Duncan P. N. Exon Smith 1cfbb6358c IR: Reduce RAUW traffic in ConstantExpr
Avoid RAUW-ing `ConstantExpr` when an operand changes unless the new
`ConstantExpr` already has users.  This prevents the RAUW from rippling
up the expression tree unnecessarily.

This commit indirectly adds test coverage for r215953 (this is how I
came across the bug).

This is part of PR20515.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215960 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 01:12:53 +00:00
..
2014-08-18 22:18:14 +00:00
2014-08-18 23:15:59 +00:00