Fix PR1816, by correcting the broken definition of APInt::countTrailingZeros.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44296 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-11-23 22:42:31 +00:00
parent 8314a0cd0f
commit 9e513acd31
3 changed files with 12 additions and 5 deletions

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@ -896,10 +896,9 @@ public:
/// countLeadingZeros - This function is an APInt version of the /// countLeadingZeros - This function is an APInt version of the
/// countLeadingZeros_{32,64} functions in MathExtras.h. It counts the number /// countLeadingZeros_{32,64} functions in MathExtras.h. It counts the number
/// of zeros from the most significant bit to the first one bit. /// of zeros from the most significant bit to the first one bit.
/// @returns getNumWords() * APINT_BITS_PER_WORD if the value is zero. /// @returns BitWidth if the value is zero.
/// @returns the number of zeros from the most significant bit to the first /// @returns the number of zeros from the most significant bit to the first
/// one bits. /// one bits.
/// @brief Count the number of leading one bits.
uint32_t countLeadingZeros() const; uint32_t countLeadingZeros() const;
/// countLeadingOnes - This function counts the number of contiguous 1 bits /// countLeadingOnes - This function counts the number of contiguous 1 bits
@ -911,8 +910,8 @@ public:
/// countTrailingZeros - This function is an APInt version of the /// countTrailingZeros - This function is an APInt version of the
/// countTrailingZoers_{32,64} functions in MathExtras.h. It counts /// countTrailingZoers_{32,64} functions in MathExtras.h. It counts
/// the number of zeros from the least significant bit to the first one bit. /// the number of zeros from the least significant bit to the first set bit.
/// @returns getNumWords() * APINT_BITS_PER_WORD if the value is zero. /// @returns BitWidth if the value is zero.
/// @returns the number of zeros from the least significant bit to the first /// @returns the number of zeros from the least significant bit to the first
/// one bit. /// one bit.
/// @brief Count the number of trailing zero bits. /// @brief Count the number of trailing zero bits.

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@ -745,7 +745,7 @@ uint32_t APInt::countLeadingZeros() const {
uint32_t remainder = BitWidth % APINT_BITS_PER_WORD; uint32_t remainder = BitWidth % APINT_BITS_PER_WORD;
if (remainder) if (remainder)
Count -= APINT_BITS_PER_WORD - remainder; Count -= APINT_BITS_PER_WORD - remainder;
return Count; return std::min(Count, BitWidth);
} }
static uint32_t countLeadingOnes_64(uint64_t V, uint32_t skip) { static uint32_t countLeadingOnes_64(uint64_t V, uint32_t skip) {

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@ -0,0 +1,8 @@
; RUN: llvm-as < %s | opt -constprop | llvm-dis | grep {ret i13 13}
; PR1816
declare i13 @llvm.cttz.i13(i13)
define i13 @test() {
%X = call i13 @llvm.cttz.i13(i13 0)
ret i13 %X
}