diff options
Diffstat (limited to 'src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java')
| -rw-r--r-- | src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java | 50 |
1 files changed, 6 insertions, 44 deletions
diff --git a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java b/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java index 29841266..9698abd9 100644 --- a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java +++ b/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java @@ -16,43 +16,6 @@ public abstract class GlobalCodeMotion { schedLate( stop); } - // ------------------------------------------------------------------------ - // Backwards walk on the CFG only, looking for unreachable code - which has - // to be an infinite loop. Insert a bogus never-taken exit to Stop, so the - // loop becomes reachable. Also, set loop nesting depth - public static void fixLoops(StopNode stop) { - // Backwards walk from Stop, looking for unreachable code - BitSet visit = new BitSet(); - HashSet<CFGNode> unreach = new HashSet<>(); - unreach.add(Parser.START); - for( Node ret : stop._inputs ) - ((ReturnNode)ret).walkUnreach(visit,unreach); - if( unreach.isEmpty() ) return; - - // Forwards walk from unreachable, looking for loops with no exit test. - visit.clear(); - for( CFGNode cfg : unreach ) - walkInfinite(cfg,visit,stop); - // Set loop depth on remaining graph - unreach.clear(); - visit.clear(); - for( Node ret : stop._inputs ) - ((ReturnNode)ret).walkUnreach(visit,unreach); - assert unreach.isEmpty(); - } - - - // Forwards walk over previously unreachable, looking for loops with no - // exit test. - static private void walkInfinite( CFGNode n, BitSet visit, StopNode stop ) { - if( visit.get(n._nid) ) return; // Been there, done that - visit.set(n._nid); - if( n instanceof LoopNode loop ) - loop.forceExit(stop); - for( Node use : n._outputs ) - if( use instanceof CFGNode cfg ) - walkInfinite(cfg,visit,stop); - } // ------------------------------------------------------------------------ // Visit all nodes in CFG Reverse Post-Order, essentially defs before uses @@ -66,7 +29,7 @@ public abstract class GlobalCodeMotion { // Reverse Post-Order on CFG for( int j=rpo.size()-1; j>=0; j-- ) { CFGNode cfg = rpo.get(j); - cfg.loopDepth(); // Pre-compute loop depth + cfg.loopDepth(); for( Node n : cfg._inputs ) _schedEarly(n,visit); if( cfg instanceof RegionNode ) @@ -138,14 +101,13 @@ public abstract class GlobalCodeMotion { // All uses done? for( Node use : n._outputs ) - if( use!=null && late[use._nid]==null && !(use instanceof PhiNode) ) + if( use!=null && late[use._nid]==null ) continue outer; // Nope, await all uses done // Loads need their memory inputs' uses also done if( n instanceof LoadNode ld ) for( Node memuse : ld.mem()._outputs ) - if( !(memuse instanceof PhiNode) && - late[memuse._nid]==null && + if( late[memuse._nid]==null && // Load-use directly defines memory (memuse._type instanceof TypeMem || // Load-use indirectly defines memory @@ -211,7 +173,7 @@ public abstract class GlobalCodeMotion { // Least loop depth first, then largest idepth private static boolean better( CFGNode lca, CFGNode best ) { - return lca._loopDepth < best._loopDepth || + return lca.loopDepth() < best.loopDepth() || (lca.idepth() > best.idepth() || best instanceof IfNode); } @@ -251,9 +213,9 @@ public abstract class GlobalCodeMotion { // private static CFGNode anti_dep( LoadNode load, CFGNode stblk, CFGNode defblk, CFGNode lca, Node st ) { // Walk store blocks "reach" from its scheduled location to its earliest - for( ; stblk != defblk; stblk = stblk.idom() ) { + for( ; stblk != defblk.idom(); stblk = stblk.idom() ) { // Store and Load overlap, need anti-dependence - if( !(stblk instanceof IfNode) && stblk._anti==load._nid ) { + if( stblk._anti==load._nid ) { lca = stblk._idom(lca,null); // Raise Loads LCA if( lca == stblk && st != null && st._inputs.find(load) == -1 ) // And if something moved, st.addDef(load); // Add anti-dep as well |