[WebAssembly] Support for atomic.wait / atomic.wake builtins

Summary:
Add support for atomic.wait / atomic.wake builtins based on the Wasm
thread proposal.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits

Differential Revision: https://reviews.llvm.org/D49396

llvm-svn: 338771

3 files changed, 43 insertions, 0 deletions

diff --git a/clang/include/clang/Basic/BuiltinsWebAssembly.def b/clang/include/clang/Basic/BuiltinsWebAssembly.def
index b3d877dcedf..45ce07292e4 100644
--- a/clang/include/clang/Basic/BuiltinsWebAssembly.def
+++ b/clang/include/clang/Basic/BuiltinsWebAssembly.def
@@ -34,4 +34,9 @@ BUILTIN(__builtin_wasm_grow_memory, "zz", "n")
 BUILTIN(__builtin_wasm_throw, "vUiv*", "r")
 BUILTIN(__builtin_wasm_rethrow, "v", "r")
 
+// Atomic wait and notify.
+BUILTIN(__builtin_wasm_atomic_wait_i32, "ii*iLLi", "n")
+BUILTIN(__builtin_wasm_atomic_wait_i64, "iLLi*LLiLLi", "n")
+BUILTIN(__builtin_wasm_atomic_notify, "ULLii*LLi", "n")
+
 #undef BUILTIN
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 4b6082aae50..c1959bdf171 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -12055,6 +12055,26 @@ Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
     Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_rethrow);
     return Builder.CreateCall(Callee);
   }
+  case WebAssembly::BI__builtin_wasm_atomic_wait_i32: {
+    Value *Addr = EmitScalarExpr(E->getArg(0));
+    Value *Expected = EmitScalarExpr(E->getArg(1));
+    Value *Timeout = EmitScalarExpr(E->getArg(2));
+    Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_atomic_wait_i32);
+    return Builder.CreateCall(Callee, {Addr, Expected, Timeout});
+  }
+  case WebAssembly::BI__builtin_wasm_atomic_wait_i64: {
+    Value *Addr = EmitScalarExpr(E->getArg(0));
+    Value *Expected = EmitScalarExpr(E->getArg(1));
+    Value *Timeout = EmitScalarExpr(E->getArg(2));
+    Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_atomic_wait_i64);
+    return Builder.CreateCall(Callee, {Addr, Expected, Timeout});
+  }
+  case WebAssembly::BI__builtin_wasm_atomic_notify: {
+    Value *Addr = EmitScalarExpr(E->getArg(0));
+    Value *Count = EmitScalarExpr(E->getArg(1));
+    Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_atomic_notify);
+    return Builder.CreateCall(Callee, {Addr, Count});
+  }
 
   default:
     return nullptr;
diff --git a/clang/test/CodeGen/builtins-wasm.c b/clang/test/CodeGen/builtins-wasm.c
index 1b647b56d1a..d1c5c303d4e 100644
--- a/clang/test/CodeGen/builtins-wasm.c
+++ b/clang/test/CodeGen/builtins-wasm.c
@@ -50,3 +50,21 @@ void f7(void) {
 // WEBASSEMBLY32: call void @llvm.wasm.rethrow()
 // WEBASSEMBLY64: call void @llvm.wasm.rethrow()
 }
+
+int f8(int *addr, int expected, long long timeout) {
+  return __builtin_wasm_atomic_wait_i32(addr, expected, timeout);
+// WEBASSEMBLY32: call i32 @llvm.wasm.atomic.wait.i32(i32* %{{.*}}, i32 %{{.*}}, i64 %{{.*}})
+// WEBASSEMBLY64: call i32 @llvm.wasm.atomic.wait.i32(i32* %{{.*}}, i32 %{{.*}}, i64 %{{.*}})
+}
+
+int f9(long long *addr, long long expected, long long timeout) {
+  return __builtin_wasm_atomic_wait_i64(addr, expected, timeout);
+// WEBASSEMBLY32: call i32 @llvm.wasm.atomic.wait.i64(i64* %{{.*}}, i64 %{{.*}}, i64 %{{.*}})
+// WEBASSEMBLY64: call i32 @llvm.wasm.atomic.wait.i64(i64* %{{.*}}, i64 %{{.*}}, i64 %{{.*}})
+}
+
+unsigned long long f10(int *addr, long long count) {
+  return __builtin_wasm_atomic_notify(addr, count);
+// WEBASSEMBLY32: call i64 @llvm.wasm.atomic.notify(i32* %{{.*}}, i64 %{{.*}})
+// WEBASSEMBLY64: call i64 @llvm.wasm.atomic.notify(i32* %{{.*}}, i64 %{{.*}})
+}