tree 03538aa5c57449027c8ca8219192cba4a49f7fec
parent 83a049f2a65d6422049e094ad75cea2301b4f4b3
author Philip Reames <listmail@philipreames.com> 1430077683 +0000
committer Philip Reames <listmail@philipreames.com> 1430077683 +0000

[RewriteStatepointsForGC] Exclude constant values from being considered live at a safepoint

There can be various constant pointers in the IR which do not get relocated at a safepoint. One example is the address of a global variable. Another example is a pointer created via inttoptr. Note that the optimizer itself likes to create such inttoptrs when locally propagating constants through dynamically dead code.

To deal with this, we need to exclude uses of constants from contributing to the liveness of a safepoint which might reach that use. At some later date, it might be worth exploring what could be done to support the relocation of various special types of "constants", but that's future work.

Differential Revision: http://reviews.llvm.org/D9236


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235821 91177308-0d34-0410-b5e6-96231b3b80d8