1 //===-- SystemZSubtarget.cpp - SystemZ 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 #include "SystemZSubtarget.h"
10 #include "MCTargetDesc/SystemZMCTargetDesc.h"
11 #include "llvm/IR/GlobalValue.h"
12 #include "llvm/Target/TargetMachine.h"
13
14 using namespace llvm;
15
16 #define DEBUG_TYPE "systemz-subtarget"
17
18 #define GET_SUBTARGETINFO_TARGET_DESC
19 #define GET_SUBTARGETINFO_CTOR
20 #include "SystemZGenSubtargetInfo.inc"
21
22 static cl::opt<bool> UseSubRegLiveness(
23 "systemz-subreg-liveness",
24 cl::desc("Enable subregister liveness tracking for SystemZ (experimental)"),
25 cl::Hidden);
26
27 // Pin the vtable to this file.
anchor()28 void SystemZSubtarget::anchor() {}
29
initializeSubtargetDependencies(StringRef CPU,StringRef TuneCPU,StringRef FS)30 SystemZSubtarget &SystemZSubtarget::initializeSubtargetDependencies(
31 StringRef CPU, StringRef TuneCPU, StringRef FS) {
32 if (CPU.empty())
33 CPU = "generic";
34 if (TuneCPU.empty())
35 TuneCPU = CPU;
36 // Parse features string.
37 ParseSubtargetFeatures(CPU, TuneCPU, FS);
38
39 // -msoft-float implies -mno-vx.
40 if (HasSoftFloat)
41 HasVector = false;
42
43 // -mno-vx implicitly disables all vector-related features.
44 if (!HasVector) {
45 HasVectorEnhancements1 = false;
46 HasVectorEnhancements2 = false;
47 HasVectorPackedDecimal = false;
48 HasVectorPackedDecimalEnhancement = false;
49 HasVectorPackedDecimalEnhancement2 = false;
50 }
51
52 return *this;
53 }
54
55 SystemZCallingConventionRegisters *
initializeSpecialRegisters()56 SystemZSubtarget::initializeSpecialRegisters() {
57 if (isTargetXPLINK64())
58 return new SystemZXPLINK64Registers;
59 else if (isTargetELF())
60 return new SystemZELFRegisters;
61 else {
62 llvm_unreachable("Invalid Calling Convention. Cannot initialize Special "
63 "Call Registers!");
64 }
65 }
66
SystemZSubtarget(const Triple & TT,const std::string & CPU,const std::string & TuneCPU,const std::string & FS,const TargetMachine & TM)67 SystemZSubtarget::SystemZSubtarget(const Triple &TT, const std::string &CPU,
68 const std::string &TuneCPU,
69 const std::string &FS,
70 const TargetMachine &TM)
71 : SystemZGenSubtargetInfo(TT, CPU, TuneCPU, FS), TargetTriple(TT),
72 SpecialRegisters(initializeSpecialRegisters()),
73 InstrInfo(initializeSubtargetDependencies(CPU, TuneCPU, FS)),
74 TLInfo(TM, *this), FrameLowering(SystemZFrameLowering::create(*this)) {}
75
enableSubRegLiveness() const76 bool SystemZSubtarget::enableSubRegLiveness() const {
77 return UseSubRegLiveness;
78 }
79
isPC32DBLSymbol(const GlobalValue * GV,CodeModel::Model CM) const80 bool SystemZSubtarget::isPC32DBLSymbol(const GlobalValue *GV,
81 CodeModel::Model CM) const {
82 // PC32DBL accesses require the low bit to be clear.
83 //
84 // FIXME: Explicitly check for functions: the datalayout is currently
85 // missing information about function pointers.
86 const DataLayout &DL = GV->getParent()->getDataLayout();
87 if (GV->getPointerAlignment(DL) == 1 && !GV->getValueType()->isFunctionTy())
88 return false;
89
90 // For the small model, all locally-binding symbols are in range.
91 if (CM == CodeModel::Small)
92 return TLInfo.getTargetMachine().shouldAssumeDSOLocal(*GV->getParent(), GV);
93
94 // For Medium and above, assume that the symbol is not within the 4GB range.
95 // Taking the address of locally-defined text would be OK, but that
96 // case isn't easy to detect.
97 return false;
98 }
99