[wasm] Lazy compilation for asm.js

src/builtins/arm/builtins-arm.cc

Index: src/builtins/arm/builtins-arm.cc
diff --git a/src/builtins/arm/builtins-arm.cc b/src/builtins/arm/builtins-arm.cc
index 378dc3664230a22a1273968ce7d410cc55470c46..f0d76b09d710c6426822433daa35b07f80300aca 100644
--- a/src/builtins/arm/builtins-arm.cc
+++ b/src/builtins/arm/builtins-arm.cc
@@ -3049,6 +3049,32 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   }
 }
 
+void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+
+    // Save all parameter registers (see wasm-linkage.cc).
+    const RegList gp_regs = r0.bit() | r1.bit() | r2.bit() | r3.bit();
+    constexpr DwVfpRegister lowest_fp_reg = d0;
+    constexpr DwVfpRegister highest_fp_reg = d7;
+
+    __ stm(db_w, sp, gp_regs);
+    __ vstm(db_w, sp, lowest_fp_reg, highest_fp_reg);
+
+    // Initialize cp register with kZero, CEntryStub will use it to set the
+    // current context on the isolate.
+    __ Move(cp, Smi::kZero);
+    __ CallRuntime(Runtime::kWasmCompileLazy);
+    // Store returned instruction start in r8.
+    __ add(r8, r0, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+    // Restore registers.
+    __ vldm(ia_w, sp, lowest_fp_reg, highest_fp_reg);
+    __ ldm(ia_w, sp, gp_regs);
+  }
+  // Now jump to the instructions of the returned code object.
+  __ Jump(r8);
+}
 #undef __
 
 }  // namespace internal