do not eliminate loop vars if there are non-loop vars in the else that are influenced by the loop var or the helper

Author: kripken

tools/eliminator/asm-eliminator-test-output.js

@@ -857,4 +857,48 @@ function elimOneLoopVar($argc, $argv) {
  HEAP32[$vararg_buffer1 >> 2] = $curri$012;
  return $retval$0 | 0;
 }
+function elimOneLoopVar2() {
+ var $storemerge3$neg9 = 0, $18 = 0, $25 = 0, $26 = 0, $30 = 0, $jp = 0;
+ $storemerge3$neg9 = -1;
+ while (1) {
+  $25 = $jp + ($26 << 2) | 0;
+  HEAP32[$25 >> 2] = ($18 + $storemerge3$neg9 | 0) + (HEAP32[$25 >> 2] | 0) | 0;
+  $30 = $26 + 1 | 0;
+  if (($30 | 0) == 63) {
+   break;
+  } else {
+   $storemerge3$neg9 = $26 ^ -1;
+   $26 = $30;
+  }
+ }
+}
+function elimOneLoopVar3() {
+ var $storemerge3$neg9 = 0, $18 = 0, $25 = 0, $26 = 0, $30 = 0, $jp = 0;
+ $storemerge3$neg9 = -1;
+ while (1) {
+  $25 = $jp + ($26 << 2) | 0;
+  HEAP32[$25 >> 2] = ($18 + $storemerge3$neg9 | 0) + (HEAP32[$25 >> 2] | 0) | 0;
+  $30 = $26 + 1 | 0;
+  if (($30 | 0) == 63) {
+   break;
+  } else {
+   $storemerge3$neg9 = $30 ^ -1;
+   $26 = $30;
+  }
+ }
+}
+function elimOneLoopVar4() {
+ var $storemerge3$neg9 = 0, $18 = 0, $25 = 0, $26 = 0, $jp = 0;
+ $storemerge3$neg9 = -1;
+ while (1) {
+  $25 = $jp + ($26 << 2) | 0;
+  HEAP32[$25 >> 2] = ($18 + $storemerge3$neg9 | 0) + (HEAP32[$25 >> 2] | 0) | 0;
+  $26 = $26 + 1 | 0;
+  if (($26 | 0) == 63) {
+   break;
+  } else {
+   $storemerge3$neg9 = $18 ^ -1;
+  }
+ }
+}
 

tools/eliminator/asm-eliminator-test.js

@@ -1086,5 +1086,50 @@ function elimOneLoopVar($argc, $argv) {
  HEAP32[$vararg_buffer1 >> 2] = $curri$012;
  return $retval$0 | 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", "looop8", "multiloop", "multiloop2", "tempDouble2", "watIf", "select2", "binary", "cute", "selfAssign", "elimOneLoopVar"]
+function elimOneLoopVar2() {
+ var $storemerge3$neg9 = 0, $18 = 0, $25 = 0, $26 = 0, $30 = 0, $jp = 0;
+ $storemerge3$neg9 = -1;
+ while (1) {
+  $25 = $jp + ($26 << 2) | 0;
+  HEAP32[$25 >> 2] = ($18 + $storemerge3$neg9 | 0) + (HEAP32[$25 >> 2] | 0) | 0;
+  $30 = $26 + 1 | 0;
+  if (($30 | 0) == 63) {
+   break;
+  } else {
+   $storemerge3$neg9 = $26 ^ -1; // $26 is a loopvar, use here is dangerous
+   $26 = $30;
+  }
+ }
+}
+function elimOneLoopVar3() {
+ var $storemerge3$neg9 = 0, $18 = 0, $25 = 0, $26 = 0, $30 = 0, $jp = 0;
+ $storemerge3$neg9 = -1;
+ while (1) {
+  $25 = $jp + ($26 << 2) | 0;
+  HEAP32[$25 >> 2] = ($18 + $storemerge3$neg9 | 0) + (HEAP32[$25 >> 2] | 0) | 0;
+  $30 = $26 + 1 | 0;
+  if (($30 | 0) == 63) {
+   break;
+  } else {
+   $storemerge3$neg9 = $30 ^ -1; // $26 is a helper, use here is dangerous
+   $26 = $30;
+  }
+ }
+}
+function elimOneLoopVar4() {
+ var $storemerge3$neg9 = 0, $18 = 0, $25 = 0, $26 = 0, $30 = 0, $jp = 0;
+ $storemerge3$neg9 = -1;
+ while (1) {
+  $25 = $jp + ($26 << 2) | 0;
+  HEAP32[$25 >> 2] = ($18 + $storemerge3$neg9 | 0) + (HEAP32[$25 >> 2] | 0) | 0;
+  $30 = $26 + 1 | 0;
+  if (($30 | 0) == 63) {
+   break;
+  } else {
+   $storemerge3$neg9 = $18 ^ -1;
+   $26 = $30;
+  }
+ }
+}
+// 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", "looop8", "multiloop", "multiloop2", "tempDouble2", "watIf", "select2", "binary", "cute", "selfAssign", "elimOneLoopVar", "elimOneLoopVar2", "elimOneLoopVar3", "elimOneLoopVar4"]
 

tools/js-optimizer.js

@@ -3550,6 +3550,25 @@ function eliminate(ast, memSafe) {
                 }
               }
             }
+            // remove loop vars that are used in the rest of the else
+            for (var i = 0; i < assigns.length; i++) {
+              if (assigns[i][0] === 'stat' && assigns[i][1][0] === 'assign') {
+                var assign = assigns[i][1];
+                if (!(assign[1] === true && assign[2][0] === 'name' && assign[3][0] === 'name') || loopers.indexOf(assign[2][1]) < 0) {
+                  // this is not one of the loop assigns
+                  traverse(assign, function(node, type) {
+                    if (type === 'name') {
+                      var index = loopers.indexOf(node[1]);
+                      if (index < 0) index = helpers.indexOf(node[1]);
+                      if (index >= 0) {
+                        loopers.splice(index, 1);
+                        helpers.splice(index, 1);
+                      }
+                    }
+                  });
+                }
+              }
+            }
             if (loopers.length === 0) return;
             for (var l = 0; l < loopers.length; l++) {
               var looper = loopers[l];