1 files changed, 79 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testsJit.cpp b/js/src/jsapi-tests/testsJit.cpp
new file mode 100644
index 0000000000..6e270d0659
--- /dev/null
+++ b/js/src/jsapi-tests/testsJit.cpp
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jsapi-tests/testsJit.h"
+
+#include "jit/JitCommon.h"
+#include "jit/Linker.h"
+
+#include "jit/MacroAssembler-inl.h"
+
+// On entry to the JIT code, save every register.
+void PrepareJit(js::jit::MacroAssembler& masm) {
+  using namespace js::jit;
+#if defined(JS_CODEGEN_ARM64)
+  masm.Mov(PseudoStackPointer64, sp);
+  masm.SetStackPointer64(PseudoStackPointer64);
+#endif
+  AllocatableRegisterSet regs(RegisterSet::All());
+  LiveRegisterSet save(regs.asLiveSet());
+#if defined(JS_CODEGEN_ARM)
+  save.add(js::jit::d15);
+#endif
+#if defined(JS_CODEGEN_MIPS32) || defined(JS_CODEGEN_MIPS64) || \
+    defined(JS_CODEGEN_LOONG64) || defined(JS_CODEGEN_RISCV64)
+  save.add(js::jit::ra);
+#elif defined(JS_USE_LINK_REGISTER)
+  save.add(js::jit::lr);
+#endif
+  masm.PushRegsInMask(save);
+}
+
+// Generate the exit path of the JIT code, which restores every register. Then,
+// make it executable and run it.
+bool ExecuteJit(JSContext* cx, js::jit::MacroAssembler& masm) {
+  using namespace js::jit;
+  AllocatableRegisterSet regs(RegisterSet::All());
+  LiveRegisterSet save(regs.asLiveSet());
+#if defined(JS_CODEGEN_ARM)
+  save.add(js::jit::d15);
+#endif
+#if defined(JS_CODEGEN_MIPS32) || defined(JS_CODEGEN_MIPS64) || \
+    defined(JS_CODEGEN_LOONG64) || defined(JS_CODEGEN_RISCV64)
+  save.add(js::jit::ra);
+#elif defined(JS_USE_LINK_REGISTER)
+  save.add(js::jit::lr);
+#endif
+  masm.PopRegsInMask(save);
+#if defined(JS_CODEGEN_ARM64)
+  // Return using the value popped into x30.
+  masm.abiret();
+
+  // Reset stack pointer.
+  masm.SetStackPointer64(PseudoStackPointer64);
+#else
+  // Exit the JIT-ed code using the ABI return style.
+  masm.abiret();
+#endif
+
+  if (masm.oom()) {
+    return false;
+  }
+
+  JitCode* code = nullptr;
+  {
+    Linker linker(masm);
+    code = linker.newCode(cx, CodeKind::Other);
+    if (!code) {
+      return false;
+    }
+  }
+
+  JS::AutoSuppressGCAnalysis suppress;
+  EnterTest test = code->as<EnterTest>();
+  CALL_GENERATED_0(test);
+  return true;
+}