summaryrefslogtreecommitdiffstats
path: root/js/src/jit-test/tests/warp/string-substring-startswith-constant-string.js
diff options
context:
space:
mode:
Diffstat (limited to 'js/src/jit-test/tests/warp/string-substring-startswith-constant-string.js')
-rw-r--r--js/src/jit-test/tests/warp/string-substring-startswith-constant-string.js92
1 files changed, 92 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/warp/string-substring-startswith-constant-string.js b/js/src/jit-test/tests/warp/string-substring-startswith-constant-string.js
new file mode 100644
index 0000000000..74ecef570d
--- /dev/null
+++ b/js/src/jit-test/tests/warp/string-substring-startswith-constant-string.js
@@ -0,0 +1,92 @@
+// Test case to cover String.prototype.substring as startsWith with a constant search string.
+//
+// String.prototype.substring comparison with a short (≤32 characters) constant string is
+// optimised during lowering.
+
+function* characters(...ranges) {
+ for (let [start, end] of ranges) {
+ for (let i = start; i <= end; ++i) {
+ yield i;
+ }
+ }
+}
+
+const ascii = [...characters(
+ [0x41, 0x5A], // A..Z
+ [0x61, 0x7A], // a..z
+ [0x30, 0x39], // 0..9
+)];
+
+const latin1 = [...characters(
+ [0xC0, 0xFF], // À..ÿ
+)];
+
+const twoByte = [...characters(
+ [0x100, 0x17E], // Ā..ž
+)];
+
+function toRope(s) {
+ // Ropes have at least two characters.
+ if (s.length < 2) {
+ return s;
+ }
+ if (s.length === 2) {
+ return newRope(s[0], s[1]);
+ }
+ return newRope(s[0], s.substring(1));
+}
+
+function atomize(s) {
+ return Object.keys({[s]: 0})[0];
+}
+
+const operators = [
+ "==", "===", "!=", "!==",
+];
+
+for (let i = 1; i <= 32; ++i) {
+ let strings = [ascii, latin1, twoByte].flatMap(codePoints => [
+ // Same string as the input.
+ String.fromCodePoint(...codePoints.slice(0, i)),
+
+ // Same length as the input, but a different string.
+ String.fromCodePoint(...codePoints.slice(1, i + 1)),
+
+ // Shorter string than the input.
+ String.fromCodePoint(...codePoints.slice(0, i - 1)),
+
+ // Longer string than the input.
+ String.fromCodePoint(...codePoints.slice(0, i + 1)),
+ ]).flatMap(x => [
+ x,
+ toRope(x),
+ newString(x, {twoByte: true}),
+ atomize(x),
+ ]);
+
+ for (let codePoints of [ascii, latin1, twoByte]) {
+ let str = String.fromCodePoint(...codePoints.slice(0, i));
+
+ for (let op of operators) {
+ let fn = Function("strings", `
+ const expected = strings.map(x => {
+ // Prevent Warp compilation when computing the expected results.
+ with ({}) ;
+ return x.substring(0, ${str.length}) ${op} "${str}";
+ });
+
+ for (let i = 0; i < 250; ++i) {
+ let idx = i % strings.length;
+ let str = strings[idx];
+
+ let lhs = str.substring(0, ${str.length}) ${op} "${str}";
+ if (lhs !== expected[idx]) throw new Error();
+
+ let rhs = "${str}" ${op} str.substring(0, ${str.length});
+ if (rhs !== expected[idx]) throw new Error();
+ }
+ `);
+ fn(strings);
+ }
+ }
+}