optimize loop vars even if there is some code (like a phi) in the if block where the loop break is, if it does not interfere

3 files changed, 54 insertions, 14 deletions

diff --git a/tools/eliminator/asm-eliminator-test-output.js b/tools/eliminator/asm-eliminator-test-output.js
index 1a5dca55..bf4b111f 100644
--- a/tools/eliminator/asm-eliminator-test-output.js
+++ b/tools/eliminator/asm-eliminator-test-output.js
@@ -24,7 +24,7 @@ function __Z11printResultPiS_j($needle, $haystack, $len) {
 }
 function _segment_holding($addr) {
  $addr = $addr | 0;
- var $sp_0 = 0, $3 = 0, $12 = 0, $_0 = 0, label = 0;
+ var $sp_0 = 0, $3 = 0, $_0 = 0, label = 0;
  $sp_0 = __gm_ + 444 | 0;
  while (1) {
   $3 = HEAP32[(($sp_0 | 0) & 16777215) >> 2] | 0;
@@ -35,13 +35,11 @@ function _segment_holding($addr) {
     break;
    }
   }
-  $12 = HEAP32[(($sp_0 + 8 | 0) & 16777215) >> 2] | 0;
-  if (($12 | 0) == 0) {
+  $sp_0 = HEAP32[(($sp_0 + 8 | 0) & 16777215) >> 2] | 0;
+  if (($sp_0 | 0) == 0) {
    $_0 = 0;
    label = 1659;
    break;
-  } else {
-   $sp_0 = $12;
   }
  }
  if (label == 1659) {
@@ -818,7 +816,7 @@ function selfAssign() {
 function elimOneLoopVar($argc, $argv) {
  $argc = $argc | 0;
  $argv = $argv | 0;
- var $arg$0 = 0, $call10 = Math_fround(0), $curri$012 = 0, $inc = 0, $j$010 = 0, $ok$0 = 0, $primes$011 = 0, $retval$0 = 0, $vararg_buffer1 = 0;
+ var $arg$0 = 0, $call10 = Math_fround(0), $curri$012 = 0, $j$010 = 0, $ok$0 = 0, $primes$011 = 0, $retval$0 = 0, $vararg_buffer1 = 0, $j$010$looptemp = 0;
  $curri$012 = 2;
  $primes$011 = 0;
  while (1) {
@@ -827,14 +825,13 @@ function elimOneLoopVar($argc, $argv) {
    if ($call10 > Math_fround(+2)) {
     $j$010 = 2;
     while (1) {
-     $inc = $j$010 + 1 | 0;
-     if ((($curri$012 | 0) % ($j$010 | 0) & -1 | 0) == 0) {
+     $j$010$looptemp = $j$010;
+     $j$010 = $j$010 + 1 | 0;
+     if ((($curri$012 | 0) % ($j$010$looptemp | 0) & -1 | 0) == 0) {
       $ok$0 = 0;
       break L15;
      }
-     if (Math_fround($inc | 0) < $call10) {
-      $j$010 = $inc;
-     } else {
+     if (!(Math_fround($j$010 | 0) < $call10)) {
       $ok$0 = 1;
       break;
      }
@@ -911,4 +908,20 @@ function elimOneLoopVarStillUsed() {
  }
  return $retval$0 | 0;
 }
+function elimOneLoopVar5() {
+ 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) {
+   f($30);
+   break;
+  } else {
+   $storemerge3$neg9 = $18 ^ -1;
+   $26 = $30;
+  }
+ }
+}
 
diff --git a/tools/eliminator/asm-eliminator-test.js b/tools/eliminator/asm-eliminator-test.js
index d5bbd8d5..5bec0507 100644
--- a/tools/eliminator/asm-eliminator-test.js
+++ b/tools/eliminator/asm-eliminator-test.js
@@ -1152,5 +1152,21 @@ function elimOneLoopVarStillUsed() {
  }
  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", "elimOneLoopVar2", "elimOneLoopVar3", "elimOneLoopVar4", "elimOneLoopVarStillUsed"]
+function elimOneLoopVar5() {
+ 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) {
+   f($30); // loop var used here, so cannot be easily optimized
+   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", "elimOneLoopVarStillUsed", "elimOneLoopVar5"]
 
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index f38ff08c..699ea280 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -3585,13 +3585,13 @@ function eliminate(ast, memSafe) {
           clearEmptyNodes(ifTrue[1]);
           clearEmptyNodes(ifFalse[1]);
           var flip = false;
-          if (ifFalse[1][0] && ifFalse[1][0][0] === 'break') { // canonicalize break in the if
+          if (ifFalse[1][0] && ifFalse[1][ifFalse[1].length-1][0] === 'break') { // canonicalize break in the if-true
             var temp = ifFalse;
             ifFalse = ifTrue;
             ifTrue = temp;
             flip = true;
           }
-          if (ifTrue[1][0] && ifTrue[1][0][0] === 'break') {
+          if (ifTrue[1][0] && ifTrue[1][ifTrue[1].length-1][0] === 'break') {
             var assigns = ifFalse[1];
             clearEmptyNodes(assigns);
             var loopers = [], helpers = [];
@@ -3628,6 +3628,17 @@ function eliminate(ast, memSafe) {
                 }
               }
             }
+            // remove loop vars that are used in the if
+            traverse(ifTrue, 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];