Landing for Zaheer Ahmad.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 590d8ce15ed03eaea8143f36710f264a257fd920..be296d325cac663a4e6ca85aa135366a86737ee5 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -3329,9 +3329,17 @@ void CEntryStub::Generate(MacroAssembler* masm) {
   // this by performing a garbage collection and retrying the
   // builtin once.
 
+  // Compute the argv pointer in a callee-saved register.
+  __ add(r6, sp, Operand(r0, LSL, kPointerSizeLog2));
+  __ sub(r6, r6, Operand(kPointerSize));
+
   // Enter the exit frame that transitions from JavaScript to C++.
   __ EnterExitFrame(save_doubles_);
 
+  // Setup argc and the builtin function in callee-saved registers.
+  __ mov(r4, Operand(r0));
+  __ mov(r5, Operand(r1));
+
   // r4: number of arguments (C callee-saved)
   // r5: pointer to builtin function (C callee-saved)
   // r6: pointer to first argument (C callee-saved)
@@ -5733,6 +5741,22 @@ void ICCompareStub::GenerateMiss(MacroAssembler* masm) {
   __ Jump(r2);
 }
 

[Erik Corry, 2011/02/04 09:55:55]

Missing blank line.

[antonm, 2011/02/04 12:59:45]

Done.

+void DirectCEntryStub::Generate(MacroAssembler* masm) {
+  __ ldr(pc, MemOperand(sp, 0));
+}
+

[Erik Corry, 2011/02/04 09:55:55]

and here

[antonm, 2011/02/04 12:59:45]

Done.

+void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
+                                    ApiFunction *function) {
+  __ mov(lr, Operand(reinterpret_cast<intptr_t>(GetCode().location()),
+                     RelocInfo::CODE_TARGET));
+  // Push return address (accessible to GC through exit frame pc).
+  ExternalReference ref =
+      ExternalReference(function, ExternalReference::DIRECT_CALL);
+  __ mov(r2, Operand(reinterpret_cast<intptr_t>(ref.address())));

[Erik Corry, 2011/02/04 09:55:55]

There is a constructor for Operand that takes an external reference.  I think
you have to use that otherwise this doesn't work correctly with snapshots.  The
snapshot code needs the reloc information from a real Operand in case the
destination is different in mksnapshot and the final executable.

[antonm, 2011/02/04 12:59:45]

Done.

+  __ add(ip, pc, Operand(4));

[Erik Corry, 2011/02/04 09:55:55]

It seems to me that omitting this add and just using ip in the next instruction
would achieve the same.  Pc is always 8 bytes ahead of the actual instruction
executing so that should be the same.

[antonm, 2011/02/04 12:59:45]

Hmm, ip would have any garbage then.  Am I missing something.

[Zaheer, 2011/02/04 13:08:05]

I think Erik meant pc.

[Erik Corry, 2011/02/04 13:19:52]

No you are right of course.

+  __ str(ip, MemOperand(sp, 0));
+  __ Jump(r2);  // Call the api function.
+}
 

[Erik Corry, 2011/02/04 09:55:55]

and missing blank line here

[antonm, 2011/02/04 12:59:45]

Done.

 #undef __