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author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-06-20 02:31:03 +0000 |
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committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-06-20 02:31:03 +0000 |
commit | 5cf39383da201784a40eb47cfd289cbe98972145 (patch) | |
tree | fefb7039496734a77f67b5cc0f11e828a98a964a /include/llvm | |
parent | 8483dacfd804c71adc73764cee7f1304d1c8977c (diff) | |
download | llvm-5cf39383da201784a40eb47cfd289cbe98972145.tar.gz llvm-5cf39383da201784a40eb47cfd289cbe98972145.tar.bz2 llvm-5cf39383da201784a40eb47cfd289cbe98972145.tar.xz |
Support: Write ScaledNumbers::getAdjusted()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211336 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm')
-rw-r--r-- | include/llvm/Analysis/BlockFrequencyInfoImpl.h | 24 | ||||
-rw-r--r-- | include/llvm/Support/ScaledNumber.h | 35 |
2 files changed, 45 insertions, 14 deletions
diff --git a/include/llvm/Analysis/BlockFrequencyInfoImpl.h b/include/llvm/Analysis/BlockFrequencyInfoImpl.h index 7ad76e5350..264aff3725 100644 --- a/include/llvm/Analysis/BlockFrequencyInfoImpl.h +++ b/include/llvm/Analysis/BlockFrequencyInfoImpl.h @@ -327,20 +327,16 @@ private: return countLeadingZeros32(Digits) + Width - 32; } - static UnsignedFloat adjustToWidth(uint64_t N, int32_t S) { - assert(S >= MinExponent); - assert(S <= MaxExponent); - if (Width == 64 || N <= DigitsLimits::max()) - return UnsignedFloat(N, S); - - // Shift right. - int Shift = 64 - Width - countLeadingZeros64(N); - DigitsType Shifted = N >> Shift; - - // Round. - assert(S + Shift <= MaxExponent); - return getRounded(UnsignedFloat(Shifted, S + Shift), - N & UINT64_C(1) << (Shift - 1)); + /// \brief Adjust a number to width, rounding up if necessary. + /// + /// Should only be called for \c Shift close to zero. + /// + /// \pre Shift >= MinExponent && Shift + 64 <= MaxExponent. + static UnsignedFloat adjustToWidth(uint64_t N, int32_t Shift) { + assert(Shift >= MinExponent && "Shift should be close to 0"); + assert(Shift <= MaxExponent - 64 && "Shift should be close to 0"); + auto Adjusted = ScaledNumbers::getAdjusted<DigitsT>(N, Shift); + return Adjusted; } static UnsignedFloat getRounded(UnsignedFloat P, bool Round) { diff --git a/include/llvm/Support/ScaledNumber.h b/include/llvm/Support/ScaledNumber.h index afdc7dc188..54b5386c5a 100644 --- a/include/llvm/Support/ScaledNumber.h +++ b/include/llvm/Support/ScaledNumber.h @@ -22,6 +22,8 @@ #ifndef LLVM_SUPPORT_SCALEDNUMBER_H #define LLVM_SUPPORT_SCALEDNUMBER_H +#include "llvm/Support/MathExtras.h" + #include <cstdint> #include <limits> #include <utility> @@ -50,6 +52,39 @@ inline std::pair<DigitsT, int16_t> getRounded(DigitsT Digits, int16_t Scale, return std::make_pair(DigitsT(1) << (getWidth<DigitsT>() - 1), Scale + 1); return std::make_pair(Digits, Scale); } + +/// \brief Adjust a 64-bit scaled number down to the appropriate width. +/// +/// Adjust a soft float with 64-bits of digits down, keeping as much +/// information as possible, and rounding up on half. +/// +/// \pre Adding 1 to \c Scale will not overflow INT16_MAX. +template <class DigitsT> +inline std::pair<DigitsT, int16_t> getAdjusted(uint64_t Digits, + int16_t Scale = 0) { + static_assert(!std::numeric_limits<DigitsT>::is_signed, "expected unsigned"); + + const int Width = getWidth<DigitsT>(); + if (Width == 64 || Digits <= std::numeric_limits<DigitsT>::max()) + return std::make_pair(Digits, Scale); + + // Shift right and round. + int Shift = 64 - Width - countLeadingZeros(Digits); + return getRounded<DigitsT>(Digits >> Shift, Scale + Shift, + Digits & (UINT64_C(1) << (Shift - 1))); +} + +/// \brief Convenience helper for adjusting to 32 bits. +inline std::pair<uint32_t, int16_t> getAdjusted32(uint64_t Digits, + int16_t Scale = 0) { + return getAdjusted<uint32_t>(Digits, Scale); +} + +/// \brief Convenience helper for adjusting to 64 bits. +inline std::pair<uint64_t, int16_t> getAdjusted64(uint64_t Digits, + int16_t Scale = 0) { + return getAdjusted<uint64_t>(Digits, Scale); +} } } |