Implement control reducer, which reduces branches and phis together in a single fixpoint.

Implement control reducer, which reduces branches and phis together in a single fixpoint.

R=bmeurer@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=24891

[Benedikt Meurer, 2014-10-23 10:45:25]

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer.cc
File src/compiler/control-reducer.cc (right):

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:239: for (InputIter i = node->inputs().begin();
i != node->inputs().end(); ++i) {
for (Node* const input : node->inputs()) if (Recurse(input)) return;

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:248: CHECK_EQ(height, stack_.size());
Windows builder will probably complain about this comparison. How about some try
jobs?

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:369: ZoneDeque<Node*> phis(zone_);
Hm, I'd like to have a ZoneStack here, i.e. a class for std::stack<ZoneDeque>

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:370: for (UseIter i = node->uses().begin(); i !=
node->uses().end(); ++i) {
for (Node* const to : node->uses()) { ... }

[titzer, 2014-10-23 11:23:45]

PTAL, addressed comments and added a bunch more tests.

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer.cc
File src/compiler/control-reducer.cc (right):

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:239: for (InputIter i = node->inputs().begin();
i != node->inputs().end(); ++i) {
On 2014/10/23 10:45:25, Benedikt Meurer wrote:
> for (Node* const input : node->inputs()) if (Recurse(input)) return;

Done.

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:248: CHECK_EQ(height, stack_.size());
On 2014/10/23 10:45:25, Benedikt Meurer wrote:
> Windows builder will probably complain about this comparison. How about some
try
> jobs?

Fixed with static_cast

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:369: ZoneDeque<Node*> phis(zone_);
On 2014/10/23 10:45:25, Benedikt Meurer wrote:
> Hm, I'd like to have a ZoneStack here, i.e. a class for std::stack<ZoneDeque>

Order doesn't really matter here, so I could as well use NodeVector.

https://codereview.chromium.org/665223006/diff/1/src/compiler/control-reducer...
src/compiler/control-reducer.cc:370: for (UseIter i = node->uses().begin(); i !=
node->uses().end(); ++i) {
On 2014/10/23 10:45:25, Benedikt Meurer wrote:
> for (Node* const to : node->uses()) { ... }

Done.

[Benedikt Meurer, 2014-10-23 11:28:52]

Ok, so how about running try jobs on that?

[Benedikt Meurer, 2014-10-26 12:58:53]

lgtm

[titzer, 2014-10-27 08:41:44]

Committed patchset #5 manually as 24891 (presubmit successful).