[turbofan] put spill slot reuse behind a flag

[turbofan] put spill slot reuse behind a flag

BUG=

Committed: https://chromium.googlesource.com/v8/v8/+/1aad0fab681e0e8e8a789c615558c65f48d8d9b3

[Jarin, 2014-11-21 10:55:38]

jarin@chromium.org changed reviewers:
+ jarin@chromium.org

[Jarin, 2014-11-21 10:55:39]

lgtm modulo bunch of comments.

https://codereview.chromium.org/748773002/diff/1/src/compiler/graph-visualize...
File src/compiler/graph-visualizer.cc (right):

https://codereview.chromium.org/748773002/diff/1/src/compiler/graph-visualize...
src/compiler/graph-visualizer.cc:726: int index = -1;
How about DCHECK((range->TopLevel()->GetSpillRange() != nullptr) ==
FLAG_turbo_reuse_spill_slots)?

https://codereview.chromium.org/748773002/diff/1/src/compiler/register-alloca...
File src/compiler/register-allocator.cc (right):

https://codereview.chromium.org/748773002/diff/1/src/compiler/register-alloca...
src/compiler/register-allocator.cc:549:
use_spill_ranges_(FLAG_turbo_reuse_spill_slots) {
Why is there this extra indirection? Can't we use the naked flag? (That will
simplify the removal once we are done.)

https://codereview.chromium.org/748773002/diff/1/src/flag-definitions.h
File src/flag-definitions.h (right):

https://codereview.chromium.org/748773002/diff/1/src/flag-definitions.h#newco...
src/flag-definitions.h:391: DEFINE_BOOL(turbo_reuse_spill_slots, false, "reuse
spill slots in TurboFan")
Please, add a TODO explaining that this is just temporary for experimentation.

[dcarney, 2014-11-21 10:56:53]

Patchset #2 (id:20001) has been deleted

[dcarney, 2014-11-21 11:03:55]

https://codereview.chromium.org/748773002/diff/1/src/compiler/graph-visualize...
File src/compiler/graph-visualizer.cc (right):

https://codereview.chromium.org/748773002/diff/1/src/compiler/graph-visualize...
src/compiler/graph-visualizer.cc:726: int index = -1;
On 2014/11/21 10:55:39, jarin wrote:
> How about DCHECK((range->TopLevel()->GetSpillRange() != nullptr) ==
> FLAG_turbo_reuse_spill_slots)?

benedikt saw a crash here, so i was fixing it - nothing to do with this cl

https://codereview.chromium.org/748773002/diff/1/src/compiler/register-alloca...
File src/compiler/register-allocator.cc (right):

https://codereview.chromium.org/748773002/diff/1/src/compiler/register-alloca...
src/compiler/register-allocator.cc:549:
use_spill_ranges_(FLAG_turbo_reuse_spill_slots) {
On 2014/11/21 10:55:39, jarin wrote:
> Why is there this extra indirection? Can't we use the naked flag? (That will
> simplify the removal once we are done.)

ok

https://codereview.chromium.org/748773002/diff/1/src/flag-definitions.h
File src/flag-definitions.h (right):

https://codereview.chromium.org/748773002/diff/1/src/flag-definitions.h#newco...
src/flag-definitions.h:391: DEFINE_BOOL(turbo_reuse_spill_slots, false, "reuse
spill slots in TurboFan")
On 2014/11/21 10:55:39, jarin wrote:
> Please, add a TODO explaining that this is just temporary for experimentation.

okay

[dcarney, 2014-11-21 11:05:01]

The CQ bit was checked by dcarney@chromium.org

[commit-bot: I haz the power, 2014-11-21 11:05:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/748773002/40001

[commit-bot: I haz the power, 2014-11-21 11:33:04]

Committed patchset #2 (id:40001)