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      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/Properties.h"
     18 #include "bcc/Support/TargetCompilerConfigs.h"
     19 
     20 #include "llvm/ADT/StringMap.h"
     21 #include "llvm/Support/Host.h"
     22 
     23 // Get ARM version number (i.e., __ARM_ARCH__)
     24 #ifdef __arm__
     25 #include <machine/cpu-features.h>
     26 #endif
     27 
     28 using namespace bcc;
     29 
     30 //===----------------------------------------------------------------------===//
     31 // ARM
     32 //===----------------------------------------------------------------------===//
     33 #if defined(PROVIDE_ARM_CODEGEN)
     34 
     35 bool ARMBaseCompilerConfig::HasThumb2() {
     36 #if !defined(TARGET_BUILD)
     37   // Cross-compiler can always generate Thumb-2 instructions.
     38   return true;
     39 #else // defined(TARGET_BUILD)
     40 #  if (__ARM_ARCH__ >= 7) || defined(__ARM_ARCH_6T2__)
     41   return true;
     42 #  else
     43   // ARM prior to V6T2 doesn't support Thumb-2.
     44   return false;
     45 #  endif
     46 #endif
     47 }
     48 
     49 void
     50 ARMBaseCompilerConfig::GetFeatureVector(std::vector<std::string> &pAttributes,
     51                                         bool pInThumbMode, bool pEnableNEON) {
     52   llvm::StringMap<bool> Features;
     53   llvm::sys::getHostCPUFeatures(Features);
     54 
     55 #if defined(ARCH_ARM_HAVE_VFP)
     56   pAttributes.push_back("+vfp3");
     57 #  if !defined(ARCH_ARM_HAVE_VFP_D32)
     58   pAttributes.push_back("+d16");
     59 #  endif
     60 #endif
     61 
     62   if (pInThumbMode) {
     63     if (HasThumb2()) {
     64       pAttributes.push_back("+thumb2");
     65     } else {
     66       pAttributes.push_back("-thumb2");
     67     }
     68   }
     69 
     70   if (pEnableNEON && Features.count("neon") && Features["neon"]) {
     71     pAttributes.push_back("+neon");
     72   } else {
     73     pAttributes.push_back("-neon");
     74     pAttributes.push_back("-neonfp");
     75   }
     76 
     77   if (!getProperty("debug.rs.arm-no-hwdiv")) {
     78     if (Features.count("hwdiv-arm") && Features["hwdiv-arm"])
     79       pAttributes.push_back("+hwdiv-arm");
     80 
     81     if (Features.count("hwdiv") && Features["hwdiv"])
     82       pAttributes.push_back("+hwdiv");
     83   }
     84 
     85   return;
     86 }
     87 
     88 ARMBaseCompilerConfig::ARMBaseCompilerConfig(const std::string &pTriple,
     89                                              bool pInThumbMode)
     90   : CompilerConfig(pTriple), mInThumbMode(pInThumbMode) {
     91 
     92   // Enable NEON by default.
     93   mEnableNEON = true;
     94 
     95   if (!getProperty("debug.rs.arm-no-tune-for-cpu"))
     96     setCPU(llvm::sys::getHostCPUName());
     97 
     98   std::vector<std::string> attributes;
     99   GetFeatureVector(attributes, mInThumbMode, mEnableNEON);
    100   setFeatureString(attributes);
    101 
    102   return;
    103 }
    104 
    105 bool ARMBaseCompilerConfig::enableNEON(bool pEnable) {
    106 #if defined(ARCH_ARM_HAVE_NEON)
    107   if (mEnableNEON != pEnable) {
    108     std::vector<std::string> attributes;
    109     GetFeatureVector(attributes, mInThumbMode, pEnable);
    110     setFeatureString(attributes);
    111     mEnableNEON = pEnable;
    112     return true;
    113   }
    114   // Fall-through
    115 #endif
    116   return false;
    117 }
    118 #endif // defined(PROVIDE_ARM_CODEGEN)
    119