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| author | Cliff Click <cliffc@acm.org> | 2024-04-23 17:23:16 +0100 |
|---|---|---|
| committer | Cliff Click <cliffc@acm.org> | 2026-10-04 13:30:41 -0700 |
| commit | dc07e454afd120722b693e09538c165c2e267e60 (patch) | |
| tree | 33ac75ed6508fbd2451af03bfd515a1901489040 /src/main | |
| parent | 628620ce49255f1b80dceee8ef3fa3e6945a0cce (diff) | |
| download | Simple-dc07e454afd120722b693e09538c165c2e267e60.tar.gz Simple-dc07e454afd120722b693e09538c165c2e267e60.zip | |
Chapter 10: Structs and Memory
Co-authored-by: Thalia Archibald <thalia@archibald.dev>
Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Dibyendu Majumdar <mobile@majumdar.org.uk>
Co-authored-by: XmiliaH <45106915+XmiliaH@users.noreply.github.com>
Co-authored-by: tannal <tannal2409@gmail.com>
Co-authored-by: hadha <helsgithub15@gmail.com>
Co-authored-by: XmiliaH <xmilia.hermit@gmail.com>
Co-authored-by: Tamás Hadházy <85063808+Hels15@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: RobertObkircher <robert.obkircher@gmail.com>
Co-authored-by: Robert Obkircher <robert.obkircher@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
Diffstat (limited to 'src/main')
34 files changed, 1250 insertions, 353 deletions
diff --git a/src/main/java/com/seaofnodes/simple/GraphEvaluator.java b/src/main/java/com/seaofnodes/simple/GraphEvaluator.java deleted file mode 100644 index 9fc51c8e..00000000 --- a/src/main/java/com/seaofnodes/simple/GraphEvaluator.java +++ /dev/null @@ -1,181 +0,0 @@ -package com.seaofnodes.simple; - -import com.seaofnodes.simple.node.*; -import com.seaofnodes.simple.type.TypeInteger; - -import java.util.Arrays; -import java.util.BitSet; -import java.util.HashMap; - -public class GraphEvaluator { - - public enum ResultType { VALUE, FALLTHROUGH, TIMEOUT } - - public record Result(ResultType type, long value) {} - - /** - * Find the start node from some node in the graph or null if there is no start node - */ - private static StartNode findStart(BitSet visit, Node node) { - if (node == null) return null; - if (node instanceof StartNode start) return start; - if( visit.get(node._nid) ) return null; - visit.set(node._nid); - for( Node def : node._inputs ) { - var res = findStart(visit,def); - if( res != null ) return res; - } - for( Node use : node._outputs ) { - var res = findStart(visit,use); - if( res != null ) return res; - } - return null; - } - - /** - * Find the control output from a control node - */ - private static Node findControl(Node control) { - for( Node use : control._outputs ) { - if (use.isCFG()) return use; - } - return null; - } - - /** - * Find the projection for a node - */ - private static ProjNode findProjection(Node node, int idx) { - for( Node use : node._outputs ) { - if (use instanceof ProjNode proj && proj._idx == idx) return proj; - } - return null; - } - - /** - * Cache values for phi and parameter projection nodes. - */ - private final HashMap<Node, Long> cacheValues = new HashMap<>(); - /** - * Cache for loop phis as they can depend on itself or other loop phis - */ - private long[] loopPhiCache = new long[16]; - - private GraphEvaluator() { - } - - private long div(DivNode div) { - long in2 = getValue(div.in(2)); - return in2 == 0 ? 0 : getValue(div.in(1)) / in2; - } - - /** - * Calculate the value of a node - */ - private long getValue(Node node) { - var cache = cacheValues.get(node); - if (cache != null) return cache; - return switch (node) { - case ConstantNode cons -> ((TypeInteger)cons.compute()).value(); - case AddNode add -> getValue(add.in(1)) + getValue(add.in(2)); - case BoolNode.EQ eq -> getValue(eq.in(1)) == getValue(eq.in(2)) ? 1 : 0; - case BoolNode.LE le -> getValue(le.in(1)) <= getValue(le.in(2)) ? 1 : 0; - case BoolNode.LT lt -> getValue(lt.in(1)) < getValue(lt.in(2)) ? 1 : 0; - case DivNode div -> div(div); - case MinusNode minus -> -getValue(minus.in(1)); - case MulNode mul -> getValue(mul.in(1)) * getValue(mul.in(2)); - case NotNode not -> getValue(not.in(1)) == 0 ? 1 : 0; - case SubNode sub -> getValue(sub.in(1)) - getValue(sub.in(2)); - default -> throw Utils.TODO("Unexpected node " + node); - }; - } - - /** - * Special case of latchPhis when phis can depend on phis of the same region. - */ - private void latchLoopPhis(RegionNode region, Node prev) { - int idx = Utils.find(region._inputs, prev); - assert idx > 0; - int i = 0; - for( Node use : region._outputs ) { - if (use instanceof PhiNode phi) { - var value = getValue(phi.in(idx)); - if (i == loopPhiCache.length) loopPhiCache = Arrays.copyOf(loopPhiCache, loopPhiCache.length*2); - loopPhiCache[i++] = value; - } - } - i = 0; - for( Node use : region._outputs ) { - if (use instanceof PhiNode phi) cacheValues.put(phi, loopPhiCache[i++]); - } - } - - /** - * Calculate the values of phis of the region and caches the values. The phis are not allowed to depend on other phis of the region. - */ - private void latchPhis(RegionNode region, Node prev) { - int idx = Utils.find(region._inputs, prev); - assert idx > 0; - for( Node use : region._outputs ) { - if (use instanceof PhiNode phi) { - var value = getValue(phi.in(idx)); - cacheValues.put(phi, value); - } - } - } - - /** - * Run the graph until either a return is found or the number of loop iterations are done. - */ - private Result evaluate(StartNode start, long parameter, int loops) { - var parameter1 = findProjection(start, 1); - if (parameter1 != null) cacheValues.put(parameter1, parameter); - Node control = findProjection(start, 0); - Node prev = start; - while (control != null) { - Node next; - switch (control) { - case RegionNode region -> { - if (region instanceof LoopNode && region.in(1) != prev) { - if (loops--<=0) return new Result(ResultType.TIMEOUT, 0); - latchLoopPhis(region, prev); - } else { - latchPhis(region, prev); - } - next = findControl(region); - } - case IfNode cond -> next = findProjection(cond, getValue(cond.in(1)) != 0 ? 0 : 1); - case ReturnNode ret -> { - return new Result(ResultType.VALUE, getValue(ret.in(1))); - } - case ProjNode ignored -> next = findControl(control); - default -> throw Utils.TODO("Unexpected control node " + control); - } - prev = control; - control = next; - } - return new Result(ResultType.FALLTHROUGH, 0); - } - - public static long evaluate(Node graph) { - return evaluate(graph, 0); - } - - public static long evaluate(Node graph, long parameter) { - return evaluate(graph, parameter, 1000); - } - - public static long evaluate(Node graph, long parameter, int loops) { - var res = evaluateWithResult(graph, parameter, loops); - if (res.type== ResultType.TIMEOUT) throw new RuntimeException("Timeout"); - return res.value; - } - - public static Result evaluateWithResult(Node graph, long parameter, int loops) { - var start = findStart(new BitSet(), graph); - if (start == null) return new Result(ResultType.TIMEOUT, 0); - var evaluator = new GraphEvaluator(); - return evaluator.evaluate(start, parameter, loops); - } - -} diff --git a/src/main/java/com/seaofnodes/simple/IRPrinter.java b/src/main/java/com/seaofnodes/simple/IRPrinter.java index 2e40ff74..621bc2d6 100644 --- a/src/main/java/com/seaofnodes/simple/IRPrinter.java +++ b/src/main/java/com/seaofnodes/simple/IRPrinter.java @@ -7,7 +7,7 @@ import com.seaofnodes.simple.node.*; public final class IRPrinter extends IRAdapter<Node> { private static final com.seaofnodes.print.IRPrinter<Node> PRINT = new com.seaofnodes.print.IRPrinter<>(new IRPrinter()); - @Override public String type(Node n) { return n._type==null ? "" : n._type.toString(); } + @Override public String type(Node n) { return n._type==null ? "" : n._type.str(); } @Override public int inputColumns() { return 3; } @Override public Kind kind(Node n) { if( n instanceof StartNode ) return Kind.START; diff --git a/src/main/java/com/seaofnodes/simple/IterPeeps.java b/src/main/java/com/seaofnodes/simple/IterPeeps.java index 41fc6916..7075d526 100644 --- a/src/main/java/com/seaofnodes/simple/IterPeeps.java +++ b/src/main/java/com/seaofnodes/simple/IterPeeps.java @@ -1,8 +1,6 @@ package com.seaofnodes.simple; -import com.seaofnodes.simple.node.ConstantNode; -import com.seaofnodes.simple.node.Node; -import com.seaofnodes.simple.node.StopNode; +import com.seaofnodes.simple.node.*; import java.util.ArrayList; import java.util.Arrays; @@ -95,6 +93,8 @@ public abstract class IterPeeps { n.moveDepsToWorklist(); assert progressOnList(stop); // Very expensive assert } + if( n.isUnused() && !(n instanceof StopNode) ) + n.kill(); // Just plain dead if( obs != null ) obs.after(n, x, true); } diff --git a/src/main/java/com/seaofnodes/simple/Parser.java b/src/main/java/com/seaofnodes/simple/Parser.java index 3c1eab96..7734f4df 100644 --- a/src/main/java/com/seaofnodes/simple/Parser.java +++ b/src/main/java/com/seaofnodes/simple/Parser.java @@ -53,14 +53,17 @@ public class Parser { /** * List of keywords disallowed as identifiers */ - private final HashSet<String> KEYWORDS = new HashSet<>(){{ + private static final HashSet<String> KEYWORDS = new HashSet<>(){{ add("break"); add("continue"); add("else"); add("false"); add("if"); add("int"); + add("new"); + add("null"); add("return"); + add("struct"); add("true"); add("while"); }}; @@ -75,14 +78,18 @@ public class Parser { ScopeNode _continueScope; ScopeNode _breakScope; + // Mapping from a Struct name to a Struct. + public static Map<String, TypeStruct> OBJS = new HashMap<>(); + public Parser(String source, TypeInteger arg) { PARSER = this; Node.reset(); IterPeeps.reset(); + OBJS.clear(); _lexer = new Lexer(source); _scope = new ScopeNode(); _continueScope = _breakScope = null; - START = new StartNode(new Type[]{ Type.CONTROL, arg }); + START = new StartNode(new Type[]{ Type.CONTROL, TypeMem.BOT, arg }); STOP = new StopNode(source); } @@ -106,8 +113,9 @@ public class Parser { _xScopes.push(_scope); // Enter a new scope for the initial control and arguments _scope.push(); - _scope.define(ScopeNode.CTRL, new ProjNode(START, 0, ScopeNode.CTRL).peephole()); - _scope.define(ScopeNode.ARG0, new ProjNode(START, 1, ScopeNode.ARG0).peephole()); + _scope.define(ScopeNode.CTRL, Type.CONTROL , new ProjNode(START, 0, ScopeNode.CTRL).peephole()); + _scope.define(ScopeNode.ARG0, TypeInteger.BOT, new ProjNode(START, 2, ScopeNode.ARG0).peephole()); + _scope.define("$mem", TypeMem.BOT, new ProjNode(START, 1, "$mem").peephole()); parseBlock(); _scope.pop(); _xScopes.pop(); @@ -144,18 +152,59 @@ public class Parser { * @return a {@link Node} or {@code null} */ private Node parseStatement() { - if (matchx("return") ) return parseReturn(); - else if (matchx("int")) return parseDecl(); - else if (match ("{" )) return require(parseBlock(),"}"); - else if (matchx("if" )) return parseIf(); - else if (matchx("while")) return parseWhile(); - else if (matchx("break")) return parseBreak(); + if( false ) return null; + else if (matchx("return") ) return parseReturn(); + else if (matchx("int") ) return parseDecl(TypeInteger.BOT); + else if (match ("{") ) return require(parseBlock(),"}"); + else if (matchx("if") ) return parseIf(); + else if (matchx("while") ) return parseWhile(); + else if (matchx("break") ) return parseBreak(); else if (matchx("continue")) return parseContinue(); - else if (matchx(";")) return null; // Empty statement + else if (matchx("struct") ) return parseStruct(); + else if (matchx(";") ) return null; // Empty statement + // declarations of vars with struct type are handled in parseExpressionStatement due + // to ambiguity else return parseExpressionStatement(); } /** + * Parse a struct field. + * <pre> + * int IDENTIFIER ; + * </pre> + */ + private Field parseField(String sname) { + if( matchx("int") ) // Currently only parsing "int" type fields + return require(Field.make(requireId().intern(),TypeInteger.BOT),";"); + throw errorSyntax("A field type is expected, only type 'int' is supported at present"); + } + + /** + * Parse a struct declaration, and return the following statement. + * Only allowed in top level scope. + * Structs cannot be redefined. + * + * @return The statement following the struct + */ + private Node parseStruct() { + if (_xScopes.size() > 1) throw errorSyntax("struct declarations can only appear in top level scope"); + String typeName = requireId(); + if ( OBJS.containsKey(typeName)) throw errorSyntax("struct '" + typeName + "' cannot be redefined"); + ArrayList<Field> fields = new ArrayList<>(); + require("{"); + while (!peek('}') && !_lexer.isEOF()) { + Field field = parseField(typeName); + if (fields.contains(field)) throw errorSyntax("Field '" + field + "' already defined in struct '" + typeName + "'"); + fields.add(field); + } + require("}"); + // Build and install the TypeStruct + TypeStruct ts = TypeStruct.make(typeName, fields); + OBJS.put(typeName, ts); // Insert the struct name in the collection of all struct names + return parseStatement(); + } + + /** * Parses a while statement * * <pre> @@ -247,7 +296,7 @@ public class Parser { cur.pop(); // If this is a continue then first time the target is null // So we just use the pruned current scope as the base for the - // continue + // "continue" if (toScope == null) return cur; // toScope is either the break scope, or a scope that was created here @@ -272,7 +321,7 @@ public class Parser { private Node parseIf() { require("("); // Parse predicate - var pred = require(parseExpression(), ")"); + var pred = require(parseExpression(), ")").keep(); // IfNode takes current control and predicate Node ifNode = new IfNode(ctrl(), pred).peephole(); // Setup projection nodes @@ -287,6 +336,7 @@ public class Parser { // Parse the true side ctrl(ifT.unkeep()); // set ctrl token to ifTrue projection + _scope.upcast(ifT,pred,false); // Up-cast predicate parseStatement(); // Parse true-side ScopeNode tScope = _scope; @@ -294,9 +344,11 @@ public class Parser { _scope = fScope; // Restore scope, then parse else block if any ifF.unkeep(); // fScope already owns the false control if (matchx("else")) { + _scope.upcast(ifF,pred,true); // Up-cast predicate parseStatement(); fScope = _scope; } + pred.unkeep(); if( tScope.nIns() != ndefs || fScope.nIns() != ndefs ) throw error("Cannot define a new name on one arm of an if"); @@ -320,7 +372,7 @@ public class Parser { */ private Node parseReturn() { var expr = require(parseExpression(), ";"); - Node ret = STOP.addReturn(new ReturnNode(ctrl(), expr).peephole()); + Node ret = STOP.addReturn(new ReturnNode(ctrl(), expr, _scope).peephole()); ctrl(new ConstantNode(Type.XCONTROL).peephole()); // Kill control return ret; } @@ -328,40 +380,86 @@ public class Parser { /** - * Parses an expression statement + * Parses an expression statement or a declaration statement where type is a struct * * <pre> - * name '=' expression ';' + * name; // Error + * type name; // Define name with default initial value + * type name = expr; // Define name with given initial value + * name = expr; // Reassign existing + * expr // Something else * </pre> * @return an expression {@link Node}, never {@code null} */ private Node parseExpressionStatement() { - var name = requireId(); - require("="); - var expr = require(parseExpression(), ";"); - if( _scope.update(name, expr)==null ) - throw error("Undefined name '" + name + "'"); + int old = _lexer._position; + Type t = type(); + String name = requireId(); + Node expr; + if( match(";") ) { // Assign a default value + // No type and no expr is an error + if( t==null ) throw errorSyntax("expression"); + expr = new ConstantNode(t.makeInit()).peephole(); + } else if( match("=") ) { // Assign "= expr;" + expr = require(parseExpression(), ";"); + } else { // Neither, so just a normal expression parse + _lexer._position = old; + return require(parseExpression(),";"); + } + + // Defining a new variable vs updating an old one + if( t != null ) { + if( _scope.define(name,t,expr) == null ) + throw error("Redefining name '" + name + "'"); + } else { + Node n = _scope.lookup(name); + t = _scope.lookupDeclaredType(name); + if( n==null ) + throw error("Undefined name '" + name + "'"); + _scope.update(name,expr); + } + if( !expr._type.isa(t) ) + throw error("Type " + expr._type.str() + " is not of declared type " + t.str()); return expr; } + // Parse a type-or-null + private Type type() { + int old = _lexer._position; + String tname = _lexer.matchId(); + if( tname==null ) return null; + if( tname.equals("int") ) return TypeInteger.BOT; + TypeStruct obj = OBJS.get(tname); + if( obj != null ) + return TypeMemPtr.make(obj,match("?")); + // Not a type; unwind the parse + _lexer._position = old; + return null; + } + /** * Parses a declStatement * * <pre> - * 'int' name = expression ';' + * type name = expression ';' * </pre> - * @return an expression {@link Node}, never {@code null} + * @return an expression {@link Node} */ - private Node parseDecl() { - // Type is 'int' for now + private Node parseDecl(Type t) { var name = requireId(); - require("="); - var expr = require(parseExpression(), ";"); - if( _scope.define(name,expr) == null ) + var expr = match(";") + // Assign a null value + ? new ConstantNode(t.makeInit()).peephole() + // Assign "= expr;" + : require(require("=").parseExpression(), ";"); + if( !expr._type.isa(t) ) + throw error("Type " + expr._type.str() + " is not of declared type " + t.str()); + if( _scope.define(name,t,expr) == null ) throw error("Redefining name '" + name + "'"); return expr; } + /** * Parse an expression of the form: * @@ -448,20 +546,21 @@ public class Parser { * Parse a unary minus expression. * * <pre> - * unaryExpr : ('-') unaryExpr | primaryExpr + * unaryExpr : ('-') | '!') unaryExpr | postfixExpr | primaryExpr * </pre> * @return a unary expression {@link Node}, never {@code null} */ private Node parseUnary() { if (match("-")) return new MinusNode(parseUnary()).peephole(); - return parsePrimary(); + if (match("!")) return new NotNode(parseUnary()).peephole(); + return parsePostfix(parsePrimary()); } /** * Parse a primary expression: * * <pre> - * primaryExpr : integerLiteral | Identifier | true | false | '(' expression ')' + * primaryExpr : integerLiteral | Identifier | true | false | null | new Identifier | '(' expression ')' * </pre> * @return a primary {@link Node}, never {@code null} */ @@ -470,6 +569,13 @@ public class Parser { if( match("(") ) return require(parseExpression(), ")"); if( matchx("true" ) ) return new ConstantNode(TypeInteger.constant(1)).peephole(); if( matchx("false") ) return new ConstantNode(TypeInteger.constant(0)).peephole(); + if( matchx("null" ) ) return new ConstantNode(TypeMemPtr.NULLPTR).peephole(); + if( matchx("new") ) { + String structName = requireId(); + TypeStruct obj = OBJS.get(structName); + if( obj == null) throw errorSyntax("Unknown struct type '" + structName + "'"); + return newStruct(obj); + } String name = _lexer.matchId(); if( name == null) throw errorSyntax("an identifier or expression"); Node n = _scope.lookup(name); @@ -478,6 +584,54 @@ public class Parser { } /** + * Return a NewNode but also generate instructions to initialize it. + */ + private Node newStruct( TypeStruct obj ) { + Node n = new NewNode(TypeMemPtr.make(obj), ctrl()).peephole().keep(); + Node initValue = new ConstantNode(TypeInteger.constant(0)).peephole(); + for( Field field : obj._fields ) { + mem(new StoreNode(field._fname, mem(), n, initValue).peephole()); + } + return n.unkeep(); + } + + // Memory is one hidden SSA variable, including across branches and loops. + private Node mem() { return _scope.lookup("$mem"); } + private Node mem(Node n) { return _scope.update("$mem",n); } + + /** + * Parse postfix expression. For now this is just a field + * expression, but in future could be array index too. + * + * <pre> + * expr ('.' IDENTIFIER)* [ = expr ] + * </pre> + */ + private Node parsePostfix(Node expr) { + if( !match(".") ) return expr; + + if( !(expr._type instanceof TypeMemPtr ptr) ) + throw error("Expected struct reference but got " + expr._type.str()); + + String name = requireId().intern(); + int idx = ptr._obj==null ? -1 : ptr._obj.find(name); + if( idx == -1 ) throw error("Accessing unknown field '" + name + "' from '" + ptr.str() + "'"); + + if( match("=") ) { + // Disambiguate "obj.fld==x" boolean test from "obj.fld=x" field assignment + if( peek('=') ) _lexer._position--; + else { + Node val = parseExpression(); + mem(new StoreNode(name, mem(), expr, val).peephole()); + return expr; // "obj.a = expr" returns the expression while updating memory + } + } + + Type declaredType = ptr._obj._fields[idx]._type; + return parsePostfix(new LoadNode(name, declaredType, mem(), expr).peephole()); + } + + /** * Parse integer literal * * <pre> @@ -497,6 +651,7 @@ public class Parser { private boolean matchx(String syntax) { return _lexer.matchx(syntax); } // Return true and do NOT skip if 'ch' is next private boolean peek(char ch) { return _lexer.peek(ch); } + private boolean peekIsId() { return _lexer.peekIsId(); } // Require and return an identifier private String requireId() { @@ -505,9 +660,11 @@ public class Parser { throw error("Expected an identifier, found '"+id+"'"); } + + // Require an exact match - private void require(String syntax) { require(null, syntax); } - private <N extends Node> N require(N n, String syntax) { + private Parser require(String syntax) { require(null, syntax); return this; } + private <N> N require(N n, String syntax) { if (match(syntax)) return n; throw errorSyntax(syntax); } @@ -594,6 +751,8 @@ public class Parser { return true; } + // Match must be exact and not followed by more ID characters. + // Prevents identifier "ifxy" from matching an "if" statement. boolean matchx(String syntax) { if( !match(syntax) ) return false; if( !isIdLetter(peek()) ) return true; @@ -606,10 +765,14 @@ public class Parser { return peek()==ch; } + boolean peekIsId() { + skipWhiteSpace(); + return isIdStart(peek()); + } + // Return an identifier or null String matchId() { - skipWhiteSpace(); - return isIdStart(peek()) ? parseId() : null; + return peekIsId() ? parseId() : null; } // Used for errors diff --git a/src/main/java/com/seaofnodes/simple/Utils.java b/src/main/java/com/seaofnodes/simple/Utils.java index 45f15327..4f2af769 100644 --- a/src/main/java/com/seaofnodes/simple/Utils.java +++ b/src/main/java/com/seaofnodes/simple/Utils.java @@ -36,4 +36,30 @@ public class Utils { return i; return -1; } + /** + * Search a list for an element by reference + * + * @param ary List to search in + * @param x Object to be searched + * @return >= 0 on success, -1 on failure + */ + public static <E> int find( E[] ary, E x ) { + for( int i=0; i<ary.length; i++ ) + if( ary[i]==x ) + return i; + return -1; + } + + // Rotate a long, nice for hashes + public static long rot( long x, int n ) { return (x<<n) | (x>>>n); } + + // Fold a 64bit hash into 32 bits + public static int fold( long x ) { return (int)((x>>32) ^ x); } + + public static boolean eq(String s0, String s1) { + if( s0==s1 ) return true; + assert s0==s0.intern(); + assert s1==s1.intern(); + return false; + } } diff --git a/src/main/java/com/seaofnodes/simple/node/AddNode.java b/src/main/java/com/seaofnodes/simple/node/AddNode.java index c299e805..e235d288 100644 --- a/src/main/java/com/seaofnodes/simple/node/AddNode.java +++ b/src/main/java/com/seaofnodes/simple/node/AddNode.java @@ -129,7 +129,7 @@ public class AddNode extends Node { for( int i=1; i<ns.length; i++ ) ns[i] = op.copy(lphi.in(i), rhs instanceof PhiNode ? rhs.in(i) : rhs).peephole(); String label = lphi._label + (rhs instanceof PhiNode rphi ? rphi._label : ""); - Node phi = new PhiNode(label,ns).peephole(); + Node phi = new PhiNode(label,lphi._declaredType,ns).peephole(); // Rotate needs another op, otherwise just the phi return lhs==lphi ? phi : op.copy(lhs.in(1),phi); } diff --git a/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/src/main/java/com/seaofnodes/simple/node/BoolNode.java index a6b8bfc7..63452dba 100644 --- a/src/main/java/com/seaofnodes/simple/node/BoolNode.java +++ b/src/main/java/com/seaofnodes/simple/node/BoolNode.java @@ -4,6 +4,7 @@ import com.seaofnodes.print.ExprPrinter; import com.seaofnodes.simple.type.Type; import com.seaofnodes.simple.type.TypeInteger; +import com.seaofnodes.simple.type.TypeMemPtr; abstract public class BoolNode extends Node { @@ -43,11 +44,25 @@ abstract public class BoolNode extends Node { if( in(1)==in(2) ) return new ConstantNode(TypeInteger.constant(doOp(3,3)?1:0)); + // Equals pushes constant to the right; 5==X becomes X==5. + if( this instanceof EQ ) { + if( !(in(2) instanceof ConstantNode) ) { + // con==noncon becomes noncon==con + if( in(1) instanceof ConstantNode ) + return new EQ(in(2),in(1)); + // Equals sorts by NID otherwise: non.high == non.low becomes non.low == non.high + else if( in(1)._nid > in(2)._nid ) + return new EQ(in(2),in(1)); + } + // Equals X==0 becomes a !X + if( (in(2)._type == TypeInteger.ZERO || in(2)._type == TypeMemPtr.NULLPTR) ) + return new NotNode(in(1)); + } + // Do we have ((phi cons) cmp con) ? // Do we have ((phi cons) cmp (phi cons)) ? // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...) - // No rotate: compares are not associative. - Node phicon = AddNode.phiCon(this,false); + Node phicon = AddNode.phiCon(this,this instanceof EQ); if( phicon!=null ) return phicon; return null; diff --git a/src/main/java/com/seaofnodes/simple/node/CastNode.java b/src/main/java/com/seaofnodes/simple/node/CastNode.java new file mode 100644 index 00000000..c1faf210 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/CastNode.java @@ -0,0 +1,36 @@ +package com.seaofnodes.simple.node; + +import com.seaofnodes.print.ExprPrinter; + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeInteger; +import com.seaofnodes.simple.IterPeeps; + + +// Upcast (join) the input to a t. Used after guard test to lift an input. +// Can also be used to make a type-assertion if ctrl is null. +public class CastNode extends Node { + private final Type _t; + public CastNode(Type t, Node ctrl, Node in) { + super(ctrl, in); + _t = t; + setType(compute()); + } + + @Override public String label() { return "("+_t.str()+")"; } + + + @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { + return p.p(label()).n(in(1)); + } + + @Override + public Type compute() { + return in(1)._type.join(_t); + } + + @Override + public Node idealize() { + return in(1)._type.isa(_t) ? in(1) : null; + } +} diff --git a/src/main/java/com/seaofnodes/simple/node/ConstantNode.java b/src/main/java/com/seaofnodes/simple/node/ConstantNode.java index cf2465e3..426736ed 100644 --- a/src/main/java/com/seaofnodes/simple/node/ConstantNode.java +++ b/src/main/java/com/seaofnodes/simple/node/ConstantNode.java @@ -53,9 +53,4 @@ public class ConstantNode extends Node { @Override int hash() { return _con.hashCode(); } - - // Dead control is its own idom root - Node idom() { return null; } - @Override int idepth() { return 0; } - } diff --git a/src/main/java/com/seaofnodes/simple/node/IfNode.java b/src/main/java/com/seaofnodes/simple/node/IfNode.java index 1c3d2c85..45f695a5 100644 --- a/src/main/java/com/seaofnodes/simple/node/IfNode.java +++ b/src/main/java/com/seaofnodes/simple/node/IfNode.java @@ -1,15 +1,16 @@ package com.seaofnodes.simple.node; +import com.seaofnodes.simple.IterPeeps; import com.seaofnodes.simple.type.Type; import com.seaofnodes.simple.type.TypeInteger; import com.seaofnodes.simple.type.TypeTuple; - public class IfNode extends MultiNode { public IfNode(Node ctrl, Node pred) { super(ctrl, pred); + IterPeeps.add(this); // Because idoms are complex, just add it } @Override diff --git a/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/src/main/java/com/seaofnodes/simple/node/LoadNode.java new file mode 100644 index 00000000..31c7699c --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/LoadNode.java @@ -0,0 +1,90 @@ +package com.seaofnodes.simple.node; + +import com.seaofnodes.print.ExprPrinter; + +import com.seaofnodes.simple.type.Type; + + +/** + * Load represents extracting a value from inside a memory object, + * in chapter 10 this means Struct fields. + */ +public class LoadNode extends MemOpNode { + + Type _declaredType; + /** + * Load a value from a ptr.field. + * + * @param name The field we are loading + * @param memSlice The whole-memory node - this is updated after a Store + * @param memPtr The ptr to the struct from where we load a field + */ + public LoadNode(String name, Type glb, Node memSlice, Node memPtr) { + super(name, memSlice, memPtr, null); + _declaredType = glb; + } + + @Override boolean canDrop(MemOpNode other, Node dep) { + return super.canDrop(other,dep) && _declaredType==((LoadNode)other)._declaredType && !clobbered(dep); + } + + // A Store directly clobbers this memory. A Phi might lead to a clobber + // through a cycle; conservatively stop rather than searching beyond it. + private boolean clobbered(Node dep) { + Node mem = mem(); + mem.addDepForwards(dep); + for( Node use : mem._outputs ) { + if( use==null ) continue; + use.addDepForwards(dep); + if( use instanceof StoreNode || use instanceof PhiNode ) return true; + } + return false; + } + + @Override + public String label() { return "Load"; } + + @Override + protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { return p.p(".").p(_name); } + + @Override + public Type compute() { + return _declaredType; + } + + @Override + public Node idealize() { + + // Simple Load-after-Store on same address. + if( mem() instanceof StoreNode st && + ptr() == st.ptr() && _name.equals(st._name) ) { // Must check same object + return st.val(); + } + + // Push a Load up through a Phi, as long as it collapses on at least + // one arm. If at a Loop, the backedge MUST collapse - else we risk + // spinning the same transform around the loop indefinitely. + // BEFORE (2 Sts, 1 Ld): AFTER (1 St, 0 Ld): + // if( pred ) ptr.x = e0; val = pred ? e0 + // else ptr.x = e1; : e1; + // val = ptr.x; ptr.x = val; + if( mem() instanceof PhiNode memphi && memphi.region()._type == Type.CONTROL && memphi.nIns()== 3 ) { + // Profit on RHS/Loop backedge + if( profit(memphi,2) || + // Else must not be a loop to count profit on LHS. + (!(memphi.region() instanceof LoopNode) && profit(memphi,1)) ) { + Node ld1 = new LoadNode(_name,_declaredType,memphi.in(1),ptr()).peephole(); + Node ld2 = new LoadNode(_name,_declaredType,memphi.in(2),ptr()).peephole(); + return new PhiNode(_name,_type,memphi.region(),ld1,ld2); + } + } + + return null; + } + + // Profitable if we find a matching Store on this Phi arm. + private boolean profit(PhiNode phi, int idx) { + Node px = phi.in(idx); + return px!=null && px.addDep(this) instanceof StoreNode st1 && ptr()==st1.ptr() && _name.equals(st1._name); + } +} diff --git a/src/main/java/com/seaofnodes/simple/node/LoopNode.java b/src/main/java/com/seaofnodes/simple/node/LoopNode.java index fa9d871e..a0ba973e 100644 --- a/src/main/java/com/seaofnodes/simple/node/LoopNode.java +++ b/src/main/java/com/seaofnodes/simple/node/LoopNode.java @@ -25,7 +25,7 @@ public class LoopNode extends RegionNode { return inProgress() ? null : super.idealize(); } + // Bypass Region idom, same as the default idom() using use entry in(1) instead of in(0) @Override int idepth() { return _idepth!=0 ? _idepth : cacheIDepth(entry().idepth()+1); } - @Override Node idom() { return entry(); } } diff --git a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java new file mode 100644 index 00000000..138f8fa5 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java @@ -0,0 +1,46 @@ +package com.seaofnodes.simple.node; + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeMemPtr; + +/** + * Convenience common base for Load and Store. + */ +public abstract class MemOpNode extends Node { + + public final String _name; + + public MemOpNode(String name, Node memSlice, Node memPtr, Node value) { + super(null, memSlice, memPtr, value); + _name = name; + } + + public Node mem() { return in(1); } + public Node ptr() { return in(2); } + + // Extra conditions for factoring matching memory operations through a Phi. + // The caller has already checked the opcode, input shape and control. + boolean canDrop(MemOpNode other, Node dep) { + ptr().addDep(dep); + if( !_name.equals(other._name) || err()!=null ) return false; + return !(ptr()._type instanceof TypeMemPtr p && + other.ptr()._type instanceof TypeMemPtr q && p._obj!=q._obj); + } + + @Override + boolean eq(Node n) { + MemOpNode mem = (MemOpNode)n; // Invariant + return _name.equals(mem._name); + } + + @Override + int hash() { return _name.hashCode(); } + + @Override + String err() { + Type ptr = ptr()._type; + return (ptr==Type.BOTTOM || (ptr instanceof TypeMemPtr tmp && tmp._nil) ) + ? "Might be null accessing '" + _name + "'" + : null; + } +} diff --git a/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/src/main/java/com/seaofnodes/simple/node/MinusNode.java index 0934c37f..5b65b3fb 100644 --- a/src/main/java/com/seaofnodes/simple/node/MinusNode.java +++ b/src/main/java/com/seaofnodes/simple/node/MinusNode.java @@ -20,5 +20,11 @@ public class MinusNode extends Node { } @Override - public Node idealize() { return null; } + public Node idealize() { + // -(-x) is x + if( in(1) instanceof MinusNode minus ) + return minus.in(1); + + return null; + } } diff --git a/src/main/java/com/seaofnodes/simple/node/NewNode.java b/src/main/java/com/seaofnodes/simple/node/NewNode.java new file mode 100644 index 00000000..857920bc --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/NewNode.java @@ -0,0 +1,36 @@ +package com.seaofnodes.simple.node; + +import com.seaofnodes.print.ExprPrinter; + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeMemPtr; + + +public class NewNode extends Node { + + TypeMemPtr _ptr; + + public NewNode(TypeMemPtr ptr, Node ctrl) { + super(ctrl); + this._ptr = ptr; + } + + @Override + public String label() { return "new"; } + + @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { + return p.p("new ").p(_ptr._obj.str()); + } + + @Override + public Type compute() { return _ptr; } + + @Override + public Node idealize() { return null; } + + @Override + boolean eq(Node n) { return this == n; } + + @Override + int hash() { return _ptr.hashCode(); } +} diff --git a/src/main/java/com/seaofnodes/simple/node/Node.java b/src/main/java/com/seaofnodes/simple/node/Node.java index 3c1ed0ab..d0752af1 100644 --- a/src/main/java/com/seaofnodes/simple/node/Node.java +++ b/src/main/java/com/seaofnodes/simple/node/Node.java @@ -17,7 +17,7 @@ import java.util.function.Function; * The Node class provides common functionality used by all subtypes. * Subtypes of Node specialize by overriding methods. */ -public abstract class Node extends BaseNode<Node> { +public abstract class Node extends BaseNode<Node> implements Cloneable { /** * Inputs to the node. These are use-def references to Nodes. @@ -26,7 +26,7 @@ public abstract class Node extends BaseNode<Node> { * Ordering is required because e.g. "a/b" is different from "b/a". * The first input (offset 0) is often a {@link #isCFG} node. */ - public final ArrayList<Node> _inputs; + public ArrayList<Node> _inputs; /** * Outputs reference Nodes that are not null and have this Node as an @@ -37,7 +37,7 @@ public abstract class Node extends BaseNode<Node> { * walked in either direction. These outputs are typically used for * efficient optimizations but otherwise have no semantics meaning. */ - public final ArrayList<Node> _outputs; + public ArrayList<Node> _outputs; /** * Current computed type for this Node. This value changes as the graph @@ -46,15 +46,6 @@ public abstract class Node extends BaseNode<Node> { public Type _type; /** - * Immediate dominator tree depth, used to approximate a real IDOM during - * parsing where we do not have the whole program, and also peepholes - * change the CFG incrementally. - * <p> - * See {@link <a href="https://en.wikipedia.org/wiki/Dominator_(graph_theory)">...</a>} - */ - char _idepth; - - /** * A private Global Static mutable counter, for unique node id generation. * To make the compiler multithreaded, this field will have to move into a TLS. * Starting with value 1, to avoid bugs confusing node ID 0 with uninitialized values. @@ -99,6 +90,8 @@ public abstract class Node extends BaseNode<Node> { public boolean isUnused() { return nOuts() == 0; } + public boolean isMem() { return false; } + /** * Change a <em>def</em> into a Node. Keeps the edges correct, by removing * the corresponding <em>use->def</em> edge. This may make the original @@ -129,6 +122,7 @@ public abstract class Node extends BaseNode<Node> { old_def.kill(); // Kill old def // Set the new_def over the old (killed) edge _inputs.set(idx,new_def); + moveDepsToWorklist(); // Return self for easy flow-coding return new_def; } @@ -173,6 +167,7 @@ public abstract class Node extends BaseNode<Node> { // Error is 'use' does not exist; ok for 'use' to be null. protected boolean delUse( Node use ) { Utils.del(_outputs, Utils.find(_outputs, use)); + moveDepsToWorklist(); // User-count and anti-dependence queries can now change. return _outputs.isEmpty(); } @@ -216,6 +211,8 @@ public abstract class Node extends BaseNode<Node> { public <N extends Node> N keep() { addUse(null); return (N)this; } // Remove bogus null. public <N extends Node> N unkeep() { delUse(null); return (N)this; } + // Test "keep" status + public boolean iskeep() { return Utils.find(_outputs,null) != -1; } // Replace self with nnn in the graph, making 'this' go dead public void subsume( Node nnn ) { @@ -225,6 +222,7 @@ public abstract class Node extends BaseNode<Node> { n.unlock(); int idx = Utils.find(n._inputs, this); n._inputs.set(idx,nnn); + n.moveDepsToWorklist(); // Rewiring can change a dependent query without changing type. nnn.addUse(n); } kill(); @@ -270,7 +268,7 @@ public abstract class Node extends BaseNode<Node> { Type old = setType(compute()); // Replace constant computations from non-constants with a constant node - if (!(this instanceof ConstantNode) && _type.isHighOrConst() ) + if( !(this instanceof ConstantNode) && _type.isHighOrConst() ) return new ConstantNode(_type).peepholeOpt(); // Global Value Numbering @@ -305,7 +303,7 @@ public abstract class Node extends BaseNode<Node> { private Node deadCodeElim(Node m) { // If self is going dead and not being returned here (Nodes returned // from peephole commonly have no uses (yet)), then kill self. - if( m != this && isUnused() ) { + if( m != this && isUnused() && !isDead() ) { // Killing self - and since self recursively kills self's inputs we // might end up killing 'm', which we are returning as a live Node. // So we add a bogus extra null output edge to stop kill(). @@ -403,11 +401,13 @@ public abstract class Node extends BaseNode<Node> { public Node dep(int idx) { return _deps.get(idx); } /** - * Add a node to the list o dependencies. Only add it if its not - * an input or output of this node, that is, it is at least one step - * away. The node being added must benefit from this node being peepholed. + * Add a node to the list of dependencies. Only add it if its not an input + * or output of this node, that is, it is at least one step away. The node + * being added must benefit from this node being peepholed. */ - Node addDep( Node dep ) { + Node addDep(Node dep) { return addDep(dep,false); } + Node addDepForwards(Node dep) { return addDep(dep,true); } + private Node addDep(Node dep, boolean forwards) { // Running peepholes during the big assert cannot have side effects // like adding dependencies. if( IterPeeps.midAssert() ) return this; @@ -415,8 +415,8 @@ public abstract class Node extends BaseNode<Node> { if( obs != null ) obs.dep(this, dep); if( _deps==null ) _deps = new ArrayList<>(); if( Utils.find(_deps ,dep) != -1 ) return this; // Already on list - if( Utils.find(_inputs,dep) != -1 ) return this; // No need for deps on immediate neighbors - if( Utils.find(_outputs,dep)!= -1 ) return this; + if( !forwards && Utils.find(_inputs,dep) != -1 ) return this; // No need for deps on immediate neighbors + if( !forwards && Utils.find(_outputs,dep)!= -1 ) return this; _deps.add(dep); return this; } @@ -490,14 +490,11 @@ public abstract class Node extends BaseNode<Node> { } /** - * Does this node contain all constants? - * Ignores in(0), as is usually control. - * In an input is not a constant, we add dep as - * a dependency to it, because dep can make progress - * if the input becomes a constant later. - * It is sufficient for one of the non-const - * inputs to have the dependency so we don't bother - * checking the rest. + * Does this node contain all constants? Ignores in(0), as is usually + * control. In an input is not a constant, we add dep as a dependency to + * it because dep can make progress if the input becomes a constant later. + * It is sufficient for one of the non-const inputs to have the dependency, + * so we don't bother checking the rest. */ boolean allCons(Node dep) { for( int i=1; i<nIns(); i++ ) @@ -508,8 +505,14 @@ public abstract class Node extends BaseNode<Node> { return true; } - // Return the immediate dominator of this Node and compute dom tree depth. - Node idom() { return in(0); } + /** + * Immediate dominator tree depth, used to approximate a real IDOM depth + * during parsing where we do not have the whole program, and also + * peepholes change the CFG incrementally. + * <p> + * See {@link <a href="https://en.wikipedia.org/wiki/Dominator_(graph_theory)">...</a>} + */ + public char _idepth; // IDOM depth approx; Zero is unset; non-zero is cached legit // Find the lowest common ancestor in the current dominator tree. Node domLCA(Node rhs) { @@ -531,11 +534,31 @@ public abstract class Node extends BaseNode<Node> { return _idepth = (char)depth; } + // Return the immediate dominator of this Node. + Node idom() { return in(0); } + // Make a shallow copy (same class) of this Node, with given inputs and // empty outputs and a new Node ID. The original inputs are ignored. // Does not need to be implemented in isCFG() nodes. Node copy(Node lhs, Node rhs) { throw Utils.TODO("Binary ops need to implement copy"); } + // Exact-class copy preserving operation attributes, with fresh identity + // and no edges, dependencies, or GVN membership. + public final Node copyEmpty() { + Node n; + try { n = (Node)clone(); } + catch( CloneNotSupportedException e ) { throw new AssertionError(e); } + n._nid = UNIQUE_ID++; + n._inputs = new ArrayList<>(); + n._outputs = new ArrayList<>(); + n._deps = null; + n._hash = 0; + return n; + } + + // Report any post-optimize errors + String err() { return null; } + /** * Used to allow repeating tests in the same JVM. This just resets the * Node unique id generator, and is done as part of making a new Parser. diff --git a/src/main/java/com/seaofnodes/simple/node/NotNode.java b/src/main/java/com/seaofnodes/simple/node/NotNode.java index 8077f108..5e556390 100644 --- a/src/main/java/com/seaofnodes/simple/node/NotNode.java +++ b/src/main/java/com/seaofnodes/simple/node/NotNode.java @@ -1,9 +1,8 @@ package com.seaofnodes.simple.node; -import com.seaofnodes.simple.type.Type; -import com.seaofnodes.simple.type.TypeInteger; - +import com.seaofnodes.simple.Utils; +import com.seaofnodes.simple.type.*; public class NotNode extends Node { public NotNode(Node in) { super(null, in); } @@ -14,9 +13,24 @@ public class NotNode extends Node { @Override public Type compute() { - if( in(1)._type instanceof TypeInteger i0 ) + Type t0 = in(1)._type; + switch( t0 ) { + case TypeInteger i0: return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0; - return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT; + case TypeMemPtr p0: + // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot + // If input in null then true + // If input is not null ptr then false + if( p0 == TypeMemPtr.TOP ) return TypeInteger.TOP; + if( p0 == TypeMemPtr.NULLPTR ) return TypeInteger.constant(1); + if( !p0._nil ) return TypeInteger.constant(0); + return TypeInteger.BOT; + case Type t: + if( t0.getClass() != Type.class ) + // Only doing NOT on ints and ptrs + throw Utils.TODO(); + return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT; + } } @Override diff --git a/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/src/main/java/com/seaofnodes/simple/node/PhiNode.java index fe6231fa..24a72aa4 100644 --- a/src/main/java/com/seaofnodes/simple/node/PhiNode.java +++ b/src/main/java/com/seaofnodes/simple/node/PhiNode.java @@ -3,13 +3,19 @@ package com.seaofnodes.simple.node; import com.seaofnodes.print.ExprPrinter; import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeMem; +import com.seaofnodes.simple.Utils; public class PhiNode extends Node { final String _label; - public PhiNode(String label, Node... inputs) { super(inputs); _label = label; } + // The Phi type we compute must stay within the domain of the Phi. + // Example Int stays Int, Ptr stays Ptr, Control stays Control, Mem stays Mem. + final Type _declaredType; + + public PhiNode(String label, Type declaredType, Node... inputs) { super(inputs); _label = label; assert declaredType!=null; _declaredType = declaredType; } @Override public String label() { return "Phi_"+_label; } @@ -24,17 +30,21 @@ public class PhiNode extends Node { Node region() { return in(0); } @Override public boolean isMultiTail() { return true; } + @Override + public boolean isMem() { return _declaredType instanceof TypeMem; } @Override public Type compute() { if( !(region() instanceof RegionNode r) ) return region()._type==Type.XCONTROL ? Type.TOP : _type; - if( r.inProgress() ) return Type.BOTTOM; - Type t = Type.TOP; + // During parsing Phis have to be computed type pessimistically. + if( r.inProgress() ) return _declaredType; + // Set type to local top of the starting type + Type t = _declaredType.glb().dual(); for (int i = 1; i < nIns(); i++) // If the region's control input is live, add this as a dependency // to the control because we can be peeped should it become dead. - if( r.in(i).addDep(this)._type != Type.XCONTROL && in(i) != this ) + if( r.in(i).addDep(this)._type != Type.XCONTROL ) t = t.meet(in(i)._type); return t; } @@ -51,34 +61,91 @@ public class PhiNode extends Node { if (live != null) return live; - // Pull "down" a common data op. One less op in the world. One more - // Phi, but Phis do not make code. - // Phi(op(A,B),op(Q,R),op(X,Y)) becomes - // op(Phi(A,Q,X), Phi(B,R,Y)). - Node op = in(1); - if( op.nIns()==3 && op.in(0)==null && !op.isCFG() && same_op() ) { - Node[] lhss = new Node[nIns()]; - Node[] rhss = new Node[nIns()]; - lhss[0] = rhss[0] = in(0); // Set Region - for( int i=1; i<nIns(); i++ ) { - lhss[i] = in(i).in(1); - rhss[i] = in(i).in(2); + // Phi(op(a,b,...),op(c,d,...)) -> op(Phi(a,c),Phi(b,d),...). + Node down; + if( same_op() && (down=drop_same_op())!=null ) return down; + + // If merging Phi(N, cast(N)) - we are losing the cast JOIN effects, so just remove. + if( nIns()==3 ) { + if( in(1) instanceof CastNode cast && cast.in(1).addDep(this)==in(2) ) return in(2); + if( in(2) instanceof CastNode cast && cast.in(1).addDep(this)==in(1) ) return in(1); + } + // If merging a null-checked null and the checked value, just use the value. + // if( val ) ..; phi(Region,False=0/null,True=val); + // then replace with plain val. + if( nIns()==3 ) { + int nullx = -1; + if( in(1)._type == in(1)._type.makeInit() ) nullx = 1; + if( in(2)._type == in(2)._type.makeInit() ) nullx = 2; + if( nullx != -1 ) { + Node val = in(3-nullx); + if( region().idom() instanceof IfNode iff && iff.pred().addDep(this)==val ) { + // Must walk the idom on the null side to make sure we hit False. + Node idom = region().in(nullx); + while( idom.in(0) != iff ) idom = idom.idom(); + if( idom instanceof ProjNode proj && proj._idx==1 ) + return val; + } } - Node phi_lhs = new PhiNode(_label,lhss).peephole(); - Node phi_rhs = new PhiNode(_label,rhss).peephole(); - return op.copy(phi_lhs,phi_rhs); } return null; } private boolean same_op() { - for( int i=2; i<nIns(); i++ ) - if( in(1).getClass() != in(i).getClass() ) - return false; + Node op = in(1); + if( op.isCFG() || op instanceof ConstantNode || op instanceof PhiNode || + op instanceof ProjNode || op instanceof NewNode || op instanceof ScopeNode ) return false; + Node busy = null; + for( int i=1; i<nIns(); i++ ) { + Node n = in(i); + if( region().in(i).addDep(this)._type==Type.XCONTROL || + op.getClass()!=n.getClass() || n.nIns()!=op.nIns() || n.in(0)!=null || !op.eq(n) ) return false; + if( n instanceof MemOpNode mem && !mem.canDrop((MemOpNode)op,this) ) return false; + // Moving a Store must remove the old effect, not duplicate it. + // Allow one shared arm: the other arms disappear into the single + // factored operation, usually reducing the total operation count. + n.addDepForwards(this); + if( n.nOuts()>1 ) { + for( Node use : n._outputs ) + if( use!=null && use!=this ) use.addDepForwards(this); + if( n instanceof StoreNode || busy!=null ) return false; + busy=n; + } + for( int j=1; j<n.nIns(); j++ ) + if( n.in(j) instanceof ScopeNode || ((n.in(j)==null) != (op.in(j)==null)) ) return false; + } return true; } + private Node drop_same_op() { + Node op = in(1), cp = op.copyEmpty(); + cp._type = null; + cp.addDef(null); + for( int j=1; j<op.nIns(); j++ ) { + Node x = op.in(j); + boolean different = false; + for( int i=2; i<nIns(); i++ ) + if( in(i).in(j)!=x ) different=true; + if( different ) { + Node[] ins = new Node[nIns()]; + ins[0] = region(); + Type t = Type.TOP; + for( int i=1; i<nIns(); i++ ) { + ins[i] = in(i).in(j); + t = t.meet(ins[i]._type); + } + PhiNode phi = new PhiNode(_label,t.glb(),ins); + x = phi.peephole(); + } + cp.addDef(x); + } + // Factoring must not widen the result (e.g. correlated And operands). + if( cp.compute().isa(compute()) ) return cp; + cp.kill(); + return null; + } + /** * If only single unique input, return it */ diff --git a/src/main/java/com/seaofnodes/simple/node/ProjNode.java b/src/main/java/com/seaofnodes/simple/node/ProjNode.java index a794dfcc..a2632110 100644 --- a/src/main/java/com/seaofnodes/simple/node/ProjNode.java +++ b/src/main/java/com/seaofnodes/simple/node/ProjNode.java @@ -3,6 +3,7 @@ package com.seaofnodes.simple.node; import com.seaofnodes.print.ExprPrinter; import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeMem; import com.seaofnodes.simple.type.TypeTuple; @@ -28,6 +29,7 @@ public class ProjNode extends Node { @Override public boolean isCFG() { return _idx==0 || ctrl() instanceof IfNode; } @Override public boolean isMultiTail() { return in(0).isMultiHead(); } + @Override public boolean isMem() { return _type instanceof TypeMem; } public MultiNode ctrl() { return (MultiNode)in(0); } @@ -39,8 +41,14 @@ public class ProjNode extends Node { @Override public Node idealize() { - if( ctrl()._type instanceof TypeTuple tt && tt._types[1-_idx]==Type.XCONTROL ) // Only true for IfNodes - return ctrl().in(0); // We become our input control + if ( ctrl() instanceof IfNode iff ) { + if ( iff._type instanceof TypeTuple tt && tt._types[1 - _idx] == Type.XCONTROL ) + return iff.in(0); // We become our input control + + // Flip a negating if-test, to remove the not + if( iff.pred().addDep(this) instanceof NotNode not ) + return new ProjNode((MultiNode)new IfNode(iff.ctrl(),not.in(1)).peephole(),1-_idx,_idx==0 ? "False" : "True"); + } return null; } diff --git a/src/main/java/com/seaofnodes/simple/node/RegionNode.java b/src/main/java/com/seaofnodes/simple/node/RegionNode.java index 315fcf0e..8b52494a 100644 --- a/src/main/java/com/seaofnodes/simple/node/RegionNode.java +++ b/src/main/java/com/seaofnodes/simple/node/RegionNode.java @@ -35,6 +35,7 @@ public class RegionNode extends Node { @Override public Node idealize() { if( inProgress() ) return null; + // Delete dead paths into a Region int path = findDeadInput(); if( path != 0 && // Do not delete the entry path of a loop (ok to remove the back @@ -51,15 +52,25 @@ public class RegionNode extends Node { while( nouts != nOuts() ) { nouts = nOuts(); for( int i=0; i<nOuts(); i++ ) - if( out(i) instanceof PhiNode phi && phi.nIns()==nIns() ) + if( out(i) instanceof PhiNode phi && phi.nIns()==nIns() ) { phi.delDef(path); + IterPeeps.addAll(phi._outputs); + } } return isDead() ? new ConstantNode(Type.XCONTROL) : delDef(path); } // If down to a single input, become that input - if( nIns()==2 && !hasPhi() ) { + if( nIns()==2 && !hasPhi() ) return in(1); // Collapse if no Phis; 1-input Phis will collapse on their own - } + + // If a CFG diamond with no merging, delete: "if( pred ) {} else {};" + if( !hasPhi() && // No Phi users, just a control user + in(1) instanceof ProjNode p1 && + in(2) instanceof ProjNode p2 && + p1.addDepForwards(this).in(0)==p2.addDepForwards(this).in(0) && + p1.in(0) instanceof IfNode iff ) + return iff.ctrl(); + return null; } diff --git a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java index bc09c623..ef4ddb3a 100644 --- a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java +++ b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java @@ -5,37 +5,33 @@ import com.seaofnodes.print.ExprPrinter; import com.seaofnodes.simple.type.*; -/** - * The Return node has two inputs. The first input is a control node and the - * second is the data node that supplies the return value. - * <p> - * In this presentation, Return functions as a Stop node, since multiple <code>return</code> statements are not possible. - * The Stop node will be introduced in Chapter 6 when we implement <code>if</code> statements. - * <p> - * The Return's output is the value from the data node. - */ +/** Keeps all preceding memory effects and the return value alive: {ctrl, $mem, value}. */ public class ReturnNode extends Node { - public ReturnNode(Node ctrl, Node data) { - super(ctrl, data); + public ReturnNode(Node ctrl, Node data, ScopeNode scope) { + super(ctrl, scope.lookup("$mem"), data); } public Node ctrl() { return in(0); } - public Node expr() { return in(1); } + public Node mem () { return in(1); } + public Node expr() { return in(2); } @Override public String label() { return "Return"; } @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { - return p.p("return ").n(expr()).p(";"); + p.p("return "); + p.n(expr()); + return p.p(";"); } @Override public boolean isCFG() { return true; } @Override public Type compute() { - return TypeTuple.make(ctrl()._type,expr()._type); + // Return exposes the complete memory state. + return TypeTuple.make(ctrl()._type,TypeMem.BOT,expr()._type); } @Override diff --git a/src/main/java/com/seaofnodes/simple/node/ScopeNode.java b/src/main/java/com/seaofnodes/simple/node/ScopeNode.java index f34d78e1..d567feb5 100644 --- a/src/main/java/com/seaofnodes/simple/node/ScopeNode.java +++ b/src/main/java/com/seaofnodes/simple/node/ScopeNode.java @@ -4,6 +4,8 @@ import com.seaofnodes.print.ExprPrinter; import com.seaofnodes.simple.IterPeeps; import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.Utils; +import com.seaofnodes.simple.type.TypeMemPtr; import java.util.*; @@ -25,10 +27,16 @@ public class ScopeNode extends Node { */ public final Stack<HashMap<String, Integer>> _scopes; + /** + * Tracks declared types for every name + */ + public Stack<HashMap<String, Type>> _types; + // A new ScopeNode public ScopeNode() { _scopes = new Stack<>(); + _types = new Stack<>(); _type = Type.BOTTOM; } @@ -70,14 +78,15 @@ public class ScopeNode extends Node { @Override public Node idealize() { return null; } - public void push() { _scopes.push(new HashMap<>()); } - public void pop() { popN(_scopes.pop().size()); } + public void push() { _scopes.push(new HashMap<>()); _types.push(new HashMap<>()); } + public void pop() { popN(_scopes.pop().size()); _types.pop(); } /** * Create a new name in the current scope */ - public Node define( String name, Node n ) { + public Node define( String name, Type declaredType, Node n ) { HashMap<String,Integer> syms = _scopes.lastElement(); + _types.lastElement().put(name,declaredType); if( syms.put(name,nIns()) != null ) return null; // Double define return addDef(n); @@ -98,7 +107,7 @@ public class ScopeNode extends Node { public Node update( String name, Node n ) { return update(name,n,_scopes.size()-1); } /** * Both recursive lookup and update. - * + * <p> * A shared implementation allows us to create lazy phis both during * lookups and updates; the lazy phi creation is part of chapter 8. * @@ -121,12 +130,21 @@ public class ScopeNode extends Node { // Set real Phi in the loop head // The phi takes its one input (no backedge yet) from a recursive // lookup, which might have insert a Phi in every loop nest. - : loop.setDef(idx,new PhiNode(name,loop.ctrl(),loop.update(name,null,nestingLevel),null).peephole()); + : loop.setDef(idx,new PhiNode(name, lookupDeclaredType(name),loop.ctrl(),loop.update(name,null,nestingLevel),null).peephole()); setDef(idx,old); } return n==null ? old : setDef(idx,n); // Not lazy, so this is the answer } + // Return declared type + public Type lookupDeclaredType( String name ) { + for( int i=_types.size(); i>0; i-- ) { + Type t = _types.get(i-1).get(name); + if( t != null ) return t; + } + return null; + } + public Node ctrl() { return in(0); } /** @@ -163,8 +181,10 @@ public class ScopeNode extends Node { // 3) Ensure that the order of defs is the same to allow easy merging for( HashMap<String,Integer> syms : _scopes ) dup._scopes.push(new HashMap<>(syms)); + for( HashMap<String,Type> ts : _types ) + dup._types.push(ts); // Types don't change, just keep stacks aligned - dup.addDef(ctrl()); // Control input is just copied + dup.addDef(ctrl()); // Control input is just copied for( int i=1; i<nIns(); i++ ) // For lazy phis on loops we use a sentinel // that will trigger phi creation on update @@ -188,8 +208,9 @@ public class ScopeNode extends Node { if( in(i) != that.in(i) ) // No need for redundant Phis // If we are in lazy phi mode we need to a lookup // by name as it will trigger a phi creation - setDef(i, new PhiNode(ns[i], r, this.lookup(ns[i]), that.lookup(ns[i])).peephole()); + setDef(i, new PhiNode(ns[i], this.lookupDeclaredType(ns[i]), r, this.lookup(ns[i]), that.lookup(ns[i])).peephole()); that.kill(); // Kill merged scope + IterPeeps.add(r); return r.unkeep().peephole(); } @@ -217,11 +238,68 @@ public class ScopeNode extends Node { IterPeeps.addAll(phi._outputs); phi.moveDepsToWorklist(); if( in != phi ) { - phi.subsume(in); + if( !phi.iskeep() ) // Keeping phi around for parser elsewhere + phi.subsume(in); setDef(i,in); // Set the update back into Scope } } } } + + + // Up-casting: using the results of an If to improve a value. + // E.g. "if( ptr ) ptr.field;" is legal because ptr is known not-null. + + // This Scope looks for direct variable uses, or certain simple + // combinations, and replaces the variable with the upcast variant. + public Node upcast( Node ctrl, Node pred, boolean invert ) { + if( ctrl._type==Type.XCONTROL ) return null; + // A single negation is handled below. For !!p (including p != null), + // also refine the underlying p without changing the Boolean result. + if( pred instanceof NotNode not && not.in(1) instanceof NotNode ) { + pred.keep(); // Recursive peepholes may rediscover this Not. + upcast(ctrl,not.in(1),!invert); + pred.unkeep(); + } + // Invert the If conditional + if( invert ) + pred = pred instanceof NotNode not ? not.in(1) : IterPeeps.add(new NotNode(pred).peephole()); + + // Direct use of a value as predicate. This is a zero/null test. + if( Utils.find(_inputs, pred) != -1 ) { + if( !(pred._type instanceof TypeMemPtr tmp) ) + // Must be an `int`, since int and ptr are the only two value types + // being tested. No representation for a generic not-null int, so no upcast. + return null; + if( tmp.isa(TypeMemPtr.VOIDPTR) ) + return null; // Already not-null, no reason to upcast + // Upcast the ptr to not-null ptr, and replace in scope + return replace(pred,new CastNode(TypeMemPtr.VOIDPTR,ctrl,pred).peephole()); + } + + if( pred instanceof NotNode not ) { + // Direct use of a !value as predicate. This is a zero/null test. + if( Utils.find(_inputs, not.in(1)) != -1 ) { + Type tinit = not.in(1)._type.makeInit(); + if( not.in(1)._type.isa(tinit) ) return null; // Already zero/null, no reason to upcast + return replace(not.in(1), new ConstantNode(tinit).peephole()); + } + } + // Apr/9/2024: Attempted to replace X with Y if guarded by a test of + // X==Y. This didn't seem to help very much, or at least in the test + // cases seen so far was a very minor help. + + // No upcast + return null; + } + + private Node replace( Node old, Node cast ) { + assert old!=null && old!=cast; + for( int i=0; i<nIns(); i++ ) + if( in(i)==old ) + setDef(i,cast); + return cast; + } + } diff --git a/src/main/java/com/seaofnodes/simple/node/StartNode.java b/src/main/java/com/seaofnodes/simple/node/StartNode.java index c2fcaba5..3404f111 100644 --- a/src/main/java/com/seaofnodes/simple/node/StartNode.java +++ b/src/main/java/com/seaofnodes/simple/node/StartNode.java @@ -2,25 +2,15 @@ package com.seaofnodes.simple.node; import com.seaofnodes.print.ExprPrinter; -import com.seaofnodes.simple.type.Type; -import com.seaofnodes.simple.type.TypeTuple; +import com.seaofnodes.simple.type.*; - -/** - * The Start node represents the start of the function. For now, we do not - * have any inputs to Start because our function does not yet accept - * parameters. When we add parameters the value of Start will be a tuple, and - * will require Projections to extract the values. We discuss this in detail - * in Chapter 9: Functions and Calls. - */ +/** The entry tuple: control, initial whole-memory state, and argument. */ public class StartNode extends MultiNode { - final TypeTuple _args; public StartNode(Type[] args) { super(); - _args = TypeTuple.make(args); - _type = _args; + _type = _args = TypeTuple.make(args); } @Override @@ -40,8 +30,6 @@ public class StartNode extends MultiNode { public Node idealize() { return null; } // No immediate dominator, and idepth==0 - @Override - Node idom() { return null; } @Override int idepth() { return 0; } - + @Override Node idom() { return null; } } diff --git a/src/main/java/com/seaofnodes/simple/node/StopNode.java b/src/main/java/com/seaofnodes/simple/node/StopNode.java index d79194d8..4b4e9615 100644 --- a/src/main/java/com/seaofnodes/simple/node/StopNode.java +++ b/src/main/java/com/seaofnodes/simple/node/StopNode.java @@ -2,6 +2,8 @@ package com.seaofnodes.simple.node; import com.seaofnodes.print.ExprPrinter; +import com.seaofnodes.simple.Parser; + import com.seaofnodes.simple.type.Type; import com.seaofnodes.simple.IterPeeps; @@ -52,9 +54,22 @@ public class StopNode extends Node { return null; } + @Override public Node idom() { return null; } + public Node addReturn(Node node) { return addDef(node); } - public StopNode iterate() { return IterPeeps.iterate(this); } + public StopNode iterate() { return IterPeeps.iterate(this).typeCheck(); } + public StopNode typeCheck() { + var obs = Parser.PARSER == null ? null : Parser.PARSER._obs; + String err = walk(n -> { + String msg = n.err(); + if( msg != null && obs != null ) obs.error(n, msg); + return msg; + }); + if( err != null ) throw new RuntimeException(err); + if( obs != null ) obs.phase("TypeCheck"); + return this; + } } diff --git a/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/src/main/java/com/seaofnodes/simple/node/StoreNode.java new file mode 100644 index 00000000..71eb0842 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/StoreNode.java @@ -0,0 +1,67 @@ +package com.seaofnodes.simple.node; + +import com.seaofnodes.print.ExprPrinter; + +import com.seaofnodes.simple.type.*; + + +/** + * Store represents setting a value to a memory based object, in chapter 10 + * this means a field inside a struct. + */ +public class StoreNode extends MemOpNode { + + /** + * @param name The struct field we are assigning to + * @param memSlice The whole-memory node - this is updated after a Store + * @param memPtr The ptr to the struct where we will store a value + * @param value Value to be stored + */ + public StoreNode(String name, Node memSlice, Node memPtr, Node value) { + super(name, memSlice, memPtr, value); + } + + @Override + public String label() { return "Store"; } + @Override + public boolean isMem() { return true; } + public Node val() { return in(3); } + + @Override + protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { + return p.p(".").p(_name).p("=").p( val()).p(";"); + } + + @Override + public Type compute() { return TypeMem.BOT; } + + @Override + public Node idealize() { + + // Simple store-after-store on same address. Should pick up the + // required init-store being stomped by a first user store. + if( mem() instanceof StoreNode st && + ptr()==st.ptr() && _name.equals(st._name) && // Must check same object + ptr()._type instanceof TypeMemPtr && // No bother if weird dead pointers + // Must have exactly one use of "this" or you get weird + // non-serializable memory effects in the worse case. + st.checkNoUseBeyond(this) ) { + setDef(1,st.mem()); + return this; + } + + return null; + } + + // Check that `this` has no uses beyond `that` + private boolean checkNoUseBeyond(Node that) { + if( nOuts()==1 ) return true; + // Add deps on the other uses (can be e.g. ScopeNode mid-parse) so that + // when the other uses go away we can retry. + for( Node use : _outputs ) + if( use != that ) + use.addDep(that); + return false; + } + +} diff --git a/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java index 64b78766..92d970d8 100644 --- a/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java +++ b/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java @@ -4,8 +4,9 @@ import com.seaofnodes.graph.GraphAdapter; import com.seaofnodes.graph.GraphSnapshot.*; import com.seaofnodes.simple.node.*; import com.seaofnodes.simple.node.Node; +import com.seaofnodes.simple.type.TypeMem; -/** Chapter 9's view of the IR; browser, transport and layout are shared. */ +/** Chapter 10's view of the IR; browser, transport and layout are shared. */ public class SimpleGraphAdapter extends GraphAdapter<Node> { @Override protected String[] edgeNames(Node n) { @@ -20,15 +21,20 @@ public class SimpleGraphAdapter extends GraphAdapter<Node> { if( n instanceof LoopNode ) return Kind.LOOP; if( n instanceof RegionNode ) return Kind.REGION; if( n instanceof PhiNode ) return Kind.PHI; - return n.isCFG() ? Kind.CTRL : Kind.DATA; + return n.isCFG() ? Kind.CTRL : isMem(n) ? Kind.MEM : Kind.DATA; } @Override protected Role role(Node n, int i) { if( n instanceof ScopeNode || n instanceof ConstantNode ) return Role.ASSOC; - if( n instanceof PhiNode ) return i == 0 ? Role.ASSOC : Role.DATA; - if( n instanceof ProjNode ) return n.isCFG() ? Role.CTRL : Role.DATA; + if( n instanceof PhiNode ) return i == 0 ? Role.ASSOC : isMem(n) ? Role.MEM : Role.DATA; + if( n instanceof ProjNode ) return n.isCFG() ? Role.CTRL : isMem(n) ? Role.MEM : Role.DATA; if( n instanceof RegionNode && i == 0 ) return Role.ASSOC; if( i == 0 || n instanceof RegionNode || n instanceof StopNode ) return Role.CTRL; + if( i == 1 && (n instanceof MemOpNode || n instanceof ReturnNode) ) return Role.MEM; + Node def = n.in(i); + if( def != null && isMem(def) ) return Role.MEM; return Role.DATA; } + + private boolean isMem(Node n) { return n.isMem() || n._type instanceof TypeMem; } } diff --git a/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java b/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java index 2c6c90ca..1980659e 100644 --- a/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java +++ b/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java @@ -7,7 +7,7 @@ import com.seaofnodes.simple.node.Node; import java.util.ArrayList; import java.io.IOException; -/** Chapter 9's compilation context; capture and event bookkeeping are shared. */ +/** Chapter 10's compilation context; capture and event bookkeeping are shared. */ public class SimpleGraphObserver extends GraphCapture<Node> { private Parser _parser; private Node _ret; @@ -25,6 +25,8 @@ public class SimpleGraphObserver extends GraphCapture<Node> { _phase = "Iter"; com.seaofnodes.simple.IterPeeps.iterate(_parser.STOP); phase(_phase); + _phase = "TypeCheck"; + _parser.STOP.typeCheck(); } @Override protected String phase() { return _phase; } @Override protected int pos() { return "Parse".equals(_phase) ? _parser.pos() : -1; } diff --git a/src/main/java/com/seaofnodes/simple/type/Field.java b/src/main/java/com/seaofnodes/simple/type/Field.java new file mode 100644 index 00000000..cdc58215 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/type/Field.java @@ -0,0 +1,59 @@ +package com.seaofnodes.simple.type; + +import com.seaofnodes.simple.Utils; +import java.util.ArrayList; + +/** + * Represents a field in a struct. This is not a Type in the type system. + */ +public class Field extends Type { + + // The pair {fieldName,type} uniquely identifies a field. + + // Field name + public final String _fname; + // Type of the field + public final Type _type; + + private Field(String fname, Type type ) { + super(TFLD); + _fname = fname; + _type = type; + } + public static Field make( String fname, Type type ) { + return new Field(fname,type).intern(); + } + + public static final Field TEST = make("test",TypeInteger.ZERO); + public static void gather(ArrayList<Type> ts) { ts.add(TEST); } + + @Override Field xmeet( Type that ) { + Field fld = (Field)that; // Invariant + assert _fname.equals(fld._fname); + return make(_fname,_type.meet(fld._type)); + } + + @Override + public Field dual() { return make(_fname,_type.dual()); } + + @Override + public Field glb() { + return make(_fname,_type.glb()); + } + + // Override in subclasses + int hash() { return _fname.hashCode() ^ _type.hashCode(); } + + boolean eq(Type t) { + Field f = (Field)t; + return Utils.eq(_fname,f._fname) && _type==f._type; + } + + + @Override + public StringBuilder print( StringBuilder sb ) { + return _type.print(sb.append(_fname).append(":")); + } + + @Override public String str() { return _fname; } +} diff --git a/src/main/java/com/seaofnodes/simple/type/Type.java b/src/main/java/com/seaofnodes/simple/type/Type.java index daaa8af6..bd9cf458 100644 --- a/src/main/java/com/seaofnodes/simple/type/Type.java +++ b/src/main/java/com/seaofnodes/simple/type/Type.java @@ -2,6 +2,7 @@ package com.seaofnodes.simple.type; import com.seaofnodes.simple.Utils; +import java.util.ArrayList; import java.util.HashMap; /** @@ -33,6 +34,10 @@ public class Type { static final byte TSIMPLE = 4; // End of the Simple Types static final byte TINT = 5; // All Integers; see TypeInteger static final byte TTUPLE = 6; // Tuples; finite collections of unrelated Types, kept in parallel + static final byte TMEM = 7; // Whole-memory token + static final byte TMEMPTR = 8; // Memory pointer type + static final byte TSTRUCT = 9; // Structs; tuples with named fields + static final byte TFLD =10; // Fields into struct public final byte _type; @@ -44,6 +49,21 @@ public class Type { public static final Type TOP = new Type( TTOP ).intern(); // ANY public static final Type CONTROL = new Type( TCTRL ).intern(); // Ctrl public static final Type XCONTROL = new Type( TXCTRL ).intern(); // ~Ctrl + public static Type[] gather() { + ArrayList<Type> ts = new ArrayList<>(); + ts.add(BOTTOM); + ts.add(CONTROL); + Field.gather(ts); + TypeInteger.gather(ts); + TypeMem.gather(ts); + TypeMemPtr.gather(ts); + TypeStruct.gather(ts); + TypeTuple.gather(ts); + int sz = ts.size(); + for( int i = 0; i < sz; i++ ) + ts.add(ts.get(i).dual()); + return ts.toArray(new Type[ts.size()]); + } // Is high or on the lattice centerline. public boolean isHighOrConst() { return _type==TTOP || _type==TXCTRL; } @@ -52,12 +72,26 @@ public class Type { // Excludes both high and low values public boolean isConstant() { return false; } - public StringBuilder print(StringBuilder sb) {return is_simple() ? sb.append(STRS[_type]) : sb;} + /** + * Display Type name in a format that's good for IR printer + */ + public StringBuilder typeName( StringBuilder sb) { return print(sb); } + + public Type makeInit() { return null; } // ---------------------------------------------------------- + // Notes on Type interning. + // At the moment it is not easy to reset the interned types + // because we hold static references to several types and these are scattered + // around. This means the INTERN cache will retain all types from + // every run of the Parser. For this to work correctly types must be + // rigorous about defining when they are the same. Also types need to be + // immutable once defined. + // The rationale for interning is performance. + // Factory method which interns "this" - protected <T extends Type> T intern() { + public <T extends Type> T intern() { T nnn = (T)INTERN.get(this); if( nnn==null ) INTERN.put(nnn=(T)this,this); @@ -95,13 +129,13 @@ public class Type { // Reverse; xmeet 2nd arg is never "is_simple" and never equal to "this". if( is_simple() ) return this.xmeet(t ); if( t.is_simple() ) return t .xmeet(this); - return xmeet(t); // Mixing 2 unrelated types + return Type.BOTTOM; // Mixing 2 unrelated types } // Compute meet right now. Overridden in subclasses. // Handle cases where 'this.is_simple()' and unequal to 't'. // Subclassed xmeet calls can assert that '!t.is_simple()'. - protected Type xmeet(Type t) { + Type xmeet(Type t) { assert is_simple(); // Should be overridden in subclass // ANY meet anything is thing; thing meet ALL is ALL if( _type==TBOT || t._type==TTOP ) return this; @@ -112,17 +146,6 @@ public class Type { return _type==TCTRL || t._type==TCTRL ? CONTROL : XCONTROL; } - // True if this "isa" t; e.g. 17 isa TypeInteger.BOT - public boolean isa( Type t ) { return meet(t)==t; } - - // ---------------------------------------------------------- - // Our lattice is defined with a MEET and a DUAL. - // JOIN is dual of meet of both duals. - public final Type join(Type t) { - if( this==t ) return this; - return dual().meet(t.dual()).dual(); - } - public Type dual() { return switch( _type ) { case TBOT -> TOP; @@ -134,8 +157,31 @@ public class Type { } // ---------------------------------------------------------- + // Our lattice is defined with a MEET and a DUAL. + // JOIN is dual of meet of both duals. + public final Type join(Type t) { + if( this==t ) return this; + return dual().meet(t.dual()).dual(); + } + + // True if this "isa" t; e.g. 17 isa TypeInteger.BOT + public boolean isa( Type t ) { return meet(t)==t; } + + /** + * Compute greatest lower bound in the lattice + */ + public Type glb() { return _type==TCTRL ? XCONTROL : BOTTOM; } + + // ---------------------------------------------------------- + // Useful in the debugger, which calls toString everywhere. + // This is a more verbose dev-friendly print. @Override public final String toString() { return print(new StringBuilder()).toString(); } + + public StringBuilder print(StringBuilder sb) { return is_simple() ? sb.append(STRS[_type]) : sb;} + + // This is used by error messages, and is a shorted print. + public String str() { return STRS[_type]; } } diff --git a/src/main/java/com/seaofnodes/simple/type/TypeInteger.java b/src/main/java/com/seaofnodes/simple/type/TypeInteger.java index ab9dbcff..8c77672b 100644 --- a/src/main/java/com/seaofnodes/simple/type/TypeInteger.java +++ b/src/main/java/com/seaofnodes/simple/type/TypeInteger.java @@ -1,5 +1,7 @@ package com.seaofnodes.simple.type; +import java.util.ArrayList; + /** * Integer Type */ @@ -28,6 +30,10 @@ public class TypeInteger extends Type { public static TypeInteger constant(long con) { return make(true, con); } + public static void gather(ArrayList<Type> ts) { ts.add(ZERO); ts.add(BOT); } + + // FIXME this display format is problematic + // In visualizer '#' gets prepended if its a constant @Override public StringBuilder print(StringBuilder sb) { if( this==TOP ) return sb.append("IntTop"); @@ -35,6 +41,22 @@ public class TypeInteger extends Type { return sb.append(_con); } + @Override public String str() { + if( this==TOP ) return "~int"; + if( this==BOT ) return "int"; + return ""+_con; + } + + /** + * Display Type name in a format that's good for IR printer + */ + @Override + public StringBuilder typeName(StringBuilder sb) { + if( this==TOP ) return sb.append("IntTop"); + if( this==BOT ) return sb.append("IntBot"); + return sb.append("Int"); + } + @Override public boolean isHighOrConst() { return _is_con || _con==0; } @@ -65,6 +87,11 @@ public class TypeInteger extends Type { } @Override + public Type glb() { return BOT; } + + @Override public TypeInteger makeInit() { return ZERO; } + + @Override int hash() { return (int)(_con ^ (_is_con ? 0 : 0x4000)); } @Override public boolean eq( Type t ) { diff --git a/src/main/java/com/seaofnodes/simple/type/TypeMem.java b/src/main/java/com/seaofnodes/simple/type/TypeMem.java new file mode 100644 index 00000000..d921bac3 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/type/TypeMem.java @@ -0,0 +1,20 @@ +package com.seaofnodes.simple.type; + +import java.util.ArrayList; + +/** A token for all memory; field values are not tracked in its type. */ +public class TypeMem extends Type { + private final boolean _high; + private TypeMem(boolean high) { super(TMEM); _high = high; } + public static final TypeMem TOP = new TypeMem(true ).intern(); + public static final TypeMem BOT = new TypeMem(false).intern(); + + public static void gather(ArrayList<Type> ts) { ts.add(BOT); } + @Override TypeMem xmeet(Type t) { return BOT; } + @Override public Type dual() { return _high ? BOT : TOP; } + @Override public Type glb() { return BOT; } + @Override int hash() { return _high ? 1 : 2; } + @Override boolean eq(Type t) { return _high==((TypeMem)t)._high; } + @Override public StringBuilder print(StringBuilder sb) { return sb.append(_high ? "MemTop" : "MemBot"); } + @Override public String str() { return print(new StringBuilder()).toString(); } +} diff --git a/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java b/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java new file mode 100644 index 00000000..6c874a93 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java @@ -0,0 +1,82 @@ +package com.seaofnodes.simple.type; + +import java.util.ArrayList; + +/** + * Represents a Pointer to memory. + * + * Null is generic pointer to non-existent memory. + * *void is a non-Null pointer to all possible structs. + * Pointers can be to specific struct types, or a union with Null. + * The distinguished *$BOT ptr represents union of *void and Null. + * The distinguished *$TOP ptr represents the dual of *$BOT. + */ +public class TypeMemPtr extends Type { + // A TypeMemPtr is pair (obj,nil) + // where obj is one of + // (null,TypeStruct). + // where nil is one of + // (true,false) meaning an explicit null is allowed or not + + public final TypeStruct _obj; // null, a TypeStruct, or sentinel TypeStruct.MANY + public final boolean _nil; + + private TypeMemPtr(TypeStruct obj, boolean nil) { + super(TMEMPTR); + _obj = obj; + _nil = nil; + } + public static TypeMemPtr make(TypeStruct obj, boolean nil) { return new TypeMemPtr(obj, nil).intern(); } + public static TypeMemPtr make(TypeStruct obj) { return TypeMemPtr.make(obj, false); } + + public static final TypeMemPtr BOT = make(TypeStruct.BOT,true); + public static final TypeMemPtr TOP = BOT.dual(); + public static final TypeMemPtr NULLPTR = make(TypeStruct.TOP,true); + public static final TypeMemPtr VOIDPTR = NULLPTR.dual(); // A bottom mix of not-null ptrs, like C's void* but not null + public static final TypeMemPtr TEST= make(TypeStruct.TEST,false); + public static void gather(ArrayList<Type> ts) { ts.add(NULLPTR); ts.add(BOT); ts.add(TEST); } + + @Override + Type xmeet(Type t) { + TypeMemPtr that = (TypeMemPtr) t; + return TypeMemPtr.make((TypeStruct)_obj.meet(that._obj), _nil | that._nil); + } + + @Override + public TypeMemPtr dual() { return TypeMemPtr.make(_obj==null ? null : _obj.dual(), !_nil); } + + @Override + public Type glb() { + if( _obj==null ) return BOT; + return make(_obj.glb(),true); + } + @Override public TypeMemPtr makeInit() { return NULLPTR; } + + @Override + int hash() { return (_obj==null ? 0xDEADBEEF : _obj.hashCode()) ^ (_nil ? 1024 : 0); } + + @Override + boolean eq(Type t) { + TypeMemPtr ptr = (TypeMemPtr)t; // Invariant + return _obj == ptr._obj && _nil == ptr._nil; + } + + // [void,name,MANY]*[,?] + @Override + public StringBuilder print(StringBuilder sb) { + if( this==BOT ) return sb.append("PtrBot"); + if( this==TOP ) return sb.append("PtrTop"); + if( this== NULLPTR) return sb.append("null"); + if( this== VOIDPTR) return sb.append("*void"); + return _obj.print(sb.append("*")).append(_nil ? "?" : ""); + } + + @Override public String str() { + if( this==BOT ) return "PtrBot"; + if( this==TOP ) return "PtrTop"; + if( this== NULLPTR) return "null"; + if( this== VOIDPTR) return "*void"; + return "*"+_obj.str()+(_nil ? "?" : ""); + } + +} diff --git a/src/main/java/com/seaofnodes/simple/type/TypeStruct.java b/src/main/java/com/seaofnodes/simple/type/TypeStruct.java new file mode 100644 index 00000000..44741def --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/type/TypeStruct.java @@ -0,0 +1,127 @@ +package com.seaofnodes.simple.type; + +import com.seaofnodes.simple.Utils; +import java.util.ArrayList; + +/** + * Represents a struct type. + */ +public class TypeStruct extends Type { + + // For now in terms of the lattice + // a struct type just stays as is + + public final String _name; + public final Field[] _fields; + + private TypeStruct(String name, Field[] fields) { + super(Type.TSTRUCT); + _name = name; + _fields = fields; + } + + public static TypeStruct make(String name, Field[] fields) { return new TypeStruct(name, fields).intern(); } + public static TypeStruct make(String name, ArrayList<Field> fields) { return make(name,fields.toArray(new Field[fields.size()])); } + + public static final TypeStruct TOP = make("$TOP",new Field [0]); + public static final TypeStruct BOT = make("$BOT",new Field [0]); + public static final TypeStruct TEST = make("test",new Field[]{Field.TEST}); + public static void gather(ArrayList<Type> ts) { ts.add(TEST); ts.add(BOT); } + + public int find(String fname) { + for( int i=0; i<_fields.length; i++ ) + if( _fields[i]._fname.equals(fname) ) + return i; + return -1; + } + + @Override + Type xmeet(Type t) { + TypeStruct that = (TypeStruct) t; + if( this==TOP ) return that; + if( that==TOP ) return this; + if( this==BOT ) return BOT; + if( that==BOT ) return BOT; + + // Within the same compilation unit, struct names are unique. If the + // names differ, its different structs. Across many compilation units, + // structs with the same name but different field layouts can be + // interned... which begs the question: + // "What is the meet of structs from two different compilation units?" + // And the answer is: "don't ask". + if( !_name.equals(that._name) ) + return BOT; // It's a struct; that's about all we know + // Now all fields should be the same, so just do field meets + assert _fields.length == that._fields.length; + Field[] flds = new Field[_fields.length]; + for( int i=0; i<_fields.length; i++ ) + flds[i] = (Field)_fields[i].meet(that._fields[i]); + return make(_name,flds); + } + + @Override + public TypeStruct dual() { + if( this==TOP ) return BOT; + if( this==BOT ) return TOP; + Field[] flds = new Field[_fields.length]; + for( int i=0; i<_fields.length; i++ ) + flds[i] = _fields[i].dual(); + return make(_name,flds); + } + + // Keeps the same struct, but lower-bounds all fields. + @Override + public TypeStruct glb() { + if( _glb() ) return this; + // Need to glb each field + Field[] flds = new Field[_fields.length]; + for( int i=0; i<_fields.length; i++ ) + flds[i] = _fields[i].glb(); + return make(_name,flds); + } + private boolean _glb() { + for( Field f : _fields ) + if( f.glb() != f ) + return false; + return true; + } + + @Override + boolean eq(Type t) { + TypeStruct ts = (TypeStruct)t; // Invariant + if( !_name.equals(ts._name) ) + return false; + if( _fields.length!=ts._fields.length ) + return false; + for( int i = 0; i < _fields.length; i++ ) + if( _fields[i] != ts._fields[i] ) + return false; + return true; + } + + @Override + int hash() { + long hash = _name.hashCode(); + for( Field f : _fields ) hash = Utils.rot(hash,13) ^ f.hashCode(); + return Utils.fold(hash); + } + + @Override + public StringBuilder print(StringBuilder sb) { + if( this==BOT ) return sb.append("StructBot"); + if( this==TOP ) return sb.append("StructTop"); + sb.append(_name).append(" {\n"); + for( Field f : _fields ) { + sb.append(" ").append(f._fname).append(":"); + f._type.print(sb); + sb.append(";\n"); + } + return sb.append("}"); + } + + @Override public String str() { + if( this==BOT ) return "StructBot"; + if( this==TOP ) return "StructTop"; + return _name; + } +} diff --git a/src/main/java/com/seaofnodes/simple/type/TypeTuple.java b/src/main/java/com/seaofnodes/simple/type/TypeTuple.java index a2a6a095..0aa019a7 100644 --- a/src/main/java/com/seaofnodes/simple/type/TypeTuple.java +++ b/src/main/java/com/seaofnodes/simple/type/TypeTuple.java @@ -1,5 +1,7 @@ package com.seaofnodes.simple.type; +import java.util.ArrayList; + public class TypeTuple extends Type { public final Type[] _types; @@ -7,8 +9,11 @@ public class TypeTuple extends Type { private TypeTuple(Type[] types) { super(TTUPLE); _types = types; } public static TypeTuple make(Type... types) { return new TypeTuple(types).intern(); } + private static TypeTuple TEST = make(TypeInteger.BOT,TypeMemPtr.TEST); + public static void gather(ArrayList<Type> ts) { ts.add(TEST); } + @Override - public Type xmeet(Type other) { + Type xmeet(Type other) { TypeTuple tt = (TypeTuple)other; // contract from xmeet assert _types.length == tt._types.length; Type[] ts = new Type[_types.length]; @@ -25,6 +30,14 @@ public class TypeTuple extends Type { } @Override + public Type glb() { + Type[] ts = new Type[_types.length]; + for( int i=0; i<_types.length; i++ ) + ts[i] = _types[i].glb(); + return make(ts); + } + + @Override public StringBuilder print(StringBuilder sb) { sb.append("["); for( Type t : _types ) @@ -34,6 +47,21 @@ public class TypeTuple extends Type { return sb; } + @Override public String str() { return print(new StringBuilder()).toString(); } + + /** + * Display Type name in a format that's good for IR printer + */ + @Override + public StringBuilder typeName(StringBuilder sb) { + sb.append("["); + for( Type t : _types ) + t.typeName(sb).append(","); + sb.setLength(sb.length()-1); + sb.append("]"); + return sb; + } + public static final TypeTuple IF_BOTH = make(new Type[]{Type. CONTROL,Type. CONTROL}); public static final TypeTuple IF_NEITHER = make(new Type[]{Type.XCONTROL,Type.XCONTROL}); public static final TypeTuple IF_TRUE = make(new Type[]{Type. CONTROL,Type.XCONTROL}); |