forked from OSchip/llvm-project
83 lines
2.9 KiB
C++
83 lines
2.9 KiB
C++
//===-- AMDGPUTargetTransformInfo.cpp - AMDGPU specific TTI pass ---------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// \file
|
|
// This file implements a TargetTransformInfo analysis pass specific to the
|
|
// AMDGPU target machine. It uses the target's detailed information to provide
|
|
// more precise answers to certain TTI queries, while letting the target
|
|
// independent and default TTI implementations handle the rest.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "AMDGPUTargetTransformInfo.h"
|
|
#include "llvm/Analysis/LoopInfo.h"
|
|
#include "llvm/Analysis/TargetTransformInfo.h"
|
|
#include "llvm/Analysis/ValueTracking.h"
|
|
#include "llvm/CodeGen/BasicTTIImpl.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Target/CostTable.h"
|
|
#include "llvm/Target/TargetLowering.h"
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "AMDGPUtti"
|
|
|
|
void AMDGPUTTIImpl::getUnrollingPreferences(Loop *L,
|
|
TTI::UnrollingPreferences &UP) {
|
|
UP.Threshold = 300; // Twice the default.
|
|
UP.MaxCount = UINT_MAX;
|
|
UP.Partial = true;
|
|
|
|
// TODO: Do we want runtime unrolling?
|
|
|
|
for (const BasicBlock *BB : L->getBlocks()) {
|
|
const DataLayout &DL = BB->getModule()->getDataLayout();
|
|
for (const Instruction &I : *BB) {
|
|
const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&I);
|
|
if (!GEP || GEP->getAddressSpace() != AMDGPUAS::PRIVATE_ADDRESS)
|
|
continue;
|
|
|
|
const Value *Ptr = GEP->getPointerOperand();
|
|
const AllocaInst *Alloca =
|
|
dyn_cast<AllocaInst>(GetUnderlyingObject(Ptr, DL));
|
|
if (Alloca) {
|
|
// We want to do whatever we can to limit the number of alloca
|
|
// instructions that make it through to the code generator. allocas
|
|
// require us to use indirect addressing, which is slow and prone to
|
|
// compiler bugs. If this loop does an address calculation on an
|
|
// alloca ptr, then we want to use a higher than normal loop unroll
|
|
// threshold. This will give SROA a better chance to eliminate these
|
|
// allocas.
|
|
//
|
|
// Don't use the maximum allowed value here as it will make some
|
|
// programs way too big.
|
|
UP.Threshold = 800;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
unsigned AMDGPUTTIImpl::getNumberOfRegisters(bool Vec) {
|
|
if (Vec)
|
|
return 0;
|
|
|
|
// Number of VGPRs on SI.
|
|
if (ST->getGeneration() >= AMDGPUSubtarget::SOUTHERN_ISLANDS)
|
|
return 256;
|
|
|
|
return 4 * 128; // XXX - 4 channels. Should these count as vector instead?
|
|
}
|
|
|
|
unsigned AMDGPUTTIImpl::getRegisterBitWidth(bool) { return 32; }
|
|
|
|
unsigned AMDGPUTTIImpl::getMaxInterleaveFactor(unsigned VF) {
|
|
// Semi-arbitrary large amount.
|
|
return 64;
|
|
}
|