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| author | Alex Lam S.L <alexlamsl@gmail.com> | 2019-11-13 20:03:48 +0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-11-13 20:03:48 +0800 |
| commit | ab15c40770410e0dbd5ebb382aa711f3bf5aeb38 (patch) | |
| tree | 186c86c12429be17746ca1f909e8c936980ed4f3 /lib | |
| parent | fe65ce965885815a30d88aa7d9eccec5443e6a3b (diff) | |
| download | tracifyjs-ab15c40770410e0dbd5ebb382aa711f3bf5aeb38.tar.gz tracifyjs-ab15c40770410e0dbd5ebb382aa711f3bf5aeb38.zip | |
enhance `switches` (#3583)
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/compress.js | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/lib/compress.js b/lib/compress.js index de07080f..92e8d3a3 100644 --- a/lib/compress.js +++ b/lib/compress.js @@ -4828,10 +4828,12 @@ merge(Compressor.prototype, { for (var i = 0, len = self.body.length; i < len && !exact_match; i++) { branch = self.body[i]; if (branch instanceof AST_Default) { - if (!default_branch) { - default_branch = branch; + var prev = body[body.length - 1]; + if (default_branch || is_break(branch.body[0], compressor) && (!prev || aborts(prev))) { + eliminate_branch(branch, prev); + continue; } else { - eliminate_branch(branch, body[body.length - 1]); + default_branch = branch; } } else if (!(value instanceof AST_Node)) { var exp = branch.expression.evaluate(compressor); @@ -4857,7 +4859,14 @@ merge(Compressor.prototype, { prev.body = []; } } - body.push(branch); + if (default_branch + && default_branch.body.length == 0 + && body[body.length - 1] === default_branch + && !branch.expression.has_side_effects(compressor)) { + default_branch.body = branch.body.slice(); + } else { + body.push(branch); + } } while (i < len) eliminate_branch(self.body[i++], body[body.length - 1]); if (body.length > 0) { @@ -4866,8 +4875,7 @@ merge(Compressor.prototype, { self.body = body; while (branch = body[body.length - 1]) { var stat = branch.body[branch.body.length - 1]; - if (stat instanceof AST_Break && compressor.loopcontrol_target(stat) === self) - branch.body.pop(); + if (is_break(stat, compressor)) branch.body.pop(); if (branch.body.length || branch instanceof AST_Case && (default_branch || branch.expression.has_side_effects(compressor))) break; if (body.pop() === default_branch) default_branch = null; @@ -4885,8 +4893,7 @@ merge(Compressor.prototype, { if (has_break || node instanceof AST_Lambda || node instanceof AST_SimpleStatement) return true; - if (node instanceof AST_Break && tw.loopcontrol_target(node) === self) - has_break = true; + if (is_break(node, tw)) has_break = true; }); self.walk(tw); if (!has_break) { @@ -4905,6 +4912,10 @@ merge(Compressor.prototype, { } return self; + function is_break(node, tw) { + return node instanceof AST_Break && tw.loopcontrol_target(node) === self; + } + function eliminate_branch(branch, prev) { if (prev && !aborts(prev)) { prev.body = prev.body.concat(branch.body); |