[llvm] r276917 - [Hexagon] Add option to bisect spill slot optimization

[Krzysztof Parzyszek via llvm-commits]

Author: kparzysz
Date: Wed Jul 27 15:58:43 2016
New Revision: 276917

URL: http://llvm.org/viewvc/llvm-project?rev=276917&view=rev
Log:
[Hexagon] Add option to bisect spill slot optimization

Modified:
    llvm/trunk/lib/Target/Hexagon/HexagonFrameLowering.cpp

Modified: llvm/trunk/lib/Target/Hexagon/HexagonFrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonFrameLowering.cpp?rev=276917&r1=276916&r2=276917&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonFrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonFrameLowering.cpp Wed Jul 27 15:58:43 2016
@@ -159,6 +159,12 @@ static cl::opt<bool> UseAllocframe("use-
 static cl::opt<bool> OptimizeSpillSlots("hexagon-opt-spill", cl::Hidden,
     cl::init(true), cl::desc("Optimize spill slots"));
 
+#ifndef NDEBUG
+static cl::opt<unsigned> SpillOptMax("spill-opt-max", cl::Hidden,
+    cl::init(UINT_MAX));
+static unsigned SpillOptCount = 0;
+#endif
+
 
 namespace llvm {
   void initializeHexagonCallFrameInformationPass(PassRegistry&);
@@ -1427,7 +1433,6 @@ bool HexagonFrameLowering::assignCalleeS
   return true;
 }
 
-
 bool HexagonFrameLowering::expandCopy(MachineBasicBlock &B,
       MachineBasicBlock::iterator It, MachineRegisterInfo &MRI,
       const HexagonInstrInfo &HII, SmallVectorImpl<unsigned> &NewRegs) const {
@@ -2126,6 +2131,10 @@ void HexagonFrameLowering::optimizeSpill
     }
   });
 
+#ifndef NDEBUG
+  bool HasOptLimit = SpillOptMax.getPosition();
+#endif
+
   // eliminate loads, when all loads eliminated, eliminate all stores.
   for (auto &B : MF) {
     auto F = BlockIndexes.find(&B);
@@ -2160,6 +2169,13 @@ void HexagonFrameLowering::optimizeSpill
         DEBUG(dbgs() << "Replacement reg:" << PrintReg(FoundR, &HRI) << '\n');
         if (FoundR == 0)
           continue;
+#ifndef NDEBUG
+        if (HasOptLimit) {
+          if (SpillOptCount >= SpillOptMax)
+            return;
+          SpillOptCount++;
+        }
+#endif
 
         // Generate the copy-in: "FoundR = COPY SrcR" at the store location.
         MachineBasicBlock::iterator StartIt = SI, NextIt;
@@ -2221,7 +2237,6 @@ void HexagonFrameLowering::optimizeSpill
   }
 }
 
-
 void HexagonFrameLowering::expandAlloca(MachineInstr *AI,
       const HexagonInstrInfo &HII, unsigned SP, unsigned CF) const {
   MachineBasicBlock &MB = *AI->getParent();