Remove an unused option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99537 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index c5e0362..7369577 100644 (file)
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -59,11 +59,6 @@ DisableCrossClassJoin("disable-cross-class-join",
                cl::desc("Avoid coalescing cross register class copies"),
                cl::init(false), cl::Hidden);
 
-static cl::opt<bool>
-PhysJoinTweak("tweak-phys-join-heuristics",
-               cl::desc("Tweak heuristics for joining phys reg with vr"),
-               cl::init(false), cl::Hidden);
-
 static RegisterPass<SimpleRegisterCoalescing>
 X("simple-register-coalescing", "Simple Register Coalescing");
 
@@ -1445,7 +1440,6 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
   const TargetRegisterClass *SrcRC= SrcIsPhys ? 0 : mri_->getRegClass(SrcReg);
   const TargetRegisterClass *DstRC= DstIsPhys ? 0 : mri_->getRegClass(DstReg);
   const TargetRegisterClass *NewRC = NULL;
-  MachineBasicBlock *CopyMBB = CopyMI->getParent();
   unsigned RealDstReg = 0;
   unsigned RealSrcReg = 0;
   if (isExtSubReg || isInsSubReg || isSubRegToReg) {
@@ -1656,60 +1650,36 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
     // these are not spillable! If the destination interval uses are far away,
     // think twice about coalescing them!
     if (!isDead && (SrcIsPhys || DstIsPhys)) {
-      // If the copy is in a loop, take care not to coalesce aggressively if the
-      // src is coming in from outside the loop (or the dst is out of the loop).
-      // If it's not in a loop, then determine whether to join them base purely
-      // by the length of the interval.
-      if (PhysJoinTweak) {
-        if (SrcIsPhys) {
-          if (!isWinToJoinVRWithSrcPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
-            mri_->setRegAllocationHint(DstInt.reg, 0, SrcReg);
-            ++numAborts;
-            DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
-            Again = true;  // May be possible to coalesce later.
-            return false;
-          }
-        } else {
-          if (!isWinToJoinVRWithDstPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
-            mri_->setRegAllocationHint(SrcInt.reg, 0, DstReg);
-            ++numAborts;
-            DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
-            Again = true;  // May be possible to coalesce later.
-            return false;
-          }
-        }
-      } else {
-        // If the virtual register live interval is long but it has low use
-        // density, do not join them, instead mark the physical register as its
-        // allocation preference.
-        LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
-        LiveInterval &JoinPInt = SrcIsPhys ? SrcInt : DstInt;
-        unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
-        unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
-
-        // Don't join with physregs that have a ridiculous number of live
-        // ranges. The data structure performance is really bad when that
-        // happens.
-        if (JoinPInt.ranges.size() > 1000) {
-          mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
-          ++numAborts;
-          DEBUG(dbgs() << "\tPhysical register too complicated, abort!\n");
-          return false;
-        }
+      // If the virtual register live interval is long but it has low use
+      // density, do not join them, instead mark the physical register as its
+      // allocation preference.
+      LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
+      LiveInterval &JoinPInt = SrcIsPhys ? SrcInt : DstInt;
+      unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
+      unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
+
+      // Don't join with physregs that have a ridiculous number of live
+      // ranges. The data structure performance is really bad when that
+      // happens.
+      if (JoinPInt.ranges.size() > 1000) {
+        mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
+        ++numAborts;
+        DEBUG(dbgs() << "\tPhysical register too complicated, abort!\n");
+        return false;
+      }
 
-        const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
-        unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
-        unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
-        float Ratio = 1.0 / Threshold;
-        if (Length > Threshold &&
-            (((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
-                                   mri_->use_nodbg_end()) / Length) < Ratio)) {
-          mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
-          ++numAborts;
-          DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
-          Again = true;  // May be possible to coalesce later.
-          return false;
-        }
+      const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
+      unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
+      unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
+      float Ratio = 1.0 / Threshold;
+      if (Length > Threshold &&
+          (((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
+                                 mri_->use_nodbg_end()) / Length) < Ratio)) {
+        mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
+        ++numAborts;
+        DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
+        Again = true;  // May be possible to coalesce later.
+        return false;
       }
     }
   }