[PATCH] D18155: Instcombine: try to avoid wasted work in ConstantFold

[escha via llvm-commits]

escha added a comment.

> Why not do the following:

> 

> 1. Drop instructions that are dead.

> 2. Check to see if any ConstExpr operands are foldable, and update the instruction

> 3. If constant, fold the constant. [no longer needs to consider constexprs]

> 4. Add to the initial instcombine worklist.


that's literally what this patch does


Repository:
  rL LLVM

http://reviews.llvm.org/D18155