[all-commits] [llvm/llvm-project] c5d1cc: [GVN] Properly invalidate ICF cache when we simpli...

[aeubanks via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c5d1ccbcdfb11c29c89a2789ac1e89cf4b270be7
      https://github.com/llvm/llvm-project/commit/c5d1ccbcdfb11c29c89a2789ac1e89cf4b270be7
  Author: Arthur Eubanks <aeubanks at google.com>
  Date:   2021-04-08 (Thu, 08 Apr 2021)

  Changed paths:
    M llvm/include/llvm/Analysis/InstructionPrecedenceTracking.h
    M llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
    M llvm/lib/Transforms/Scalar/GVN.cpp
    A llvm/test/Transforms/GVN/simplify-icf-cache-invalidation.ll

  Log Message:
  -----------
  [GVN] Properly invalidate ICF cache when we simplify a value

This fixes a "Cached first special instruction is wrong!" assert.

The assert fires because replacing a value with another can cause an
instruction to no longer be "special" to ICF. In this case,
devirtualization happened, turning an indirect call to a
call to a willreturn function which is no longer special.

Reviewed By: nikic, rnk

Differential Revision: https://reviews.llvm.org/D99977