tree 28af39e759c1e1f979ec2029a35b9d8cb9b107cd
parent 7e2d27bc554eb607c90e55c89d2537f5d711234c
author Thomas Lively <tlively@google.com> 1593911484 -0700
committer Thomas Lively <tlively@google.com> 1593911484 -0700

[WebAssembly] Do not assume br_table range checks will be gt_u

OSS-Fuzz and the Emscripten test suite uncovered some edge cases in
which the range check instruction seemed to be an (i32.const 0) or
other unexpected instruction, triggering an assertion. Unfortunately
the reproducers are rather complicated, so they don't make good unit
tests. This commit removes the bad assertion and conservatively
optimizes range checks only when the range check instruction is
i32.gt_u.

Differential Revision: https://reviews.llvm.org/D83169