[PATCH] D14670: Fix bug 25440: GVN assertion after coercing loads

[Weiming Zhao via llvm-commits]

weimingz updated this revision to Diff 40465.
weimingz added a comment.

(this patch is mainly for discussion)

Hi Berlin,

Very appreciate for the explanation. 
My previous order about NextNum was indeed wrong, and thus addToLeaderTable was never executed, which masked the another problem:  
the newly created inst (%0) will get the VN before %sub.ptr.rhs.cast25. The NextNum check won’t prevent this.

Looks like we should only assign numbers for new instrs that would have been visited (we only do make ups). For new instrs inserted in future points, we just leave it and wait for it to be processed naturally.
But I can't find such support from existing GVN framework. I have an approximated solution in the patch.

Any suggestions?


http://reviews.llvm.org/D14670

Files:
  lib/Transforms/Scalar/GVN.cpp
  test/Transforms/GVN/pr25440.ll

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