1 //===-- VEMCExpr.cpp - VE specific MC expression classes ------------------===//
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 // This file contains the implementation of the assembly expression modifiers
10 // accepted by the VE architecture (e.g. "%hi", "%lo", ...).
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "VEMCExpr.h"
15 #include "llvm/BinaryFormat/ELF.h"
16 #include "llvm/MC/MCAssembler.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCObjectStreamer.h"
19 #include "llvm/MC/MCSymbolELF.h"
20 #include "llvm/MC/MCValue.h"
21 
22 using namespace llvm;
23 
24 #define DEBUG_TYPE "vemcexpr"
25 
26 const VEMCExpr *VEMCExpr::create(VariantKind Kind, const MCExpr *Expr,
27                                  MCContext &Ctx) {
28   return new (Ctx) VEMCExpr(Kind, Expr);
29 }
30 
31 void VEMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
32 
33   bool closeParen = printVariantKind(OS, Kind);
34 
35   const MCExpr *Expr = getSubExpr();
36   Expr->print(OS, MAI);
37 
38   if (closeParen)
39     OS << ')';
40   printVariantKindSuffix(OS, Kind);
41 }
42 
43 bool VEMCExpr::printVariantKind(raw_ostream &OS, VariantKind Kind) {
44   switch (Kind) {
45   case VK_VE_None:
46   case VK_VE_REFLONG:
47     return false;
48 
49   case VK_VE_HI32:
50   case VK_VE_LO32:
51   case VK_VE_PC_HI32:
52   case VK_VE_PC_LO32:
53   case VK_VE_GOT_HI32:
54   case VK_VE_GOT_LO32:
55   case VK_VE_GOTOFF_HI32:
56   case VK_VE_GOTOFF_LO32:
57   case VK_VE_PLT_HI32:
58   case VK_VE_PLT_LO32:
59   case VK_VE_TLS_GD_HI32:
60   case VK_VE_TLS_GD_LO32:
61   case VK_VE_TPOFF_HI32:
62   case VK_VE_TPOFF_LO32:
63     // Use suffix for these variant kinds
64     return false;
65   }
66   return true;
67 }
68 
69 void VEMCExpr::printVariantKindSuffix(raw_ostream &OS, VariantKind Kind) {
70   switch (Kind) {
71   case VK_VE_None:
72   case VK_VE_REFLONG:
73     break;
74   case VK_VE_HI32:
75     OS << "@hi";
76     break;
77   case VK_VE_LO32:
78     OS << "@lo";
79     break;
80   case VK_VE_PC_HI32:
81     OS << "@pc_hi";
82     break;
83   case VK_VE_PC_LO32:
84     OS << "@pc_lo";
85     break;
86   case VK_VE_GOT_HI32:
87     OS << "@got_hi";
88     break;
89   case VK_VE_GOT_LO32:
90     OS << "@got_lo";
91     break;
92   case VK_VE_GOTOFF_HI32:
93     OS << "@gotoff_hi";
94     break;
95   case VK_VE_GOTOFF_LO32:
96     OS << "@gotoff_lo";
97     break;
98   case VK_VE_PLT_HI32:
99     OS << "@plt_hi";
100     break;
101   case VK_VE_PLT_LO32:
102     OS << "@plt_lo";
103     break;
104   case VK_VE_TLS_GD_HI32:
105     OS << "@tls_gd_hi";
106     break;
107   case VK_VE_TLS_GD_LO32:
108     OS << "@tls_gd_lo";
109     break;
110   case VK_VE_TPOFF_HI32:
111     OS << "@tpoff_hi";
112     break;
113   case VK_VE_TPOFF_LO32:
114     OS << "@tpoff_lo";
115     break;
116   }
117 }
118 
119 VEMCExpr::VariantKind VEMCExpr::parseVariantKind(StringRef name) {
120   return StringSwitch<VEMCExpr::VariantKind>(name)
121       .Case("hi", VK_VE_HI32)
122       .Case("lo", VK_VE_LO32)
123       .Case("pc_hi", VK_VE_PC_HI32)
124       .Case("pc_lo", VK_VE_PC_LO32)
125       .Case("got_hi", VK_VE_GOT_HI32)
126       .Case("got_lo", VK_VE_GOT_LO32)
127       .Case("gotoff_hi", VK_VE_GOTOFF_HI32)
128       .Case("gotoff_lo", VK_VE_GOTOFF_LO32)
129       .Case("plt_hi", VK_VE_PLT_HI32)
130       .Case("plt_lo", VK_VE_PLT_LO32)
131       .Case("tls_gd_hi", VK_VE_TLS_GD_HI32)
132       .Case("tls_gd_lo", VK_VE_TLS_GD_LO32)
133       .Case("tpoff_hi", VK_VE_TPOFF_HI32)
134       .Case("tpoff_lo", VK_VE_TPOFF_LO32)
135       .Default(VK_VE_None);
136 }
137 
138 VE::Fixups VEMCExpr::getFixupKind(VEMCExpr::VariantKind Kind) {
139   switch (Kind) {
140   default:
141     llvm_unreachable("Unhandled VEMCExpr::VariantKind");
142   case VK_VE_REFLONG:
143     return VE::fixup_ve_reflong;
144   case VK_VE_HI32:
145     return VE::fixup_ve_hi32;
146   case VK_VE_LO32:
147     return VE::fixup_ve_lo32;
148   case VK_VE_PC_HI32:
149     return VE::fixup_ve_pc_hi32;
150   case VK_VE_PC_LO32:
151     return VE::fixup_ve_pc_lo32;
152   case VK_VE_GOT_HI32:
153     return VE::fixup_ve_got_hi32;
154   case VK_VE_GOT_LO32:
155     return VE::fixup_ve_got_lo32;
156   case VK_VE_GOTOFF_HI32:
157     return VE::fixup_ve_gotoff_hi32;
158   case VK_VE_GOTOFF_LO32:
159     return VE::fixup_ve_gotoff_lo32;
160   case VK_VE_PLT_HI32:
161     return VE::fixup_ve_plt_hi32;
162   case VK_VE_PLT_LO32:
163     return VE::fixup_ve_plt_lo32;
164   case VK_VE_TLS_GD_HI32:
165     return VE::fixup_ve_tls_gd_hi32;
166   case VK_VE_TLS_GD_LO32:
167     return VE::fixup_ve_tls_gd_lo32;
168   case VK_VE_TPOFF_HI32:
169     return VE::fixup_ve_tpoff_hi32;
170   case VK_VE_TPOFF_LO32:
171     return VE::fixup_ve_tpoff_lo32;
172   }
173 }
174 
175 bool VEMCExpr::evaluateAsRelocatableImpl(MCValue &Res,
176                                          const MCAsmLayout *Layout,
177                                          const MCFixup *Fixup) const {
178   if (!getSubExpr()->evaluateAsRelocatable(Res, Layout, Fixup))
179     return false;
180 
181   Res =
182       MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
183 
184   return true;
185 }
186 
187 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
188   switch (Expr->getKind()) {
189   case MCExpr::Target:
190     llvm_unreachable("Can't handle nested target expr!");
191     break;
192 
193   case MCExpr::Constant:
194     break;
195 
196   case MCExpr::Binary: {
197     const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
198     fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
199     fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
200     break;
201   }
202 
203   case MCExpr::SymbolRef: {
204     // We're known to be under a TLS fixup, so any symbol should be
205     // modified. There should be only one.
206     const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
207     cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS);
208     break;
209   }
210 
211   case MCExpr::Unary:
212     fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
213     break;
214   }
215 }
216 
217 void VEMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
218   Streamer.visitUsedExpr(*getSubExpr());
219 }
220 
221 void VEMCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
222   switch (getKind()) {
223   default:
224     return;
225   case VK_VE_TLS_GD_HI32:
226   case VK_VE_TLS_GD_LO32:
227   case VK_VE_TPOFF_HI32:
228   case VK_VE_TPOFF_LO32:
229     break;
230   }
231   fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
232 }
233