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.
28 void SystemZSubtarget::anchor() {}
29 
30 SystemZSubtarget &
31 SystemZSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS) {
32   StringRef CPUName = CPU;
33   if (CPUName.empty())
34     CPUName = "generic";
35   // Parse features string.
36   ParseSubtargetFeatures(CPUName, /*TuneCPU*/ CPUName, FS);
37 
38   // -msoft-float implies -mno-vx.
39   if (HasSoftFloat)
40     HasVector = false;
41 
42   // -mno-vx implicitly disables all vector-related features.
43   if (!HasVector) {
44     HasVectorEnhancements1 = false;
45     HasVectorEnhancements2 = false;
46     HasVectorPackedDecimal = false;
47     HasVectorPackedDecimalEnhancement = false;
48   }
49 
50   return *this;
51 }
52 
53 SystemZSubtarget::SystemZSubtarget(const Triple &TT, const std::string &CPU,
54                                    const std::string &FS,
55                                    const TargetMachine &TM)
56     : SystemZGenSubtargetInfo(TT, CPU, /*TuneCPU*/ CPU, FS),
57       HasDistinctOps(false), HasLoadStoreOnCond(false), HasHighWord(false),
58       HasFPExtension(false), HasPopulationCount(false),
59       HasMessageSecurityAssist3(false), HasMessageSecurityAssist4(false),
60       HasResetReferenceBitsMultiple(false), HasFastSerialization(false),
61       HasInterlockedAccess1(false), HasMiscellaneousExtensions(false),
62       HasExecutionHint(false), HasLoadAndTrap(false),
63       HasTransactionalExecution(false), HasProcessorAssist(false),
64       HasDFPZonedConversion(false), HasEnhancedDAT2(false),
65       HasVector(false), HasLoadStoreOnCond2(false),
66       HasLoadAndZeroRightmostByte(false), HasMessageSecurityAssist5(false),
67       HasDFPPackedConversion(false),
68       HasMiscellaneousExtensions2(false), HasGuardedStorage(false),
69       HasMessageSecurityAssist7(false), HasMessageSecurityAssist8(false),
70       HasVectorEnhancements1(false), HasVectorPackedDecimal(false),
71       HasInsertReferenceBitsMultiple(false),
72       HasMiscellaneousExtensions3(false), HasMessageSecurityAssist9(false),
73       HasVectorEnhancements2(false), HasVectorPackedDecimalEnhancement(false),
74       HasEnhancedSort(false), HasDeflateConversion(false), HasSoftFloat(false),
75       TargetTriple(TT), InstrInfo(initializeSubtargetDependencies(CPU, FS)),
76       TLInfo(TM, *this), TSInfo(), FrameLowering() {}
77 
78 
79 bool SystemZSubtarget::enableSubRegLiveness() const {
80   return UseSubRegLiveness;
81 }
82 
83 bool SystemZSubtarget::isPC32DBLSymbol(const GlobalValue *GV,
84                                        CodeModel::Model CM) const {
85   // PC32DBL accesses require the low bit to be clear.
86   //
87   // FIXME: Explicitly check for functions: the datalayout is currently
88   // missing information about function pointers.
89   const DataLayout &DL = GV->getParent()->getDataLayout();
90   if (GV->getPointerAlignment(DL) == 1 && !GV->getValueType()->isFunctionTy())
91     return false;
92 
93   // For the small model, all locally-binding symbols are in range.
94   if (CM == CodeModel::Small)
95     return TLInfo.getTargetMachine().shouldAssumeDSOLocal(*GV->getParent(), GV);
96 
97   // For Medium and above, assume that the symbol is not within the 4GB range.
98   // Taking the address of locally-defined text would be OK, but that
99   // case isn't easy to detect.
100   return false;
101 }
102