// 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) {
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);
}
}
} 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;
}
}
}