From: Evan Cheng <evan.cheng@apple.com>
Date: Sat, 7 Feb 2009 01:21:47 +0000 (+0000)
Subject: Don't sink the instruction if TargetRegisterInfo::isSafeToMoveRegClassDefs doesn... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b6f5417edb8ad11e06d3a6527e452945e5349a97;p=oota-llvm.git

Don't sink the instruction if TargetRegisterInfo::isSafeToMoveRegClassDefs doesn't think it's safe. This works around PR1911.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63994 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/MachineSink.cpp b/lib/CodeGen/MachineSink.cpp
index 87114396f9e..a85a41fbaee 100644
--- a/lib/CodeGen/MachineSink.cpp
+++ b/lib/CodeGen/MachineSink.cpp
@@ -167,6 +167,10 @@ bool MachineSinking::SinkInstruction(MachineInstr *MI, bool &SawStore) {
     } else {
       // Virtual register uses are always safe to sink.
       if (MO.isUse()) continue;
+
+      // If it's not safe to move defs of the register class, then abort.
+      if (!TII->isSafeToMoveRegClassDefs(RegInfo->getRegClass(Reg)))
+        return false;
       
       // FIXME: This picks a successor to sink into based on having one
       // successor that dominates all the uses.  However, there are cases where