From: Dan Gohman <gohman@apple.com>
Date: Wed, 3 Dec 2008 19:30:13 +0000 (+0000)
Subject: Add a comment about callee-saved registers.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ebb0a31103f353e330ea998f1a9e283a387b6ef7;p=oota-llvm.git

Add a comment about callee-saved registers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60495 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index 09125d04887..bd9783281cc 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -278,6 +278,8 @@ bool SchedulePostRATDList::BreakAntiDependencies() {
   // TODO: If the callee saves and restores these, then we can potentially
   // use them between the save and the restore. To do that, we could scan
   // the exit blocks to see which of these registers are defined.
+  // Alternatively, calle-saved registers that aren't saved and restored
+  // could be marked live-in in every block.
   for (const unsigned *I = TRI->getCalleeSavedRegs(); *I; ++I) {
     unsigned Reg = *I;
     Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);