[wasm] Lazy compilation for asm.js

src/builtins/arm/builtins-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/assembler-inl.h"
 #include "src/codegen.h"
 #include "src/counters.h"
 #include "src/debug/debug.h"
@@ skipping 3031 matching lines @@
   __ Jump(r4);
 
   __ bind(&stack_overflow);
   {
     FrameScope frame(masm, StackFrame::MANUAL);
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ bkpt(0);
   }
 }
 
+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
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM