X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FCalcSpillWeights.cpp;h=1f6909028eab862ee569d49dc52f60f6a99f603c;hb=0526d167a9f8fcd476f4382d933dda208a4eb5c8;hp=4833731fc177a34a186458aa1080f2fac75c1c93;hpb=76604af7748badc535017534f5f4c627516fdd7a;p=oota-llvm.git

diff --git a/lib/CodeGen/CalcSpillWeights.cpp b/lib/CodeGen/CalcSpillWeights.cpp
index 4833731fc17..1f6909028ea 100644
--- a/lib/CodeGen/CalcSpillWeights.cpp
+++ b/lib/CodeGen/CalcSpillWeights.cpp
@@ -7,8 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "calcspillweights"
-
 #include "llvm/CodeGen/CalcSpillWeights.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
@@ -20,8 +18,11 @@
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
 using namespace llvm;
 
+#define DEBUG_TYPE "calcspillweights"
+
 void llvm::calculateSpillWeightsAndHints(LiveIntervals &LIS,
                            MachineFunction &MF,
                            const MachineLoopInfo &MLI,
@@ -95,9 +96,9 @@ static bool isRematerializable(const LiveInterval &LI,
 void
 VirtRegAuxInfo::calculateSpillWeightAndHint(LiveInterval &li) {
   MachineRegisterInfo &mri = MF.getRegInfo();
-  const TargetRegisterInfo &tri = *MF.getTarget().getRegisterInfo();
-  MachineBasicBlock *mbb = 0;
-  MachineLoop *loop = 0;
+  const TargetRegisterInfo &tri = *MF.getSubtarget().getRegisterInfo();
+  MachineBasicBlock *mbb = nullptr;
+  MachineLoop *loop = nullptr;
   bool isExiting = false;
   float totalWeight = 0;
   SmallPtrSet<MachineInstr*, 8> visited;
@@ -149,7 +150,11 @@ VirtRegAuxInfo::calculateSpillWeightAndHint(LiveInterval &li) {
     unsigned hint = copyHint(mi, li.reg, tri, mri);
     if (!hint)
       continue;
-    float hweight = Hint[hint] += weight;
+    // Force hweight onto the stack so that x86 doesn't add hidden precision,
+    // making the comparison incorrectly pass (i.e., 1 > 1 == true??).
+    //
+    // FIXME: we probably shouldn't use floats at all.
+    volatile float hweight = Hint[hint] += weight;
     if (TargetRegisterInfo::isPhysicalRegister(hint)) {
       if (hweight > bestPhys && mri.isAllocatable(hint))
         bestPhys = hweight, hintPhys = hint;
@@ -182,7 +187,7 @@ VirtRegAuxInfo::calculateSpillWeightAndHint(LiveInterval &li) {
   // it is a preferred candidate for spilling.
   // FIXME: this gets much more complicated once we support non-trivial
   // re-materialization.
-  if (isRematerializable(li, LIS, *MF.getTarget().getInstrInfo()))
+  if (isRematerializable(li, LIS, *MF.getSubtarget().getInstrInfo()))
     totalWeight *= 0.5F;
 
   li.weight = normalize(totalWeight, li.getSize());