[SCCP] Can't go from overdefined to constant
authorDavid Majnemer <david.majnemer@gmail.com>
Thu, 7 Jan 2016 19:25:39 +0000 (19:25 +0000)
committerDavid Majnemer <david.majnemer@gmail.com>
Thu, 7 Jan 2016 19:25:39 +0000 (19:25 +0000)
commite9b0c81b34562003bbe86393d6cc291249dcece0
treefab791020157e2c40e8c0a75152163de7da0ffd4
parente310804af05622fd5056ac0ef8950ff5fc998fec
[SCCP] Can't go from overdefined to constant

The fix for PR23999 made us mark loads of null as producing the constant
undef which upsets the lattice.  Instead, keep the load as "undefined".
This fixes PR26044.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257087 91177308-0d34-0410-b5e6-96231b3b80d8
lib/Transforms/Scalar/SCCP.cpp
test/Transforms/IPConstantProp/PR26044.ll [new file with mode: 0644]