1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-23 13:02:52 +02:00
llvm-mirror/lib/Target/AMDGPU/AMDGPUSubtarget.cpp
Matt Arsenault 9317a1de75 AMDGPU: Enable FeatureFlatForGlobal on Volcanic Islands
Accomplishes what r292982 was supposed to, which ended up
only really making the necessary test changes.

This should be applied to the 4.0 branch.

Patch by Vedran Miletić <vedran@miletic.net>

llvm-svn: 293310
2017-01-27 17:42:26 +00:00

372 lines
11 KiB
C++

//===-- AMDGPUSubtarget.cpp - AMDGPU Subtarget Information ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file
/// \brief Implements the AMDGPU specific subclass of TargetSubtarget.
//
//===----------------------------------------------------------------------===//
#include "AMDGPUSubtarget.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/CodeGen/MachineScheduler.h"
#include "llvm/Target/TargetFrameLowering.h"
#include <algorithm>
using namespace llvm;
#define DEBUG_TYPE "amdgpu-subtarget"
#define GET_SUBTARGETINFO_ENUM
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "AMDGPUGenSubtargetInfo.inc"
AMDGPUSubtarget::~AMDGPUSubtarget() = default;
AMDGPUSubtarget &
AMDGPUSubtarget::initializeSubtargetDependencies(const Triple &TT,
StringRef GPU, StringRef FS) {
// Determine default and user-specified characteristics
// On SI+, we want FP64 denormals to be on by default. FP32 denormals can be
// enabled, but some instructions do not respect them and they run at the
// double precision rate, so don't enable by default.
//
// We want to be able to turn these off, but making this a subtarget feature
// for SI has the unhelpful behavior that it unsets everything else if you
// disable it.
SmallString<256> FullFS("+promote-alloca,+fp64-fp16-denormals,+load-store-opt,");
if (isAmdHsaOS()) // Turn on FlatForGlobal for HSA.
FullFS += "+flat-for-global,+unaligned-buffer-access,";
FullFS += FS;
ParseSubtargetFeatures(GPU, FullFS);
// Unless +-flat-for-global is specified, turn on FlatForGlobal for all OS-es
// on VI and newer hardware to avoid assertion failures due to missing ADDR64
// variants of MUBUF instructions.
if (!hasAddr64() && !FS.contains("flat-for-global")) {
FlatForGlobal = true;
}
// FIXME: I don't think think Evergreen has any useful support for
// denormals, but should be checked. Should we issue a warning somewhere
// if someone tries to enable these?
if (getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS) {
FP64FP16Denormals = false;
FP32Denormals = false;
}
// Set defaults if needed.
if (MaxPrivateElementSize == 0)
MaxPrivateElementSize = 4;
return *this;
}
AMDGPUSubtarget::AMDGPUSubtarget(const Triple &TT, StringRef GPU, StringRef FS,
const TargetMachine &TM)
: AMDGPUGenSubtargetInfo(TT, GPU, FS),
TargetTriple(TT),
Gen(TT.getArch() == Triple::amdgcn ? SOUTHERN_ISLANDS : R600),
IsaVersion(ISAVersion0_0_0),
WavefrontSize(64),
LocalMemorySize(0),
LDSBankCount(0),
MaxPrivateElementSize(0),
FastFMAF32(false),
HalfRate64Ops(false),
FP32Denormals(false),
FP64FP16Denormals(false),
FPExceptions(false),
FlatForGlobal(false),
UnalignedScratchAccess(false),
UnalignedBufferAccess(false),
EnableXNACK(false),
DebuggerInsertNops(false),
DebuggerReserveRegs(false),
DebuggerEmitPrologue(false),
EnableVGPRSpilling(false),
EnablePromoteAlloca(false),
EnableLoadStoreOpt(false),
EnableUnsafeDSOffsetFolding(false),
EnableSIScheduler(false),
DumpCode(false),
FP64(false),
IsGCN(false),
GCN1Encoding(false),
GCN3Encoding(false),
CIInsts(false),
SGPRInitBug(false),
HasSMemRealTime(false),
Has16BitInsts(false),
HasMovrel(false),
HasVGPRIndexMode(false),
HasScalarStores(false),
HasInv2PiInlineImm(false),
HasSDWA(false),
HasDPP(false),
FlatAddressSpace(false),
R600ALUInst(false),
CaymanISA(false),
CFALUBug(false),
HasVertexCache(false),
TexVTXClauseSize(0),
ScalarizeGlobal(false),
FeatureDisable(false),
InstrItins(getInstrItineraryForCPU(GPU)) {
initializeSubtargetDependencies(TT, GPU, FS);
}
// FIXME: These limits are for SI. Did they change with the larger maximum LDS
// size?
unsigned AMDGPUSubtarget::getMaxLocalMemSizeWithWaveCount(unsigned NWaves) const {
switch (NWaves) {
case 10:
return 1638;
case 9:
return 1820;
case 8:
return 2048;
case 7:
return 2340;
case 6:
return 2730;
case 5:
return 3276;
case 4:
return 4096;
case 3:
return 5461;
case 2:
return 8192;
default:
return getLocalMemorySize();
}
}
unsigned AMDGPUSubtarget::getOccupancyWithLocalMemSize(uint32_t Bytes) const {
if (Bytes <= 1638)
return 10;
if (Bytes <= 1820)
return 9;
if (Bytes <= 2048)
return 8;
if (Bytes <= 2340)
return 7;
if (Bytes <= 2730)
return 6;
if (Bytes <= 3276)
return 5;
if (Bytes <= 4096)
return 4;
if (Bytes <= 5461)
return 3;
if (Bytes <= 8192)
return 2;
return 1;
}
std::pair<unsigned, unsigned> AMDGPUSubtarget::getFlatWorkGroupSizes(
const Function &F) const {
// Default minimum/maximum flat work group sizes.
std::pair<unsigned, unsigned> Default =
AMDGPU::isCompute(F.getCallingConv()) ?
std::pair<unsigned, unsigned>(getWavefrontSize() * 2,
getWavefrontSize() * 4) :
std::pair<unsigned, unsigned>(1, getWavefrontSize());
// TODO: Do not process "amdgpu-max-work-group-size" attribute once mesa
// starts using "amdgpu-flat-work-group-size" attribute.
Default.second = AMDGPU::getIntegerAttribute(
F, "amdgpu-max-work-group-size", Default.second);
Default.first = std::min(Default.first, Default.second);
// Requested minimum/maximum flat work group sizes.
std::pair<unsigned, unsigned> Requested = AMDGPU::getIntegerPairAttribute(
F, "amdgpu-flat-work-group-size", Default);
// Make sure requested minimum is less than requested maximum.
if (Requested.first > Requested.second)
return Default;
// Make sure requested values do not violate subtarget's specifications.
if (Requested.first < getMinFlatWorkGroupSize())
return Default;
if (Requested.second > getMaxFlatWorkGroupSize())
return Default;
return Requested;
}
std::pair<unsigned, unsigned> AMDGPUSubtarget::getWavesPerEU(
const Function &F) const {
// Default minimum/maximum number of waves per execution unit.
std::pair<unsigned, unsigned> Default(1, 0);
// Default/requested minimum/maximum flat work group sizes.
std::pair<unsigned, unsigned> FlatWorkGroupSizes = getFlatWorkGroupSizes(F);
// If minimum/maximum flat work group sizes were explicitly requested using
// "amdgpu-flat-work-group-size" attribute, then set default minimum/maximum
// number of waves per execution unit to values implied by requested
// minimum/maximum flat work group sizes.
unsigned MinImpliedByFlatWorkGroupSize =
getMaxWavesPerEU(FlatWorkGroupSizes.second);
bool RequestedFlatWorkGroupSize = false;
// TODO: Do not process "amdgpu-max-work-group-size" attribute once mesa
// starts using "amdgpu-flat-work-group-size" attribute.
if (F.hasFnAttribute("amdgpu-max-work-group-size") ||
F.hasFnAttribute("amdgpu-flat-work-group-size")) {
Default.first = MinImpliedByFlatWorkGroupSize;
RequestedFlatWorkGroupSize = true;
}
// Requested minimum/maximum number of waves per execution unit.
std::pair<unsigned, unsigned> Requested = AMDGPU::getIntegerPairAttribute(
F, "amdgpu-waves-per-eu", Default, true);
// Make sure requested minimum is less than requested maximum.
if (Requested.second && Requested.first > Requested.second)
return Default;
// Make sure requested values do not violate subtarget's specifications.
if (Requested.first < getMinWavesPerEU() ||
Requested.first > getMaxWavesPerEU())
return Default;
if (Requested.second > getMaxWavesPerEU())
return Default;
// Make sure requested values are compatible with values implied by requested
// minimum/maximum flat work group sizes.
if (RequestedFlatWorkGroupSize &&
Requested.first > MinImpliedByFlatWorkGroupSize)
return Default;
return Requested;
}
R600Subtarget::R600Subtarget(const Triple &TT, StringRef GPU, StringRef FS,
const TargetMachine &TM) :
AMDGPUSubtarget(TT, GPU, FS, TM),
InstrInfo(*this),
FrameLowering(TargetFrameLowering::StackGrowsUp, getStackAlignment(), 0),
TLInfo(TM, *this) {}
SISubtarget::SISubtarget(const Triple &TT, StringRef GPU, StringRef FS,
const TargetMachine &TM) :
AMDGPUSubtarget(TT, GPU, FS, TM),
InstrInfo(*this),
FrameLowering(TargetFrameLowering::StackGrowsUp, getStackAlignment(), 0),
TLInfo(TM, *this) {}
void SISubtarget::overrideSchedPolicy(MachineSchedPolicy &Policy,
unsigned NumRegionInstrs) const {
// Track register pressure so the scheduler can try to decrease
// pressure once register usage is above the threshold defined by
// SIRegisterInfo::getRegPressureSetLimit()
Policy.ShouldTrackPressure = true;
// Enabling both top down and bottom up scheduling seems to give us less
// register spills than just using one of these approaches on its own.
Policy.OnlyTopDown = false;
Policy.OnlyBottomUp = false;
// Enabling ShouldTrackLaneMasks crashes the SI Machine Scheduler.
if (!enableSIScheduler())
Policy.ShouldTrackLaneMasks = true;
}
bool SISubtarget::isVGPRSpillingEnabled(const Function& F) const {
return EnableVGPRSpilling || !AMDGPU::isShader(F.getCallingConv());
}
unsigned SISubtarget::getKernArgSegmentSize(const MachineFunction &MF,
unsigned ExplicitArgBytes) const {
unsigned ImplicitBytes = getImplicitArgNumBytes(MF);
if (ImplicitBytes == 0)
return ExplicitArgBytes;
unsigned Alignment = getAlignmentForImplicitArgPtr();
return alignTo(ExplicitArgBytes, Alignment) + ImplicitBytes;
}
unsigned SISubtarget::getOccupancyWithNumSGPRs(unsigned SGPRs) const {
if (getGeneration() >= SISubtarget::VOLCANIC_ISLANDS) {
if (SGPRs <= 80)
return 10;
if (SGPRs <= 88)
return 9;
if (SGPRs <= 100)
return 8;
return 7;
}
if (SGPRs <= 48)
return 10;
if (SGPRs <= 56)
return 9;
if (SGPRs <= 64)
return 8;
if (SGPRs <= 72)
return 7;
if (SGPRs <= 80)
return 6;
return 5;
}
unsigned SISubtarget::getOccupancyWithNumVGPRs(unsigned VGPRs) const {
if (VGPRs <= 24)
return 10;
if (VGPRs <= 28)
return 9;
if (VGPRs <= 32)
return 8;
if (VGPRs <= 36)
return 7;
if (VGPRs <= 40)
return 6;
if (VGPRs <= 48)
return 5;
if (VGPRs <= 64)
return 4;
if (VGPRs <= 84)
return 3;
if (VGPRs <= 128)
return 2;
return 1;
}
unsigned SISubtarget::getMaxNumSGPRs() const {
if (hasSGPRInitBug())
return SISubtarget::FIXED_SGPR_COUNT_FOR_INIT_BUG;
if (getGeneration() >= VOLCANIC_ISLANDS)
return 102;
return 104;
}