Improve FastCloneShallowArray/ObjectStubs with VFP copying on ARM

src/arm/macro-assembler-arm.cc

 // Copyright 2012 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 3144 matching lines @@
   }
   ASSERT(!tmp.is(no_reg));
 
   for (int i = 0; i < field_count; i++) {
     ldr(tmp, FieldMemOperand(src, i * kPointerSize));
     str(tmp, FieldMemOperand(dst, i * kPointerSize));
   }
 }
 
 
+void MacroAssembler::VFPCopyFields(Register dst, Register src, int field_count,
+                                   SwVfpRegister first, SwVfpRegister last) {
+  ASSERT(CpuFeatures::IsEnabled(VFP2));
+  ASSERT_LE(first.code(), last.code());

[danno, 2012/10/29 15:29:24]

In debug mode, can you please actually verify in generated code assert that the
pointers are not tagged?

+  int available_words = last.code() - first.code() + 1;
+
+  while (field_count > 0) {
+    int words_to_copy = Min(field_count, available_words);
+    SwVfpRegister copy_last =
+        SwVfpRegister::from_code(first.code() + words_to_copy - 1);
+    vldm(ia_w, src, first, copy_last);
+    vstm(ia_w, dst, first, copy_last);
+    field_count -= words_to_copy;
+  }
+}
+
 void MacroAssembler::CopyBytes(Register src,
                                Register dst,
                                Register length,
                                Register scratch) {
   Label align_loop, align_loop_1, word_loop, byte_loop, byte_loop_1, done;
 
   // Align src before copying in word size chunks.
   bind(&align_loop);
   cmp(length, Operand(0));
   b(eq, &done);
@@ skipping 663 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM