1 //===-- PPCMCExpr.cpp - PPC specific MC expression classes ----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "PPCMCExpr.h"
11 #include "llvm/MC/MCAsmInfo.h"
12 #include "llvm/MC/MCAssembler.h"
13 #include "llvm/MC/MCContext.h"
14 
15 using namespace llvm;
16 
17 #define DEBUG_TYPE "ppcmcexpr"
18 
19 const PPCMCExpr*
20 PPCMCExpr::Create(VariantKind Kind, const MCExpr *Expr,
21                   bool isDarwin, MCContext &Ctx) {
22   return new (Ctx) PPCMCExpr(Kind, Expr, isDarwin);
23 }
24 
25 void PPCMCExpr::PrintImpl(raw_ostream &OS) const {
26   if (isDarwinSyntax()) {
27     switch (Kind) {
28     default: llvm_unreachable("Invalid kind!");
29     case VK_PPC_LO: OS << "lo16"; break;
30     case VK_PPC_HI: OS << "hi16"; break;
31     case VK_PPC_HA: OS << "ha16"; break;
32     }
33 
34     OS << '(';
35     getSubExpr()->print(OS);
36     OS << ')';
37   } else {
38     getSubExpr()->print(OS);
39 
40     switch (Kind) {
41     default: llvm_unreachable("Invalid kind!");
42     case VK_PPC_LO: OS << "@l"; break;
43     case VK_PPC_HI: OS << "@h"; break;
44     case VK_PPC_HA: OS << "@ha"; break;
45     case VK_PPC_HIGHER: OS << "@higher"; break;
46     case VK_PPC_HIGHERA: OS << "@highera"; break;
47     case VK_PPC_HIGHEST: OS << "@highest"; break;
48     case VK_PPC_HIGHESTA: OS << "@highesta"; break;
49     }
50   }
51 }
52 
53 bool
54 PPCMCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
55                                      const MCAsmLayout *Layout) const {
56   MCValue Value;
57 
58   if (!getSubExpr()->EvaluateAsRelocatable(Value, Layout))
59     return false;
60 
61   if (Value.isAbsolute()) {
62     int64_t Result = Value.getConstant();
63     switch (Kind) {
64       default:
65         llvm_unreachable("Invalid kind!");
66       case VK_PPC_LO:
67         Result = Result & 0xffff;
68         break;
69       case VK_PPC_HI:
70         Result = (Result >> 16) & 0xffff;
71         break;
72       case VK_PPC_HA:
73         Result = ((Result + 0x8000) >> 16) & 0xffff;
74         break;
75       case VK_PPC_HIGHER:
76         Result = (Result >> 32) & 0xffff;
77         break;
78       case VK_PPC_HIGHERA:
79         Result = ((Result + 0x8000) >> 32) & 0xffff;
80         break;
81       case VK_PPC_HIGHEST:
82         Result = (Result >> 48) & 0xffff;
83         break;
84       case VK_PPC_HIGHESTA:
85         Result = ((Result + 0x8000) >> 48) & 0xffff;
86         break;
87     }
88     Res = MCValue::get(Result);
89   } else {
90     if (!Layout)
91       return false;
92 
93     MCContext &Context = Layout->getAssembler().getContext();
94     const MCSymbolRefExpr *Sym = Value.getSymA();
95     MCSymbolRefExpr::VariantKind Modifier = Sym->getKind();
96     if (Modifier != MCSymbolRefExpr::VK_None)
97       return false;
98     switch (Kind) {
99       default:
100         llvm_unreachable("Invalid kind!");
101       case VK_PPC_LO:
102         Modifier = MCSymbolRefExpr::VK_PPC_LO;
103         break;
104       case VK_PPC_HI:
105         Modifier = MCSymbolRefExpr::VK_PPC_HI;
106         break;
107       case VK_PPC_HA:
108         Modifier = MCSymbolRefExpr::VK_PPC_HA;
109         break;
110       case VK_PPC_HIGHERA:
111         Modifier = MCSymbolRefExpr::VK_PPC_HIGHERA;
112         break;
113       case VK_PPC_HIGHER:
114         Modifier = MCSymbolRefExpr::VK_PPC_HIGHER;
115         break;
116       case VK_PPC_HIGHEST:
117         Modifier = MCSymbolRefExpr::VK_PPC_HIGHEST;
118         break;
119       case VK_PPC_HIGHESTA:
120         Modifier = MCSymbolRefExpr::VK_PPC_HIGHESTA;
121         break;
122     }
123     Sym = MCSymbolRefExpr::Create(&Sym->getSymbol(), Modifier, Context);
124     Res = MCValue::get(Sym, Value.getSymB(), Value.getConstant());
125   }
126 
127   return true;
128 }
129 
130 // FIXME: This basically copies MCObjectStreamer::AddValueSymbols. Perhaps
131 // that method should be made public?
132 static void AddValueSymbols_(const MCExpr *Value, MCAssembler *Asm) {
133   switch (Value->getKind()) {
134   case MCExpr::Target:
135     llvm_unreachable("Can't handle nested target expr!");
136 
137   case MCExpr::Constant:
138     break;
139 
140   case MCExpr::Binary: {
141     const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
142     AddValueSymbols_(BE->getLHS(), Asm);
143     AddValueSymbols_(BE->getRHS(), Asm);
144     break;
145   }
146 
147   case MCExpr::SymbolRef:
148     Asm->getOrCreateSymbolData(cast<MCSymbolRefExpr>(Value)->getSymbol());
149     break;
150 
151   case MCExpr::Unary:
152     AddValueSymbols_(cast<MCUnaryExpr>(Value)->getSubExpr(), Asm);
153     break;
154   }
155 }
156 
157 void PPCMCExpr::AddValueSymbols(MCAssembler *Asm) const {
158   AddValueSymbols_(getSubExpr(), Asm);
159 }
160