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authorAlex Lam S.L <alexlamsl@gmail.com>2018-01-29 15:13:25 +0800
committerGitHub <noreply@github.com>2018-01-29 15:13:25 +0800
commit6fa3fbeae84200c90ff47dde03545742a861be17 (patch)
tree215e071834d2e876aa925e651363c489324592ec
parent4eb4cb656cc4f3850c403689cf29e529f4c67944 (diff)
downloadtracifyjs-6fa3fbeae84200c90ff47dde03545742a861be17.tar.gz
tracifyjs-6fa3fbeae84200c90ff47dde03545742a861be17.zip
compress chained compound assignments (#2850)
-rw-r--r--lib/compress.js63
-rw-r--r--test/compress/collapse_vars.js11
-rw-r--r--test/compress/reduce_vars.js94
3 files changed, 125 insertions, 43 deletions
diff --git a/lib/compress.js b/lib/compress.js
index 07128aff..81af151b 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -320,6 +320,7 @@ merge(Compressor.prototype, {
function reset_def(compressor, def) {
def.assignments = 0;
+ def.chained = false;
def.direct_access = false;
def.escaped = false;
if (def.scope.uses_eval || def.scope.uses_with) {
@@ -485,19 +486,27 @@ merge(Compressor.prototype, {
});
def(AST_Assign, function(tw) {
var node = this;
- if (node.operator != "=" || !(node.left instanceof AST_SymbolRef)) return;
+ if (!(node.left instanceof AST_SymbolRef)) return;
var d = node.left.definition();
- if (safe_to_assign(tw, d, node.right)) {
- d.references.push(node.left);
- d.assignments++;
- d.fixed = function() {
- return node.right;
- };
- mark(tw, d, false);
- node.right.walk(tw);
- mark(tw, d, true);
- return true;
- }
+ var fixed = d.fixed;
+ if (!fixed && node.operator != "=") return;
+ if (!safe_to_assign(tw, d, node.right)) return;
+ d.references.push(node.left);
+ d.assignments++;
+ if (node.operator != "=") d.chained = true;
+ d.fixed = node.operator == "=" ? function() {
+ return node.right;
+ } : function() {
+ return make_node(AST_Binary, node, {
+ operator: node.operator.slice(0, -1),
+ left: fixed instanceof AST_Node ? fixed : fixed(),
+ right: node.right
+ });
+ };
+ mark(tw, d, false);
+ node.right.walk(tw);
+ mark(tw, d, true);
+ return true;
});
def(AST_Binary, function(tw) {
if (!lazy_op(this.operator)) return;
@@ -672,6 +681,32 @@ merge(Compressor.prototype, {
if (this.bfinally) this.bfinally.walk(tw);
return true;
});
+ def(AST_Unary, function(tw, descend) {
+ var node = this;
+ if (node.operator != "++" && node.operator != "--") return;
+ if (!(node.expression instanceof AST_SymbolRef)) return;
+ var d = node.expression.definition();
+ var fixed = d.fixed;
+ if (!fixed) return;
+ if (!safe_to_assign(tw, d, true)) return;
+ d.references.push(node.expression);
+ d.assignments++;
+ d.chained = true;
+ d.fixed = function() {
+ return make_node(AST_Binary, node, {
+ operator: node.operator.slice(0, -1),
+ left: make_node(AST_UnaryPrefix, node, {
+ operator: "+",
+ expression: fixed instanceof AST_Node ? fixed : fixed()
+ }),
+ right: make_node(AST_Number, node, {
+ value: 1
+ })
+ });
+ };
+ mark(tw, d, true);
+ return true;
+ });
def(AST_VarDef, function(tw, descend) {
var node = this;
var d = node.name.definition();
@@ -2946,7 +2981,7 @@ merge(Compressor.prototype, {
if (def.value.has_side_effects(compressor)) {
def.value.walk(tw);
}
- if (def.name.fixed_value() === def.value) {
+ if (!node_def.chained && def.name.fixed_value() === def.value) {
fixed_ids[node_def.id] = def;
}
}
@@ -3164,7 +3199,7 @@ merge(Compressor.prototype, {
&& self.variables.get(sym.name) === (node_def = sym.definition())) {
if (node instanceof AST_Assign) {
node.right.walk(tw);
- if (node.left.fixed_value() === node.right) {
+ if (!node_def.chained && node.left.fixed_value() === node.right) {
fixed_ids[node_def.id] = node;
}
}
diff --git a/test/compress/collapse_vars.js b/test/compress/collapse_vars.js
index 970f822e..4172b33b 100644
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -52,13 +52,8 @@ collapse_vars_side_effects_1: {
console.log.bind(console)(s.charAt(i++), s.charAt(i++), s.charAt(i++), 7);
}
function f2() {
- var log = console.log.bind(console),
- s = "abcdef",
- i = 2,
- x = s.charAt(i++),
- y = s.charAt(i++),
- z = s.charAt(i++);
- log(x, i, y, z, 7);
+ var s = "abcdef", i = 2;
+ console.log.bind(console)(s.charAt(i++), 5, s.charAt(i++), s.charAt(i++), 7);
}
function f3() {
var s = "abcdef",
@@ -72,7 +67,7 @@ collapse_vars_side_effects_1: {
var i = 10,
x = i += 2,
y = i += 3;
- console.log.bind(console)(x, i += 4, y, i);
+ console.log.bind(console)(x, i += 4, y, 19);
}
f1(), f2(), f3(), f4();
}
diff --git a/test/compress/reduce_vars.js b/test/compress/reduce_vars.js
index 4009c35b..2231587d 100644
--- a/test/compress/reduce_vars.js
+++ b/test/compress/reduce_vars.js
@@ -76,14 +76,12 @@ modified: {
console.log(a + 1);
console.log(b + 1);
}
-
function f1() {
var a = 1, b = 2;
--b;
console.log(a + 1);
console.log(b + 1);
}
-
function f2() {
var a = 1, b = 2, c = 3;
b = c;
@@ -92,7 +90,6 @@ modified: {
console.log(a + c);
console.log(a + b + c);
}
-
function f3() {
var a = 1, b = 2, c = 3;
b *= c;
@@ -101,7 +98,6 @@ modified: {
console.log(a + c);
console.log(a + b + c);
}
-
function f4() {
var a = 1, b = 2, c = 3;
if (a) {
@@ -114,28 +110,26 @@ modified: {
console.log(a + c);
console.log(a + b + c);
}
-
function f5(a) {
B = a;
- console.log(A ? 'yes' : 'no');
- console.log(B ? 'yes' : 'no');
+ console.log(typeof A ? "yes" : "no");
+ console.log(typeof B ? "yes" : "no");
}
+ f0(), f1(), f2(), f3(), f4(), f5();
}
expect: {
function f0() {
var b = 2;
b++;
console.log(2);
- console.log(b + 1);
+ console.log(4);
}
-
function f1() {
var b = 2;
--b;
console.log(2);
- console.log(b + 1);
+ console.log(2);
}
-
function f2() {
3;
console.log(4);
@@ -143,16 +137,14 @@ modified: {
console.log(4);
console.log(7);
}
-
function f3() {
var b = 2;
b *= 3;
- console.log(1 + b);
- console.log(b + 3);
+ console.log(7);
+ console.log(9);
console.log(4);
- console.log(1 + b + 3);
+ console.log(10);
}
-
function f4() {
var b = 2, c = 3;
b = c;
@@ -161,13 +153,33 @@ modified: {
console.log(1 + c);
console.log(1 + b + c);
}
-
function f5(a) {
B = a;
- console.log(A ? 'yes' : 'no');
- console.log(B ? 'yes' : 'no');
+ console.log(typeof A ? "yes" : "no");
+ console.log(typeof B ? "yes" : "no");
}
+ f0(), f1(), f2(), f3(), f4(), f5();
}
+ expect_stdout: [
+ "2",
+ "4",
+ "2",
+ "2",
+ "4",
+ "6",
+ "4",
+ "7",
+ "7",
+ "9",
+ "4",
+ "10",
+ "4",
+ "6",
+ "4",
+ "7",
+ "yes",
+ "yes",
+ ]
}
unsafe_evaluate: {
@@ -745,7 +757,7 @@ iife: {
expect: {
!function(a, b, c) {
b++;
- console.log(0, 1 * b, 5);
+ console.log(0, 3, 5);
}(1, 2, 3);
}
expect_stdout: true
@@ -766,7 +778,7 @@ iife_new: {
expect: {
var A = new function(a, b, c) {
b++;
- console.log(0, 1 * b, 5);
+ console.log(0, 3, 5);
}(1, 2, 3);
}
expect_stdout: true
@@ -5383,3 +5395,43 @@ issue_2836: {
}
expect_stdout: "PASS"
}
+
+lvalues_def_1: {
+ options = {
+ reduce_vars: true,
+ toplevel: true,
+ unused: true,
+ }
+ input: {
+ var b = 1;
+ var a = b++, b = NaN;
+ console.log(a, b);
+ }
+ expect: {
+ var b = 1;
+ var a = b++;
+ b = NaN;
+ console.log(a, b);
+ }
+ expect_stdout: "1 NaN"
+}
+
+lvalues_def_2: {
+ options = {
+ reduce_vars: true,
+ toplevel: true,
+ unused: true,
+ }
+ input: {
+ var b = 1;
+ var a = b += 1, b = NaN;
+ console.log(a, b);
+ }
+ expect: {
+ var b = 1;
+ var a = b += 1;
+ b = NaN;
+ console.log(a, b);
+ }
+ expect_stdout: "2 NaN"
+}