diff options
| -rw-r--r-- | tools/js-optimizer.js | 32 |
1 files changed, 7 insertions, 25 deletions
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js index a317543d..7bb0b403 100644 --- a/tools/js-optimizer.js +++ b/tools/js-optimizer.js @@ -410,31 +410,6 @@ function optimizeShifts(ast) { subNode[3] = addShift(subNode[3]); return subNode; } - if (subNode[0] == 'binary' && subNode[1] == '<<' && subNode[3][0] == 'num') { - if (subNode[3][1] > shifts) { - subNode[3][1] -= shifts; - return subNode; - } - // fall through to >> case - subNode[1] = '>>'; - subNode[3][1] *= -1; - } - if (subNode[0] == 'binary' && subNode[1] == '>>') { - if (subNode[3][0] == 'num') { - subNode[3][1] += shifts; - // XXX this may be wrong, if we removed a |0 that assumed we had this >> which |0's anyhow! - // should we only do this if CORRECT_OVERFLOWS is false? need more metadata for that - if (subNode[3][1] == 0) return subNode[2]; - } else { - subNode[3] = ['binary', '+', subNode[3], ['num', shifts]]; - } - return subNode; - } - if (subNode[0] == 'num') { - assert(subNode[1] % Math.pow(2, shifts) == 0, subNode); - subNode[1] /= Math.pow(2, shifts); // bake the shift in - return subNode; - } if (subNode[0] == 'name' && !subNode[2]) { // names are returned with a shift, but we also note their being shifted var name = subNode[1]; if (vars[name]) { @@ -543,6 +518,13 @@ function optimizeShifts(ast) { } // Before recombining, do some additional optimizations traverse(fun, function(node, type) { + if (type == 'binary' && node[1] == '>>' && node[2][0] == 'num' && node[3][0] == 'num') { + var subNode = node[2]; + var shifts = node[3][1]; + assert(subNode[1] % Math.pow(2, shifts) == 0, subNode); + subNode[1] /= Math.pow(2, shifts); // bake the shift in + return subNode; + } // Optimize the case of ($a*80)>>2 if (type == 'binary' && node[1] in SIMPLE_SHIFTS && node[2][0] == 'binary' && node[2][1] == '*') { |