[strong] Simplify (and sortof optimize) string addition for strong mode.

[strong] Simplify (and sortof optimize) string addition for strong mode.

In strong mode, whenever either operand to an addition is a string, both
must be strings, so we can just use a simple string map check instead of
the STRING_ADD_LEFT / STRING_ADD_RIGHT machinery, which tries to do sloppy
and strict mode conversions before giving up.

R=jarin@chromium.org

Committed: https://crrev.com/6a58370c7f85ddd72590eebcdc03f15425b8ed1f
Cr-Commit-Position: refs/heads/master@{#30146}

[Benedikt Meurer, 2015-08-13 05:36:02]

Hey Jaro,

An easy starter in the morning :-)
Please take a look.

Thanks,
Benedikt

[Jarin, 2015-08-13 06:23:51]

lgtm with a nit and a question.

https://codereview.chromium.org/1287203002/diff/1/src/hydrogen.cc
File src/hydrogen.cc (right):

https://codereview.chromium.org/1287203002/diff/1/src/hydrogen.cc#newcode10907
src/hydrogen.cc:10907: if (left_type->Is(Type::String())) {
Could not you say here 

if (left_type->Is(Type::String()) || is_strong(strength)) {
  left = BuildCheckString(left);
} 

And then below say

if (!left_type->Is(Type::String()) && !is_strong(strength)) {
  DCHECK(right_type->Is(Type::String()));
  if (left_type->Is(Type::Number())) {
    ...

https://codereview.chromium.org/1287203002/diff/1/src/hydrogen.cc#newcode10920
src/hydrogen.cc:10920: // In strong mode, if the left hand side of an additition
is a string,
additition -> addition (Here and below.)

[Benedikt Meurer, 2015-08-13 06:31:14]

https://codereview.chromium.org/1287203002/diff/1/src/hydrogen.cc
File src/hydrogen.cc (right):

https://codereview.chromium.org/1287203002/diff/1/src/hydrogen.cc#newcode10907
src/hydrogen.cc:10907: if (left_type->Is(Type::String())) {
Restructured to simplify strong case as per offline discussion.

https://codereview.chromium.org/1287203002/diff/1/src/hydrogen.cc#newcode10920
src/hydrogen.cc:10920: // In strong mode, if the left hand side of an additition
is a string,
On 2015/08/13 06:23:50, Jarin wrote:
> additition -> addition (Here and below.)

Done.

[Benedikt Meurer, 2015-08-13 06:32:29]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-08-13 06:32:29]

The patchset sent to the CQ was uploaded after l-g-t-m from jarin@chromium.org
Link to the patchset: https://codereview.chromium.org/1287203002/#ps40001
(title: "Small beautification.")

[commit-bot: I haz the power, 2015-08-13 06:32:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1287203002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1287203002/40001

[commit-bot: I haz the power, 2015-08-13 07:05:12]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-08-13 07:05:28]

Patchset 3 (id:??) landed as
https://crrev.com/6a58370c7f85ddd72590eebcdc03f15425b8ed1f
Cr-Commit-Position: refs/heads/master@{#30146}