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[WebAssembly] Use localexec as default TLS model for non-Emscripten targets

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Only Emscripten supports dynamic linking with threads. To use
thread-local storage for other targets, this change defaults to the
`localexec` model.

Differential Revision: https://reviews.llvm.org/D130053
This commit is contained in:
Andrew Brown 2022-07-25 13:16:07 -07:00 committed by Sam Clegg
parent 35ea84ad6a
commit 3696a789d2
3 changed files with 27 additions and 31 deletions
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30
llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
View file

@ -577,8 +577,9 @@ LowerCallResults(MachineInstr &CallResults, DebugLoc DL, MachineBasicBlock *BB,
CallParams.removeOperand(0);
// For funcrefs, call_indirect is done through __funcref_call_table and the
// funcref is always installed in slot 0 of the table, therefore instead of having
// the function pointer added at the end of the params list, a zero (the index in
// funcref is always installed in slot 0 of the table, therefore instead of
// having the function pointer added at the end of the params list, a zero
// (the index in
// __funcref_call_table is added).
if (IsFuncrefCall) {
Register RegZero =
@ -1156,7 +1157,7 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI,
// If the callee is a GlobalAddress node (quite common, every direct call
// is) turn it into a TargetGlobalAddress node so that LowerGlobalAddress
// doesn't at MO_GOT which is not needed for direct calls.
GlobalAddressSDNode* GA = cast<GlobalAddressSDNode>(Callee);
GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Callee);
Callee = DAG.getTargetGlobalAddress(GA->getGlobal(), DL,
getPointerTy(DAG.getDataLayout()),
GA->getOffset());
@ -1719,20 +1720,12 @@ WebAssemblyTargetLowering::LowerGlobalTLSAddress(SDValue Op,
const GlobalValue *GV = GA->getGlobal();
// 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 (GV->getThreadLocalMode() != GlobalValue::LocalExecTLSModel &&
!Subtarget->getTargetTriple().isOSEmscripten()) {
report_fatal_error("only -ftls-model=local-exec is supported for now on "
"non-Emscripten OSes: variable " +
GV->getName(),
false);
}
auto model = GV->getThreadLocalMode();
// Currently only Emscripten supports dynamic linking with threads. Therefore,
// on other targets, if we have thread-local storage, only the local-exec
// model is possible.
auto model = Subtarget->getTargetTriple().isOSEmscripten()
? GV->getThreadLocalMode()
: GlobalValue::LocalExecTLSModel;
// Unsupported TLS modes
assert(model != GlobalValue::NotThreadLocal);
@ -1791,8 +1784,7 @@ SDValue WebAssemblyTargetLowering::LowerGlobalAddress(SDValue Op,
if (GV->getValueType()->isFunctionTy()) {
BaseName = MF.createExternalSymbolName("__table_base");
OperandFlags = WebAssemblyII::MO_TABLE_BASE_REL;
}
else {
} else {
BaseName = MF.createExternalSymbolName("__memory_base");
OperandFlags = WebAssemblyII::MO_MEMORY_BASE_REL;
}

11
llvm/test/CodeGen/WebAssembly/tls-general-dynamic.ll
View file

@ -1,11 +1,8 @@
; RUN: not llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics 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,atomics -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,atomics --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,atomics --mtriple wasm32-unknown-emscripten -fast-isel | FileCheck %s --check-prefixes=CHECK,TLS
; This test checks experimental Emscripten-specific `generaldynamic` TLS support. See `tls-local-exec.ll` for non-Emscripten targets (since it lowers all TLS to `localexec`).
; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics | FileCheck %s --check-prefixes=CHECK,TLS
; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics -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,atomics | FileCheck %s --check-prefixes=CHECK,NO-TLS
target triple = "wasm32-unknown-unknown"
; ERROR: LLVM ERROR: only -ftls-model=local-exec is supported for now on non-Emscripten OSes: variable tls
target triple = "wasm32-unknown-emscripten"
; CHECK-LABEL: address_of_tls:
; CHECK-NEXT: .functype address_of_tls () -> (i32)

17
llvm/test/CodeGen/WebAssembly/tls-local-exec.ll
View file

@ -1,6 +1,13 @@
; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics | FileCheck %s --check-prefixes=CHECK,TLS
; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics -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,atomics | FileCheck %s --check-prefixes=CHECK,NO-TLS
; Run the tests with the `localexec` TLS mode specified.
; RUN: sed -e 's/\[\[TLS_MODE\]\]/(localexec)/' %s | llc -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics - | FileCheck --check-prefixes=CHECK,TLS %s
; RUN: sed -e 's/\[\[TLS_MODE\]\]/(localexec)/' %s | llc -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics -fast-isel - | FileCheck --check-prefixes=CHECK,TLS %s
; Also, run the same tests without a specified TLS mode--this should still emit `localexec` code on non-Emscripten targtes which don't currently support dynamic linking.
; RUN: sed -e 's/\[\[TLS_MODE\]\]//' %s | llc -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics - | FileCheck --check-prefixes=CHECK,TLS %s
; RUN: sed -e 's/\[\[TLS_MODE\]\]//' %s | llc -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=+bulk-memory,atomics -fast-isel - | FileCheck --check-prefixes=CHECK,TLS %s
; Finally, when bulk memory is disabled, no TLS code should be generated.
; RUN: sed -e 's/\[\[TLS_MODE\]\]/(localexec)/' %s | llc -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -mattr=-bulk-memory,atomics - | FileCheck --check-prefixes=CHECK,NO-TLS %s
target triple = "wasm32-unknown-unknown"
; CHECK-LABEL: address_of_tls:
@ -89,8 +96,8 @@ define i32 @tls_size() {
; CHECK-NEXT: .p2align 2
; CHECK-NEXT: tls:
; CHECK-NEXT: .int32 0
@tls = internal thread_local(localexec) global i32 0
@tls = internal thread_local[[TLS_MODE]] global i32 0
@tls_external = external thread_local(localexec) global i32, align 4
@tls_external = external thread_local[[TLS_MODE]] global i32, align 4
declare i32 @llvm.wasm.tls.size.i32()