lib/Target/WebAssembly/WebAssemblySubtarget.cpp

   1 //===-- WebAssemblySubtarget.cpp - WebAssembly Subtarget Information ------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// This file implements the WebAssembly-specific subclass of
  11 /// TargetSubtarget.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "WebAssemblySubtarget.h"
  16 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
  17 #include "WebAssemblyInstrInfo.h"
  18 #include "llvm/Support/TargetRegistry.h"
  19 using namespace llvm;
  20
  21 #define DEBUG_TYPE "wasm-subtarget"
  22
  23 #define GET_SUBTARGETINFO_CTOR
  24 #define GET_SUBTARGETINFO_TARGET_DESC
  25 #include "WebAssemblyGenSubtargetInfo.inc"
  26
  27 WebAssemblySubtarget &
  28 WebAssemblySubtarget::initializeSubtargetDependencies(StringRef FS) {
  29   // Determine default and user-specified characteristics
  30
  31   if (CPUString.empty())
  32     CPUString = "generic";
  33
  34   ParseSubtargetFeatures(CPUString, FS);
  35   return *this;
  36 }
  37
  38 WebAssemblySubtarget::WebAssemblySubtarget(const Triple &TT,
  39                                            const std::string &CPU,
  40                                            const std::string &FS,
  41                                            const TargetMachine &TM)
  42     : WebAssemblyGenSubtargetInfo(TT, CPU, FS), CPUString(CPU),
  43       TargetTriple(TT), FrameLowering(),
  44       InstrInfo(initializeSubtargetDependencies(FS)), TSInfo(),
  45       TLInfo(TM, *this) {}
  46
  47 bool WebAssemblySubtarget::enableAtomicExpand() const {
  48   // If atomics are disabled, atomic ops are lowered instead of expanded
  49   return hasAtomics();
  50 }
  51
  52 bool WebAssemblySubtarget::enableMachineScheduler() const {
  53   // Disable the MachineScheduler for now. Even with ShouldTrackPressure set and
  54   // enableMachineSchedDefaultSched overridden, it appears to have an overall
  55   // negative effect for the kinds of register optimizations we're doing.
  56   return false;
  57 }
  58
  59 bool WebAssemblySubtarget::useAA() const { return true; }