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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(LegalizerHelper &Helper, MachineInstr &MI) const override;
32 
33 private:
34   void setFCmpLibcallsGNU();
35   void setFCmpLibcallsAEABI();
36 
37   struct FCmpLibcallInfo {
38     // Which libcall this is.
39     RTLIB::Libcall LibcallID;
40 
41     // The predicate to be used when comparing the value returned by the
42     // function with a relevant constant (currently hard-coded to zero). This is
43     // necessary because often the libcall will return e.g. a value greater than
44     // 0 to represent 'true' and anything negative to represent 'false', or
45     // maybe 0 to represent 'true' and non-zero for 'false'. If no comparison is
46     // needed, this should be CmpInst::BAD_ICMP_PREDICATE.
47     CmpInst::Predicate Predicate;
48   };
49   using FCmpLibcallsList = SmallVector<FCmpLibcallInfo, 2>;
50 
51   // Map from each FCmp predicate to the corresponding libcall infos. A FCmp
52   // instruction may be lowered to one or two libcalls, which is why we need a
53   // list. If two libcalls are needed, their results will be OR'ed.
54   using FCmpLibcallsMapTy = IndexedMap<FCmpLibcallsList>;
55 
56   FCmpLibcallsMapTy FCmp32Libcalls;
57   FCmpLibcallsMapTy FCmp64Libcalls;
58 
59   // Get the libcall(s) corresponding to \p Predicate for operands of \p Size
60   // bits.
61   FCmpLibcallsList getFCmpLibcalls(CmpInst::Predicate, unsigned Size) const;
62 };
63 } // End llvm namespace.
64 #endif
65