infrastructure to track the costs of outlining, and to possibly change outlining thresholds as we go

1 files changed, 17 insertions, 8 deletions

diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index 29b36cad..c5b21175 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -3106,7 +3106,7 @@ function outline(ast) {
     // Reserve an extra two spots per possible outlining: one for control flow var, the other for control flow data
     // The control variables are zeroed out when calling an outlined function, and after using
     // the value after they return.
-    asmData.maxOutlinings = Math.round(3*measureSize(func)/sizeToOutline);
+    asmData.maxOutlinings = Math.round(3*measureSize(func)/extraInfo.sizeToOutline);
     asmData.totalStackSize = stackSize + (stack.length + 2*asmData.maxOutlinings)*8;
     asmData.controlStackPos = function(i) { return stackSize + (stack.length + i)*8 };
     asmData.controlDataStackPos = function(i) { return stackSize + (stack.length + i)*8 + 4 };
@@ -3210,9 +3210,17 @@ function outline(ast) {
 
   var CONTROL_BREAK = 1, CONTROL_BREAK_LABEL = 2, CONTROL_CONTINUE = 3, CONTROL_CONTINUE_LABEL = 4, CONTROL_RETURN_VOID = 5, CONTROL_RETURN_INT = 6, CONTROL_RETURN_DOUBLE = 7;
 
-  var sizeToOutline = extraInfo.sizeToOutline;
-  var level = 0;
+  var sizeToOutline = null; // customized per function and as we make progress
+  function calculateThreshold(func) {
+    sizeToOutline = extraInfo.sizeToOutline;
+    var size = measureSize(func);
+    //var desiredChunks = Math.ceil(size/extraInfo.sizeToOutline);
+    ////sizeToOutline = Math.round((extraInfo.sizeToOutline + (2*size/desiredChunks))/3);
+    //sizeToOutline = Math.round(size/desiredChunks);
+    printErr('trying to reduce the size of ' + func[1] + ' which is ' + size + ' (>= ' + extraInfo.sizeToOutline + '), aim for ' + sizeToOutline);
+  }
 
+  var level = 0;
   var outliningParents = {}; // function name => parent it was outlined from
 
   function doOutline(func, asmData, stats, start, end) {
@@ -3225,13 +3233,13 @@ function outline(ast) {
     // analyze variables, and find 'owned' variables - that only appear in the outlined code, and do not need any spill support
     var codeInfo = analyzeCode(func, asmData, code);
     var allCodeInfo = analyzeCode(func, asmData, func);
-    //printErr(' do outline ' + [func[1], level, 'range:', start, end, 'of', stats.length, newIdent, measureSize(code), JSON.stringify(codeInfo.labels), JSON.stringify(codeInfo.breaks), JSON.stringify(codeInfo.continues)]);
     var owned = { sp: 1 }; // sp is always owned, each has its own
     keys(setUnion(codeInfo.reads, codeInfo.writes)).forEach(function(v) {
       if (allCodeInfo.reads[v] === codeInfo.reads[v] && allCodeInfo.writes[v] === codeInfo.writes[v] && !(v in asmData.params)) {
         owned[v] = 1;
       }
     });
+    printErr('attempting outline ' + [func[1], newIdent, 'overhead:', setSize(setSub(codeInfo.writes, owned)), setSize(setSub(codeInfo.reads, owned))]);
     var reps = [];
     // wipe out control variable
     reps.push(['stat', makeAssign(makeStackAccess(ASM_INT, asmData.controlStackPos(outlineIndex)), ['num', 0])]);
@@ -3426,6 +3434,7 @@ function outline(ast) {
       }
     }
     outliningParents[newIdent] = func[1];
+    calculateThreshold(func);
     return [newFunc];
   }
 
@@ -3452,7 +3461,7 @@ function outline(ast) {
     }
     while (1) {
       i--;
-      calcMinIndex();
+      calcMinIndex(); // TODO: optimize
       if (i < minIndex) {
         // we might be done. but, if we have just outlined, do a further attempt from the beginning.
         // (but only if the total costs are not extravagant)
@@ -3536,7 +3545,7 @@ function outline(ast) {
         var newFuncs = doOutline(func, asmData, stats, i, end); // outline [i, .. ,end] inclusive
         if (newFuncs.length) {
           ret.push.apply(ret, newFuncs);
-          printErr('performed outline on ' + func[1] + ' of ' + sizeSeen + ', func is now size ' + measureSize(func) + ' ==> ' + newFuncs[0][1]);
+          printErr('performed outline on ' + func[1] + ' of ' + sizeSeen + ', => ' + newFuncs[0][1]);
         }
         sizeSeen = 0;
         end = i-1;
@@ -3566,10 +3575,10 @@ function outline(ast) {
     funcs.forEach(function(func) {
       var asmData = normalizeAsm(func);
       var size = measureSize(func);
-      if (size >= sizeToOutline) {
-        printErr('trying to reduce the size of ' + func[1] + ' which is ' + size + ' (>= ' + sizeToOutline + ')');
+      if (size >= extraInfo.sizeToOutline) {
         aggressiveVariableElimination(func, asmData);
         flatten(func, asmData);
+        calculateThreshold(func);
         analyzeFunction(func, asmData);
         var stats = getStatements(func);
         var ret = outlineStatements(func, asmData, stats, 0.9*size);