Author: djg
Date: Wed Feb 13 15:11:05 2008
New Revision: 47086
URL: http://llvm.org/viewvc/llvm-project?rev=47086&view=rev
Log:
Add countTrailingOnes member functions to APInt.
Modified:
llvm/trunk/include/llvm/ADT/APInt.h
llvm/trunk/lib/Support/APInt.cpp
Modified: llvm/trunk/include/llvm/ADT/APInt.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/APInt.h?rev=47086&r1=47085&r2=47086&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/APInt.h (original)
+++ llvm/trunk/include/llvm/ADT/APInt.h Wed Feb 13 15:11:05 2008
@@ -913,8 +913,9 @@
/// one bits.
uint32_t countLeadingZeros() const;
- /// countLeadingOnes - This function counts the number of contiguous 1 bits
- /// in the high order bits. The count stops when the first 0 bit is reached.
+ /// countLeadingOnes - This function is an APInt version of the
+ /// countLeadingOnes_{32,64} functions in MathExtras.h. It counts the number
+ /// of ones from the most significant bit to the first zero bit.
/// @returns 0 if the high order bit is not set
/// @returns the number of 1 bits from the most significant to the least
/// @brief Count the number of leading one bits.
@@ -929,6 +930,15 @@
/// @brief Count the number of trailing zero bits.
uint32_t countTrailingZeros() const;
+ /// countTrailingOnes - This function is an APInt version of the
+ /// countTrailingOnes_{32,64} functions in MathExtras.h. It counts
+ /// the number of ones from the least significant bit to the first zero bit.
+ /// @returns BitWidth if the value is all ones.
+ /// @returns the number of ones from the least significant bit to the first
+ /// zero bit.
+ /// @brief Count the number of trailing one bits.
+ uint32_t countTrailingOnes() const;
+
/// countPopulation - This function is an APInt version of the
/// countPopulation_{32,64} functions in MathExtras.h. It counts the number
/// of 1 bits in the APInt value.
Modified: llvm/trunk/lib/Support/APInt.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/APInt.cpp?rev=47086&r1=47085&r2=47086&view=diff
==============================================================================
--- llvm/trunk/lib/Support/APInt.cpp (original)
+++ llvm/trunk/lib/Support/APInt.cpp Wed Feb 13 15:11:05 2008
@@ -813,6 +813,18 @@
return std::min(Count, BitWidth);
}
+uint32_t APInt::countTrailingOnes() const {
+ if (isSingleWord())
+ return std::min(uint32_t(CountTrailingOnes_64(VAL)), BitWidth);
+ uint32_t Count = 0;
+ uint32_t i = 0;
+ for (; i < getNumWords() && pVal[i] == -1; ++i)
+ Count += APINT_BITS_PER_WORD;
+ if (i < getNumWords())
+ Count += CountTrailingOnes_64(pVal[i]);
+ return std::min(Count, BitWidth);
+}
+
uint32_t APInt::countPopulation() const {
if (isSingleWord())
return CountPopulation_64(VAL);
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