[llvm] r366275 - [WebAssembly] Compile all TLS on Emscripten as local-exec
Guanzhong Chen via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 16 15:22:08 PDT 2019
Author: quantum
Date: Tue Jul 16 15:22:08 2019
New Revision: 366275
URL: http://llvm.org/viewvc/llvm-project?rev=366275&view=rev
Log:
[WebAssembly] Compile all TLS on Emscripten as local-exec
Summary:
Currently, on Emscripten, dynamic linking is not supported with threads.
This means that if thread-local storage is used, it must be used in a
statically-linked executable. Hence, local-exec is the only possible model.
This diff compiles all TLS variables to use local-exec on Emscripten as a
temporary measure until dynamic linking is supported with threads.
The goal for this is to allow C++ types with constructors to be thread-local.
Currently, when `clang` compiles a `thread_local` variable with a constructor,
it generates `__tls_guard` variable:
@__tls_guard = internal thread_local global i8 0, align 1
As no TLS model is specified, this is treated as general-dynamic, which we do
not support (and cannot support without implementing dynamic linking support
with threads in Emscripten). As a result, any C++ constructor in `thread_local`
variables would not compile.
By compiling all `thread_local` as local-exec, `__tls_guard` will compile and
we can support C++ constructors with TLS without implementing dynamic linking
with threads.
Depends on D64537
Reviewers: tlively, aheejin, sbc100
Reviewed By: aheejin
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64776
Added:
llvm/trunk/test/CodeGen/WebAssembly/tls-general-dynamic.ll
llvm/trunk/test/CodeGen/WebAssembly/tls-local-exec.ll
Removed:
llvm/trunk/test/CodeGen/WebAssembly/tls.ll
Modified:
llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp?rev=366275&r1=366274&r2=366275&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp Tue Jul 16 15:22:08 2019
@@ -179,9 +179,17 @@ void WebAssemblyDAGToDAGISel::Select(SDN
report_fatal_error("cannot use thread-local storage without bulk memory",
false);
+ // Currently Emscripten does not support dynamic linking with threads.
+ // Therefore, if we have thread-local storage, only the local-exec model
+ // is possible.
+ // TODO: remove this and implement proper TLS models once Emscripten
+ // supports dynamic linking with threads.
if (GA->getGlobal()->getThreadLocalMode() !=
- GlobalValue::LocalExecTLSModel) {
- report_fatal_error("only -ftls-model=local-exec is supported for now",
+ GlobalValue::LocalExecTLSModel &&
+ !Subtarget->getTargetTriple().isOSEmscripten()) {
+ report_fatal_error("only -ftls-model=local-exec is supported for now on "
+ "non-Emscripten OSes: variable " +
+ GA->getGlobal()->getName(),
false);
}
Added: llvm/trunk/test/CodeGen/WebAssembly/tls-general-dynamic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/tls-general-dynamic.ll?rev=366275&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/tls-general-dynamic.ll (added)
+++ llvm/trunk/test/CodeGen/WebAssembly/tls-general-dynamic.ll Tue Jul 16 15:22:08 2019
@@ -0,0 +1,86 @@
+; RUN: not llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory 2>&1 | FileCheck %s --check-prefix=ERROR
+; RUN: not llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory -fast-isel 2>&1 | FileCheck %s --check-prefix=ERROR
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory --mtriple wasm32-unknown-emscripten | FileCheck %s --check-prefixes=CHECK,TLS
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory --mtriple wasm32-unknown-emscripten -fast-isel | FileCheck %s --check-prefixes=CHECK,TLS
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=-bulk-memory | FileCheck %s --check-prefixes=CHECK,NO-TLS
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+; ERROR: LLVM ERROR: only -ftls-model=local-exec is supported for now on non-Emscripten OSes: variable tls
+
+; CHECK-LABEL: address_of_tls:
+; CHECK-NEXT: .functype address_of_tls () -> (i32)
+define i32 @address_of_tls() {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const tls
+ ; NO-TLS-NEXT: return
+ ret i32 ptrtoint(i32* @tls to i32)
+}
+
+; CHECK-LABEL: ptr_to_tls:
+; CHECK-NEXT: .functype ptr_to_tls () -> (i32)
+define i32* @ptr_to_tls() {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const tls
+ ; NO-TLS-NEXT: return
+ ret i32* @tls
+}
+
+; CHECK-LABEL: tls_load:
+; CHECK-NEXT: .functype tls_load () -> (i32)
+define i32 @tls_load() {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: i32.load 0
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const 0
+ ; NO-TLS-NEXT: i32.load tls
+ ; NO-TLS-NEXT: return
+ %tmp = load i32, i32* @tls, align 4
+ ret i32 %tmp
+}
+
+; CHECK-LABEL: tls_store:
+; CHECK-NEXT: .functype tls_store (i32) -> ()
+define void @tls_store(i32 %x) {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: i32.store 0
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const 0
+ ; NO-TLS-NEXT: i32.store tls
+ ; NO-TLS-NEXT: return
+ store i32 %x, i32* @tls, align 4
+ ret void
+}
+
+; CHECK-LABEL: tls_size:
+; CHECK-NEXT: .functype tls_size () -> (i32)
+define i32 @tls_size() {
+; CHECK-NEXT: global.get __tls_size
+; CHECK-NEXT: return
+ %1 = call i32 @llvm.wasm.tls.size.i32()
+ ret i32 %1
+}
+
+; CHECK: .type tls, at object
+; TLS-NEXT: .section .tbss.tls,"",@
+; NO-TLS-NEXT: .section .bss.tls,"",@
+; CHECK-NEXT: .p2align 2
+; CHECK-NEXT: tls:
+; CHECK-NEXT: .int32 0
+ at tls = internal thread_local global i32 0
+
+declare i32 @llvm.wasm.tls.size.i32()
Added: llvm/trunk/test/CodeGen/WebAssembly/tls-local-exec.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/tls-local-exec.ll?rev=366275&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/tls-local-exec.ll (added)
+++ llvm/trunk/test/CodeGen/WebAssembly/tls-local-exec.ll Tue Jul 16 15:22:08 2019
@@ -0,0 +1,82 @@
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory | FileCheck %s --check-prefixes=CHECK,TLS
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory -fast-isel | FileCheck %s --check-prefixes=CHECK,TLS
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=-bulk-memory | FileCheck %s --check-prefixes=CHECK,NO-TLS
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+; CHECK-LABEL: address_of_tls:
+; CHECK-NEXT: .functype address_of_tls () -> (i32)
+define i32 @address_of_tls() {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const tls
+ ; NO-TLS-NEXT: return
+ ret i32 ptrtoint(i32* @tls to i32)
+}
+
+; CHECK-LABEL: ptr_to_tls:
+; CHECK-NEXT: .functype ptr_to_tls () -> (i32)
+define i32* @ptr_to_tls() {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const tls
+ ; NO-TLS-NEXT: return
+ ret i32* @tls
+}
+
+; CHECK-LABEL: tls_load:
+; CHECK-NEXT: .functype tls_load () -> (i32)
+define i32 @tls_load() {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: i32.load 0
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const 0
+ ; NO-TLS-NEXT: i32.load tls
+ ; NO-TLS-NEXT: return
+ %tmp = load i32, i32* @tls, align 4
+ ret i32 %tmp
+}
+
+; CHECK-LABEL: tls_store:
+; CHECK-NEXT: .functype tls_store (i32) -> ()
+define void @tls_store(i32 %x) {
+ ; TLS-DAG: global.get __tls_base
+ ; TLS-DAG: i32.const tls
+ ; TLS-NEXT: i32.add
+ ; TLS-NEXT: i32.store 0
+ ; TLS-NEXT: return
+
+ ; NO-TLS-NEXT: i32.const 0
+ ; NO-TLS-NEXT: i32.store tls
+ ; NO-TLS-NEXT: return
+ store i32 %x, i32* @tls, align 4
+ ret void
+}
+
+; CHECK-LABEL: tls_size:
+; CHECK-NEXT: .functype tls_size () -> (i32)
+define i32 @tls_size() {
+; CHECK-NEXT: global.get __tls_size
+; CHECK-NEXT: return
+ %1 = call i32 @llvm.wasm.tls.size.i32()
+ ret i32 %1
+}
+
+; CHECK: .type tls, at object
+; TLS-NEXT: .section .tbss.tls,"",@
+; NO-TLS-NEXT: .section .bss.tls,"",@
+; CHECK-NEXT: .p2align 2
+; CHECK-NEXT: tls:
+; CHECK-NEXT: .int32 0
+ at tls = internal thread_local(localexec) global i32 0
+
+declare i32 @llvm.wasm.tls.size.i32()
Removed: llvm/trunk/test/CodeGen/WebAssembly/tls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/tls.ll?rev=366274&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/tls.ll (original)
+++ llvm/trunk/test/CodeGen/WebAssembly/tls.ll (removed)
@@ -1,82 +0,0 @@
-; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory | FileCheck %s --check-prefixes=CHECK,TLS
-; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory -fast-isel | FileCheck %s --check-prefixes=CHECK,TLS
-; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=-bulk-memory | FileCheck %s --check-prefixes=CHECK,NO-TLS
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32-unknown-unknown"
-
-; CHECK-LABEL: address_of_tls:
-; CHECK-NEXT: .functype address_of_tls () -> (i32)
-define i32 @address_of_tls() {
- ; TLS-DAG: global.get __tls_base
- ; TLS-DAG: i32.const tls
- ; TLS-NEXT: i32.add
- ; TLS-NEXT: return
-
- ; NO-TLS-NEXT: i32.const tls
- ; NO-TLS-NEXT: return
- ret i32 ptrtoint(i32* @tls to i32)
-}
-
-; CHECK-LABEL: ptr_to_tls:
-; CHECK-NEXT: .functype ptr_to_tls () -> (i32)
-define i32* @ptr_to_tls() {
- ; TLS-DAG: global.get __tls_base
- ; TLS-DAG: i32.const tls
- ; TLS-NEXT: i32.add
- ; TLS-NEXT: return
-
- ; NO-TLS-NEXT: i32.const tls
- ; NO-TLS-NEXT: return
- ret i32* @tls
-}
-
-; CHECK-LABEL: tls_load:
-; CHECK-NEXT: .functype tls_load () -> (i32)
-define i32 @tls_load() {
- ; TLS-DAG: global.get __tls_base
- ; TLS-DAG: i32.const tls
- ; TLS-NEXT: i32.add
- ; TLS-NEXT: i32.load 0
- ; TLS-NEXT: return
-
- ; NO-TLS-NEXT: i32.const 0
- ; NO-TLS-NEXT: i32.load tls
- ; NO-TLS-NEXT: return
- %tmp = load i32, i32* @tls, align 4
- ret i32 %tmp
-}
-
-; CHECK-LABEL: tls_store:
-; CHECK-NEXT: .functype tls_store (i32) -> ()
-define void @tls_store(i32 %x) {
- ; TLS-DAG: global.get __tls_base
- ; TLS-DAG: i32.const tls
- ; TLS-NEXT: i32.add
- ; TLS-NEXT: i32.store 0
- ; TLS-NEXT: return
-
- ; NO-TLS-NEXT: i32.const 0
- ; NO-TLS-NEXT: i32.store tls
- ; NO-TLS-NEXT: return
- store i32 %x, i32* @tls, align 4
- ret void
-}
-
-; CHECK-LABEL: tls_size:
-; CHECK-NEXT: .functype tls_size () -> (i32)
-define i32 @tls_size() {
-; CHECK-NEXT: global.get __tls_size
-; CHECK-NEXT: return
- %1 = call i32 @llvm.wasm.tls.size.i32()
- ret i32 %1
-}
-
-; CHECK: .type tls, at object
-; TLS-NEXT: .section .tbss.tls,"",@
-; NO-TLS-NEXT: .section .bss.tls,"",@
-; CHECK-NEXT: .p2align 2
-; CHECK-NEXT: tls:
-; CHECK-NEXT: .int32 0
- at tls = internal thread_local(localexec) global i32 0
-
-declare i32 @llvm.wasm.tls.size.i32()
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