Check TRI->getReservedRegs because other allocators do it. Even though

it makes no sense for allocation_order iterators to visit reserved regs.
The inline spiller depends on AliasAnalysis.
Manage the Query state to avoid uninitialized or stale results.

llvm-svn: 118800

1 files changed, 12 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/RegAllocBase.h b/llvm/lib/CodeGen/RegAllocBase.h
index 8c3971dee14..c8c78567f87 100644
--- a/llvm/lib/CodeGen/RegAllocBase.h
+++ b/llvm/lib/CodeGen/RegAllocBase.h
@@ -106,6 +106,15 @@ protected:
   // A RegAlloc pass should call this before allocatePhysRegs.
   void init(const TargetRegisterInfo &tri, VirtRegMap &vrm, LiveIntervals &lis);
 
+  // Get an initialized query to check interferences between lvr and preg.  Note
+  // that Query::init must be called at least once for each physical register
+  // before querying a new live virtual register. This ties queries_ and
+  // physReg2liu_ together.
+  LiveIntervalUnion::Query &query(LiveInterval &lvr, unsigned preg) {
+    queries_[preg].init(&lvr, &physReg2liu_[preg]);
+    return queries_[preg];
+  }
+  
   // The top-level driver. The output is a VirtRegMap that us updated with
   // physical register assignments.
   //
@@ -135,7 +144,7 @@ protected:
   // Helper for spilling all live virtual registers currently unified under preg
   // that interfere with the most recently queried lvr.  Return true if spilling
   // was successful, and append any new spilled/split intervals to splitLVRs.
-  bool spillInterferences(unsigned preg,
+  bool spillInterferences(LiveInterval &lvr, unsigned preg,
                           SmallVectorImpl<LiveInterval*> &splitLVRs);
 
 #ifndef NDEBUG
@@ -146,7 +155,8 @@ protected:
 private:
   void seedLiveVirtRegs(LiveVirtRegQueue &lvrQ);
 
-  void spillReg(unsigned reg, SmallVectorImpl<LiveInterval*> &splitLVRs);
+  void spillReg(LiveInterval &lvr, unsigned reg,
+                SmallVectorImpl<LiveInterval*> &splitLVRs);
 };
 
 } // end namespace llvm