signal() nounwind
ret void
; CHECK-LABEL: @g(
; Make sure that the store to @ip hasn't been removed.
; CHECK: store {{.*}} @ip
; CHECK: ret
}