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Diffstat (limited to 'contrib/llvm/lib/Target/R600/AMDGPUTargetTransformInfo.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/R600/AMDGPUTargetTransformInfo.cpp | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/R600/AMDGPUTargetTransformInfo.cpp b/contrib/llvm/lib/Target/R600/AMDGPUTargetTransformInfo.cpp new file mode 100644 index 0000000..6dacc74 --- /dev/null +++ b/contrib/llvm/lib/Target/R600/AMDGPUTargetTransformInfo.cpp @@ -0,0 +1,82 @@ +//===-- 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; +} |