Fixes to RegExp-IA32.

src/regexp-macro-assembler-ia32.cc

Index: src/regexp-macro-assembler-ia32.cc
diff --git a/src/regexp-macro-assembler-ia32.cc b/src/regexp-macro-assembler-ia32.cc
index 516006dfaafc794cacaf4cd76a8f9f4d18617c18..72291082c5b3958e093afa929122b454d6a1b74d 100644
--- a/src/regexp-macro-assembler-ia32.cc
+++ b/src/regexp-macro-assembler-ia32.cc
@@ -192,12 +192,13 @@ void RegExpMacroAssemblerIA32::CheckCharacters(Vector<const uc16> str,
   __ mov(ebx, esi);
   __ lea(edi, Operand(esi, edi, times_1, byte_offset));
   LoadConstantBufferAddress(esi, &constant_buffer);
-  __ mov(ecx, str.length());
-  if (mode_ == ASCII) {
-    __ rep_cmpsb();
+  if ((str.length() * char_size()) & 0x03 == 0) {
+    // String content is a multiple of sizoef(uint32_t).
+    __ mov(ecx, str.length() * char_size() >> 2);
+    __ rep_cmpsl();

[Erik Corry, 2008/11/27 13:04:36]

Premature optimization!
Did you get rid of ASCII mode?

   } else {
-    ASSERT(mode_ == UC16);
-    __ rep_cmpsw();
+    __ mov(ecx, str.length() * char_size());
+    __ rep_cmpsb();
   }
   __ mov(esi, ebx);
   __ mov(edi, eax);
@@ -232,7 +233,8 @@ void RegExpMacroAssemblerIA32::CheckNotBackReference(
   if (mode_ == ASCII) {
     __ rep_cmpsb();

[Erik Corry, 2008/11/27 13:04:36]

One of the if bodies is a suffix of the other.  That suggests a simplification!

   } else {
-    __ rep_cmpsw();
+    __ add(ecx, Operand(ecx));
+    __ rep_cmpsb();
   }
   __ pop(esi);
   __ mov(edi, Operand(ebx));