llvm-6502/include/llvm/Transforms/Utils/BypassSlowDivision.h
Chandler Carruth d04a8d4b33 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 16:50:05 +00:00

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1.3 KiB
C++

//===- llvm/Transforms/Utils/BypassSlowDivision.h --------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains an optimization for div and rem on architectures that
// execute short instructions significantly faster than longer instructions.
// For example, on Intel Atom 32-bit divides are slow enough that during
// runtime it is profitable to check the value of the operands, and if they are
// positive and less than 256 use an unsigned 8-bit divide.
//
//===----------------------------------------------------------------------===//
#ifndef TRANSFORMS_UTILS_BYPASSSLOWDIVISION_H
#define TRANSFORMS_UTILS_BYPASSSLOWDIVISION_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/Function.h"
namespace llvm {
/// This optimization identifies DIV instructions that can be
/// profitably bypassed and carried out with a shorter, faster divide.
bool bypassSlowDivision(Function &F,
Function::iterator &I,
const DenseMap<unsigned int, unsigned int> &BypassWidth);
} // End llvm namespace
#endif