This is done similar to weak embedded objects in optimized code (r17102). The
reference from optimized code to a cell is treated weakly in marking visitors
if the cell points to a JSObject. After marking we iterate over all cells
embedded in optimized code. If a cell is not marked but its value is marked,
then we revive the cell by marking it. Otherwise, the cell value is dead, so
we mark the code for deoptimization.
BUG=v8:2073
TEST=cctest/test-heap/CellsInOptimizedCodeAreWeak
LOG=Y
R=hpayer@chromium.org, mstarzinger@chromium.org
Review URL: https://codereview.chromium.org/117483002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18616 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In the process:
- Add a command-line flag --opt-code-positions to track source position information throughout optimized code.
- Add a subclass of the hydrogen graph builder to ensure that the source position is properly set on the graph builder for all generated hydrogen code.
- Overhaul handling of source positions in hydrogen to ensure they are passed through to generated code consistently and in most cases transparently.
Originally reviewed in this CL: https://codereview.chromium.org/24957003/
Review URL: https://codereview.chromium.org/29123008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17295 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Port r17073 (ba68149)
Original commit message:
- Detect unreachable basic blocks of code either following an unconditional deopt or after a provably untaken branch of HBranch or HCompareObjectEqAndBranch instructions.
- Emit dummy uses in unreachable blocks during Hydrogen -> Lithium translation.
BUG=chromium:258519
R=mstarzinger@chromium.org, plind44@gmail.com
Review URL: https://codereview.chromium.org/25708004
Patch from Balazs Kilvady <kilvadyb@homejinni.com>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17084 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
