case Token::NOT: {
Comment cmnt(masm_, "[ UnaryOperation (NOT)");
- Label materialize_true, materialize_false;
- Label* if_true = NULL;
- Label* if_false = NULL;
- Label* fall_through = NULL;
-
- // Notice that the labels are swapped.
- context()->PrepareTest(&materialize_true, &materialize_false,
- &if_false, &if_true, &fall_through);
- if (context()->IsTest()) ForwardBailoutToChild(expr);
- VisitForControl(expr->expression(), if_true, if_false, fall_through);
- context()->Plug(if_false, if_true); // Labels swapped.
+ if (context()->IsEffect()) {
+ // Unary NOT has no side effects so it's only necessary to visit the
+ // subexpression. Match the optimizing compiler by not branching.
+ VisitForEffect(expr->expression());
+ } else {
+ Label materialize_true, materialize_false;
+ Label* if_true = NULL;
+ Label* if_false = NULL;
+ Label* fall_through = NULL;
+
+ // Notice that the labels are swapped.
+ context()->PrepareTest(&materialize_true, &materialize_false,
+ &if_false, &if_true, &fall_through);
+ if (context()->IsTest()) ForwardBailoutToChild(expr);
+ VisitForControl(expr->expression(), if_true, if_false, fall_through);
+ context()->Plug(if_false, if_true); // Labels swapped.
+ }
break;
}
case Token::NOT: {
Comment cmnt(masm_, "[ UnaryOperation (NOT)");
-
- Label materialize_true, materialize_false;
- Label* if_true = NULL;
- Label* if_false = NULL;
- Label* fall_through = NULL;
- // Notice that the labels are swapped.
- context()->PrepareTest(&materialize_true, &materialize_false,
- &if_false, &if_true, &fall_through);
- if (context()->IsTest()) ForwardBailoutToChild(expr);
- VisitForControl(expr->expression(), if_true, if_false, fall_through);
- context()->Plug(if_false, if_true); // Labels swapped.
+ if (context()->IsEffect()) {
+ // Unary NOT has no side effects so it's only necessary to visit the
+ // subexpression. Match the optimizing compiler by not branching.
+ VisitForEffect(expr->expression());
+ } else {
+ Label materialize_true, materialize_false;
+ Label* if_true = NULL;
+ Label* if_false = NULL;
+ Label* fall_through = NULL;
+ // Notice that the labels are swapped.
+ context()->PrepareTest(&materialize_true, &materialize_false,
+ &if_false, &if_true, &fall_through);
+ if (context()->IsTest()) ForwardBailoutToChild(expr);
+ VisitForControl(expr->expression(), if_true, if_false, fall_through);
+ context()->Plug(if_false, if_true); // Labels swapped.
+ }
break;
}
case Token::NOT: {
Comment cmnt(masm_, "[ UnaryOperation (NOT)");
- Label materialize_true, materialize_false;
- Label* if_true = NULL;
- Label* if_false = NULL;
- Label* fall_through = NULL;
- // Notice that the labels are swapped.
- context()->PrepareTest(&materialize_true, &materialize_false,
- &if_false, &if_true, &fall_through);
- if (context()->IsTest()) ForwardBailoutToChild(expr);
- VisitForControl(expr->expression(), if_true, if_false, fall_through);
- context()->Plug(if_false, if_true); // Labels swapped.
+ if (context()->IsEffect()) {
+ // Unary NOT has no side effects so it's only necessary to visit the
+ // subexpression. Match the optimizing compiler by not branching.
+ VisitForEffect(expr->expression());
+ } else {
+ Label materialize_true, materialize_false;
+ Label* if_true = NULL;
+ Label* if_false = NULL;
+ Label* fall_through = NULL;
+ // Notice that the labels are swapped.
+ context()->PrepareTest(&materialize_true, &materialize_false,
+ &if_false, &if_true, &fall_through);
+ if (context()->IsTest()) ForwardBailoutToChild(expr);
+ VisitForControl(expr->expression(), if_true, if_false, fall_through);
+ context()->Plug(if_false, if_true); // Labels swapped.
+ }
break;
}
// Deoptimization after a logical not in an effect context should not see a
// value for the logical not expression.
-function test(n) {
+function test0(n) {
var a = new Array(n);
for (var i = 0; i < n; ++i) {
// ~ of a non-numeric value is used to trigger deoptimization.
// OSR (after deoptimization) is used to observe the stack height mismatch.
for (var i = 0; i < 5; ++i) {
for (var j = 1; j < 12; ++j) {
- test(j * 1000);
+ test0(j * 1000);
}
}
+
+
+// Similar test with a different subexpression of unary !.
+function test1(n) {
+ var a = new Array(n);
+ for (var i = 0; i < n; ++i) {
+ a[i] = void(!(- 'object')) % ~(delete 4);
+ }
+}
+
+for (i = 0; i < 5; ++i) {
+ for (j = 1; j < 12; ++j) {
+ test1(j * 1000);
+ }
+}
+
+
+// A similar issue, different subexpression of unary ! (e0 !== e1 is
+// translated into !(e0 == e1)) and different effect context.
+function side_effect() { }
+function observe(x, y) { return x; }
+function test2(x) {
+ return observe(this,
+ (((side_effect.observe <= side_effect.side_effect) !== false),
+ x + 1));
+}
+
+for (var i = 0; i < 1000000; ++i) test2(0);
+test2(test2);