John Stalcup has uploaded a new change for review.
https://gwt-review.googlesource.com/2580
Change subject: reduces Java AST optimization time by bailing out when the
rate of change slows to a crawl (only applies on optimization levels less
than 9)
..
reduces Java AST optimization time by bailing out when the rate of change
slows to a crawl (only applies on optimization levels less than 9)
Change-Id: Iabf844d6a02f694e8d14103377f74f46e4e01915
---
M dev/core/src/com/google/gwt/dev/jjs/JavaToJavaScriptCompiler.java
1 file changed, 57 insertions(+), 26 deletions(-)
diff --git
a/dev/core/src/com/google/gwt/dev/jjs/JavaToJavaScriptCompiler.java
b/dev/core/src/com/google/gwt/dev/jjs/JavaToJavaScriptCompiler.java
index b7ccabb..431ab9d 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/JavaToJavaScriptCompiler.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/JavaToJavaScriptCompiler.java
@@ -252,15 +252,27 @@
private static final String ENUM_NAME_OBFUSCATION_PROPERTY
= compiler.enum.obfuscate.names;
/**
+ * Continuing to apply optimizations till the rate of change reaches
this value causes the AST to
+ * reach a fixed point.
+ */
+ private static final int FIXED_POINT_CHANGE_RATE = 0;
+
+ /**
+ * Ending optimization passes when the rate of change has reached this
value results in
+ * gaining nearly all of the impact while avoiding the long tail of
costly but low-impact passes.
+ */
+ private static final float EFFICIENT_CHANGE_RATE = 0.01f;
+
+ /**
* Compiles a particular permutation, based on a precompiled unified AST.
*
* @param logger the logger to use
- * @param unifiedAst the result of a
- * {@link #precompile(TreeLogger, ModuleDef,
RebindPermutationOracle, String[], String[], JJSOptions, boolean,
PrecompilationMetricsArtifact)}
+ * @param unifiedAst the result of a {@link #precompile(TreeLogger,
ModuleDef,
+ * RebindPermutationOracle, String[], String[], JJSOptions,
boolean,
+ * PrecompilationMetricsArtifact)}
* @param permutation the permutation to compile
* @return the output JavaScript
- * @throws UnableToCompleteException if an error other than
- * {@link OutOfMemoryError} occurs
+ * @throws UnableToCompleteException if an error other than {@link
OutOfMemoryError} occurs
*/
public static PermutationResult compilePermutation(TreeLogger logger,
UnifiedAst unifiedAst,
Permutation permutation) throws UnableToCompleteException {
@@ -768,11 +780,16 @@
Event optimizeEvent =
SpeedTracerLogger.start(CompilerEventType.OPTIMIZE);
ListOptimizerStats allOptimizerStats = new
ArrayListOptimizerStats();
-int counter = 0;
-int optimizationLevel = options.getOptimizationLevel();
+int passCount = 0;
+int nodeCount = getNodeCount(jprogram);
+int lastNodeCount;
+
+int passLimit = options.getOptimizationLevel();
+float minimumChangeRate = passLimit OptionOptimize.OPTIMIZE_LEVEL_MAX
+? EFFICIENT_CHANGE_RATE : FIXED_POINT_CHANGE_RATE;
while (true) {
- counter++;
- if (optimizationLevel OptionOptimize.OPTIMIZE_LEVEL_MAX counter
optimizationLevel) {
+ passCount++;
+ if (passLimit OptionOptimize.OPTIMIZE_LEVEL_MAX passCount
passLimit) {
break;
}
if (Thread.interrupted()) {
@@ -781,9 +798,14 @@
}
AstDumper.maybeDumpAST(jprogram);
OptimizerStats stats =
- optimizeLoop(Pass + counter, jprogram,
options.isAggressivelyOptimize());
+ optimizeLoop(Pass + passCount, jprogram,
options.isAggressivelyOptimize(), nodeCount);
allOptimizerStats.add(stats);
- if (!stats.didChange()) {
+ lastNodeCount = nodeCount;
+ nodeCount = getNodeCount(jprogram);
+
+ float nodeChangeRate = stats.getNumMods() / (float) lastNodeCount;
+ float sizeChangeRate = (lastNodeCount - nodeCount) / (float)
lastNodeCount;
+ if (nodeChangeRate = minimumChangeRate sizeChangeRate =
minimumChangeRate) {
break;
}
}
@@ -849,15 +871,15 @@
protected static OptimizerStats optimizeLoop(String passName, JProgram
jprogram,
boolean isAggressivelyOptimize) {
-Event optimizeEvent =
SpeedTracerLogger.start(CompilerEventType.OPTIMIZE, phase, loop);
-
-// Count the number of nodes in the AST so we can measure the
efficiency of
-// the optimizers.
-Event countEvent =
SpeedTracerLogger.start(CompilerEventType.OPTIMIZE, phase, countNodes);
TreeStatistics treeStats = new TreeStatistics();
treeStats.accept(jprogram);
-int numNodes = treeStats.getNodeCount();
-countEvent.end();
+int nodeCount = treeStats.getNodeCount();
+return optimizeLoop(Early Optimization, jprogram, false, nodeCount);
+ }
+
+ protected static OptimizerStats optimizeLoop(String passName, JProgram
jprogram,
+
