Don't let HCheck instructions prevent GVN.

Don't let HCheck instructions prevent GVN.

R=johnniwinther@google.com, karlklose@google.com, kasperl@google.com

Committed: https://code.google.com/p/dart/source/detail?r=23906

[kasperl, 2013-06-12 10:42:56]

LGTM.

[Johnni Winther, 2013-06-12 11:06:08]

lgtm

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/ssa/nodes.dart (right):

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/ssa/nodes.dart:1325: return
selector.name == other.selector.name;
Why not [: selector == other.selector :] ?

[karlklose, 2013-06-12 13:12:38]

LGTM.

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/ssa/nodes.dart (right):

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/ssa/nodes.dart:624: if (user != from
&& user is HCheck && user.checkedInput == to) {
I would prefer:
for (HInstruction user in to.usedBy) {	
  if (user is! HCheck) continue;
  HCheck check = user;
  if (user.checkedInput == to) {
    better = better.prepend;
  }
}

[ngeoffray, 2013-06-12 13:55:09]

Thanks all.

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/ssa/nodes.dart (right):

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/ssa/nodes.dart:624: if (user != from
&& user is HCheck && user.checkedInput == to) {
On 2013/06/12 13:12:38, karlklose wrote:
> I would prefer:
> for (HInstruction user in to.usedBy) {	
>   if (user is! HCheck) continue;
>   HCheck check = user;
>   if (user.checkedInput == to) {
>     better = better.prepend;
>   }
> }

Done.

https://codereview.chromium.org/15917017/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/ssa/nodes.dart:1325: return
selector.name == other.selector.name;
On 2013/06/12 11:06:08, Johnni Winther wrote:
> Why not [: selector == other.selector :] ?

Because if we end up here, we know the receiver is the same, but the selectors
may not have been updated with the receiver type. So Selector.operator== will
return false, even though it's the same receiver.

[ngeoffray, 2013-06-12 14:14:40]

Committed patchset #2 manually as r23906 (presubmit successful).