From 736c658c274404084b15b450b2ab72d0e7569586 Mon Sep 17 00:00:00 2001 From: Dibyendu Majumdar Date: Fri, 3 Nov 2023 21:21:54 +0000 Subject: Backport changes in Chapter 5 to previous chapters and update Chapter5 documentation (#34) * Backport changes from chapter 5 to older chapters (#30) * Fix wrong indent * Backport to chapter 4 * Backport to chapter 3 * Backport to chapter 2 * Backport to chapter 1 * Add if statement to comment (#32) * Update visuals for chapters 1,2 & 3. Reenable drawing of edges from constants to Start for these chapters. * Update visuals for chapters 4. Revise text to explain the labeling of edges in graphs and that we omit edge from Constant to Start nodes from chapter 4. * Add code snippets for if statement parsing and the duplication and merging of ScopeNodes. Explain how scopeNodes are duplicated and merged. * Add constant check to minus node (#31) * Fix closing root block with } (#33) * Backport fix closing root block with } to chapter 4 and 3 (#35) * Show use-def edge from Phi to Region as dotted edge. Add example of Phi peephole. Update visuals. Add more examples. * Fix visuals in chapter 1 and README in chapter 4. * Remove subheading * Adjust spaces --------- Co-authored-by: XmiliaH <45106915+XmiliaH@users.noreply.github.com> --- .../main/java/com/seaofnodes/simple/GraphVisualizer.java | 16 ++++++---------- .../src/main/java/com/seaofnodes/simple/Parser.java | 3 ++- .../main/java/com/seaofnodes/simple/node/MinusNode.java | 2 +- .../main/java/com/seaofnodes/simple/node/ScopeNode.java | 12 ++++++++++++ 4 files changed, 21 insertions(+), 12 deletions(-) (limited to 'chapter05/src/main/java') diff --git a/chapter05/src/main/java/com/seaofnodes/simple/GraphVisualizer.java b/chapter05/src/main/java/com/seaofnodes/simple/GraphVisualizer.java index f3942edb..01b5aeeb 100644 --- a/chapter05/src/main/java/com/seaofnodes/simple/GraphVisualizer.java +++ b/chapter05/src/main/java/com/seaofnodes/simple/GraphVisualizer.java @@ -146,7 +146,7 @@ public class GraphVisualizer { // Walk the node edges private void nodeEdges(StringBuilder sb, Collection all) { // All them edge labels - sb.append("\tedge [ fontname=Helvetica, fontsize=8 ];\n"); + sb.append("\tedge [ fontname=Helvetica, fontsize=8 ];\n"); for( Node n : all ) { // Do not display the Constant->Start edge; // ProjNodes handled by Multi; @@ -155,16 +155,12 @@ public class GraphVisualizer { continue; int i=0; for( Node def : n._inputs ) { - // Do not draw the Phi->Region edge (in red); instead Phis are - // on a line with their Region, and we draw an invisible line - // from the Region to the Phi, to force all the Phis to the - // right of the Region. if( n instanceof PhiNode && def instanceof RegionNode ) { - sb.append('\t').append(def.uniqueName()); + // Draw a dotted use->def edge from Phi to Region. + sb.append('\t').append(n.uniqueName()); sb.append(" -> "); - sb.append(n.uniqueName()); - sb.append(" [style=invis]\n"); - + sb.append(def.uniqueName()); + sb.append(" [style=dotted taillabel=").append(i).append("];\n"); } else if( def != null ) { // Most edges land here use->def sb.append('\t').append(n.uniqueName()).append(" -> "); @@ -176,7 +172,7 @@ public class GraphVisualizer { sb.append("[taillabel=").append(i); // control edges are colored red if( def.isCFG() ) - sb.append("; color=red"); + sb.append(" color=red"); sb.append("];\n"); } i++; diff --git a/chapter05/src/main/java/com/seaofnodes/simple/Parser.java b/chapter05/src/main/java/com/seaofnodes/simple/Parser.java index 8bf343b3..a132fce0 100644 --- a/chapter05/src/main/java/com/seaofnodes/simple/Parser.java +++ b/chapter05/src/main/java/com/seaofnodes/simple/Parser.java @@ -94,6 +94,7 @@ public class Parser { _scope.define(CTRL , new ProjNode(START, 0, CTRL ).peephole()); _scope.define("arg", new ProjNode(START, 1, "arg").peephole()); parseBlock(); + if (!_lexer.isEOF()) throw error("Syntax error, unexpected " + _lexer.getAnyNextToken()); return STOP; } finally { @@ -129,7 +130,7 @@ public class Parser { * Parses a statement * * 
-     *     returnStatement | declStatement | blockStatement | expressionStatement
+     *     returnStatement | declStatement | blockStatement | ifStatement | expressionStatement
      *
* @return a {@link Node} or {@code null} */ diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java index 834f4c11..533155d9 100644 --- a/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java +++ b/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java @@ -20,7 +20,7 @@ public class MinusNode extends Node { @Override public Type compute() { if (in(1)._type instanceof TypeInteger i0) - return TypeInteger.constant(-i0.value()); + return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0; return TypeBot.BOTTOM; } diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/ScopeNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/ScopeNode.java index 64061030..61fac118 100644 --- a/chapter05/src/main/java/com/seaofnodes/simple/node/ScopeNode.java +++ b/chapter05/src/main/java/com/seaofnodes/simple/node/ScopeNode.java @@ -105,6 +105,10 @@ public class ScopeNode extends Node { * The new Scope is a full-fledged Node with proper use<->def edges. */ public ScopeNode dup() { + // Our goals are: + // 1) duplicate the name bindings of the ScopeNode across all stack levels + // 2) Make the new ScopeNode a user of all the nodes bound + // 3) Ensure that the order of defs is the same to allow easy merging ScopeNode dup = new ScopeNode(); for( HashMap tab : _scopes ) dup._scopes.push(new HashMap<>(tab)); @@ -114,6 +118,14 @@ public class ScopeNode extends Node { return dup; } + /** + * Merges the names whose node bindings differ, by creating Phi node for such names + * The names could occur at all stack levels, but a given name can only differ in the + * innermost stack level where the name is bound. + * + * @param that The ScopeNode to be merged into this + * @return A new Region node representing the merge point + */ public RegionNode mergeScopes(ScopeNode that) { RegionNode r = (RegionNode)ctrl(new RegionNode(null,ctrl(), that.ctrl()).peephole()); for( int i=1; i