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[turbofan] Fix bug in String.fromCharCode optimization

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The optimization was replacing
  String.fromCharCode(x) == "y"
with x == y instead of (x & 0xFFFF) == y if x was outside
of uint16 range.

Bug: v8:7340, v8:7531
Change-Id: I967306cc2e05c28de82e16cf1b2312fe47396a7d
Reviewed-on: https://chromium-review.googlesource.com/979808
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52214}
This commit is contained in:
Sigurd Schneider 2018-03-26 10:40:24 +02:00 committed by Commit Bot
parent de66f94d18
commit 44d59bf7f1
2 changed files with 13 additions and 0 deletions
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9
src/compiler/typed-optimization.cc
View File

@ -409,6 +409,15 @@ TypedOptimization::TryReduceStringComparisonOfStringFromSingleCharCode(
const Operator* comparison_op = NumberComparisonFor(comparison->op());
Node* from_char_code_repl = NodeProperties::GetValueInput(from_char_code, 0);
Type* from_char_code_repl_type = NodeProperties::GetType(from_char_code_repl);
if (!from_char_code_repl_type->Is(type_cache_.kUint16)) {
// Convert to signed int32 to satisfy type of {NumberBitwiseAnd}.
from_char_code_repl =
graph()->NewNode(simplified()->NumberToInt32(), from_char_code_repl);
from_char_code_repl = graph()->NewNode(
simplified()->NumberBitwiseAnd(), from_char_code_repl,
jsgraph()->Constant(std::numeric_limits<uint16_t>::max()));
}
Node* constant_repl = jsgraph()->Constant(string->Get(0));
Node* number_comparison = nullptr;

4
test/mjsunit/constant-folding-2.js
View File

@ -275,6 +275,10 @@ test(function stringCodePointAt() {
assertSame(undefined, "äϠ<C3A4>".codePointAt(1 + 4294967295));
}, 10);
test(function stringFromCharCode() {
assertEquals("！", String.fromCharCode(0x10FF01));
}, 2);
test(function int32Mod() {
assertEquals(-0, -2147483648 % (-1));
});