1 //===- CmpInstAnalysis.cpp - Utils to help fold compares ---------------===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
12 //===----------------------------------------------------------------------===//
23       // False -> 0  in getICmpCode()
34       // True -> 7  in getICmpCode()
78                                 Value *&X, APInt &Mask, bool LookThruTrunc) {  in decomposeBitTestICmp()  argument
89     // X < 0 is equivalent to (X & SignMask) != 0.  in decomposeBitTestICmp()
90     if (!C->isZero())  in decomposeBitTestICmp()
92     Mask = APInt::getSignMask(C->getBitWidth());  in decomposeBitTestICmp()
96     // X <= -1 is equivalent to (X & SignMask) != 0.  in decomposeBitTestICmp()
97     if (!C->isAllOnes())  in decomposeBitTestICmp()
99     Mask = APInt::getSignMask(C->getBitWidth());  in decomposeBitTestICmp()
103     // X > -1 is equivalent to (X & SignMask) == 0.  in decomposeBitTestICmp()
104     if (!C->isAllOnes())  in decomposeBitTestICmp()
106     Mask = APInt::getSignMask(C->getBitWidth());  in decomposeBitTestICmp()
110     // X >= 0 is equivalent to (X & SignMask) == 0.  in decomposeBitTestICmp()
111     if (!C->isZero())  in decomposeBitTestICmp()
113     Mask = APInt::getSignMask(C->getBitWidth());  in decomposeBitTestICmp()
117     // X <u 2^n is equivalent to (X & ~(2^n-1)) == 0.  in decomposeBitTestICmp()
118     if (!C->isPowerOf2())  in decomposeBitTestICmp()
120     Mask = -*C;  in decomposeBitTestICmp()
124     // X <=u 2^n-1 is equivalent to (X & ~(2^n-1)) == 0.  in decomposeBitTestICmp()
127     Mask = ~*C;  in decomposeBitTestICmp()
131     // X >u 2^n-1 is equivalent to (X & ~(2^n-1)) != 0.  in decomposeBitTestICmp()
134     Mask = ~*C;  in decomposeBitTestICmp()
138     // X >=u 2^n is equivalent to (X & ~(2^n-1)) != 0.  in decomposeBitTestICmp()
139     if (!C->isPowerOf2())  in decomposeBitTestICmp()
141     Mask = -*C;  in decomposeBitTestICmp()
146   if (LookThruTrunc && match(LHS, m_Trunc(m_Value(X)))) {  in decomposeBitTestICmp()
147     Mask = Mask.zext(X->getType()->getScalarSizeInBits());  in decomposeBitTestICmp()
149     X = LHS;  in decomposeBitTestICmp()