Ensure stack alignment in ARM port...

src/arm/codegen-arm.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5637 matching lines @@
     __ orr(r4, lhs_mantissa, Operand(lhs_exponent, LSL, kSmiTagSize), SetCC);
     __ mov(r0, Operand(r4), LeaveCC, ne);
     __ mov(pc, Operand(lr), LeaveCC, ne);  // Return conditionally.
     // Now they are equal if and only if the lhs exponent is zero in its
     // low 31 bits.
     __ mov(r0, Operand(rhs_exponent, LSL, kSmiTagSize));
     __ mov(pc, Operand(lr));
   } else {
     // Call a native function to do a comparison between two non-NaNs.
     // Call C routine that may not cause GC or other trouble.
-    __ mov(r5, Operand(ExternalReference::compare_doubles()));
-    __ Jump(r5);  // Tail call.
+    __ push(lr);
+    __ PrepareCallCFunction(4, r5);  // Two doubles count as 4 arguments.
+    __ CallCFunction(ExternalReference::compare_doubles(), 4);
+    __ pop(pc);  // Return.
   }
 }
 
 
 // See comment at call site.
 static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm) {
     // If either operand is a JSObject or an oddball value, then they are
     // not equal since their pointers are different.
     // There is no test for undetectability in strict equality.
     ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
@@ skipping 1406 matching lines @@
   ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
   __ pop(pc);
 }
 
 
 void CEntryStub::GenerateCore(MacroAssembler* masm,
                               Label* throw_normal_exception,
                               Label* throw_termination_exception,
                               Label* throw_out_of_memory_exception,
                               bool do_gc,
-                              bool always_allocate) {
+                              bool always_allocate,
+                              int frame_alignment_skew) {
   // r0: result parameter for PerformGC, if any
   // r4: number of arguments including receiver  (C callee-saved)
   // r5: pointer to builtin function  (C callee-saved)
   // r6: pointer to the first argument (C callee-saved)
 
   if (do_gc) {
     // Passing r0.
-    ExternalReference gc_reference = ExternalReference::perform_gc_function();
-    __ Call(gc_reference.address(), RelocInfo::RUNTIME_ENTRY);
+    __ PrepareCallCFunction(1, r1);
+    __ CallCFunction(ExternalReference::perform_gc_function(), 1);
   }
 
   ExternalReference scope_depth =
       ExternalReference::heap_always_allocate_scope_depth();
   if (always_allocate) {
     __ mov(r0, Operand(scope_depth));
     __ ldr(r1, MemOperand(r0));
     __ add(r1, r1, Operand(1));
     __ str(r1, MemOperand(r0));
   }
 
   // Call C built-in.
   // r0 = argc, r1 = argv
   __ mov(r0, Operand(r4));
   __ mov(r1, Operand(r6));
 
+  int frame_alignment = MacroAssembler::ActivationFrameAlignment();
+  int frame_alignment_mask = frame_alignment - 1;
+#if defined(V8_HOST_ARCH_ARM)
+  if (FLAG_debug_code) {
+    if (frame_alignment > kPointerSize) {
+      Label alignment_as_expected;
+      ASSERT(IsPowerOf2(frame_alignment));
+      __ sub(r2, sp, Operand(frame_alignment_skew));
+      __ tst(r2, Operand(frame_alignment_mask));
+      __ b(eq, &alignment_as_expected);
+      // Don't use Check here, as it will call Runtime_Abort re-entering here.
+      __ stop("Unexpected alignment");
+      __ bind(&alignment_as_expected);
+    }
+  }
+#endif
+
+  // Just before the call (jump) below lr is pushed, so the actual alignment is
+  // adding one to the current skew.
+  int alignment_before_call =
+      (frame_alignment_skew + kPointerSize) & frame_alignment_mask;
+  if (alignment_before_call > 0) {
+    // Push until the alignment before the call is met.
+    __ mov(r2, Operand(0));
+    for (int i = alignment_before_call;
+        (i & frame_alignment_mask) != 0;
+        i += kPointerSize) {
+      __ push(r2);
+    }
+  }
+
   // TODO(1242173): To let the GC traverse the return address of the exit
   // frames, we need to know where the return address is. Right now,
   // we push it on the stack to be able to find it again, but we never
   // restore from it in case of changes, which makes it impossible to
   // support moving the C entry code stub. This should be fixed, but currently
   // this is OK because the CEntryStub gets generated so early in the V8 boot
   // sequence that it is not moving ever.
-  masm->add(lr, pc, Operand(4));  // compute return address: (pc + 8) + 4
+  masm->add(lr, pc, Operand(4));  // Compute return address: (pc + 8) + 4
   masm->push(lr);
   masm->Jump(r5);
 
+  // Restore sp back to before aligning the stack.
+  if (alignment_before_call > 0) {
+    __ add(sp, sp, Operand(alignment_before_call));
+  }
+
   if (always_allocate) {
     // It's okay to clobber r2 and r3 here. Don't mess with r0 and r1
     // though (contain the result).
     __ mov(r2, Operand(scope_depth));
     __ ldr(r3, MemOperand(r2));
     __ sub(r3, r3, Operand(1));
     __ str(r3, MemOperand(r2));
   }
 
   // check for failure result
@@ skipping 66 matching lines @@
   Label throw_normal_exception;
   Label throw_termination_exception;
   Label throw_out_of_memory_exception;
 
   // Call into the runtime system.
   GenerateCore(masm,
                &throw_normal_exception,
                &throw_termination_exception,
                &throw_out_of_memory_exception,
                false,
-               false);
+               false,
+               -kPointerSize);
 
   // Do space-specific GC and retry runtime call.
   GenerateCore(masm,
                &throw_normal_exception,
                &throw_termination_exception,
                &throw_out_of_memory_exception,
                true,
-               false);
+               false,
+               0);
 
   // Do full GC and retry runtime call one final time.
   Failure* failure = Failure::InternalError();
   __ mov(r0, Operand(reinterpret_cast<int32_t>(failure)));
   GenerateCore(masm,
                &throw_normal_exception,
                &throw_termination_exception,
                &throw_out_of_memory_exception,
                true,
-               true);
+               true,
+               kPointerSize);
 
   __ bind(&throw_out_of_memory_exception);
   GenerateThrowUncatchable(masm, OUT_OF_MEMORY);
 
   __ bind(&throw_termination_exception);
   GenerateThrowUncatchable(masm, TERMINATION);
 
   __ bind(&throw_normal_exception);
   GenerateThrowTOS(masm);
 }
@@ skipping 1659 matching lines @@
 
   // Just jump to runtime to add the two strings.
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal