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1 //===-- ARMFixupKinds.h - ARM Specific Fixup Entries ------------*- C++ -*-===//
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 #ifndef LLVM_ARM_ARMFIXUPKINDS_H
11 #define LLVM_ARM_ARMFIXUPKINDS_H
12 
13 #include "llvm/MC/MCFixup.h"
14 
15 namespace llvm {
16 namespace ARM {
17 enum Fixups {
18   // fixup_arm_ldst_pcrel_12 - 12-bit PC relative relocation for symbol
19   // addresses
20   fixup_arm_ldst_pcrel_12 = FirstTargetFixupKind,
21 
22   // fixup_t2_ldst_pcrel_12 - Equivalent to fixup_arm_ldst_pcrel_12, with
23   // the 16-bit halfwords reordered.
24   fixup_t2_ldst_pcrel_12,
25 
26   // fixup_arm_pcrel_10_unscaled - 10-bit PC relative relocation for symbol
27   // addresses used in LDRD/LDRH/LDRB/etc. instructions. All bits are encoded.
28   fixup_arm_pcrel_10_unscaled,
29   // fixup_arm_pcrel_10 - 10-bit PC relative relocation for symbol addresses
30   // used in VFP instructions where the lower 2 bits are not encoded
31   // (so it's encoded as an 8-bit immediate).
32   fixup_arm_pcrel_10,
33   // fixup_t2_pcrel_10 - Equivalent to fixup_arm_pcrel_10, accounting for
34   // the short-swapped encoding of Thumb2 instructions.
35   fixup_t2_pcrel_10,
36   // fixup_thumb_adr_pcrel_10 - 10-bit PC relative relocation for symbol
37   // addresses where the lower 2 bits are not encoded (so it's encoded as an
38   // 8-bit immediate).
39   fixup_thumb_adr_pcrel_10,
40   // fixup_arm_adr_pcrel_12 - 12-bit PC relative relocation for the ADR
41   // instruction.
42   fixup_arm_adr_pcrel_12,
43   // fixup_t2_adr_pcrel_12 - 12-bit PC relative relocation for the ADR
44   // instruction.
45   fixup_t2_adr_pcrel_12,
46   // fixup_arm_condbranch - 24-bit PC relative relocation for conditional branch
47   // instructions.
48   fixup_arm_condbranch,
49   // fixup_arm_uncondbranch - 24-bit PC relative relocation for
50   // branch instructions. (unconditional)
51   fixup_arm_uncondbranch,
52   // fixup_t2_condbranch - 20-bit PC relative relocation for Thumb2 direct
53   // uconditional branch instructions.
54   fixup_t2_condbranch,
55   // fixup_t2_uncondbranch - 20-bit PC relative relocation for Thumb2 direct
56   // branch unconditional branch instructions.
57   fixup_t2_uncondbranch,
58 
59   // fixup_arm_thumb_br - 12-bit fixup for Thumb B instructions.
60   fixup_arm_thumb_br,
61 
62   // The following fixups handle the ARM BL instructions. These can be
63   // conditionalised; however, the ARM ELF ABI requires a different relocation
64   // in that case: R_ARM_JUMP24 instead of R_ARM_CALL. The difference is that
65   // R_ARM_CALL is allowed to change the instruction to a BLX inline, which has
66   // no conditional version; R_ARM_JUMP24 would have to insert a veneer.
67   //
68   // MachO does not draw a distinction between the two cases, so it will treat
69   // fixup_arm_uncondbl and fixup_arm_condbl as identical fixups.
70 
71   // fixup_arm_uncondbl - Fixup for unconditional ARM BL instructions.
72   fixup_arm_uncondbl,
73 
74   // fixup_arm_condbl - Fixup for ARM BL instructions with nontrivial
75   // conditionalisation.
76   fixup_arm_condbl,
77 
78   // fixup_arm_blx - Fixup for ARM BLX instructions.
79   fixup_arm_blx,
80 
81   // fixup_arm_thumb_bl - Fixup for Thumb BL instructions.
82   fixup_arm_thumb_bl,
83 
84   // fixup_arm_thumb_blx - Fixup for Thumb BLX instructions.
85   fixup_arm_thumb_blx,
86 
87   // fixup_arm_thumb_cb - Fixup for Thumb branch instructions.
88   fixup_arm_thumb_cb,
89 
90   // fixup_arm_thumb_cp - Fixup for Thumb load/store from constant pool instrs.
91   fixup_arm_thumb_cp,
92 
93   // fixup_arm_thumb_bcc - Fixup for Thumb conditional branching instructions.
94   fixup_arm_thumb_bcc,
95 
96   // The next two are for the movt/movw pair
97   // the 16bit imm field are split into imm{15-12} and imm{11-0}
98   fixup_arm_movt_hi16, // :upper16:
99   fixup_arm_movw_lo16, // :lower16:
100   fixup_t2_movt_hi16, // :upper16:
101   fixup_t2_movw_lo16, // :lower16:
102 
103   // It is possible to create an "immediate" that happens to be pcrel.
104   // movw r0, :lower16:Foo-(Bar+8) and movt  r0, :upper16:Foo-(Bar+8)
105   // result in different reloc tags than the above two.
106   // Needed to support ELF::R_ARM_MOVT_PREL and ELF::R_ARM_MOVW_PREL_NC
107   fixup_arm_movt_hi16_pcrel, // :upper16:
108   fixup_arm_movw_lo16_pcrel, // :lower16:
109   fixup_t2_movt_hi16_pcrel, // :upper16:
110   fixup_t2_movw_lo16_pcrel, // :lower16:
111 
112   // Marker
113   LastTargetFixupKind,
114   NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind
115 };
116 }
117 }
118 
119 #endif
120