[PATCH] D119803: [WebAssembly] Make __wasm_lpad_context thread-local

[Heejin Ahn via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGc60d8229651c: [WebAssembly] Make __wasm_lpad_context thread-local (authored by aheejin).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D119803/new/

https://reviews.llvm.org/D119803

Files:
  llvm/lib/CodeGen/WasmEHPrepare.cpp
  llvm/test/CodeGen/WebAssembly/wasmehprepare.ll


Index: llvm/test/CodeGen/WebAssembly/wasmehprepare.ll
===================================================================
--- llvm/test/CodeGen/WebAssembly/wasmehprepare.ll
+++ llvm/test/CodeGen/WebAssembly/wasmehprepare.ll
@@ -1,9 +1,11 @@
-; RUN: opt < %s -winehprepare -demote-catchswitch-only -wasmehprepare -S | FileCheck %s
+; RUN: opt < %s -winehprepare -demote-catchswitch-only -wasmehprepare -S | FileCheck %s --check-prefixes=CHECK,NO-TLS
+; RUN: opt < %s -winehprepare -demote-catchswitch-only -wasmehprepare -S --mattr=+atomics,+bulk-memory | FileCheck %s --check-prefixes=CHECK,TLS
 
 target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
-; CHECK: @__wasm_lpad_context = external global { i32, i8*, i32 }
+; NO-TLS: @__wasm_lpad_context = external global { i32, i8*, i32 }
+; TLS: @__wasm_lpad_context = external thread_local global { i32, i8*, i32 }
 
 @_ZTIi = external constant i8*
 %struct.Temp = type { i8 }
Index: llvm/lib/CodeGen/WasmEHPrepare.cpp
===================================================================
--- llvm/lib/CodeGen/WasmEHPrepare.cpp
+++ llvm/lib/CodeGen/WasmEHPrepare.cpp
@@ -212,9 +212,21 @@
 
   assert(F.hasPersonalityFn() && "Personality function not found");
 
-  // __wasm_lpad_context global variable
+  // __wasm_lpad_context global variable.
+  // If the target supports TLS, make this thread-local. We can't just
+  // unconditionally make it thread-local and depend on
+  // CoalesceFeaturesAndStripAtomics to downgrade it, because stripping TLS has
+  // the side effect of disallowing the object from being linked into a
+  // shared-memory module, which we don't want to be responsible for.
   LPadContextGV = cast<GlobalVariable>(
       M.getOrInsertGlobal("__wasm_lpad_context", LPadContextTy));
+  Attribute FSAttr = F.getFnAttribute("target-features");
+  if (FSAttr.isValid()) {
+    StringRef FS = FSAttr.getValueAsString();
+    if (FS.contains("+atomics") && FS.contains("+bulk-memory"))
+      LPadContextGV->setThreadLocalMode(GlobalValue::GeneralDynamicTLSModel);
+  }
+
   LPadIndexField = IRB.CreateConstGEP2_32(LPadContextTy, LPadContextGV, 0, 0,
                                           "lpad_index_gep");
   LSDAField =


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