vm/opto/chaitin.cpp

104   // Bigger area lowers score, encourages spilling this live range.
105   // Bigger cost raise score, prevents spilling this live range.
160 // Make all Nodes map directly to their final live range; no need for
181   // brand new live ranges but have not told the allocator yet.
302 // Renumber the live ranges to compact them.  Makes the IFG smaller.
311   // compacted live range with no further chaining.  There are no chains or
317     // Ignore unallocated live ranges
354   // Need live-ness for the IFG; need the IFG for coalescing.  If the
356   // all copy-related live ranges low and then using the max copy-related
357   // live range as a cut-off for LIVE and the IFG.  In other words, I can
359   PhaseLive live(_cfg, _lrg_map.names(), &live_arena, false);
367   // - effectively ending SSA form.  This requires either coalescing live
381     _live = NULL;                 // Mark live as being not available
386     live.compute(_lrg_map.max_lrg_id()); // Compute liveness
387     _live = &live;                // Mark LIVE as being available
391   // derived pointers.  This makes base pointers live up to the where the
392   // derived pointer is made, but not beyond.  Really, they need to be live
393   // across any GC point where the derived value is live.  So this code looks
394   // at all the GC points, and "stretches" the live range of any base pointer
398     // Since some live range stretched, I need to recompute live
404     live.compute(_lrg_map.max_lrg_id());
405     _live = &live;
443     live.compute(_lrg_map.max_lrg_id());
444     _live = &live;
481       live.compute(_lrg_map.max_lrg_id()); // Compute LIVE
482       _live = &live;
492       // If max live ranges greater than cutoff, don't color the stack.
543     // Nuke the live-ness and interference graph and LiveRanGe info
554       live.compute(_lrg_map.max_lrg_id());
555       _live = &live;
566       // Check for few live ranges determines how aggressive coalesce is.
678   // number.  A few get the ZERO live range number.  These do not
680   // only one instance is simultaneously live at a time.
689       // Pre-color to the zero live range, or pick virtual register
700   // Use ssa names to populate the live range maps or if no mask
710       // Pre-color to the zero live range, or pick virtual register
727   // Nail down the frame pointer live range
759         // Check for float-vs-int live range (used in register-pressure
800         // Check for vector live range (only if vector register is used).
1008           // Later, AFTER aggressive, this live range will have to spill
1078 // colorability of the graph.  If any live range was of low-degree before
1091       // hi-degree live range will not interfere with the color choices
1092       // of said hi-degree live range.  The Simplify reverse-stack-coloring
1129       // lo-degree live ranges always get a register.
1194   // No more lo-degree no-copy live ranges to simplify
1247         // _must_spill live ranges are already on the low degree list.
1278       // a float live range it's degree will drop by 2 and you can skip the
1292       // wins.  Ties happen because all live ranges in question have spilled
1296       // Ties also happen when live ranges are defined and used only inside
1298       // In such case choose bound live range over unbound to free registers
1312     // The live range we choose for spilling is either hi-degree, or very
1313     // rarely it can be low-degree.  If we choose a hi-degree live range
1432   assert( lrg.num_regs() >= 2, "dead live ranges do not color" );
1476     // live range that cannot color in the current chunk, and it
1560       // If the live range is not bound, then we actually had some choices
1590     // Live range is live and no colors available
1831 // base pointer that is live across the Safepoint for oopmap building.  The
1845     IndexSet liveout(_live->live(block));
1852       // extends its live range BUT cannot be part of the cycle.  If this
1853       // extended live range overlaps with the update of the loop-phi value
1875       // Ignore the occasional brand-new live range
1877         // Remove from live-out set
1891         // Now scan for a live derived pointer
1910             // See if the base pointer is already live to this point.
1911             // Since I'm working on the SSA form, live-ness amounts to
1912             // reaching def's.  So if I find the base's live range then
1914             if ((_lrg_map.live_range_id(base) >= _lrg_map.max_lrg_id() || // (Brand new base (hence not live) or
1915                  !liveout.member(_lrg_map.live_range_id(base))) && // not live) AND
1918               // Base pointer is not currently live.  Since I stretched
1920               // boundaries, the global live info is now incorrect.
1921               // Recompute live.
1923             } // End of if base pointer is not live to debug info
1925         } // End of scan all live data for derived ptrs crossing GC point
1928       // Make all inputs live
1944   // If I created a new live range I need to recompute live
2043   // Print live-out info at end of block
2046     IndexSet *live = _live->live(b);
2047     IndexSetIterator elements(live);
2179     // Display which live ranges need to be split and the allocator's state
2180     tty->print_cr("Graph-Coloring Iteration %d will split the following live ranges", _trip_cnt);
2312       tty->print("Attempt to print live range index beyond max live range.\n");