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 &
initializeSubtargetDependencies(StringRef FS)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 
WebAssemblySubtarget(const Triple & TT,const std::string & CPU,const std::string & FS,const TargetMachine & TM)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 
enableAtomicExpand() const47 bool WebAssemblySubtarget::enableAtomicExpand() const {
48   // If atomics are disabled, atomic ops are lowered instead of expanded
49   return hasAtomics();
50 }
51 
enableMachineScheduler() const52 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 
useAA() const59 bool WebAssemblySubtarget::useAA() const { return true; }
60