track number of uses properly for loop variable removal

3 files changed, 43 insertions, 2 deletions

diff --git a/tools/eliminator/asm-eliminator-test-output.js b/tools/eliminator/asm-eliminator-test-output.js
index 8cd11541..9b874ba6 100644
--- a/tools/eliminator/asm-eliminator-test-output.js
+++ b/tools/eliminator/asm-eliminator-test-output.js
@@ -5031,4 +5031,21 @@ function looop6() {
   }
   moar(i);
 }
+function looop7() {
+  var $old_0_i107_i = 0, $current_0_i108_i = 0, $696 = 0;
+  $old_0_i107_i = $draw_left_i;
+  while (1) {
+    $current_0_i108_i = HEAP32[$old_0_i107_i >> 2] | 0;
+    if (($current_0_i108_i | 0) == 0) {
+      break;
+    }
+    $696 = $current_0_i108_i + 4 | 0;
+    if (($current_0_i108_i | 0) == ($P_3207_i | 0)) {
+      break;
+    } else {
+      $old_0_i107_i = $696;
+    }
+  }
+  HEAP32[$old_0_i107_i >> 2] = HEAP32[$696 >> 2] | 0;
+}
 
diff --git a/tools/eliminator/asm-eliminator-test.js b/tools/eliminator/asm-eliminator-test.js
index 6f881654..9524bde2 100644
--- a/tools/eliminator/asm-eliminator-test.js
+++ b/tools/eliminator/asm-eliminator-test.js
@@ -6755,5 +6755,22 @@ function looop6() {
   }
   moar(helper); // this is cool
 }
-// EMSCRIPTEN_GENERATED_FUNCTIONS: ["asm", "__Z11printResultPiS_j", "_segment_holding", "__ZN5identC2EiPKcPci", "_vec2Length", "exc", "label", "confuusion", "tempDouble", "_org_apache_harmony_luni_util_NumberConverter_freeFormat__", "__ZN23b2EdgeAndPolygonContact8EvaluateEP10b2ManifoldRK11b2TransformS4_", "_java_nio_charset_Charset_forNameInternal___java_lang_String", "looop2", "looop3", "looop4", "looop5", "looop6"]
+function looop7() {
+  var $old_0_i107_i = 0, $current_0_i108_i = 0, $696 = 0;
+  $old_0_i107_i = $draw_left_i;
+  while (1) {
+    $current_0_i108_i = HEAP32[$old_0_i107_i >> 2] | 0;
+    if (($current_0_i108_i | 0) == 0) {
+      break;
+    }
+    $696 = $current_0_i108_i + 4 | 0;
+    if (($current_0_i108_i | 0) == ($P_3207_i | 0)) {
+      break;
+    } else {
+      $old_0_i107_i = $696;
+    }
+  }
+  HEAP32[$old_0_i107_i >> 2] = HEAP32[$696 >> 2] | 0;
+}
+// EMSCRIPTEN_GENERATED_FUNCTIONS: ["asm", "__Z11printResultPiS_j", "_segment_holding", "__ZN5identC2EiPKcPci", "_vec2Length", "exc", "label", "confuusion", "tempDouble", "_org_apache_harmony_luni_util_NumberConverter_freeFormat__", "__ZN23b2EdgeAndPolygonContact8EvaluateEP10b2ManifoldRK11b2TransformS4_", "_java_nio_charset_Charset_forNameInternal___java_lang_String", "looop2", "looop3", "looop4", "looop5", "looop6", "looop7"]
 
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index a3a58f2b..67ce2b3d 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -1854,6 +1854,7 @@ function eliminate(ast, memSafe) {
     // First, find the potentially eliminatable functions: that have one definition and one use
     var definitions = {};
     var uses = {};
+    var namings = {};
     var values = {};
     var locals = {};
     var varsToRemove = {}; // variables being removed, that we can eliminate all 'var x;' of (this refers to 'var' nodes we should remove)
@@ -1896,6 +1897,8 @@ function eliminate(ast, memSafe) {
           if (!values[name]) values[name] = node[3];
           if (node[1] === true) { // not +=, -= etc., just =
             uses[name]--; // because the name node will show up by itself in the previous case
+            if (!namings[name]) namings[name] = 0;
+            namings[name]++; // offset it here, this tracks the total times we are named
           }
         }
       } else if (type == 'switch') {
@@ -1903,6 +1906,10 @@ function eliminate(ast, memSafe) {
       }
     });
 
+    for (var used in uses) {
+      namings[used] = (namings[used] || 0) + uses[used];
+    }
+
     // we cannot eliminate variables if there is a switch
     if (hasSwitch && !asm) return;
 
@@ -2372,7 +2379,7 @@ function eliminate(ast, memSafe) {
             if (assign[1] === true && assign[2][0] == 'name' && assign[3][0] == 'name') {
               var looper = assign[2][1];
               var helper = assign[3][1];
-              if (definitions[helper] == 1 && seenUses[looper] == uses[looper] + 1 &&  // +1, because uses does not count the definition
+              if (definitions[helper] == 1 && seenUses[looper] == namings[looper] &&
                   !helperReplacements[helper] && !helperReplacements[looper]) {
                 // the remaining issue is whether looper is used after the assignment to helper and before the last line (where we assign to it)
                 var found = -1;