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Diffstat (limited to 'contrib/llvm/lib/Support/BranchProbability.cpp')
| -rw-r--r-- | contrib/llvm/lib/Support/BranchProbability.cpp | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/contrib/llvm/lib/Support/BranchProbability.cpp b/contrib/llvm/lib/Support/BranchProbability.cpp deleted file mode 100644 index 195e2d58d8e1..000000000000 --- a/contrib/llvm/lib/Support/BranchProbability.cpp +++ /dev/null @@ -1,112 +0,0 @@ -//===-------------- lib/Support/BranchProbability.cpp -----------*- C++ -*-===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file implements Branch Probability class. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Support/BranchProbability.h" -#include "llvm/Config/llvm-config.h" -#include "llvm/Support/Debug.h" -#include "llvm/Support/Format.h" -#include "llvm/Support/raw_ostream.h" -#include <cassert> - -using namespace llvm; - -const uint32_t BranchProbability::D; - -raw_ostream &BranchProbability::print(raw_ostream &OS) const { - if (isUnknown()) - return OS << "?%"; - - // Get a percentage rounded to two decimal digits. This avoids - // implementation-defined rounding inside printf. - double Percent = rint(((double)N / D) * 100.0 * 100.0) / 100.0; - return OS << format("0x%08" PRIx32 " / 0x%08" PRIx32 " = %.2f%%", N, D, - Percent); -} - -#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) -LLVM_DUMP_METHOD void BranchProbability::dump() const { print(dbgs()) << '\n'; } -#endif - -BranchProbability::BranchProbability(uint32_t Numerator, uint32_t Denominator) { - assert(Denominator > 0 && "Denominator cannot be 0!"); - assert(Numerator <= Denominator && "Probability cannot be bigger than 1!"); - if (Denominator == D) - N = Numerator; - else { - uint64_t Prob64 = - (Numerator * static_cast<uint64_t>(D) + Denominator / 2) / Denominator; - N = static_cast<uint32_t>(Prob64); - } -} - -BranchProbability -BranchProbability::getBranchProbability(uint64_t Numerator, - uint64_t Denominator) { - assert(Numerator <= Denominator && "Probability cannot be bigger than 1!"); - // Scale down Denominator to fit in a 32-bit integer. - int Scale = 0; - while (Denominator > UINT32_MAX) { - Denominator >>= 1; - Scale++; - } - return BranchProbability(Numerator >> Scale, Denominator); -} - -// If ConstD is not zero, then replace D by ConstD so that division and modulo -// operations by D can be optimized, in case this function is not inlined by the -// compiler. -template <uint32_t ConstD> -static uint64_t scale(uint64_t Num, uint32_t N, uint32_t D) { - if (ConstD > 0) - D = ConstD; - - assert(D && "divide by 0"); - - // Fast path for multiplying by 1.0. - if (!Num || D == N) - return Num; - - // Split Num into upper and lower parts to multiply, then recombine. - uint64_t ProductHigh = (Num >> 32) * N; - uint64_t ProductLow = (Num & UINT32_MAX) * N; - - // Split into 32-bit digits. - uint32_t Upper32 = ProductHigh >> 32; - uint32_t Lower32 = ProductLow & UINT32_MAX; - uint32_t Mid32Partial = ProductHigh & UINT32_MAX; - uint32_t Mid32 = Mid32Partial + (ProductLow >> 32); - - // Carry. - Upper32 += Mid32 < Mid32Partial; - - uint64_t Rem = (uint64_t(Upper32) << 32) | Mid32; - uint64_t UpperQ = Rem / D; - - // Check for overflow. - if (UpperQ > UINT32_MAX) - return UINT64_MAX; - - Rem = ((Rem % D) << 32) | Lower32; - uint64_t LowerQ = Rem / D; - uint64_t Q = (UpperQ << 32) + LowerQ; - - // Check for overflow. - return Q < LowerQ ? UINT64_MAX : Q; -} - -uint64_t BranchProbability::scale(uint64_t Num) const { - return ::scale<D>(Num, N, D); -} - -uint64_t BranchProbability::scaleByInverse(uint64_t Num) const { - return ::scale<0>(Num, D, N); -} |
