diff options
Diffstat (limited to 'chapter27/src/main')
| -rw-r--r-- | chapter27/src/main/java/com/seaofnodes/simple/node/LoadNode.java | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/chapter27/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/chapter27/src/main/java/com/seaofnodes/simple/node/LoadNode.java index b9dd2af6..736d91a2 100644 --- a/chapter27/src/main/java/com/seaofnodes/simple/node/LoadNode.java +++ b/chapter27/src/main/java/com/seaofnodes/simple/node/LoadNode.java @@ -208,7 +208,12 @@ public class LoadNode extends MemOpNode { // skipping it can make a compound assignment read the old value. if( st._alias==1 ) return null; addDep(st.ptr()); - if( _alias==st._alias && ptr==address(st.ptr()) && off()==st.off() ) return st; + if( _alias==st._alias && ptr==address(st.ptr()) && off()==st.off() ) { + // A full-width load cannot narrow the forwarded value. + if( _declaredType instanceof TypeInteger ti && ti.log_size()==3 && + !addDep(st.val())._type.isa(_type) ) return null; + return st; + } if( _alias==st._alias && !neverAlias(ptr,address(st.ptr())) && !addDep(off())._type.join(addDep(st.off())._type).isHigh() ) return null; mem=st.mem(); @@ -313,8 +318,15 @@ public class LoadNode extends MemOpNode { // Signed extension int shift = Long.numberOfLeadingZeros(ti._max)-1; Node shf = con(shift); - if( shf._type==TypeInteger.ZERO ) + if( shf._type==TypeInteger.ZERO ) { + // A constructor's loop Phi may still have an unsettled type. + // Wait for it instead of weakening the typed Load's users. + if( !val._type.isa(_type) ) { + addDep(val); + return null; + } return val; + } Node shl = new ShlNode(null,val,shf.keep()).peephole(); return new SarNode(null,shl,shf.unkeep()); } |