* Have an ASCII and a UC16 interpreter for Irregexp bytecodes -...

* Have an ASCII and a UC16 interpreter for Irregexp bytecodes -
  never have to convert an ASCII string to UC16 for Irregexp.
* Generate slightly different code when we know the subject string
  is ASCII.

Committed: http://code.google.com/p/v8/source/detail?r=941

[Lasse Reichstein, 2008-12-09 07:43:07]

http://codereview.chromium.org/13247/diff/1/4
File src/jsregexp.cc (right):

http://codereview.chromium.org/13247/diff/1/4#newcode966
Line 966: FlattenString(subject);
The string is also flattened in the IA32 branch (line 889). You could move this
outside the switch.

http://codereview.chromium.org/13247/diff/1/4#newcode1721
Line 1721: const int max_char = ascii ? 0x7f : 0xffff;
Use String::kMaxAsciiCharCode instead of 0x7f?

http://codereview.chromium.org/13247/diff/1/4#newcode1781
Line 1781: macro_assembler->CheckCharacterLT(from, &next_range);
How about a CheckCharacterRange(from, to, char_is_in_class)?
That would allow the assembler to do the unsigned-range-check-hack? "if (x -
from < to - from) ..."

http://codereview.chromium.org/13247/diff/1/4#newcode1910
Line 1910: if (quarks[j] > 0x7f) {
Use String::kMaxAsciiCharCode