Fix loop side-effects of deoptimizing loops with a nested live OSR loop.

Fix loop side-effects of deoptimizing loops with a nested live OSR loop.

R=titzer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=18263

[titzer, 2013-12-05 17:52:08]

https://chromiumcodereview.appspot.com/106723002/diff/20001/src/hydrogen-gvn.cc
File src/hydrogen-gvn.cc (right):

https://chromiumcodereview.appspot.com/106723002/diff/20001/src/hydrogen-gvn....
src/hydrogen-gvn.cc:409: if (block->IsLoopHeader()) {
Can you turn this whole thing into a do {} while() ?

https://chromiumcodereview.appspot.com/106723002/diff/20001/src/hydrogen-gvn....
src/hydrogen-gvn.cc:573: TRACE_GVN_3("Hoisting loop invariant instruction %d %d
%s\n",
would like to see

"Hoisting loop invariant instruction i%d to block B%d" and I think you can drop
the loop kills for now.

https://chromiumcodereview.appspot.com/106723002/diff/20001/test/mjsunit/regr...
File test/mjsunit/regress/regress-context-osr.js (right):

https://chromiumcodereview.appspot.com/106723002/diff/20001/test/mjsunit/regr...
test/mjsunit/regress/regress-context-osr.js:39: }
Can you please write versions for 4 and 5 loop nesting levels? You may also be
able to reduce the OSR count as well.

[Toon Verwaest, 2013-12-05 18:22:56]

Addressed comments, minus the more nested loops. Those would take too long with
the current setup.

[titzer, 2013-12-05 18:29:38]

LGTM

[Toon Verwaest, 2013-12-05 18:31:13]

Committed patchset #2 manually as r18263.