HomePhabricator

[RS4GC] Avoid crashing on gep scalar_base, vector_idx

Authored by reames on Jan 24 2019, 8:08 AM.

Description

[RS4GC] Avoid crashing on gep scalar_base, vector_idx

This is an alternative to https://reviews.llvm.org/D57103. After discussion, we dedicided to check this in as a temporary workaround, and pursue a true fix under the original thread.

The issue at hand is that the base rewriting algorithm doesn't consider the fact that GEPs can turn a scalar input into a vector of outputs. We had handling for scalar GEPs and fully vector GEPs (i.e. all vector operands), but not the scalar-base + vector-index forms. A true fix here requires treating GEP analogously to extractelement or shufflevector.

This patch is merely a workaround. It simply hides the crash at the cost of some ugly code gen for this presumable very rare pattern.

Differential Revision: https://reviews.llvm.org/D57138

llvm-svn: 352059

Details

Committed
reamesJan 24 2019, 8:08 AM
Differential Revision
D57138: [RS4GC] Avoid crashing on gep scalar, vector_idx
Parents
rGf7098b3a041e: [CMake] Get back some variables used in AddLLVM.cmake
Branches
Unknown
Tags
Unknown