[wasm] Lazy compilation for asm.js

src/builtins/x64/builtins-x64.cc

Index: src/builtins/x64/builtins-x64.cc
diff --git a/src/builtins/x64/builtins-x64.cc b/src/builtins/x64/builtins-x64.cc
index b4f63c6a33b08dbb840e8b9895477fe53f38ddb2..f3d6f252de8442a5a15155f90427bbdfc08769c5 100644
--- a/src/builtins/x64/builtins-x64.cc
+++ b/src/builtins/x64/builtins-x64.cc
@@ -3185,6 +3185,41 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   Generate_OnStackReplacementHelper(masm, true);
 }
 
+void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+
+    // Save all parameter registers (see wasm-linkage.cc). They might be
+    // overwritten in the runtime call below.
+    // Other registers (like context and root) are not relevant here. The
+    // CEntryStub will overwrite them anyway.
+    constexpr Register gp_regs[]{rax, rbx, rcx, rdx, rsi, rdi};
+    constexpr XMMRegister xmm_regs[]{xmm1, xmm2, xmm3, xmm4, xmm5, xmm6};
+
+    for (auto reg : gp_regs) __ Push(reg);
+    __ subp(rsp, Immediate(16 * arraysize(xmm_regs)));
+    for (int i = 0, e = arraysize(xmm_regs); i < e; ++i) {
+      __ movdqu(Operand(rsp, 16 * i), xmm_regs[i]);
+    }
+
+    // Initialize rsi register with kZero, CEntryStub will use it to set the
+    // current context on the isolate.
+    __ Move(rsi, Smi::kZero);
+    __ CallRuntime(Runtime::kWasmCompileLazy);
+    // Store returned instruction start in r11.
+    __ leap(r11, FieldOperand(rax, Code::kHeaderSize));
+
+    // Restore registers.
+    for (int i = arraysize(xmm_regs) - 1; i >= 0; --i) {
+      __ movdqu(xmm_regs[i], Operand(rsp, 16 * i));
+    }
+    __ addp(rsp, Immediate(16 * arraysize(xmm_regs)));
+    for (int i = arraysize(gp_regs) - 1; i >= 0; --i) __ Pop(gp_regs[i]);
+  }
+  // Now jump to the instructions of the returned code object.
+  __ jmp(r11);
+}
+
 #undef __
 
 }  // namespace internal