LowerSwitch: Use ConstantInt for CaseRange::{Low,High}

Case values are always ConstantInt. This allows us to remove
a bunch of casts. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228312 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/LowerSwitch.cpp b/lib/Transforms/Utils/LowerSwitch.cpp
index 8141049a8179fb4bb7e223637a2ff30ecec9ff91..b3bdae47d94cdee44dbf4e34fd74f4c2406b8b39 100644 (file)
--- a/lib/Transforms/Utils/LowerSwitch.cpp
+++ b/lib/Transforms/Utils/LowerSwitch.cpp
@@ -67,11 +67,11 @@ namespace {
     }
 
     struct CaseRange {
-      Constant* Low;
-      Constant* High;
+      ConstantInt* Low;
+      ConstantInt* High;
       BasicBlock* BB;
 
-      CaseRange(Constant *low, Constant *high, BasicBlock *bb)
+      CaseRange(ConstantInt *low, ConstantInt *high, BasicBlock *bb)
           : Low(low), High(high), BB(bb) {}
     };
 
@@ -220,14 +220,14 @@ LowerSwitch::switchConvert(CaseItr Begin, CaseItr End, ConstantInt *LowerBound,
 
   CaseRange &Pivot = *(Begin + Mid);
   DEBUG(dbgs() << "Pivot ==> "
-               << cast<ConstantInt>(Pivot.Low)->getValue()
-               << " -" << cast<ConstantInt>(Pivot.High)->getValue() << "\n");
+               << Pivot.Low->getValue()
+               << " -" << Pivot.High->getValue() << "\n");
 
   // NewLowerBound here should never be the integer minimal value.
   // This is because it is computed from a case range that is never
   // the smallest, so there is always a case range that has at least
   // a smaller value.
-  ConstantInt *NewLowerBound = cast<ConstantInt>(Pivot.Low);
+  ConstantInt *NewLowerBound = Pivot.Low;
 
   // Because NewLowerBound is never the smallest representable integer
   // it is safe here to subtract one.
@@ -236,16 +236,16 @@ LowerSwitch::switchConvert(CaseItr Begin, CaseItr End, ConstantInt *LowerBound,
 
   if (!UnreachableRanges.empty()) {
     // Check if the gap between LHS's highest and NewLowerBound is unreachable.
-    int64_t GapLow = cast<ConstantInt>(LHS.back().High)->getSExtValue() + 1;
+    int64_t GapLow = LHS.back().High->getSExtValue() + 1;
     int64_t GapHigh = NewLowerBound->getSExtValue() - 1;
     IntRange Gap = { GapLow, GapHigh };
     if (GapHigh >= GapLow && IsInRanges(Gap, UnreachableRanges))
-      NewUpperBound = cast<ConstantInt>(LHS.back().High);
+      NewUpperBound = LHS.back().High;
   }
 
   DEBUG(dbgs() << "LHS Bounds ==> ";
         if (LowerBound) {
-          dbgs() << cast<ConstantInt>(LowerBound)->getSExtValue();
+          dbgs() << LowerBound->getSExtValue();
         } else {
           dbgs() << "NONE";
         }
@@ -253,7 +253,7 @@ LowerSwitch::switchConvert(CaseItr Begin, CaseItr End, ConstantInt *LowerBound,
         dbgs() << "RHS Bounds ==> ";
         dbgs() << NewLowerBound->getSExtValue() << " - ";
         if (UpperBound) {
-          dbgs() << cast<ConstantInt>(UpperBound)->getSExtValue() << "\n";
+          dbgs() << UpperBound->getSExtValue() << "\n";
         } else {
           dbgs() << "NONE\n";
         });
@@ -304,11 +304,11 @@ BasicBlock* LowerSwitch::newLeafBlock(CaseRange& Leaf, Value* Val,
                         Leaf.Low, "SwitchLeaf");
   } else {
     // Make range comparison
-    if (cast<ConstantInt>(Leaf.Low)->isMinValue(true /*isSigned*/)) {
+    if (Leaf.Low->isMinValue(true /*isSigned*/)) {
       // Val >= Min && Val <= Hi --> Val <= Hi
       Comp = new ICmpInst(*NewLeaf, ICmpInst::ICMP_SLE, Val, Leaf.High,
                           "SwitchLeaf");
-    } else if (cast<ConstantInt>(Leaf.Low)->isZero()) {
+    } else if (Leaf.Low->isZero()) {
       // Val >= 0 && Val <= Hi --> Val <=u Hi
       Comp = new ICmpInst(*NewLeaf, ICmpInst::ICMP_ULE, Val, Leaf.High,
                           "SwitchLeaf");      
@@ -333,8 +333,8 @@ BasicBlock* LowerSwitch::newLeafBlock(CaseRange& Leaf, Value* Val,
   for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
     PHINode* PN = cast<PHINode>(I);
     // Remove all but one incoming entries from the cluster
-    uint64_t Range = cast<ConstantInt>(Leaf.High)->getSExtValue() -
-                     cast<ConstantInt>(Leaf.Low)->getSExtValue();    
+    uint64_t Range = Leaf.High->getSExtValue() -
+                     Leaf.Low->getSExtValue();
     for (uint64_t j = 0; j < Range; ++j) {
       PN->removeIncomingValue(OrigBlock);
     }
@@ -362,8 +362,8 @@ unsigned LowerSwitch::Clusterify(CaseVector& Cases, SwitchInst *SI) {
   if (Cases.size()>=2)
     for (CaseItr I = Cases.begin(), J = std::next(Cases.begin());
          J != Cases.end();) {
-      int64_t nextValue = cast<ConstantInt>(J->Low)->getSExtValue();
-      int64_t currentValue = cast<ConstantInt>(I->High)->getSExtValue();
+      int64_t nextValue = J->Low->getSExtValue();
+      int64_t currentValue = I->High->getSExtValue();
       BasicBlock* nextBB = J->BB;
       BasicBlock* currentBB = I->BB;
 
@@ -420,8 +420,8 @@ void LowerSwitch::processSwitchInst(SwitchInst *SI) {
     // know that the value passed to the switch must be exactly one of the case
     // values.
     assert(!Cases.empty());
-    LowerBound = cast<ConstantInt>(Cases.front().Low);
-    UpperBound = cast<ConstantInt>(Cases.back().High);
+    LowerBound = Cases.front().Low;
+    UpperBound = Cases.back().High;
 
     DenseMap<BasicBlock *, unsigned> Popularity;
     unsigned MaxPop = 0;
@@ -430,8 +430,8 @@ void LowerSwitch::processSwitchInst(SwitchInst *SI) {
     IntRange R = { INT64_MIN, INT64_MAX };
     UnreachableRanges.push_back(R);
     for (const auto &I : Cases) {
-      int64_t Low = cast<ConstantInt>(I.Low)->getSExtValue();
-      int64_t High = cast<ConstantInt>(I.High)->getSExtValue();
+      int64_t Low = I.Low->getSExtValue();
+      int64_t High = I.High->getSExtValue();
 
       IntRange &LastRange = UnreachableRanges.back();
       if (LastRange.Low == Low) {