Do a separate pass to compute spill weights because doing it inline

with live intervals was missing registers that were used before they
were defined (in the arbitrary order live intervals numbers
instructions).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10603 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 10 deletions

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index e4b134bc9d..b34a65bc64 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -106,6 +106,33 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
 
     computeIntervals();
 
+    // compute spill weights
+    const LoopInfo& loopInfo = getAnalysis<LoopInfo>();
+
+    for (MbbIndex2MbbMap::iterator
+             it = mbbi2mbbMap_.begin(), itEnd = mbbi2mbbMap_.end();
+         it != itEnd; ++it) {
+        MachineBasicBlock* mbb = it->second;
+
+        unsigned loopDepth = loopInfo.getLoopDepth(mbb->getBasicBlock());
+
+        for (MachineBasicBlock::iterator mi = mbb->begin(), miEnd = mbb->end();
+             mi != miEnd; ++mi) {
+            MachineInstr* instr = *mi;
+            for (int i = instr->getNumOperands() - 1; i >= 0; --i) {
+                MachineOperand& mop = instr->getOperand(i);
+
+                if (!mop.isVirtualRegister())
+                    continue;
+
+                unsigned reg = mop.getAllocatedRegNum();
+                Reg2IntervalMap::iterator r2iit = r2iMap_.find(reg);
+                assert(r2iit != r2iMap_.end());
+                intervals_[r2iit->second].weight += pow(10.0F, loopDepth);
+            }
+        }
+    }
+
     return true;
 }
 
@@ -255,8 +282,6 @@ void LiveIntervals::computeIntervals()
 {
     DEBUG(std::cerr << "computing live intervals:\n");
 
-    const LoopInfo& loopInfo = getAnalysis<LoopInfo>();
-
     for (MbbIndex2MbbMap::iterator
              it = mbbi2mbbMap_.begin(), itEnd = mbbi2mbbMap_.end();
          it != itEnd; ++it) {
@@ -264,8 +289,6 @@ void LiveIntervals::computeIntervals()
         DEBUG(std::cerr << "machine basic block: "
               << mbb->getBasicBlock()->getName() << "\n");
 
-        unsigned loopDepth = loopInfo.getLoopDepth(mbb->getBasicBlock());
-
         for (MachineBasicBlock::iterator mi = mbb->begin(), miEnd = mbb->end();
              mi != miEnd; ++mi) {
             MachineInstr* instr = *mi;
@@ -296,12 +319,6 @@ void LiveIntervals::computeIntervals()
                     else
                         handleVirtualRegisterDef(mbb, mi, reg);
                 }
-
-                // update weights
-                Reg2IntervalMap::iterator r2iit = r2iMap_.find(reg);
-                if (r2iit != r2iMap_.end() &&
-                    reg >= MRegisterInfo::FirstVirtualRegister)
-                    intervals_[r2iit->second].weight += pow(10.0F, loopDepth);
             }
         }
     }