diff options
Diffstat (limited to 'chapter17a/src/main/java/com')
| -rw-r--r-- | chapter17a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/chapter17a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java b/chapter17a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java index eba99128..c6d02b27 100644 --- a/chapter17a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java +++ b/chapter17a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java @@ -207,10 +207,11 @@ public abstract class GlobalCodeMotion { lca = anti_dep(load,late[st._nid],st.cfg0(),lca,st,anti); break; case PhiNode phi: - // Repeat anti-dep for matching Phi inputs. - // No anti-dep edges but may raise the LCA. + // Inputs carrying different memory might overwrite this alias. + // Raise the LCA for those paths; unchanged memory does not + // clobber the load. No scheduling edge to the Phi. for( int i=1; i<phi.nIns(); i++ ) - if( phi.in(i)==load.mem() ) + if( phi.in(i)!=load.mem() ) lca = anti_dep(load,phi.region().cfg(i),load.mem().cfg0(),lca,null,anti); break; default: throw Utils.TODO(); @@ -223,7 +224,9 @@ public abstract class GlobalCodeMotion { private static CFGNode anti_dep( LoadNode load, CFGNode stblk, CFGNode defblk, CFGNode lca, Node st, int[] anti ) { // Preserve the full store range for the earlier evaluator scheduler. // It places nodes independently of GCM and may hoist this store. - for( ; stblk != defblk.idom(); stblk = stblk.idom() ) { + // Another Phi input need not be dominated by this memory definition. + // Include its depth, and retain the sentinel for an entry's null idom. + for( ; stblk != defblk.idom() && stblk.idepth() >= defblk.idepth(); stblk = stblk.idom() ) { // Store and Load overlap, need anti-dependence if( anti[stblk._nid]==load._nid ) { lca = stblk.domLCA(lca,null); // Raise Loads LCA |