Fix issues with Arm's use of embedded constant pools

src/ppc/assembler-ppc.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 226 matching lines @@
   desc->buffer_size = buffer_size_;
   desc->instr_size = pc_offset();
   desc->reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
   desc->constant_pool_size =
       (constant_pool_offset ? desc->instr_size - constant_pool_offset : 0);
   desc->origin = this;
 }
 
 
 void Assembler::Align(int m) {
-#if V8_TARGET_ARCH_PPC64
-  DCHECK(m >= 4 && base::bits::IsPowerOfTwo64(m));
-#else
   DCHECK(m >= 4 && base::bits::IsPowerOfTwo32(m));
-#endif
-  // First ensure instruction alignment
-  while (pc_offset() & (kInstrSize - 1)) {
+  DCHECK((pc_offset() & (kInstrSize - 1)) == 0);
+  while ((pc_offset() & (m - 1)) != 0) {
+    nop();
+  }
+}
+
+
+void Assembler::DataAlign(int m) {

[rmcilroy, 2015/06/09 14:14:43]

These are all the same aren't they? Couldn't you just implement this in the
arch-independent assembler.cc?

[MTBrandyberry, 2015/06/09 14:19:08]

I didn't see a precedent for services like this in AssemblerBase.  I'd be happy
to put it there.

+  DCHECK(m >= 2 && base::bits::IsPowerOfTwo32(m));
+  while ((pc_offset() & (m - 1)) != 0) {
     db(0);
   }
-  // Then pad to requested alignedment with nops
-  while (pc_offset() & (m - 1)) {
-    nop();
-  }
 }
 
 
 void Assembler::CodeTargetAlign() { Align(8); }
 
 
 Condition Assembler::GetCondition(Instr instr) {
   switch (instr & kCondMask) {
     case BT:
       return eq;
@@ skipping 2173 matching lines @@
         pc_offset() + kMaxCondBranchReach - kMaxBlockTrampolineSectionSize;
   }
   return;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC