No need to look through bitcasts for DbgInfoIntrinsic

[oota-llvm.git] / lib / Transforms / InstCombine / InstCombineCompares.cpp

diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 90ab4f43df0933fb476a7645256b69493f8761e8..e59406c636ac512447113ecf674276b2cd85e2fe 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -705,7 +705,7 @@ Instruction *InstCombiner::FoldICmpAddOpCst(ICmpInst &ICI,
   // so the values can never be equal.  Similiarly for all other "or equals"
   // operators.
   
-  // (X+1) <u X        --> X >u (MAXUINT-1)        --> X != 255
+  // (X+1) <u X        --> X >u (MAXUINT-1)        --> X == 255
   // (X+2) <u X        --> X >u (MAXUINT-2)        --> X > 253
   // (X+MAXUINT) <u X  --> X >u (MAXUINT-MAXUINT)  --> X != 0
   if (Pred == ICmpInst::ICMP_ULT || Pred == ICmpInst::ICMP_ULE) {
@@ -713,7 +713,8 @@ Instruction *InstCombiner::FoldICmpAddOpCst(ICmpInst &ICI,
     if (isNUW)
       return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(X->getContext())); 
     
-    Value *R = ConstantExpr::getSub(ConstantInt::get(CI->getType(), -1ULL), CI);
+    Value *R = 
+      ConstantExpr::getSub(ConstantInt::getAllOnesValue(CI->getType()), CI);
     return new ICmpInst(ICmpInst::ICMP_UGT, X, R);
   }
   
@@ -1418,11 +1419,33 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI,
       }
     } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(LHSI)) {
       // Handle icmp {eq|ne} <intrinsic>, intcst.
-      if (II->getIntrinsicID() == Intrinsic::bswap) {
+      switch (II->getIntrinsicID()) {
+      case Intrinsic::bswap:
         Worklist.Add(II);
         ICI.setOperand(0, II->getOperand(1));
         ICI.setOperand(1, ConstantInt::get(II->getContext(), RHSV.byteSwap()));
         return &ICI;
+      case Intrinsic::ctlz:
+      case Intrinsic::cttz:
+        // ctz(A) == bitwidth(a)  ->  A == 0 and likewise for !=
+        if (RHSV == RHS->getType()->getBitWidth()) {
+          Worklist.Add(II);
+          ICI.setOperand(0, II->getOperand(1));
+          ICI.setOperand(1, ConstantInt::get(RHS->getType(), 0));
+          return &ICI;
+        }
+        break;
+      case Intrinsic::ctpop:
+        // popcount(A) == 0  ->  A == 0 and likewise for !=
+        if (RHS->isZero()) {
+          Worklist.Add(II);
+          ICI.setOperand(0, II->getOperand(1));
+          ICI.setOperand(1, RHS);
+          return &ICI;
+        }
+        break;
+      default:
+       break;
       }
     }
   }