Commit Graph

3 Commits

Author SHA1 Message Date
Thomas Lively 755a895915 Revert "[WebAssembly] Eliminate range checks on br_tables"
This reverts commit f99d5f8c32.
The change was causing UBSan and other failures on some bots.
2020-06-03 01:26:53 -07:00
Thomas Lively f99d5f8c32 [WebAssembly] Eliminate range checks on br_tables
Summary:
Jump tables for most targets cannot handle out of range indices by
themselves, so LLVM emits range checks to guard the jump
tables. WebAssembly, on the other hand, implements jump tables using
the br_table instruction, which takes a default branch target as an
operand, making the range checks redundant. This patch introduces a
new MachineFunction pass in the WebAssembly backend to find and
eliminate the redundant range checks.

Reviewers: aheejin, dschuff

Subscribers: mgorny, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80863
2020-06-02 13:14:27 -07:00
Derek Schuff ec4be57655 [WebAssembly] Enable IndirectBrExpandPass
Wasm doesn't have a direct way to lower indirectbr, so hook up the
IndirectBrExpandPass to lower indirectbr into a switch.

Fixes PR42498

Reviewers: aheejin

Differential Revision: https://reviews.llvm.org/D64161

llvm-svn: 365096
2019-07-03 23:54:06 +00:00