Numeric literals and Number() with exponents > 308 or < -324 ignore the significand decimal shift #5320

Numeric literals and Number(string) check whether the explicit exponent exceeds 308 or -324 before adding the decimal offset from the significand's digits, prematurely returning Infinity or 0. In ecma_utf8_string_to_number, exponent_sign * exponent is compared against NUMBER_MAX_DECIMAL_EXPONENT (308) and NUMBER_MIN_DECIMAL_EXPONENT (-324) inside the exponent loop before decimal_exponent is added.

JerryScript revision

v3.0.0 (b7069350c)

Build platform

macOS 26.3 (Darwin 25.3.0 arm64)

Build steps

tools/build.py --clean --debug

Test case

print(0.1e309);
print(50e-325);
print(Number("100e-325"));

Execution steps

build/bin/jerry testcase.js

Output

Infinity
0
0

Expected behavior

1e+308
5e-324
1e-323

V8, SpiderMonkey, and JavaScriptCore print 1e+308, 5e-324, and 1e-323 per ECMA-262 StringNumericValue.

Credit: https://ucsbplse.github.io/