Add new HSeqStringGetChar instruction.

Add new HSeqStringGetChar instruction.

This instruction is required for copying characters from sequential
strings in the hydrogenized StringAddStub.

BUG=v8:2990
R=svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=17565

[Benedikt Meurer, 2013-11-07 10:44:55]

Hey Sven,
Next (baby) step towards hydrogenized StringAddStub. :-)
PTAL
-- Benedikt

[Sven Panne, 2013-11-07 12:45:13]

LGTM, just a few whining comments about the situation in general... :-}

https://codereview.chromium.org/63863005/diff/1/src/arm/lithium-codegen-arm.cc
File src/arm/lithium-codegen-arm.cc (right):

https://codereview.chromium.org/63863005/diff/1/src/arm/lithium-codegen-arm.c...
src/arm/lithium-codegen-arm.cc:1965: __ cmp(scratch, Operand(encoding ==
String::ONE_BYTE_ENCODING
Hmmm, a pattern like this comes up several times and all this copy-n-paste is
not really nice. Things would be much nicer if String::Encoding was not an
old-skool enum, but a real class. Then we could have something like
Encoding::ToTag(), but this is probably just OO dreaming... :-/

https://codereview.chromium.org/63863005/diff/1/src/arm/lithium-codegen-arm.c...
src/arm/lithium-codegen-arm.cc:1971: if (encoding == String::ONE_BYTE_ENCODING)
{
This would be nicer with the upcoming "Load" and a yet-to-be written
Encoding::ToRepresentation(). :-)

[Benedikt Meurer, 2013-11-07 12:59:49]

Committed patchset #2 manually as r17562 (presubmit successful).

[Benedikt Meurer, 2013-11-07 13:43:15]

Committed patchset #3 manually as r17565 (presubmit successful).