make bitshift64 use integer constants for the op

3 files changed, 14 insertions, 11 deletions

diff --git a/src/analyzer.js b/src/analyzer.js
index d91bbe73..cafd4745 100644
--- a/src/analyzer.js
+++ b/src/analyzer.js
@@ -655,7 +655,7 @@ function analyzer(data, sidePass) {
                     assert(sourceBits == 64, 'TODO: handle nonconstant shifts on != 64 bits');
                     value.intertype = 'value';
                     value.ident = 'Runtime' + (ASM_JS ? '_' : '.') + 'bitshift64(' + sourceElements[0].ident + ', ' +
-                                                          sourceElements[1].ident + ',"' + value.op + '",' + value.params[1].ident + '$0);' +
+                                                          sourceElements[1].ident + ',' + Runtime['BITSHIFT64_' + value.op.toUpperCase()] + ',' + value.params[1].ident + '$0);' +
                                   'var ' + value.assignTo + '$0 = ' + makeGetTempDouble(0, 'i32') + ', ' + value.assignTo + '$1 = ' + makeGetTempDouble(1, 'i32') + ';';
                     value.assignTo = null;
                     i++;
diff --git a/src/parseTools.js b/src/parseTools.js
index e0c99c52..4e95164e 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -1908,7 +1908,7 @@ function processMathop(item) {
       case 'ashr':
       case 'lshr': {
         if (!isNumber(idents[1])) {
-          return '(Runtime' + (ASM_JS ? '_' : '.') + 'bitshift64(' + idents[0] + '[0], ' + idents[0] + '[1],"' + op + '",' + stripCorrections(idents[1]) + '[0]|0),' +
+          return '(Runtime' + (ASM_JS ? '_' : '.') + 'bitshift64(' + idents[0] + '[0], ' + idents[0] + '[1],' + Runtime['BITSHIFT64_' + op.toUpperCase()] + ',' + stripCorrections(idents[1]) + '[0]|0),' +
             '[' + makeGetTempDouble(0, 'i32') + ',' + makeGetTempDouble(1, 'i32') + '])';
         }
         bits = parseInt(idents[1]);
diff --git a/src/runtime.js b/src/runtime.js
index 9d5e5e1f..d1475bd4 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -123,42 +123,45 @@ var Runtime = {
   FLOAT_TYPES: set('float', 'double'),
 
   // Mirrors processMathop's treatment of constants (which we optimize directly)
+  BITSHIFT64_SHL: 0,
+  BITSHIFT64_ASHR: 1,
+  BITSHIFT64_LSHR: 2,
   bitshift64: function(low, high, op, bits) {
     var ret;
     var ander = Math.pow(2, bits)-1;
     if (bits < 32) {
       switch (op) {
-        case 'shl':
+        case Runtime.BITSHIFT64_SHL:
           ret = [low << bits, (high << bits) | ((low&(ander << (32 - bits))) >>> (32 - bits))];
           break;
-        case 'ashr':
+        case Runtime.BITSHIFT64_ASHR:
           ret = [(((low >>> bits ) | ((high&ander) << (32 - bits))) >> 0) >>> 0, (high >> bits) >>> 0];
           break;
-        case 'lshr':
+        case Runtime.BITSHIFT64_LSHR:
           ret = [((low >>> bits) | ((high&ander) << (32 - bits))) >>> 0, high >>> bits];
           break;
       }
     } else if (bits == 32) {
       switch (op) {
-        case 'shl':
+        case Runtime.BITSHIFT64_SHL:
           ret = [0, low];
           break;
-        case 'ashr':
+        case Runtime.BITSHIFT64_ASHR:
           ret = [high, (high|0) < 0 ? ander : 0];
           break;
-        case 'lshr':
+        case Runtime.BITSHIFT64_LSHR:
           ret = [high, 0];
           break;
       }
     } else { // bits > 32
       switch (op) {
-        case 'shl':
+        case Runtime.BITSHIFT64_SHL:
           ret = [0, low << (bits - 32)];
           break;
-        case 'ashr':
+        case Runtime.BITSHIFT64_ASHR:
           ret = [(high >> (bits - 32)) >>> 0, (high|0) < 0 ? ander : 0];
           break;
-        case 'lshr':
+        case Runtime.BITSHIFT64_LSHR:
           ret = [high >>>  (bits - 32) , 0];
           break;
       }