Improve FastCloneShallowArray/ObjectStubs with VFP copying on ARM

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
===================================================================
--- src/arm/macro-assembler-arm.cc	(revision 12502)
+++ src/arm/macro-assembler-arm.cc	(working copy)
@@ -3162,6 +3162,22 @@
 }
 
 
+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,