[PATCH] D83017: [WebAssembly] Do not omit range checks for i64 switches

[Thomas Lively via Phabricator via llvm-commits]

tlively created this revision.
tlively added reviewers: aheejin, dschuff, kripken.
Herald added subscribers: llvm-commits, sunfish, hiraditya, jgravelle-google, sbc100.
Herald added a project: LLVM.
tlively edited the summary of this revision.

Since the br_table instruction takes an i32, switches over
i64s (and larger integers) must use the i32.wrap_i64 instruction to
truncate the table index. This truncation makes numbers just over 2^32
indistinguishable from small numbers, so it was a miscompilation to
omit the range check preceding these br_tables. This change fixes the
problem by skipping the "fixing" of the br_table when its index is the
result of a i32.wrap_i64 instruction.

Fixes PR46447.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D83017

Files:
  llvm/lib/Target/WebAssembly/WebAssemblyFixBrTableDefaults.cpp
  llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
  llvm/test/CodeGen/WebAssembly/switch.ll

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