diff options
Diffstat (limited to 'chapter24/src/main/java/com')
| -rw-r--r-- | chapter24/src/main/java/com/seaofnodes/simple/Parser.java | 159 |
1 files changed, 65 insertions, 94 deletions
diff --git a/chapter24/src/main/java/com/seaofnodes/simple/Parser.java b/chapter24/src/main/java/com/seaofnodes/simple/Parser.java index 95d178f0..43908685 100644 --- a/chapter24/src/main/java/com/seaofnodes/simple/Parser.java +++ b/chapter24/src/main/java/com/seaofnodes/simple/Parser.java @@ -533,47 +533,6 @@ public class Parser { return parseTrinary(pred,"else"); } - /** - * Handles a conditional expression needed for chaining operators. - * a < x < b the bounded var is x here</> - * @return a {@link Node}, never {@code null} - */ - private Node make_and_conditional(Node lhs, Node ext,boolean swap, Node bounded_var) { - lhs.keep(); - ext.keep(); - - Node ifNode = new IfNode(ctrl(), lhs).peephole(); - - Node ifT = new CProjNode(ifNode. keep(), 0, "True" ).peephole().keep(); - Node ifF = new CProjNode(ifNode.unkeep(), 1, "False").peephole().keep(); - - ScopeNode fScope = _scope.dup(); - - // true - ctrl(ifT.unkeep()); - _scope.addGuards(ifT,lhs,false); - Node rhs = parseShift(); - _scope.removeGuards(ifT); - fScope.balanceIf(_scope); - ScopeNode tScope = _scope; - _scope = fScope; - ctrl(ifF.unkeep()); - _scope.addGuards(ifF,lhs,true); - _scope.removeGuards(ifF); - - _scope = tScope; - tScope.balanceIf(fScope); - ext.setDef(swap ? 2: 1, bounded_var); - ext.setDef(swap ? 1 :2, rhs); - ext.peephole(); - - RegionNode r = ctrl(tScope.mergeScopes(fScope, loc())); - Node ret = peep(new PhiNode("",ext._type.meet(lhs._type).glb(false),r,ext.unkeep(),lhs.unkeep())); - - r.peephole(); - return ret; - } - // Parse a conditional expression, merging results. private Node parseTrinary( Node pred, String fside ) { // IfNode takes current control and predicate @@ -1072,86 +1031,98 @@ public class Parser { } private Node parseBitwise() { - Node lhs = parseComparison(); + Node lhs = parseEquality(); while( true ) { if( false ) ; else if( matchOp('&') ) lhs = new AndNode(loc(),lhs,null); else if( matchOp('|') ) lhs = new OrNode(loc(),lhs,null); else if( match ("^") ) lhs = new XorNode(loc(),lhs,null); else break; - lhs.setDef(2,parseComparison()); + lhs.setDef(2,parseEquality()); lhs = peep(lhs); } return lhs; } + + + /** + * Parse an eq/ne expression + */ + private Node parseEquality() { + Node lhs = parseComparison(); + while( true ) { + boolean eq = false; + if( match("==") ) eq = true; + else if( !match("!=") ) break; + lhs = peep(new BoolNode.EQ(lhs,parseComparison())); + if( !eq ) lhs = peep(new NotNode(lhs)); + } + return lhs; + } + /** * Parse an expression of the form: * * <pre> - * expr : additiveExpr op additiveExpr + * expr : shiftExpr < shiftExpr <= shiftExpr... + * expr : shiftExpr > shiftExpr >= shiftExpr... * </pre> * @return an comparator expression {@link Node}, never {@code null} */ private Node parseComparison() { - var lhs = parseShift(); - Node bound_var = null; - boolean found_bl = false; + Node lhs = parseShift(); + int dir = 0; while( true ) { - int idx=0; boolean negate=false; - // Test for any local nodes made, and "keep" lhs during peepholes - // chain operators + int dir0; if( false ) ; - else if( match("==") ) { - if(found_bl) { - return make_and_conditional(lhs, new BoolNode.EQ(null, null), false, bound_var); - } - idx=2; lhs = new BoolNode.EQ(lhs, null); - } - else if( match("!=") ) { - if(found_bl) { - return make_and_conditional(lhs, peep(new NotNode(new BoolNode.EQ(null, null))), false, bound_var); - } - idx=2; lhs = new BoolNode.EQ(lhs, null); negate=true; - } - else if( match("<=") ) { - if(found_bl) { - return make_and_conditional(lhs, new BoolNode.LE(null, null), false, bound_var); - } - idx=2; lhs = new BoolNode.LE(lhs, null); - } - else if( match("<" ) ) { - if(found_bl) { - return make_and_conditional(lhs, new BoolNode.LT(null, null), false, bound_var); - } - idx=2; lhs = new BoolNode.LT(lhs, null); - } - else if( match(">=") ) { - if(found_bl) { - return make_and_conditional(lhs, new BoolNode.LE(null, null), true, bound_var); - } - idx=1; lhs = new BoolNode.LE(null, lhs); - } - else if( match(">" ) ) { - if(found_bl) { - return make_and_conditional(lhs, new BoolNode.LT(null, null), true, bound_var); - } - idx=1; lhs = new BoolNode.LT(null, lhs); - } + else if( match("<=" ) ) dir0 = -1; + else if( match(">=" ) ) dir0 = -2; + else if( match("<" ) ) dir0 = 1; + else if( match(">" ) ) dir0 = 2; else break; - // Peepholes can fire, but lhs is already "hooked", kept alive - lhs.setDef(idx,parseShift()); - found_bl = true; - bound_var = lhs.in(idx); - lhs = peep(lhs.widen()); - if( negate ) // Extra negate for != - lhs = peep(new NotNode(lhs)); + // Check and record direction + if( dir==0 ) { + dir = Math.abs(dir0); + Node rhs = parseShift(); + lhs = makeCompBool(dir0,lhs,rhs); // Convert to a bool + } else if( dir == Math.abs(dir0) ) { + // e0 < lhs < ??? + lhs.keep(); + Node ifNode = new IfNode(ctrl(), lhs).peephole(); + Node ifT = new CProjNode(ifNode. keep(), 0, "True" ).peephole(); + Node ifF = new CProjNode(ifNode.unkeep(), 1, "False").peephole(); + // False side does nothing + ScopeNode fScope = _scope.dup(); + fScope.ctrl(ifF); + // True side executes next part of range + ctrl(ifT); + _scope.addGuards(ifT,lhs,false); + Node rhs = parseShift(); + _scope.removeGuards(ifT); // TODO: I think should remain true as long as possible + Node next = makeCompBool(dir0, lhs, rhs).keep(); + // Merge result + RegionNode r = ctrl(_scope.mergeScopes(fScope, loc())); + assert next._type.meet(lhs._type).isa( TypeInteger.BOOL ); + lhs = peep(new PhiNode("",TypeInteger.BOOL,r,next.unkeep(),lhs.unkeep())); + r.peephole(); + } else { + throw error("Mixing relational directions in a chained relational test"); + } } - found_bl = false; return lhs; } + private Node makeCompBool( int dir0, Node lhs, Node rhs ) { + // Convert to a bool + if( Math.abs(dir0)==2 ) // Swap direction + { Node tmp = lhs; lhs = rhs; rhs = tmp; } + lhs = peep(dir0 < 0 ? new BoolNode.LE(lhs,rhs) : new BoolNode.LT(lhs,rhs)); + return peep(lhs.widen()); + } + + /** * Parse an additive expression * |