Do not use deprecated ARM instructions in DirectCEntryStub::GenerateCall.

Non-ancient versions of the ARM-ARM explicitly deprecate most uses of the PC
within instructions and older ARM implementations have a non-predictable offset
(8 or 12) for some of these deprecated uses. Avoiding the deprecated instruction
costs us one additional instruction in DirectCEntryStub::GenerateCall, but this
should not cause any significant performance degradation.

The deoptimizer still uses the PC in a stm instruction, but it is a bit unclear
what to do about that, so simply a comment has been added to reconsider this in
the future.
Review URL: http://codereview.chromium.org/7633014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8916 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/code-stubs-arm.cc

@@ -6319,7 +6319,9 @@ void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
                      RelocInfo::CODE_TARGET));
   __ mov(r2, Operand(function));
   // Push return address (accessible to GC through exit frame pc).
-  __ str(pc, MemOperand(sp, 0));
+  // Note that using pc with str is deprecated.
+  __ add(ip, pc, Operand(4));
+  __ str(ip, MemOperand(sp, 0));
   __ Jump(r2);  // Call the api function.
 }
 
@@ -6329,7 +6331,9 @@ void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
   __ mov(lr, Operand(reinterpret_cast<intptr_t>(GetCode().location()),
                      RelocInfo::CODE_TARGET));
   // Push return address (accessible to GC through exit frame pc).
-  __ str(pc, MemOperand(sp, 0));
+  // Note that using pc with str is deprecated.
+  __ add(ip, pc, Operand(4));
+  __ str(ip, MemOperand(sp, 0));
   __ Jump(target);  // Call the C++ function.
 }
 

src/arm/deoptimizer-arm.cc

@@ -593,6 +593,8 @@ void Deoptimizer::EntryGenerator::Generate() {
   __ vstm(db_w, sp, first, last);
 
   // Push all 16 registers (needed to populate FrameDescription::registers_).
+  // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
+  // handle this a bit differently.
   __ stm(db_w, sp, restored_regs  | sp.bit() | lr.bit() | pc.bit());
 
   const int kSavedRegistersAreaSize =