diff options
Diffstat (limited to 'lib/compress.js')
| -rw-r--r-- | lib/compress.js | 76 |
1 files changed, 57 insertions, 19 deletions
diff --git a/lib/compress.js b/lib/compress.js index c4aee690..3653a5fa 100644 --- a/lib/compress.js +++ b/lib/compress.js @@ -8424,7 +8424,6 @@ merge(Compressor.prototype, { OPT(AST_Switch, function(self, compressor) { if (!compressor.option("switches")) return self; - var branch; var value = self.expression.evaluate(compressor); if (!(value instanceof AST_Node)) { var orig = self.expression; @@ -8435,10 +8434,12 @@ merge(Compressor.prototype, { if (value instanceof AST_Node) { value = self.expression.evaluate(compressor, true); } - var decl = []; var body = []; + var branch; + var decl = []; var default_branch; var exact_match; + var side_effects = []; for (var i = 0, len = self.body.length; i < len && !exact_match; i++) { branch = self.body[i]; if (branch instanceof AST_Default) { @@ -8450,13 +8451,9 @@ merge(Compressor.prototype, { default_branch = branch; } } else if (!(value instanceof AST_Node)) { - var exp = branch.expression.evaluate(compressor); - if (!(exp instanceof AST_Node) && exp !== value) { - eliminate_branch(branch, body[body.length - 1]); - continue; - } - if (exp instanceof AST_Node) exp = branch.expression.evaluate(compressor, true); - if (exp === value) { + var exp = branch.expression; + var val = exp.evaluate(compressor, true); + if (val === value) { exact_match = branch; if (default_branch) { var default_index = body.indexOf(default_branch); @@ -8464,18 +8461,41 @@ merge(Compressor.prototype, { eliminate_branch(default_branch, body[default_index - 1]); default_branch = null; } + } else if (!(val instanceof AST_Node)) { + if (exp.has_side_effects(compressor)) side_effects.push(exp); + eliminate_branch(branch, body[body.length - 1]); + continue; } } - if (aborts(branch)) { + if (exact_match || i == len - 1 || aborts(branch)) { var prev = body[body.length - 1]; - if (aborts(prev) && prev.body.length == branch.body.length - && make_node(AST_BlockStatement, prev, prev).equivalent_to(make_node(AST_BlockStatement, branch, branch))) { - prev.body = []; + var statements = branch.body; + if (aborts(prev)) switch (prev.body.length - statements.length) { + case 1: + var stat = prev.body[prev.body.length - 1]; + if (!is_break(stat, compressor)) break; + statements = statements.concat(stat); + case 0: + var prev_block = make_node(AST_BlockStatement, prev, prev); + var next_block = make_node(AST_BlockStatement, branch, { body: statements }); + if (prev_block.equivalent_to(next_block)) prev.body = []; + } + } + if (side_effects.length) { + if (branch instanceof AST_Default) { + body.push(make_node(AST_Case, self, { expression: make_sequence(self, side_effects), body: [] })); + } else { + side_effects.push(branch.expression); + branch.expression = make_sequence(self, side_effects); } + side_effects = []; } body.push(branch); } while (i < len) eliminate_branch(self.body[i++], body[body.length - 1]); + if (side_effects.length && !exact_match) { + body.push(make_node(AST_Case, self, { expression: make_sequence(self, side_effects), body: [] })); + } while (branch = body[body.length - 1]) { var stat = branch.body[branch.body.length - 1]; if (is_break(stat, compressor)) branch.body.pop(); @@ -8492,12 +8512,30 @@ merge(Compressor.prototype, { eliminate_branch(branch); if (body.pop() === default_branch) default_branch = null; } - if (body.length == 0) { - return make_node(AST_BlockStatement, self, { - body: decl.concat(make_node(AST_SimpleStatement, self.expression, { - body: self.expression - })) - }).optimize(compressor); + if (!branch) { + decl.push(make_node(AST_SimpleStatement, self.expression, { body: self.expression })); + if (side_effects.length) decl.push(make_node(AST_SimpleStatement, self, { + body: make_sequence(self, side_effects), + })); + return make_node(AST_BlockStatement, self, { body: decl }).optimize(compressor); + } + if (exact_match ? !branch.expression.has_side_effects(compressor) : branch === default_branch) { + while (branch = body[body.length - 2]) { + if (branch instanceof AST_Default) break; + if (!has_declarations_only(branch)) break; + var exp = branch.expression; + if (exp.has_side_effects(compressor)) { + var prev = body[body.length - 3]; + if (prev && !aborts(prev)) break; + if (exact_match) { + exact_match.expression = make_sequence(self, [ exp, exact_match.expression ]); + } else { + default_branch.body.unshift(make_node(AST_SimpleStatement, self, { body: exp })); + } + } + eliminate_branch(branch); + body.splice(-2, 1); + } } body[0].body = decl.concat(body[0].body); self.body = body; |