CompilerConfig.cpp revision 5379131149cfd74e2b65b7b4f31c0b8e8b2f8fa0 
1/*
2 * Copyright 2012, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "bcc/CompilerConfig.h"
18
19#include "Log.h"
20#include "Properties.h"
21
22#include "bcc/Config.h"
23
24#include <llvm/CodeGen/SchedulerRegistry.h>
25#include <llvm/MC/SubtargetFeature.h>
26#include <llvm/Support/Host.h>
27#include <llvm/Support/TargetRegistry.h>
28
29using namespace bcc;
30
31#if defined (PROVIDE_X86_CODEGEN) && !defined(__HOST__)
32
33namespace {
34
35// Utility function to add feature flags supported by the running CPU.
36// This function is only needed for on-device bcc for x86.
37void AddX86NativeCPUFeatures(std::vector<std::string>* attributes) {
38  llvm::StringMap<bool> features;
39  if (llvm::sys::getHostCPUFeatures(features)) {
40    for (const auto& f : features)
41      attributes->push_back((f.second ? '+' : '-') + f.first().str());
42  }
43
44  // LLVM generates AVX code that treats a long3 as 256 bits, while
45  // RenderScript considers a long3 192 bits (http://b/28879581)
46  attributes->push_back("-avx");
47}
48
49}
50#endif // (PROVIDE_X86_CODEGEN) && !defined(__HOST__)
51
52CompilerConfig::CompilerConfig(const std::string &pTriple)
53  : mTriple(pTriple), mFullPrecision(true), mTarget(nullptr) {
54  //===--------------------------------------------------------------------===//
55  // Default setting of target options
56  //===--------------------------------------------------------------------===//
57
58  // Use soft-float ABI.  This only selects the ABI (and is applicable only to
59  // ARM targets).  Codegen still uses hardware FPU by default.  To use software
60  // floating point, add 'soft-float' feature to mFeatureString below.
61  mTargetOpts.FloatABIType = llvm::FloatABI::Soft;
62
63  //===--------------------------------------------------------------------===//
64  // Default setting for code model
65  //===--------------------------------------------------------------------===//
66  mCodeModel = llvm::CodeModel::Small;
67
68  //===--------------------------------------------------------------------===//
69  // Default setting for optimization level (-O2)
70  //===--------------------------------------------------------------------===//
71  mOptLevel = llvm::CodeGenOpt::Default;
72
73  //===--------------------------------------------------------------------===//
74  // Default setting for architecture type
75  //===--------------------------------------------------------------------===//
76  mArchType = llvm::Triple::UnknownArch;
77
78  initializeTarget();
79  initializeArch();
80
81  return;
82}
83
84bool CompilerConfig::initializeTarget() {
85  std::string error;
86  mTarget = llvm::TargetRegistry::lookupTarget(mTriple, error);
87  if (mTarget != nullptr) {
88    return true;
89  } else {
90    ALOGE("Cannot initialize llvm::Target for given triple '%s'! (%s)",
91          mTriple.c_str(), error.c_str());
92    return false;
93  }
94}
95
96bool CompilerConfig::initializeArch() {
97  if (mTarget != nullptr) {
98    mArchType = llvm::Triple::getArchTypeForLLVMName(mTarget->getName());
99  } else {
100    mArchType = llvm::Triple::UnknownArch;
101    return false;
102  }
103
104  // Configure each architecture for any necessary additional flags.
105  std::vector<std::string> attributes;
106  switch (mArchType) {
107#if defined(PROVIDE_ARM_CODEGEN)
108  case llvm::Triple::arm: {
109    llvm::StringMap<bool> features;
110    llvm::sys::getHostCPUFeatures(features);
111
112#if defined(__HOST__) || defined(ARCH_ARM_HAVE_VFP)
113    attributes.push_back("+vfp3");
114#if !defined(__HOST__) && !defined(ARCH_ARM_HAVE_VFP_D32)
115    attributes.push_back("+d16");
116#endif  // !__HOST__ && !ARCH_ARM_HAVE_VFP_D32
117#endif  // __HOST__ || ARCH_ARM_HAVE_VFP
118
119#if defined(__HOST__) || defined(ARCH_ARM_HAVE_NEON)
120    // Only enable NEON on ARM if we have relaxed precision floats.
121    if (!mFullPrecision) {
122      attributes.push_back("+neon");
123    } else {
124#endif  // __HOST__ || ARCH_ARM_HAVE_NEON
125      attributes.push_back("-neon");
126      attributes.push_back("-neonfp");
127#if defined(__HOST__) || defined(ARCH_ARM_HAVE_NEON)
128    }
129#endif  // __HOST__ || ARCH_ARM_HAVE_NEON
130
131    if (!getProperty("debug.rs.arm-no-hwdiv")) {
132      if (features.count("hwdiv-arm") && features["hwdiv-arm"])
133        attributes.push_back("+hwdiv-arm");
134
135      if (features.count("hwdiv") && features["hwdiv"])
136        attributes.push_back("+hwdiv");
137    }
138
139    // Enable fp16 attribute if available in the feature list.  This feature
140    // will not be added in the host version of bcc or bcc_compat since
141    // 'features' would correspond to features in an x86 host.
142    if (features.count("fp16") && features["fp16"])
143      attributes.push_back("+fp16");
144
145#if defined(PROVIDE_ARM64_CODEGEN)
146    // On AArch64, asimd in /proc/cpuinfo signals the presence of hardware
147    // half-precision conversion instructions.  getHostCPUFeatures translates
148    // this to "neon".  If PROVIDE_ARM64_CODEGEN is set, enable "+fp16" for ARM
149    // codegen if "neon" is present in features.
150    if (features.count("neon") && features["neon"])
151      attributes.push_back("+fp16");
152#endif // PROVIDE_ARM64_CODEGEN
153
154#if defined(TARGET_BUILD)
155    if (!getProperty("debug.rs.arm-no-tune-for-cpu")) {
156#ifdef DEFAULT_ARM_CODEGEN
157      setCPU(llvm::sys::getHostCPUName());
158#endif
159    }
160#endif  // TARGET_BUILD
161
162    break;
163  }
164#endif  // PROVIDE_ARM_CODEGEN
165
166#if defined(PROVIDE_ARM64_CODEGEN)
167  case llvm::Triple::aarch64:
168#if defined(TARGET_BUILD)
169    if (!getProperty("debug.rs.arm-no-tune-for-cpu")) {
170#ifdef DEFAULT_ARM64_CODEGEN
171      setCPU(llvm::sys::getHostCPUName());
172#endif
173    }
174#endif  // TARGET_BUILD
175    break;
176#endif  // PROVIDE_ARM64_CODEGEN
177
178#if defined (PROVIDE_MIPS_CODEGEN)
179  case llvm::Triple::mips:
180  case llvm::Triple::mipsel:
181    if (!mRelocModel.hasValue()) {
182      mRelocModel = llvm::Reloc::Static;
183    }
184    break;
185#endif  // PROVIDE_MIPS_CODEGEN
186
187#if defined (PROVIDE_MIPS64_CODEGEN)
188  case llvm::Triple::mips64:
189  case llvm::Triple::mips64el:
190    // Default revision for MIPS64 Android is R6.
191    setCPU("mips64r6");
192    break;
193#endif // PROVIDE_MIPS64_CODEGEN
194
195#if defined (PROVIDE_X86_CODEGEN)
196  case llvm::Triple::x86:
197    getTargetOptions().UseInitArray = true;
198#if defined (DEFAULT_X86_CODEGEN) && !defined (__HOST__)
199    setCPU(llvm::sys::getHostCPUName());
200    AddX86NativeCPUFeatures(&attributes);
201#else
202    // generic fallback for 32bit x86 targets
203    setCPU("atom");
204#endif // DEFAULT_X86_CODEGEN && !__HOST__
205    break;
206#endif  // PROVIDE_X86_CODEGEN
207
208#if defined (PROVIDE_X86_CODEGEN)
209// PROVIDE_X86_CODEGEN is defined for both x86 and x86_64
210  case llvm::Triple::x86_64:
211#if defined(DEFAULT_X86_64_CODEGEN) && !defined(__HOST__)
212    setCPU(llvm::sys::getHostCPUName());
213    AddX86NativeCPUFeatures(&attributes);
214#else
215    // generic fallback for 64bit x86 targets
216    setCPU("core2");
217#endif
218    // x86_64 needs small CodeModel if use PIC_ reloc, or else dlopen failed with TEXTREL.
219    if (mRelocModel.hasValue() && mRelocModel.getValue() == llvm::Reloc::PIC_) {
220      setCodeModel(llvm::CodeModel::Small);
221    } else {
222      setCodeModel(llvm::CodeModel::Medium);
223    }
224    getTargetOptions().UseInitArray = true;
225    break;
226#endif  // PROVIDE_X86_CODEGEN
227
228  default:
229    ALOGE("Unsupported architecture type: %s", mTarget->getName());
230    return false;
231  }
232
233  setFeatureString(attributes);
234  return true;
235}
236
237void CompilerConfig::setFeatureString(const std::vector<std::string> &pAttrs) {
238  llvm::SubtargetFeatures f;
239
240  for (std::vector<std::string>::const_iterator attr_iter = pAttrs.begin(),
241           attr_end = pAttrs.end();
242       attr_iter != attr_end; attr_iter++) {
243    f.AddFeature(*attr_iter);
244  }
245
246  mFeatureString = f.getString();
247  return;
248}
249