From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Wed, 20 Apr 2011 22:14:17 +0000 (+0000)
Subject: Permit remat when a virtual register has multiple defs.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=08c5a347a05e73a34c70ec8b694b1e89b96a6bf5;p=oota-llvm.git

Permit remat when a virtual register has multiple defs.

TII::isTriviallyReMaterializable() shouldn't depend on any properties of the
register being defined by the instruction. Rematerialization is going to create
a new virtual register anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129882 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 15340a3f108..b9fcd3804d7 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -388,11 +388,6 @@ isReallyTriviallyReMaterializableGeneric(const MachineInstr *MI,
     if (MO.isDef() != (i == 0))
       return false;
 
-    // For the def, it should be the only def of that register.
-    if (MO.isDef() && (llvm::next(MRI.def_begin(Reg)) != MRI.def_end() ||
-                       MRI.isLiveIn(Reg)))
-      return false;
-
     // Don't allow any virtual-register uses. Rematting an instruction with
     // virtual register uses would length the live ranges of the uses, which
     // is not necessarily a good idea, certainly not "trivial".