CompilerConfig.cpp revision 060bd2d6771e781ddbf5424c50af149fd0d80432 
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/Support/CompilerConfig.h"
18#include "bcc/Config/Config.h"
19#include "bcc/Support/Properties.h"
20
21#include <llvm/CodeGen/SchedulerRegistry.h>
22#include <llvm/MC/SubtargetFeature.h>
23#include <llvm/Support/Host.h>
24#include <llvm/Support/TargetRegistry.h>
25
26#include "bcc/Support/Log.h"
27
28using namespace bcc;
29
30CompilerConfig::CompilerConfig(const std::string &pTriple)
31  : mTriple(pTriple), mFullPrecision(true), mTarget(NULL) {
32  //===--------------------------------------------------------------------===//
33  // Default setting of register sheduler
34  //===--------------------------------------------------------------------===//
35  llvm::RegisterScheduler::setDefault(llvm::createDefaultScheduler);
36
37  //===--------------------------------------------------------------------===//
38  // Default setting of target options
39  //===--------------------------------------------------------------------===//
40  // Use hardfloat ABI by default.
41  //
42  // TODO(all): Need to detect the CPU capability and decide whether to use
43  // softfp. To use softfp, change the following 2 lines to
44  //
45  // options.FloatABIType = llvm::FloatABI::Soft;
46  // options.UseSoftFloat = true;
47  mTargetOpts.FloatABIType = llvm::FloatABI::Soft;
48  mTargetOpts.UseSoftFloat = false;
49
50  // Enable frame pointer elimination optimization by default.
51  mTargetOpts.NoFramePointerElim = false;
52
53  //===--------------------------------------------------------------------===//
54  // Default setting for code model
55  //===--------------------------------------------------------------------===//
56  mCodeModel = llvm::CodeModel::Small;
57
58  //===--------------------------------------------------------------------===//
59  // Default setting for relocation model
60  //===--------------------------------------------------------------------===//
61  mRelocModel = llvm::Reloc::Default;
62
63  //===--------------------------------------------------------------------===//
64  // Default setting for optimization level (-O2)
65  //===--------------------------------------------------------------------===//
66  mOptLevel = llvm::CodeGenOpt::Default;
67
68  //===--------------------------------------------------------------------===//
69  // Default setting for architecture type
70  //===--------------------------------------------------------------------===//
71  mArchType = llvm::Triple::UnknownArch;
72
73  initializeTarget();
74  initializeArch();
75
76  return;
77}
78
79bool CompilerConfig::initializeTarget() {
80  std::string error;
81  mTarget = llvm::TargetRegistry::lookupTarget(mTriple, error);
82  if (mTarget != NULL) {
83    return true;
84  } else {
85    ALOGE("Cannot initialize llvm::Target for given triple '%s'! (%s)",
86          mTriple.c_str(), error.c_str());
87    return false;
88  }
89}
90
91bool CompilerConfig::initializeArch() {
92  if (mTarget != NULL) {
93    mArchType = llvm::Triple::getArchTypeForLLVMName(mTarget->getName());
94  } else {
95    mArchType = llvm::Triple::UnknownArch;
96    return false;
97  }
98
99  // Configure each architecture for any necessary additional flags.
100  switch (mArchType) {
101#if defined(PROVIDE_ARM_CODEGEN)
102  case llvm::Triple::arm: {
103    llvm::StringMap<bool> features;
104    llvm::sys::getHostCPUFeatures(features);
105    std::vector<std::string> attributes;
106
107#if defined(__HOST__) || defined(ARCH_ARM_HAVE_VFP)
108    attributes.push_back("+vfp3");
109#if !defined(__HOST__) && !defined(ARCH_ARM_HAVE_VFP_D32)
110    attributes.push_back("+d16");
111#endif  // !__HOST__ && !ARCH_ARM_HAVE_VFP_D32
112#endif  // __HOST__ || ARCH_ARM_HAVE_VFP
113
114#if defined(__HOST__) || defined(ARCH_ARM_HAVE_NEON)
115    // Only enable NEON on ARM if we have relaxed precision floats.
116    if (!mFullPrecision) {
117      attributes.push_back("+neon");
118    } else {
119#endif  // __HOST__ || ARCH_ARM_HAVE_NEON
120      attributes.push_back("-neon");
121      attributes.push_back("-neonfp");
122#if defined(__HOST__) || defined(ARCH_ARM_HAVE_NEON)
123    }
124#endif  // __HOST__ || ARCH_ARM_HAVE_NEON
125
126    if (!getProperty("debug.rs.arm-no-hwdiv")) {
127      if (features.count("hwdiv-arm") && features["hwdiv-arm"])
128        attributes.push_back("+hwdiv-arm");
129
130      if (features.count("hwdiv") && features["hwdiv"])
131        attributes.push_back("+hwdiv");
132    }
133
134    setFeatureString(attributes);
135
136#if defined(TARGET_BUILD)
137    if (!getProperty("debug.rs.arm-no-tune-for-cpu")) {
138      setCPU(llvm::sys::getHostCPUName());
139    }
140#endif  // TARGET_BUILD
141
142    break;
143  }
144#endif  // PROVIDE_ARM_CODEGEN
145
146#if defined(PROVIDE_ARM64_CODEGEN)
147  case llvm::Triple::aarch64:
148#if defined(TARGET_BUILD)
149    if (!getProperty("debug.rs.arm-no-tune-for-cpu")) {
150      setCPU(llvm::sys::getHostCPUName());
151    }
152#endif  // TARGET_BUILD
153    break;
154#endif  // PROVIDE_ARM64_CODEGEN
155
156#if defined (PROVIDE_MIPS_CODEGEN)
157  case llvm::Triple::mips:
158  case llvm::Triple::mipsel:
159  case llvm::Triple::mips64:
160  case llvm::Triple::mips64el:
161    setRelocationModel(llvm::Reloc::Static);
162    break;
163#endif  // PROVIDE_MIPS_CODEGEN
164
165#if defined (PROVIDE_X86_CODEGEN)
166  case llvm::Triple::x86:
167    // Disable frame pointer elimination optimization on x86 family.
168    getTargetOptions().NoFramePointerElim = true;
169    getTargetOptions().UseInitArray = true;
170    break;
171#endif  // PROVIDE_X86_CODEGEN
172
173#if defined (PROVIDE_X86_CODEGEN)
174  case llvm::Triple::x86_64:
175    setCodeModel(llvm::CodeModel::Medium);
176    // Disable frame pointer elimination optimization on x86 family.
177    getTargetOptions().NoFramePointerElim = true;
178    getTargetOptions().UseInitArray = true;
179    break;
180#endif  // PROVIDE_X86_CODEGEN
181
182  default:
183    ALOGE("Unsupported architecture type: %s", mTarget->getName());
184    return false;
185  }
186
187  return true;
188}
189
190void CompilerConfig::setFeatureString(const std::vector<std::string> &pAttrs) {
191  llvm::SubtargetFeatures f;
192
193  for (std::vector<std::string>::const_iterator attr_iter = pAttrs.begin(),
194           attr_end = pAttrs.end();
195       attr_iter != attr_end; attr_iter++) {
196    f.AddFeature(*attr_iter);
197  }
198
199  mFeatureString = f.getString();
200  return;
201}
202