lib/Target/ARM/ARMLegalizerInfo.h

   1 //===- ARMLegalizerInfo ------------------------------------------*- C++ -*-==//
   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 /// \file
   9 /// This file declares the targeting of the Machinelegalizer class for ARM.
  10 /// \todo This should be generated by TableGen.
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_TARGET_ARM_ARMMACHINELEGALIZER_H
  14 #define LLVM_LIB_TARGET_ARM_ARMMACHINELEGALIZER_H
  15
  16 #include "llvm/ADT/IndexedMap.h"
  17 #include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
  18 #include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
  19 #include "llvm/CodeGen/RuntimeLibcalls.h"
  20 #include "llvm/IR/Instructions.h"
  21
  22 namespace llvm {
  23
  24 class ARMSubtarget;
  25
  26 /// This class provides the information for the target register banks.
  27 class ARMLegalizerInfo : public LegalizerInfo {
  28 public:
  29   ARMLegalizerInfo(const ARMSubtarget &ST);
  30
  31   bool legalizeCustom(MachineInstr &MI, MachineRegisterInfo &MRI,
  32                       MachineIRBuilder &MIRBuilder,
  33                       GISelChangeObserver &Observer) const override;
  34
  35 private:
  36   void setFCmpLibcallsGNU();
  37   void setFCmpLibcallsAEABI();
  38
  39   struct FCmpLibcallInfo {
  40     // Which libcall this is.
  41     RTLIB::Libcall LibcallID;
  42
  43     // The predicate to be used when comparing the value returned by the
  44     // function with a relevant constant (currently hard-coded to zero). This is
  45     // necessary because often the libcall will return e.g. a value greater than
  46     // 0 to represent 'true' and anything negative to represent 'false', or
  47     // maybe 0 to represent 'true' and non-zero for 'false'. If no comparison is
  48     // needed, this should be CmpInst::BAD_ICMP_PREDICATE.
  49     CmpInst::Predicate Predicate;
  50   };
  51   using FCmpLibcallsList = SmallVector<FCmpLibcallInfo, 2>;
  52
  53   // Map from each FCmp predicate to the corresponding libcall infos. A FCmp
  54   // instruction may be lowered to one or two libcalls, which is why we need a
  55   // list. If two libcalls are needed, their results will be OR'ed.
  56   using FCmpLibcallsMapTy = IndexedMap<FCmpLibcallsList>;
  57
  58   FCmpLibcallsMapTy FCmp32Libcalls;
  59   FCmpLibcallsMapTy FCmp64Libcalls;
  60
  61   // Get the libcall(s) corresponding to \p Predicate for operands of \p Size
  62   // bits.
  63   FCmpLibcallsList getFCmpLibcalls(CmpInst::Predicate, unsigned Size) const;
  64 };
  65 } // End llvm namespace.
  66 #endif