tree e4175cc9d02bd86754df69d950cef2c2e5803eda
parent 9ed8afc86da83bb307213d728029463f2210b891
author serge-sans-paille <sguelton@redhat.com> 1583230238 +0100
committer Copybara-Service <copybara-worker@google.com> 1616739650 -0700

Syndicate, test and fix base64 implementation

llvm/Support/Base64, fix its implementation and provide a decent test suite.

Previous implementation code was using + operator instead of | to combine

results, which is a problem when shifting signed values. (0xFF << 16) is
implicitly converted to a (signed) int, and thus results in 0xffff0000,
h is
negative. Combining negative numbers with a + in that context is not what we
want to do.

This is a recommit of 5a1958f2673f8c771e406a7e309e160b432c9a79 with UB removved.

This fixes https://github.com/llvm/llvm-project/issues/149.

Differential Revision: https://reviews.llvm.org/D75057

GitOrigin-RevId: 1454c27b60447d969d0c1ecaf20b2186fe9d85ec