[PATCH] D130053: [WebAssembly] Use `localexec` as default TLS model for non-Emscripten targets

[Andrew Brown via Phabricator via llvm-commits]

abrown updated this revision to Diff 445889.
abrown added a comment.

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

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

Additionally, this changes the tests slightly:

- Ignore non-Emscripten test cases for general dynamic TLS model
- Use default thread-local model (i.e., `localexec`)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D130053/new/

https://reviews.llvm.org/D130053

Files:
  llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
  llvm/test/CodeGen/WebAssembly/tls-general-dynamic.ll
  llvm/test/CodeGen/WebAssembly/tls-local-exec.ll


Index: llvm/test/CodeGen/WebAssembly/tls-local-exec.ll
===================================================================
--- llvm/test/CodeGen/WebAssembly/tls-local-exec.ll
+++ llvm/test/CodeGen/WebAssembly/tls-local-exec.ll
@@ -89,8 +89,8 @@
 ; CHECK-NEXT: .p2align 2
 ; CHECK-NEXT: tls:
 ; CHECK-NEXT: .int32 0
- at tls = internal thread_local(localexec) global i32 0
+ at tls = internal thread_local global i32 0
 
- at tls_external = external thread_local(localexec) global i32, align 4
+ at tls_external = external thread_local global i32, align 4
 
 declare i32 @llvm.wasm.tls.size.i32()
Index: llvm/test/CodeGen/WebAssembly/tls-general-dynamic.ll
===================================================================
--- llvm/test/CodeGen/WebAssembly/tls-general-dynamic.ll
+++ llvm/test/CodeGen/WebAssembly/tls-general-dynamic.ll
@@ -1,12 +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
 ; 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
-
 ; CHECK-LABEL: address_of_tls:
 ; CHECK-NEXT: .functype  address_of_tls () -> (i32)
 define i32 @address_of_tls() {
Index: llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
===================================================================
--- llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -577,8 +577,9 @@
     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 @@
     // 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 @@
 
   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 @@
       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;
       }


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