Implement the getBitsSet function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35310 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Reid Spencer 2007-03-24 23:27:48 +00:00
parent 3f3ee6e588
commit 8f969ee62c

View File

@ -340,7 +340,16 @@ public:
/// @param loBit the index of the lowest bit set.
/// @returns An APInt value with the requested bits set.
/// @brief Get a value with a block of bits set.
static APInt getBitsSet(uint32_t numBits, uint32_t hiBit, uint32_t loBit = 0);
static APInt getBitsSet(uint32_t numBits, uint32_t hiBit, uint32_t loBit = 0){
assert(hiBit < numBits && "hiBit out of range");
assert(loBit < numBits && "loBit out of range");
if (hiBit < loBit)
return getLowBitsSet(numBits, hiBit+1) |
getHighBitsSet(numBits, numBits-loBit+1);
else if (loBit == 0)
return getLowBitsSet(numBits, hiBit+1);
return getLowBitsSet(numBits, hiBit-loBit+1).shl(loBit);
}
/// Constructs an APInt value that has the top hiBitsSet bits set.
/// @param numBits the bitwidth of the result