CodeGen: add __yield intrinsic for ARM
The __yield intrinsic generates a hint instruction to indicate that the thread
is not performing any useful operations at the moment. This is for
compatibility with MSVC, although, the intrinsic is also part of the ACLE, and
is enabled globally as a result.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207275 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/BuiltinsARM.def b/include/clang/Basic/BuiltinsARM.def
index aab9255..99dbb9a 100644
--- a/include/clang/Basic/BuiltinsARM.def
+++ b/include/clang/Basic/BuiltinsARM.def
@@ -65,4 +65,7 @@
BUILTIN(__builtin_arm_dmb, "vUi", "nc")
BUILTIN(__builtin_arm_dsb, "vUi", "nc")
+// MSVC
+BUILTIN(__yield, "v", "")
+
#undef BUILTIN
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index d267ece..56fa69a 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -4326,6 +4326,11 @@
Value *CodeGenFunction::EmitARMBuiltinExpr(unsigned BuiltinID,
const CallExpr *E) {
+ if (BuiltinID == ARM::BI__yield) {
+ Function *F = CGM.getIntrinsic(Intrinsic::arm_hint);
+ return Builder.CreateCall(F, llvm::ConstantInt::get(Int32Ty, 1));
+ }
+
if (BuiltinID == ARM::BI__clear_cache) {
assert(E->getNumArgs() == 2 && "__clear_cache takes 2 arguments");
const FunctionDecl *FD = E->getDirectCallee();
diff --git a/test/CodeGen/builtins-arm-microsoft.c b/test/CodeGen/builtins-arm-microsoft.c
new file mode 100644
index 0000000..682ec91
--- /dev/null
+++ b/test/CodeGen/builtins-arm-microsoft.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -triple thumbv7-windows -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple armv7-eabi -emit-llvm -o - %s | FileCheck %s
+// REQUIRES: arm-registered-target
+
+void test_yield_intrinsic() {
+ __yield();
+}
+
+// CHECK: call void @llvm.arm.hint(i32 1)
+
