llvm-6502/include/llvm/Transforms/Vectorize.h
Nadav Rotem 8383b539ff Add support for bottom-up SLP vectorization infrastructure.
This commit adds the infrastructure for performing bottom-up SLP vectorization (and other optimizations) on parallel computations.
The infrastructure has three potential users:

  1. The loop vectorizer needs to be able to vectorize AOS data structures such as (sum += A[i] + A[i+1]).

  2. The BB-vectorizer needs this infrastructure for bottom-up SLP vectorization, because bottom-up vectorization is faster to compute.

  3. A loop-roller needs to be able to analyze consecutive chains and roll them into a loop, in order to reduce code size. A loop roller does not need to create vector instructions, and this infrastructure separates the chain analysis from the vectorization.

This patch also includes a simple (100 LOC) bottom up SLP vectorizer that uses the infrastructure, and can vectorize this code:

void SAXPY(int *x, int *y, int a, int i) {
  x[i]   = a * x[i]   + y[i];
  x[i+1] = a * x[i+1] + y[i+1];
  x[i+2] = a * x[i+2] + y[i+2];
  x[i+3] = a * x[i+3] + y[i+3];
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179117 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-09 19:44:35 +00:00

141 lines
4.1 KiB
C++

//===-- Vectorize.h - Vectorization Transformations -------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header file defines prototypes for accessor functions that expose passes
// in the Vectorize transformations library.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_VECTORIZE_H
#define LLVM_TRANSFORMS_VECTORIZE_H
namespace llvm {
class BasicBlock;
class BasicBlockPass;
class Pass;
//===----------------------------------------------------------------------===//
/// @brief Vectorize configuration.
struct VectorizeConfig {
//===--------------------------------------------------------------------===//
// Target architecture related parameters
/// @brief The size of the native vector registers.
unsigned VectorBits;
/// @brief Vectorize boolean values.
bool VectorizeBools;
/// @brief Vectorize integer values.
bool VectorizeInts;
/// @brief Vectorize floating-point values.
bool VectorizeFloats;
/// @brief Vectorize pointer values.
bool VectorizePointers;
/// @brief Vectorize casting (conversion) operations.
bool VectorizeCasts;
/// @brief Vectorize floating-point math intrinsics.
bool VectorizeMath;
/// @brief Vectorize the fused-multiply-add intrinsic.
bool VectorizeFMA;
/// @brief Vectorize select instructions.
bool VectorizeSelect;
/// @brief Vectorize comparison instructions.
bool VectorizeCmp;
/// @brief Vectorize getelementptr instructions.
bool VectorizeGEP;
/// @brief Vectorize loads and stores.
bool VectorizeMemOps;
/// @brief Only generate aligned loads and stores.
bool AlignedOnly;
//===--------------------------------------------------------------------===//
// Misc parameters
/// @brief The required chain depth for vectorization.
unsigned ReqChainDepth;
/// @brief The maximum search distance for instruction pairs.
unsigned SearchLimit;
/// @brief The maximum number of candidate pairs with which to use a full
/// cycle check.
unsigned MaxCandPairsForCycleCheck;
/// @brief Replicating one element to a pair breaks the chain.
bool SplatBreaksChain;
/// @brief The maximum number of pairable instructions per group.
unsigned MaxInsts;
/// @brief The maximum number of candidate instruction pairs per group.
unsigned MaxPairs;
/// @brief The maximum number of pairing iterations.
unsigned MaxIter;
/// @brief Don't try to form odd-length vectors.
bool Pow2LenOnly;
/// @brief Don't boost the chain-depth contribution of loads and stores.
bool NoMemOpBoost;
/// @brief Use a fast instruction dependency analysis.
bool FastDep;
/// @brief Initialize the VectorizeConfig from command line options.
VectorizeConfig();
};
//===----------------------------------------------------------------------===//
//
// BBVectorize - A basic-block vectorization pass.
//
BasicBlockPass *
createBBVectorizePass(const VectorizeConfig &C = VectorizeConfig());
//===----------------------------------------------------------------------===//
//
// LoopVectorize - Create a loop vectorization pass.
//
Pass *createLoopVectorizePass();
//===----------------------------------------------------------------------===//
//
// SLPVectorizer - Create a bottom-up SLP vectorizer pass.
//
Pass *createSLPVectorizerPass();
//===----------------------------------------------------------------------===//
/// @brief Vectorize the BasicBlock.
///
/// @param BB The BasicBlock to be vectorized
/// @param P The current running pass, should require AliasAnalysis and
/// ScalarEvolution. After the vectorization, AliasAnalysis,
/// ScalarEvolution and CFG are preserved.
///
/// @return True if the BB is changed, false otherwise.
///
bool vectorizeBasicBlock(Pass *P, BasicBlock &BB,
const VectorizeConfig &C = VectorizeConfig());
} // End llvm namespace
#endif